@article { author = {Hafez, Shereen and Hafez, Amir and Amr, Haitham and Aboudorra, Hesham}, title = {Effect of Different Filler Loading on Fracture Resistance of CAD/CAM Resin Composite restoration in Premolar Teeth: An In vitro Study}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2457-2465}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72613}, abstract = {Objective: to assess the effect of different filler loading on the fracture resistance of CAD/CAM composite inlays when restoring MOD cavity in premolar teeth.Materials and methods: A two type of CAD/CAM resin composite block with different amount of filler loading were used in this study as the follow: Grandio Bloc with high filler loading (HFL) about 86% filler and BRILLIANT Crios with low filler loading (LFL) about 70% filler. A 40 maxillary premolar were divided equally into four main groups (10 teeth each); a positive control group of unprepared teeth and a negative control group with prepared and unrestored MOD cavity. While the two other restored groups in which teeth with prepared MOD cavities were restored either with the high filler loading Grandio Bloc CAD/CAM resin composite inlay or low filler loading BRILLIANT CAD/CAM resin composite blocks. A standardized MOD cavity were prepared in premolar teeth using the inlay preparation kit. working and master models were fabricated. A new restoration was created in the Cerec in-lab software version. The restoration were processed and cemented in place using Dual-link universal Resin cement. All specimen groups (positive control, negative control and restored groups) were tested for fracture resistance using universal testing machine. Fractured teeth were examined with USB digital microscope at 25X magnification. Two-way ANOVA (Analysis of Variance) was used to compare between groups. Tukey’s post-hoc test was used for pair-wise comparison between the mean when ANOVA value were significant. The significance level was set at P≤0.005.Results: There was no statistical significant difference between the intact teeth group and HFL GRANDIO inlays and LFL BRIILIANT CRIOS. However there were statistically significant between prepared but not filled teeth groups and all other groups. The HFL GRANDIO inlays restored teeth group recorded high mean value than LFL BRIILIANT CRIOS but without statistically significant difference between them. A mixed type of failure was detected; cohesive failure either within tooth and restoration and adhesive failure along cement line. Conclusions: the proper balance between filler and polymer matrix was able to improve the mechanical performance of resin composite blocks despite amount of filler loading. The use of CAD/CAM resin composite could be considered a perfect choice in the restoration of badly broken vital posterior teeth.}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72613.html}, eprint = {https://edj.journals.ekb.eg/article_72613_311f937de014ffa6d242e70568ea9ef7.pdf} } @article { author = {Aboudorra, Hesham A. and Amr, Haitham and El zohairy, Ahmed and Hafez, Amir and Hassan, Ahmed}, title = {Internal fit evaluation of all ceramic restoration fabricated by two CAD/CAM milling systems using cone beam CT (CBCT)}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2467-2479}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72614}, abstract = {Objective: to evaluate the internal fit of all ceramic restoration fabricated by two CAD/CAM milling systems using cone beam CT (CBCT).Materials and methods: A total number of 20 all ceramic restorations were manufactured in this study, and were equally divided into two main groups (n=10) according to the type of CAD/CAM system used in the manufacturing process. Group I (Cerec in-lab system) and group II (Everest system) using the e.max CAD blocks specified for each milling system. specially designed stainless steel die was manufactured with specified dimensions. The die was scanned, the all ceramic restoration was designed and milled according to the different CAD/CAM milling systems used, and then crystallization procedure was carried. Duplication of the metal die into epoxy resin dies was performed and the final all ceramic restorations were the placed over the epoxy resin dies and examined for internal gap measurement using cone beam computed tomography (CBCT). Numerical data were explored for normality using Kolmogorov-Smirnov test of normality. Normally distributed (parametric data), were presented as mean, standard deviation and were compared between groups using independent t test. Non-parametric data were compared between groups using Mann Whiney U test. Gingival, axial and occlusal segments were compared using Friedman test and Wilcoxon signed rank test. The significance level was set at p < 0.05. Statistical analysis was performed with SPSS 18.0 for windows.Results: Comparison between groups using the mean of the 3 successive sections in bucco-lingual section revealed that a higher mean value was recorded in Cerec for each of the gingival, axial and occlusal segments, with no statistically significant difference between groups (p=0.138, p=0.06, p=0.276 respectively), while in mesio distal section a higher mean value was recorded in Cerec in the gingival and axial segments, with no significant difference between groups (p=0.296, p=0.568 respectively). In the occlusal section, a higher mean value was recorded in Kavo Everest, with no statistically significant difference between groups (p=0.734). Comparison of gingival, axial and occlusal segments within the same group in bucco-lingual section revealed that in Kavo Everest group, a significantly higher mean value was recorded in occlusal segment in comparison to the gingival and axial segments (p=0.001). In cerec group, a significantly higher mean value was recorded in occlusal segment in comparison to the gingival and axial segments (p=0.00), while in mesio distal section , in Kavo Everest group, a significantly higher mean value was recorded in occlusal segment in comparison to the gingival and axial segments (p=0.00). In Cerec group, a significantly higher mean value was recorded in occlusal segment in comparison to the gingival and axial segments (p=0.00).Conclusion: The technique of CAD/CAM milling system has affected the internal fit of CAD/CAM all-ceramic restorations.}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72614.html}, eprint = {https://edj.journals.ekb.eg/article_72614_3f62b5d8d7a69416714c5b687eaf9576.pdf} } @article { author = {ElAsfouri, Heba and Saba, Abeer Ahmed}, title = {Comparative Evaluation of the Adaptation of Two Calcium Silicate-Based Endodontic Sealers with a Conventional Resin-Based Sealer to Dentinal Walls: An In vitro Scanning Electron Microscopic Study}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2481-2489}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72660}, abstract = {Aim of the study: The aim of this study was to compare the adaptation of two calcium silicate-based root canal sealers with a resin-based sealer to root canal walls at the middle and apical levels using scanning electron microscope.Material and methods: Twenty-six single-canalled lower premolars were instrumented and randomly divided into three groups according to the sealer used with gutta-percha (n=8); AH plus, Bioroot RCS, and Endoseal MTA. Two random specimens served as the blank control group to assess the smear layer removal from the dentinal walls. Teeth were sectioned at middle and apical levels and gap width was evaluated using scanning electron microscope. Data were statistically analyzed with significance level set at p ≤ 0.05. Results: At the apical and mid-root levels, the highest mean values were found in Endoseal MTA group followed by Bioroot RCS group while the lowest mean value was found in AH Plus group with statistically significant difference between all groups. Statistically significant differences were found between Endoseal MTA and each of Bioroot RCS and AH Plus groups. No statistically significant difference was found between Bioroot RCS and AH Plus groups. Conclusions: AH Plus and Bioroot RCS showed statistically better results than Endoseal MTA regarding adaptation to the root canal walls.}, keywords = {AH Plus,Bioroot RCS,Endoseal MTA,adaptation,Scanning electron microscope}, url = {https://edj.journals.ekb.eg/article_72660.html}, eprint = {https://edj.journals.ekb.eg/article_72660_3f57b473b68e27ebf3f61c61944d1d9f.pdf} } @article { author = {Rabie, Ziad}, title = {Effect of Fiber Reinforcement on Fracture Resistance and Fracture Toughness for Long Span Provisional Restorations}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2491-2502}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72661}, abstract = {Aim of the work: This study was aimed to determine the effect of fiber reinforcement on the fracture load and toughness of long span provisional restorations. Materials and method: Two types of commercially available provisional materials were selected Protemp™4 and Structur3. Two mechanical tests were performed to evaluate the fracture load and fracture toughness for each material. Twenty samples of four units, fixed partial dentures were fabricated to evaluate the fracture loading of both materials. The samples of each group were further subdivided into two equal subgroups (10 samples each). The first subgroup served as control, without fiber reinforcement while, the second subgroup included the addition of ultrahigh modulus polyethylene fibers (UHMPE) which is delivered pre-impregnated by the manufacturer. An electronic scale were used to pre-weight the fibers, then cut to a predetermined length (2.0mm) before incorporation in the resin mix to represent 3% weight of the control sample. For fracture toughness test, twenty rectangular samples (2.5X5X25 mm) from each material were fabricated. Ten samples for each subgroup were used with and without addition of the fibers. The samples were soaked before testing in artificial saliva for 14 days and then were thermocycled for 2500 cycles between 5oC and 55oC.Conclusions: Structur3 provisional material showed higher fracture load and fracture toughness mean values than Protemp™ 4. Fiber impregnation into provisional restorations enhanced the fracture load significantly but did not show the same improvement with the fracture toughness.}, keywords = {Fiber reinforcement,Fracture load,Ffracture toughness,Provisional restorations}, url = {https://edj.journals.ekb.eg/article_72661.html}, eprint = {https://edj.journals.ekb.eg/article_72661_1f633b543d6177c9e8223dfd22e07837.pdf} } @article { author = {Rabie, Ziad}, title = {Reinforcement effect of polyethylene fiber to composite cores of endodontically treated teeth}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2503-2510}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72662}, abstract = {Statement of problem: Severely damaged teeth frequently require placement of a core before preparation to receive an indirect restoration. However, the choice of the core material may also influence the outcome although reliable research data are scare. Purpose: The purpose of this study was to evaluate the effect of short fiber-reinforced composite resin of endodontically treated teeth restored with and without root canal posts. Methods: Sixty human extracted maxillary incisors were sectioned at the cemento-enamel junction. The root canals were prepared and obturated with gutta percha. Three groups of direct complete crowns were fabricated (n = 20 per group); Group A: made from particulate filler composite resin (Corestore 2, Kerr, control), Group B: particulate filler composite resin with fiber post (Aestheti-Post; Bisco), Group C: made from particulate filler composite resin with fiber post and short polyethylene fibers substructure (Ribbond Inc.). After finishing and polishing, the specimens were stored in 100% humidity at 37°C for 24 hours before they were statically loaded with a cross-head speed of 0.5 mm/min until fracture. Data were analyzed with 1-way ANOVA followed by Ryan-Einot-Gabriel-Welsch multiple-range test (α=.05). Results: ANOVA revealed that restorations made from particulate filler composite resin with fiber post and short polyethylene fibers substructure had higher fracture resistance capacity (309 N) (p< 0.05) than restorations made from particulate filler composite resin with fiber post (258 N). Control group had significant lower fracture resistance (178 N) (P<0.05).Conclusion: Polyethylene fiber may be an effective and practical method for reinforcement of the composite core material of endodontically treated teeth.}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72662.html}, eprint = {https://edj.journals.ekb.eg/article_72662_73e514efd4e72168f725815305e57283.pdf} } @article { author = {Mosallam, Rania and Mohamed, Mona}, title = {Comparison of Salivary pH Changes of Young Adults with Mineral and Alkaline Water Rinse After acidic challenge. A Clinical Study}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2511-2516}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.73171}, abstract = {Objective: The present study was conducted to compare the effect of mineral water and alkaline water after an acidic challenge on salivary pH of adults.Methods: 30 dental students in the age group of 20-25 years were randomly divided into two groups according to type of water rinse used either mineral or alkaline water. The salivary pH was measured at baseline, after candy intake and after water rinse. The results obtained were compared for normality using Kolmogorov-Smirnov and Shapiro-Wilk tests and One-way ANOVA followed by Paired sample t-test. Results: A statistically significance difference was found in salivary pH between baseline, after candy and after water rinsing. Candy significantly lowered salivary pH. Mineral and alkaline water brought pH back with non-significant difference with baseline values. However, there was no significance difference between mineral and alkaline water. Conclusion: Rinsing mouth with water after acidic challenge leads to neutralization of salivary pH thus preventing caries process in young adults.}, keywords = {Mineral water,Alkaline water,Salivary pH}, url = {https://edj.journals.ekb.eg/article_73171.html}, eprint = {https://edj.journals.ekb.eg/article_73171_106a62c552279dbba26c7fc38917adae.pdf} } @article { author = {Attia, Mazen and Ebeid, Kamal}, title = {Influence of inlay preparation design on the trueness of different impression techniques}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2517-2526}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72615}, abstract = {Statement of problem. Limited data is available on the effect of inlay preparation design on the trueness of digital impressions obtained by intra-oral scanners and conventional impressions. Purpose. The purpose of this study was to evaluate the influence of inlay preparation design on the trueness of different impression techniquesMaterial and methods. Two typodont resin teeth representing maxillary first premolars were prepared for disto-occlusal inlay preparations with two different divergent angels (6° and 12°). The prepared teeth were mounted in two typodont dental models and were used as reference models. Each reference model was scanned using an extra-oral scanner. A total of 40 digital impressions of the reference models were obtained using two different intra-oral scanners (3Shape Trios and Cerec Omnicam). For the conventional impressions, each reference model was duplicated 10 times for each preparation design (n=10) using a stock metal-tray and a vinyl polysiloxane impression material to obtain a total of 20 conventional impressions. Then, all impressions were scanned using the previously used extra-oral scanner. Subsequently, all impressions were poured with modified dental stone, then each cast was scanned 10 times for each preparation design (n=10) using the same extra-oral scanner to obtain a total of 20 working casts. Both reference models and all (STL) files (n=80) were loaded into a 3D reverse engineering software. For the trueness measurement, color difference maps and reports (n=80) were obtained by superimposing the digital data sets of the scans from the two intra-oral scanners onto the reference model, then (3D) deviation analysis was performed with the best-fit algorithm method. By using this method, for each superimposition, the root mean square (RMS) of the amount of deviation at each measurement point was recorded.Results. Two-way ANOVA revealed statistically significant differences between the taper, impression technique, and significant interaction. 12° taper showed statistically significant higher trueness values when compared to 6° taper. As for impression technique, the impression scan and the cast scan were statistically significantly better than the intra-oral scan. However, there was no statistically significant difference either between the impression scan and the cast scan or between the Omnicam and the 3Shape Trios scan.Conclusion. Inlay preparation with 12 degrees axial wall divergence is significantly better than the 6 degrees axial wall divergence, in terms of trueness.Clinical implications. Special care should be considered during capturing the image while using intra-oral scanners for inlay restorations.}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72615.html}, eprint = {https://edj.journals.ekb.eg/article_72615_7dd79d73344eccdaf35e64bc080a7813.pdf} } @article { author = {Bogari, Dania}, title = {The Challenge of Diagnosing Vertical Root Fracture: A Case Report}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2527-2530}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72616}, abstract = {Diagnosing a vertical root fracture has been a challenge for both general dentists and endodontists. In this report, we emphasize the importance of obtaining radiographs from three angulations to aid in the diagnosis of vertical root fracture. This step is an easy and cost-effective way to give the clinician a three-dimensional image of the tooth anatomy/morphology and etiology and will hopefully aid in obtaining the correct diagnosis and treatment plan.}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72616.html}, eprint = {https://edj.journals.ekb.eg/article_72616_dda8753a188a839a381575a6a3eae2a5.pdf} } @article { author = {Mohamed, Mohamed}, title = {THE INFLUENCE OF ACIDIC BUFFER AND MECHANICAL BRUSHING ON THE WEIGHT LOSS AND SURFACE ROUGHNESS OF THREE DIFFERENT CAD-CAM MATERIALS}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2531-2542}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72617}, abstract = {Aim of the work was to investigate the effect of pH media and the influence of the mechanical tooth brushing on the weight loss and surface roughness (Ra) of zirconia-reinforced lithium silicate glass ceramic, hybrid ceramic material and composite material. Materials & Methods: Three types of dental materials were selected. One Composite resin material (Cerasmart), Lithium silicate glass ceramic with 10% Zirconia (Celtra Duo) and one hybrid ceramic (Vita Enamic). Eighty one disc shaped specimens (2mm in height and 12 mm in diameter) were fabricated from three different CAD/CAM materials then divided into three groups of twenty seven specimens each (n = 27) based on the treatments received. Group I Twenty seven specimens 9 from each material, recieve no treatment and were weighted examined by optical microscpe for surface topogrphy. Group II, Twenty seven specimens 9 from each material were stored in acidic buffer for168 hours then weighted. Group III, Twenty seven specimens 9 from each material were subjected to mechanical brushining and examined by optical microscpe (for quantity and quality of surface roughness). The raw data were obtained from different tests and analyzed. T test and One-way ANOVA were conducted to compare the effect of the acidic buffer storage period and mechanical brushing on the weight loss and surface roughness respectively .Resuts: Comparison between weight loss before and after acidic buffer storage in the three groups using ANOVA analysis test showed that there was no significant difference between the three groups regarding to weight loss (0.05). The weight loss of Cerasmart group was heigher than the other two groups and there was no significant difference in surface roughness among the tested groups following 50,000 brushing cycles. The Vita Enamic materials showed lower surface roughness mean value compared to surface roughness value of Celtra Duo and Cerasmart material .Conclusions: Within the limitations of the present study, there was no significant difference in both weight loss and surface roughness of tested materials after 168 hours storage in acidic buffer and Simulated 5 years of brushing but Cerasmart composite has the highest weight loss and surface roughness}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72617.html}, eprint = {https://edj.journals.ekb.eg/article_72617_ff60fa60b9ec5b8c60ec9f00cabad41d.pdf} } @article { author = {Sadony, Doaa and Abozaid, Hanan}, title = {Antibacterial effect of chitosan nanoparticles in combination with diode laser on E.coli bacterial strain}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2543-2549}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72663}, abstract = {Background /Aim: The antibacterial effect was assessed by dead/live technique by conjunction between chitosan nanoparticle and diode laser (970nm), were chitosan has an excellent biocompatibility with tissues; save to human with no side effect; excellent bioactivity effect; chelation ability, good absorptive capacity, and antimicrobial activity regarding gram-positive and gram-negative bacteria. The studies have showed chitosan mechanism action related to the films formed around the cell which prevents nutrients absorption. Other res,earch indicates that, using laser radiation in the treatment of dental hard tissue and helping in the root canal formation, the addition effects of diode laser is bacteriostatic effect on bacterial strains present in root canal. The laser radiation was transmitted through quartz optical fibers, which could introducing laser light inside root canal, around canal curvatures and irregularities more easily. Throughout this review the aim of our study is present and discuss the antimicrobial activity of chitosan nanoparticles in combination with diode laser against oral bacteria especially the E.coli and aimed for developing commercial products such as an irrigant solution for root canal. The aim of this study was to estimate the ability of 970-nm diode laser to disinfection in combination with chitosan nanoparticlesagainst negative charged E.coli bacterial strain Materials and methods: The root canals of 40 extracted single-rooted incisors teeth were prepared by rotary system. After crown removal, the roots were autoclaved. The teeth were inoculated with E. coli suspension for two weeks. The samples were divided into four groups (n=10). The samples of the first group G1 (n=10) were inoculated with bacteria only as control group, the second group G2 (n=10) were inoculated with bacteria & chitosan, the group will be divided in 2 subgroup according to the time of incubation (60 seconds, 90 seconds) (n=5). The third group G3 were inoculated with bacteria and treated with a 970-nm diode laser, the group will be divided in 2 subgroup according to the time of laser irradiation (60 seconds, and 90 seconds) (n=5). The fourth group G4 (n=10) were inoculated with bacteria &chitosan and treated with diode laser, the group will be divided in 2 subgroup according to the time of laser irradiation (60 seconds, and 90 seconds) (n=5). Bacterial samples were taken from the root canals and the cultivation. was carried out. The standard deviation of colony-forming units (CFU) for each specimen were measured to compare the reduction in CFU in each group. Results: low mean CFU/mL is recorded in Group2 (chitosan with laser) followed by Group3 (chitosan) and Group 4 (laser), respectively. The difference in CFU/mL between the three groups is statistical significant (P ≤ 0.05).Conclusion: The results of this research show that 970-nm diode laser in combination with chitosan nanoparticles could be used as a complementary disinfection device in root canal treatment and ability to increase the success rate in endodontic therapy.}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72663.html}, eprint = {https://edj.journals.ekb.eg/article_72663_a4fb18761a26810fab2bbed9014e294f.pdf} } @article { author = {Elhatery, Abeer}, title = {Effect of Zirconia Nanoparticles Incorporation on Some Properties of One High - Impact Heat cured PMMA Resin}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2551-2560}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72618}, abstract = {PURPOSE: To evaluate the effect of ZrO2 nanoparticles incorporation (in two different ratios 1% and 3%) on some properties of one high-impact heat cured PMMA resin material when it was processed by two different methods (Conventional and Microwave curing methods).Materials & Methods: One high-impact heat cured PMMA resin (Trevalon Hi) was used in this study to be modified with nano-ZrO2 in two different ratios (1% and 3%). Both unmodified and modified high-impact heat cured PMMA resin were subjected to three different tests (Flexural strength test, Microhardness test, and Color stability test). A total of ninety specimens were prepared, thirty specimens for each test (N=30). Within each test specimens, there were three groups (n=10), (HI) group: was prepared from high-impact heat cured PMMA resin without modification by nano-ZrO2 (as a control group). (1%n-ZrO2 HI) group: was prepared from high-impact heat cured PMMA resin modified by 1% nano- ZrO2. (3%n-ZrO2 HI) group: was prepared from high-impact heat cured PMMA resin modified by 3% nano- ZrO2.Within each group, five specimens were prepared by conventional water-bath curing method, while the other five specimens were prepared by microwave curing. The significance level was set at P ≤ 0.05. Statistical analysis was performed with IBM® SPSS® Statistics Version 20 for Windows.Results: Modification of high-impact heat cured PMMA resin with (1% and 3%) nano-ZrO2 resulted in significant increasing in the mean values of flexural strength and VHN of all tested groups (p<0.05), while the effect on the color stability of the resin was slight. Conclusion: Within the limitation of this study, modification of high-impact heat cured PMMA resin with zirconia nanoparticles up to 3% could improve the flexural strength and surface microhardness with slight effect on the color. Microwave curing of high-impact heat cured PMMA resin gives better results than conventional one.}, keywords = {Zirconia Nanoparticles,High-impact heat cured PMMA resin,Microwave Curing,flexural strength,Microhardness,and Color stability}, url = {https://edj.journals.ekb.eg/article_72618.html}, eprint = {https://edj.journals.ekb.eg/article_72618_a5f925df10041ffc9fd0fc0c4da6e2ac.pdf} } @article { author = {Rizk, Fardos and El Shafei, Sara}, title = {Osseointegrated implants versus zirconium mucosal inserts in complete denture patients}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2561-2566}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72619}, abstract = {Purpose: To evaluate the effect of osseointegrated implants versus mucosal inserts used for retention of complete dentures. Materials and Methods: Twelve completely edentulous patients were selected for this study and divided into two groups of six. Group I received implant retained maxillary overdentures, while group II received maxillary overdentures retained by muchor zirconium mucosal inserts. Bone changes in both groups were evaluated using cone beam ct at insertion and after six and twelve months. Results: The results showed that the bone changes produced in mucosal overdenture wearers were greater than those produced in implant overdenture wearers. Conclusion: Zirconium mucosal inserts caused more bone changes than osseointegrated implants.}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72619.html}, eprint = {https://edj.journals.ekb.eg/article_72619_165435fc0132db497b8bff5829c062a8.pdf} } @article { author = {Al Assar, Mohammad}, title = {Effect of intra-radicular rehabilitation techniques on push-out bond strength of fiber-reinforced posts in extremely flared canals}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2567-2576}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72620}, abstract = {Statement of the problem: Which technique should be followed to restore excessively flared canals, augmentation of intra-radicular dentin or customization of fiber post? The question asked by many practitioners. Purpose: To compare the effect of different intra-radicular rehabilitation techniques on push-out bond strength of fiber posts in extremely flared canals. Materials and Methods: Eighteen freshly extracted human maxillary central incisors roots were endodontically treated and embedded in acrylic blocks. The root canals were excessively flared and divided into six groups according to the technique of intra-radicular rehabilitation; Gr1: Augmentation of intra-radicular dentin by bulk-fill packable composite then cementation of Glassix plus post, Gr2: Augmentation of intra-radicular dentin by bulk-fill packable composite and direct use of Glassix plus post, Gr3: Augmentation of intra-radicular dentin by flowable composite then cementation of Glassix plus post, Gr4: Augmentation of intra-radicular dentin by flowable composite and direct use of Glassix plus post, Gr5: Customization of Glassix plus post by bulk-fill packable composite then cementation of the customized post, and Gr6: Customization of Glassix plus post by bulk-fill packable composite with simultaneous cementation. The roots were sectioned, thermocycled and the specimens were subjected to push-out test in universal testing machine. The maximum failure load was recorded and used to calculate the push-out bond strength. Data was statistically analyzed and failure mode was assessed using magnifying lens. Results: The highest mean value was recorded in Gr1, followed by Gr2, then Gr4, Gr3, Gr5, with the lowest mean recorded in Gr6. ANOVA test revealed the difference was statistically significant (p=0.0028). Tukey post hoc test revealed no significant difference between groups 1,2,3,4. Gr3 and Gr4 were not significantly different from all other groups.Conclusions: 1) Higher bond strengths are achievable with augmentation of excessively flared canals compared to customization of prefabricated fiber posts, 2) Augmentation of intra-radicular dentin is highly recommended by bulk-fill packable composite rather than flowable composite, 3) Cementation of light-transmitting post is an important step after augmentation of root dentin by bulk-fill composite, and 4) Use of light-transmitting post in conjunction with bulk-fill composite exhibits synergetic effect in curing depth manifested by high bond strengths. However, the use of one step-single curing method is not recommended. Clinical Significance: For extremely flared canals, it is advisable to use bulk-fill packable composite for augmentation of root dentin, followed by adhesive cementation of light-transmitting post. Always remember that augmentation of intra-radicular dentin is much better than customization of fiber post.}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72620.html}, eprint = {https://edj.journals.ekb.eg/article_72620_61f169bdbd0ad7943955ddc1c5524324.pdf} } @article { author = {Temirek, Marwa}, title = {Influence of hydrophobic resin coating on micro-tensile bond strength of different adhesives: an in – vitro study}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2577-2586}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72621}, abstract = {Recently, the etch-and-rinse and self-etching approaches are the two strategies of resin-based adhesive systems to accomplish the bonding to enamel and dentin. The increased amount of solvents and hydrophilic monomers in the adhesive formulations lead to greater amount of residual solvents entrapped in the adhesive layer. Consequently, the resulting polymers will be more susceptible to degradation over time. One of the methods for more durable bond includes the application of an additional layer of a hydrophobic resin coating over the polymerized simplified adhesive. The aim of this in –vitro study was to evaluate the influence of hydrophobic resin coating on micro-tensile bond strength of different adhesives Eighty freshly sound human molars were divided into three main groups according to method of bonding (A), where (A1) represents teeth bonded using Single Bond Universal Adhesive in total each approach, (A2) represents teeth bonded using Single Bond Universal Adhesive in self-etch approach while (A3) represents teeth bonded using Self Etch Future Single Bond DC Bonding System. Each (A) group will be then subdivided into two additional subgroups according to the addition of hydrophobic resin coating into (B1) which stands for teeth with additional hydrophobic resin coating and (B2) which stands for teeth without additional of hydrophobic resin coating. Each (AB) group will be finally subdivided into two smaller subgroups according to the effect of thermocycling, where (T1) denotes the teeth which were thermocycled, and (T2) denotes the teeth which were not thermocycled. The occlusal dentin surface of each molar was prepared on two levels: Superficial level (below the dentino enamel junction by 0.5 mm) and deep level (below the dentino enamel junction by 1.5 mm). For all specimens, after bonding procedures either total etch or self etch, a hydrophobic resin coating was added for the assigned groups. Resin composite was applied; thermo-cycling was done for the assigned groups. Teeth were sectioned into a series of 1 mm thick slabs and microtensile bond strength testing was done. Two representative specimens of each group were selected for Ultramorphological Examination. Mode of application, addition of adhesive layer and thermocycling had a significant effect on bond strength. Within the limits of this study, we concluded that regarding bonding efficacy to enamel and dentine, conventional 3-step etch-and-rinse adhesives are still not surpassed by the newer simplified self etch adhesive systems. Addition of the hydrophobic bonding resin coating improved bonding to dentine especially when used with all-in-one self-etch adhesive systems.  }, keywords = {}, url = {https://edj.journals.ekb.eg/article_72621.html}, eprint = {https://edj.journals.ekb.eg/article_72621_52b5ff742bcf87e356344a0e2da6ff5a.pdf} } @article { author = {Temirek, Marwa}, title = {Effect of packing technique and curing time on the marginal sealing and surface hardness of two bulk-fill resin composites}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2587-2596}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72622}, abstract = {Recent advances in dental resin based restorative materials have given rise to development of composites for bulk placement, to replace the need for incremental layering. Clinical consequences of microleakage are secondary caries, pulp inflammation, marginal discoloration, postoperative sensitivity, and the longevity of filling. Surface hardness is one of the mechanical properties of the restoration that should always be taken into account, particularly when they are faced with large areas of heavy masticatory forces. Accordingly, the current study was conducted to investigate the effect of packing technique and curing time on the marginal sealing and surface hardness of two bulk fill resin composites.Standardized class II proximal box cavities were prepared on the mesial and distal surface of the selected premolar teeth with the total of 48 cavities. The prepared cavities were randomly divided into 2 main groups, 24 cavities each, according to the placement technique used for cavity restoration either placement of bulkfill single increment of 4 mm depth or incremental placement of two increments of 2 mm each. Each group was subdivided into 2 subgroups, 12 cavities each, according to the bulk fill composite resin used; X-trafil bulkfill composite and Quixfil bulkfill composite. These subgroups were then subdivided into two smaller groups, 6 cavities each, according to the curing times either curing for 10 seconds following the manufacturers’ instructions or curing for 20 seconds. For all specimens, after bonding procedures, bulk-fill resin composites were manipulated and applied in cavities as the previously assigned methodology, specimens were then immersed in 2% methylene blue dye for 24 hours. Teeth were sectioned and viewed under a binocular stereomicroscope. Readings were recorded.A total of 80 cylindrical resin composite specimens were prepared. samples were divided into 4 groups according to the type of bulk fill composite (X-tra fil or Quixfil) and irradiation time (10s or 20s). The resin composite was applied in the mold, covered with mylar strips and light cured using LED light curing unit with an intensity of 1200mW/cm2. Vickers Microhardness tester was used with microindentation carried out using a load of 500g. Three readings for each surface were taken and an average reading was calculated. X-trafil bulkfill composite showed significantly lower degree of leakage than Quixfil bulkfill composite. No significant difference in microleakage was shown between different curing times nor different application techniques. X-trafil bulkfill composite showed significantly higher microhardness than Quixfil bulkfill composite Curing for 10 seconds showed significantly higher microhardness. Bulk-fill single increment of 4 mm recorded significantly higher microhardness value. Within the limitations of the current study, we can conclude that 4-mm bulk fill packing of bulkfill composite resin, cured for 10 seconds, had adequate marginal sealing performance. Surface microhardness of bulkfill composite resin packed at 4-mm bulk fill, cured for 10 seconds, is acceptable.}, keywords = {bulkfill composite,Microleakage,Microhardness}, url = {https://edj.journals.ekb.eg/article_72622.html}, eprint = {https://edj.journals.ekb.eg/article_72622_0d7582c5b64e7fb3a9f675b9235103af.pdf} } @article { author = {Metwally, Azza and Gamal, Mohamed}, title = {Evaluation Of Stresses Distribution Pattern In Implant- Retained Maxillary Obturators Using Nova-Lock, Ball & Locator-Bar Attachment Systems. (Three Dimensional Finite Element Analysis)}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2597-2605}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72623}, abstract = {Purpose: This study was an in in-vitro study conducted to compare the stress distribution pattern in implant retained maxillary obturators with three different attachment systems with the aid of three dimensional finite element analysis.Methods: CT scan was made for a patient with hemi-maxillectomy defect. The CT scan file was exported to a personal computer with Materialize Mimics 10.01 program (Materialize, interactive medical image (Materialize Leuven, Belgium). Mimics were utilized to modify the CT scan of the maxilla to construct 3-D model with Solid Works, Concord, Massachusetts, USA) for finite element stress analysis. All components of the models were constructed thereafter, superimposed till construction of maxillary obturator models. Three implants were inserted in the alveolar bone on the intact side. Ball & Nova-lock locator/ bar attachment systems were simulated according to their structural configurations. A static load of 100 N load was applied vertically & obliquely on the defect side. ANSYS program (Canonsburg, PA, USA) was utilized to solve the problems, The resultant Von Misses stresses in bone surrounding implants were evaluated and compared in the 3 studied models.Results: The highest Von Misses stresses were found in cortical bony layers around the implant adjacent to defect & the least stresses at the area of 3rd implant. Nova-lock retained implant obturtors had recorded the least Von Misses stresses (20. 479 &21.675 Mpa) in comparison to Ball (40.762 & 41.488 Mpa) & locator bar attachment systems (43.526 & 47.203 Mpa) under vertical & oblique load application respectively. All models had shown the highest stresses on oblique load application on the defect side.Conclusions: Within the limitations of this study various conclusions could be drawn: The load direction has more important role than the attachment type in stress distribution pattern in implant retained maxillary obturators.Nova- lock attachment system may induce the least stresses onto implant/ bone interface followed by Ball & locator bar attachment systems.The Locator/ bar attachment may allow better stress distribution in implant retained maxillary obturators than other Bar systems.}, keywords = {maxillary,Obturators,Implants,attachments,stresses,FEA}, url = {https://edj.journals.ekb.eg/article_72623.html}, eprint = {https://edj.journals.ekb.eg/article_72623_3872febcc679da65f1857430d4253080.pdf} } @article { author = {Sultan, Mayada}, title = {Antibacterial Effect of Aloe Vera and Glass Ionomer Modified by Aloe Vera on Streptococcus mutans}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2607-2616}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72664}, abstract = {Objective: To evaluate the antibacterial effect of Aloe Vera and glass ionomer modified by Aloe Vera on Streptococcus mutans in comparison to Chlorhexidine.Methods: A total of fifty samples were used in the study and divided into 5 groups according to the materials used (n=10) Group 1:2% Chlorhexidine gluconate(CHX); Group 2: Aloe Vera (AV); Group 3: Glass ionomer (GI); Group 4: 2% Chlorhexidine gluconate added to glass ionomer (CHX+ GI) and Group 5: Aloe Vera added to glass ionomer (AV+GI) and. The antibacterial effect of each group were assessed by disc diffusion methods after two-time intervals: 24 and 48 hours. Data were tabulated and statistically analyzed using Two-way ANOVA followed by Bonferroni’s post-hoc test.Results: There was a statistically significant difference between the materials used on inhibition zone diameter after 24 and 48 hours. CHX showed the statistically significantly highest mean inhibition zone diameter followed by AV > CHX + GI > AV + GI. GI group showed the lowest mean inhibition zone diameter with a statistically significantly. Conclusion: Aloe Vera is beneficial in the inhibition of Streptococcus mutans growth up to 48 hours. The incorporation of Aloe Vera in glass ionomers seems to improve the antibacterial activity of glass ionomer restoration.}, keywords = {Aloe vera,chlorhexidine,Glass Ionomer,Streptococcus mutans,Antibacterial activity}, url = {https://edj.journals.ekb.eg/article_72664.html}, eprint = {https://edj.journals.ekb.eg/article_72664_83f84f0e2f798bb31f1ecc31d2c7496c.pdf} } @article { author = {Safy, Rehab and Elgamily, Hanaa}, title = {Impact of Cinnamon and Cloves Extracts Incorporated in Fluoride Varnish Containing CPP-ACP on Microhardness and Color of Enamel}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2617-2623}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72624}, abstract = {Objective: The current study aimed to evaluate the effects of methanolic extracts of Cinnamon and Cloves mixed with Fluoride Varnish Containing CPP-ACP (MI Varnish™) treatments on the enamel microhardness and color. Material and Methods: Forty enamel specimens obtained from twenty human impacted third molars were randomly divided into four groups (n = 10) according to surface treatment: (G1) MI Varnish™ mixed with methanolic extract of Cinnamon; (G2) MI Varnish™ mixed with methanolic extract of Cloves; (G3) MI Varnish™ mixed with methanolic extracts of Cinnamon and Cloves meanwhile (G4) MI Varnish™ alone. Specimens were subjected to pH cycling. Color (ΔE) and surface microhardness were measured for each specimen at base line, after demineralization and post treatment. Results: The highest microhardness values presented in MI Varnish alone (G4) and MI Varnish™ mixed with methanolic extracts of Cinnamon and Cloves (G3) without any significant difference between them, followed by MI Varnish™ mixed with methanolic extract of Cinnamon (G1), while the lowest hardness values were found in MI Varnish™ mixed with methanolic extract of Cloves (G2). There was an increase in ΔE3 values for all groups. Conclusions: Under the limitations of the current study, application of Cinnamon and Clove as herbal antibacterial medicaments does not affect enamel microhardness negatively when added with the MI paste at certain ratio. Meanwhile, unacceptable color changes of enamel surface are expected.}, keywords = {Cinnamon,Cloves,enamel,Microhardness,Color}, url = {https://edj.journals.ekb.eg/article_72624.html}, eprint = {https://edj.journals.ekb.eg/article_72624_1aa5486d9da23fb44b22562d3004daca.pdf} } @article { author = {Elsherief, Samia and Elmarsafy, Sahar and Youssef, Abdel-Rahman}, title = {Bacterial leakage analysis of root canal obturated using single cone technique with three different root canal sealers and three different coronal restorative}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2625-2633}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72625}, abstract = {Introduction: The main aim of root canal therapy is adequate sealing to prevent reinfection with subsequent periapical disease. The aim: The aim of this study was to compare the sealing ability of root canal filled teeth using three different sealers and three different restorative materials by bacterial penetration method during a 30-day period. Materials and Methods: Seventy-two single rooted teeth were prepared using Protaper Next. Obturation was done using single cone technique .The teeth were randomly divided into three groups of 24 samples according to the sealer used as following; group 1: Bioceramic sealer (BS), group 2: MTA fillapex (MTA) and group 3: Tagdseal sealer (TG). The samples then randomly subdivided into 3 groups of 8 samples according to the coronal restoration of the specimens as following; subgroup A: Composite (Tetric Ceram + Tetric N Bond), subgroup B: Compomer (Compoglass F + Adhese SE) and subgroup C:Glass Ionomer (Ketac N + Ketac primer).Therefore, there was 9 final groups; I, II, III, IV, V, VI, VII, VIII, IX.After setting time, the samples were incorporated in a bacterial leakage model, using E. faecalis. Leakage was evaluated by turbidity in lower chamber in 30-day period. Statistical analysis was done using One-wayANOVA test, and post hoc pairwise comparison was done using Tukey test. Results: The results showed that group I (BS - Composite) presented the lowest means of bacterial leakage after all periods of evaluation. On the other hand, the (MTA – Glass Ionomer) material showed the highest means of leakage. There was a significant difference between the means of the bacterial colonies recorded in the nine groups at one, 2 and 4 weeks; while at 3 weeks the difference was insignificant. Conclusion : Bioceramic sealer with composite restoration showed the least bacterial leakage.}, keywords = {single cone obturation,Bacterial leakage,mineral trioxide aggregate-based sealer,resin-based sealer,bioceramic sealer,coronal restoration}, url = {https://edj.journals.ekb.eg/article_72625.html}, eprint = {https://edj.journals.ekb.eg/article_72625_2cd0e31cc8fe660317c9f7789029fead.pdf} } @article { author = {El-Sayed, Ahmed and Salah El Din, Amr and AbuElmagd, Inass}, title = {Evaluating Dimension accuracy of three differently fabricated denture base materials}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2635-2640}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72626}, abstract = {Objective: to compare the accuracy of three different denture base materials used in maxillary edentulous archMaterials and Methods: ten patients were selected, with completely edentulous arches, for each patient three finial PMMA denture bases were done using different construction technique pack and press, computer aided design/ computer aided manufacturing CAD/CAM milled and selective laser sintering (SLS) PMMA denture base All denture bases in this study were submitted for CBCT scanning for dimension accuracy and volume linear evaluation.Results: The mean and standard deviation values were calculated for each group in each test. Data were explored for normality using Kolmogorov-Smirnov and Shapiro-Wilk tests, data showed parametric (normal) distribution. A statistically significant difference was found between (Heat cure acrylic denture), (CAD/CAM denture) and (Laser sintering denture)Conclusion: also press and pack technique is more time consuming regarding number of visits but less dimensional changes than CAD/CAM and (SLS) selective laser sintering.}, keywords = {denture base,dimension accuracy,CAD/CAM,SLS& dimension accuracy}, url = {https://edj.journals.ekb.eg/article_72626.html}, eprint = {https://edj.journals.ekb.eg/article_72626_56b16a36a3931ecd6ea7c8d250beeb1d.pdf} } @article { author = {Metwally, Azza}, title = {Comparison Of Patient Satisfaction & Occlusal Force Distribution pattern In CAD/ CAM and conventional Complete Dentures Using The T-Scan III Computerized Occlusal Analysis System. (RCT)}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2641-2649}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72627}, abstract = {Purpose: This study was conducted to evaluate patient satisfaction & percentage of occlusal force distribution patterns in CAD/CAM and conventional dentures.Materials & Methods: Twenty completely edentulous patients were selected from the out-patient clinic, Faculty of dentistry, Cairo University. Patients were selected with moderately developed residual ridges, sufficient inter-arch space, no muscular disorders & with previous denture experience. Patients were randomly divided into two groups (I) & (II). Group (I): Patients had received CAD/ CAM complete dentures. Group (II): Patient had received conventionally constructed complete dentures. Patient satisfaction was evaluated in the two studied groups following certain items with the aid of a questionnaire after one week, one month & three months. T-scan device was utilized to evaluate occlusal force distribution in the two studied groups one week after denture insertion. Occlusal adjustment was made after occlusal forces analysis to re equilibrate occlusal force distribution. Mean values were recorded, tabulated & statistically analyzed. Results: The results of this study revealed that patients were more satisfied with CAD/ CAM complete dentures than conventional dentures. Occlusal force % was significantly decreased in anterior area of the dentures in both studied groups after occlusal equilibration made after occlusal adjustment. The % of occlusal force was better distributed on the posterior right & left areas in Group (I) & (II). However, CAD/CAM dentures had shown significantly less % force in the anterior area & better force distribution in the posterior areas than conventional ones especially after T scan analysis & occlusal re-equilibration.Conclusions: Within the limitations of the present study it may be concluded that:Patients may be more satisfied with CAD/ CAM than conventional dentures.CAD/CAM denture may provide better occlusal force distribution patterns than conventional ones. T- Scan computerized occlusal analysis helps to obtain bilateral balanced occlusion in complete dentures.}, keywords = {CAD/ CAM,compete dentures,patient satisfaction,T-Scan,occlusion force distribution}, url = {https://edj.journals.ekb.eg/article_72627.html}, eprint = {https://edj.journals.ekb.eg/article_72627_46d0db7f7ff4a899decfbaeb2827325d.pdf} } @article { author = {Osman, Reham and Fahmy, Ahmed}, title = {A Comparison of microbial flora in peri-implant sulcular fluid of ball versus locator retained mandibular implant overdentures. A randomized crossover study}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2651-2659}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72667}, abstract = {Purpose: To evaluate the microbial flora in peri-implant sulcular fluid of edentulous patients rehabilitated with ball and socket and locator retained mandibular 2-implant overdentures.Materials and Methods: 14 edentulous patients were recruited to receive two mandibular implant overdentures and new conventional maxillary complete dentures. Mandibular implant overdentures (MIODs) were retained either by locator or ball attachment systems in random order. After 6 months of function, the attachment systems in the existing dentures were replaced with the other type of attachment. The prevalence of streptococci and staphylococci species (spp.) was analyzedusing blood-agar media at 3, 6 and 9 weeks after pick-up of attachments. The data was then collected, tabulated and statistically analyzed using SPSS. Results: No significant difference was found in bacterial count of either Streptococcus or Staphylococcus spp. between two attachment systems (Ball and socket, Locator) at any of the evaluated time intervals with P-value > 0.05Conclusions: Within the limitations of this study, it can be concluded that there is no difference in microbial flora between the two attachment systems. It can also be suggested that the locator attachments are valid treatment alternative for ball abutments to retain mandibular 2-implant overdentures from a biological point of view.}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72667.html}, eprint = {https://edj.journals.ekb.eg/article_72667_6af6c4c3bb01abc6016993b622f751d6.pdf} } @article { author = {Abd Alhady, Abdallah.}, title = {Effect of solvent of one-step self-etch adhesives on the marginal integrity of resin composite to enamel and dentin}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2661-2671}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72669}, abstract = {The aim of this study was to evaluate the marginal integrity of a solvent-free one-step self-etch adhesive (Bond 1SF) and to compare it with ethanol-water based adhesive (Single Bond Universal (SB)) and acetone-water based adhesive (G-aenial Bond (GB)), at different storage times. Class V cavities (2×3.5×2.5 mm) were prepared on the buccal aspects of 90 human molars. The adhesives were applied to the cavities then the specimens were restored with A2 shade of Z250XT composite resin. Each group was evaluated for dye penetration under a stereomicroscope at X32 after one day, one month, and six months. Statistical analyses were carried out. In addition, in each experimental group, one specimen were prepared for analysis under SEM. Results: There were a significant differences in microleakage between the three adhesives at one day, Bond 1SF (B1SF) was the highest one. Whereas, there were no significant differences at six months. There were a significant differences in microleakage between the occlusal and gingival margin microleakage. Gingival margin microleakage was higher than that of occlusal margin. Conclusion: Storage time has adverse effect on the marginal integrity of solvent containing one-step self-etch adhesive while has no adverse effect on one-step solvent-free self-etch adhesive, microleakage increase obviously at the gingival margin, the type of solvent has a positive effect on the marginal integrity, ethanol-water based one step self-etch adhesives showed superior marginal integrity}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72669.html}, eprint = {https://edj.journals.ekb.eg/article_72669_c999dd7cfb7f608488f35176d292c723.pdf} } @article { author = {Osman, Reham and Abd El Razek, Wael}, title = {A three-dimensional finite element stress analysis of two different implant distributions supporting and retaining mandibular overdentures}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2673-2679}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72628}, abstract = {Statement of Problem: Hinging mandibular overdentures retained by anterior interforaminal implants results in denture rotation and posterior basal bone resorption. Wide spread implant distribution and posterior implant placement can improve overdenture support. Aim of study: To evaluate the biomechanical aspects of novel implant distribution used to support mandibular overdentures and compare it with commonly used design. The novel design consists of mid-symphyseal and bilateral posterior implants in the first molar region as opposed to conventional design with anterior mid-symphyseal and bilateral implants in the canine region.Materials and Methods: Two finite element models were created. In the two models a mid-symphyseal implant was simulated. In the first model (D1), 2 more implants were placed in the canine region bilaterally while for the second model (D2), the 2 additional implants were placed posteriorly in the first molar region. Unilateral vertical and oblique loads were applied on central fossa of right first molar and palatal aspect of central incisors in each model. Von Mises stress distribution was evaluated in the implants and peri-implant bone. Denture displacement was also calculated for each model. Results: There was a slight increase in maximum Von-Mises stress values recorded in both implants and peri-implant bone under both vertical and oblique load in D2 when compared to D1. D1 showed higher denture displacement values when compared to D2. Conclusions: Posterior implant placement resulted in improved denture support and minimal denture displacement on the expense of transferring extra load to the posterior implants. However, increased functional load on posterior implants is expected to have a positive effect on preservation of the residual alveolar ridge. D2 is an acceptable alternative prosthodontic design to D1 when anatomical factor permits.}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72628.html}, eprint = {https://edj.journals.ekb.eg/article_72628_e1f091e438804e98d3acc0b4f8341f13.pdf} } @article { author = {El Afandy, Hebatalla and fawzy, Aya}, title = {Evaluation of mechanical properties of maxillofacial silicone after long term exposure to different conditions}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2681-2689}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72629}, abstract = {Purpose: The aim of this study was to examine the effect of dark room storage, neutral soap (shampoo) and outdoor weathering on the mechanical properties (roughness, flexibility and elastic recovery) of maxillofacial silicone elastomer.Material and Methods: 60 specimen were prepared and divided into 3 groups (n=20).And conditioned differently as follows: Group I: Dark room storage; Group II: Neutral soap disinfection (shampoo); Group III: Outdoor natural weathering for 2 months. Specimens were subjected to roughness evaluation using scanning electron microscope, flexibility test and elastic recovery by means of materials testing device (Model LRX-plus; Lloyd Instruments Ltd., Fareham, UK) before storage, after 1 month and one more after another 1 month.Results: There was significant increase in the roughness of natural weathering group, roughness decreases in dark room and shampoo groups. There was increase also in the flexibility in natural weathering group and decrease in dark room and shampoo groups. Finally in the recovery percentage there was decrease in natural weathering group but increase in both dark room and shampoo groups. Conclusions: Natural weathering conditions affected the mechanical properties of maxillofacial silicone.}, keywords = {Maxillofacial silicone elastomer,roughness,Mechanical Properties}, url = {https://edj.journals.ekb.eg/article_72629.html}, eprint = {https://edj.journals.ekb.eg/article_72629_52b7cc6598ca86d0766a94a42e9c3365.pdf} } @article { author = {El Afandy, Hebatalla}, title = {Evaluation the retention of upper complete denture with different acrylic denture base materials}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2691-2698}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72630}, abstract = {Objective: to evaluate the retention of thermoplastic upper complete denture versus heat cured upper complete dentureAbstract: Successful denture is affected by altered biomechanical phenomenon of support, stability and retention. Polymethyl-methacrylate (PMMA) has been used to construct the dentures for ages. Some problems were described with these prosthesis that lead to fracture and allergy to methyl methacrylate monomer. The introduction of the nylon-derived denture base materials in 1950s smooth the way for a new type of dentures. It was found that soft dentures are excellent alternate to traditional hard-fitted dentures. Several advantages to flexible dentures over the traditional rigid denture bases were noted like translucency of the material that picks up the underlying tissue tones.Material and methods: Fourteen completely edentulous patients were randomly divided into two groups. Group I received thermoplastic upper complete denture. Group II received heat cured upper complete denture. a readymade metallic bar was attached to the contact area between upper second premolar and upper first molar bilateral using self-cure acrylic resin, its center coincide with the geometrical center of the denture. Retention was measured using digital force gauge Retention force was measured as the maximum force needed to completely dislodge the maxillary denture. This step was repeated three times, three readings were taken and the average was recorded for each patient in both groups. The measurements were taken after 1 week of denture insertion and repeated 1, 3, 6 months after denture delivery.Results: group I showed a little increase in denture retention than group II at the time of denture insertion, 1 and 3 months after but after 6 months it showed marked decrease in the denture retention. On the other hand the group II showed increase in the denture retention at time of denture insertion, 1 and 3 months after with slight decrease after 6 months.Conclusion: The use of thermoplastic and heat cured acrylic resin has no significant difference regarding the denture retention. The time intervals for denture retention showed increase in denture retention regarding the time factors .}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72630.html}, eprint = {https://edj.journals.ekb.eg/article_72630_734eb8d8cae480f07d9ac871fdea711c.pdf} } @article { author = {Safy, Rehab and Ragab, Mai}, title = {Comparative Histological Study of Two Different Pulp Capping Agents in Rabbits Teeth}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2699-2707}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72631}, abstract = {Objective: Evaluation of the histological pulp response following direct pulp capping with Galla Chinensis Extract (GCE) in comparison to Mineral Trioxide Aggregate (MTA) in rabbits’ teeth. Methodology: Intentional pulp exposure on the labial surfaces of permanent central incisors of twenty male rabbits was done. Split mouth technique was utilized for applying the capping material where MTA was used for capping upper and lower right central incisors while, GCE was used for capping upper and lower left central incisors. The teeth were restored by glass inonomer cement (GIC) as permanent restorations. Rabbits were divided randomly into two groups 10 rabbits each according to pulp capping period (two and four weeks). After animal scarification teeth were dissected and prepared for histological evaluation using Hematoxylin Eosin (HE) stains.Results: GCE group showed significantly higher mean dentin bridge thickness than MTA group at four weeks, also it showed significantly higher median inflammatory cell scores than MTA group at both time intervals. Conclusions: GCE is a promising direct pulp capping material with less biological pulp response in comparison to MTA.}, keywords = {Pulp capping,GCE,MTA,Histological evaluation}, url = {https://edj.journals.ekb.eg/article_72631.html}, eprint = {https://edj.journals.ekb.eg/article_72631_83bfb1b205488ea67b4cb67fb07699e6.pdf} } @article { author = {Asaad, Rasha}, title = {Effect of thermo-mechanical cycling on the shear bond strength of porcelain to milled and cast cobalt-chromium alloys}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2709-2722}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72671}, abstract = {Statement of problem: Most of the failures in metal-ceramic restorations occurs at the interface between the two materials. For long term clinical performance, these restorations should have adequate bond strength between metal and ceramic. Few data is available in regards to the metal-ceramic bond strength of Cobalt Chromium (Co-Cr) alloys fabricated by computer aided designing design/computer aided manufacturing CAD/CAM technology.Purpose of the study: The purpose of this in vitro study was to explore the influence of Co-Cr fabrication techniques on shear bond strength of porcelain to milled and cast Co-Cr alloys and to evaluate failure mode with & without thermo-mechanical cycling.Materials & Methods: A total of 20 disc samples (10 mm diameter x 4 mm thickness) were fabricated of Co-Cr alloy and divided into two groups (10 discs each) according to their fabrication technique: Group I: fabricated by CAD/CAM milling and Group II: fabricated by conventional casting. Then porcelain build up for all discs (10 mm diameter x 2mm thickness) was done using feldspathic porcelain. Each group was subdivided according to discs’ exposure to thermo-mechanical cycling into two sub-groups (5 discs each). Sub-group A : without thermo-mechanical cycling and Sub-group B: with thermo-mechanical cycling. All the disc samples were subjected to the shear bond strength (SBS) test and the failure mode was investigated under digital microscope at 40 X. Data were statistically analyzed using Independent sample t-test and Two-way ANOVA test (P ≤ 0.05).Results: The results showed that the fabrication techniques were statistically insignificantly affecting the SBS of both CAD/CAM milled and conventional casting groups. Regarding the thermo-mechanical cycling, the CAD/CAM milled and conventional casting groups without thermo-mechanical cycling showed a statistically significantly higher SBS than those with thermo-mechanical cycling. Failure mode was mixed type for all disc samples.Conclusions: Fabrication technique of Co-Cr alloy had no significant effect on SBS. Thermo-mechanical cycling of milled and cast Co-Cr samples significantly affecting SBS with the superiority of the non-thermo-mechanical cycled samples. All the tested samples showed SBS values within the clinically acceptable levels. CAD/ CAM fabricated Co -Cr may be considered a promising alternative to conventional cast Co-Cr for metal ceramic prosthesis in terms of SBS.}, keywords = {milled,cast,Cobalt Chromium,Shear bond strength,thermo-mechanical cycling}, url = {https://edj.journals.ekb.eg/article_72671.html}, eprint = {https://edj.journals.ekb.eg/article_72671_da711adebf66e76dcf4ec80300c1ad86.pdf} } @article { author = {Rehan, Ali}, title = {ANTIBACTERIAL ACTIVITY OF TWO CALCIUM SILICATE-BASED ROOT CANAL SEALERS AGAINST ENTEROCOCCUS FAECALIS}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2723-2730}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72652}, abstract = {Aim: The purpose of the study was to compare between EndoSequence BC® and EndoSeal MTA® sealers regarding their antibacterial activity against Enterococcus faecalis. Methods: The “Direct contact test” was the method used to evaluate the antibacterial effect of the 2 tested sealers. Each sealer was dispensed at the bottom of 96-well plates. Three unfilled wells were used as control group. Samples were evaluated under three setting conditions: fresh sealer, one week-old, and one month-old. Aliquots of the bacterial suspension were placed on the tested sealers and in the control wells. After incubation for 1 hour, the liquid portion of the suspension evaporated providing direct exposure between the bacteria and the surface of sealers. BHI broth (245 μl) was added then to each well and the plates were gradually mixed for two minutes; 15 μl of the bacterial suspension was transferred from each well to corresponding wells in other plates. The kinetics of bacterial growth in each plate was followed by densitometric measurement every hour for 3 hours, using a spectrophotometer. Results: Endoseal showed the stronger antimicrobial effect in different setting conditions. Both sealers have extended antibacterial activity up to one month. Conclusion: Endoseal is the most effective in eliminating E. faecalis and may be the most useful sealer for preventing bacterial infection when treating root canals.}, keywords = {EndoSequence BC®,EndoSeal MTA®,Enterococcus faecalis,Bioceramics,Antibacterial activity}, url = {https://edj.journals.ekb.eg/article_72652.html}, eprint = {https://edj.journals.ekb.eg/article_72652_7b1594503a890a36aee85d05d05f7739.pdf} } @article { author = {Hamama, Hamdi}, title = {Characterization of Bioactive Restoration/Dentine Interface}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2731-2738}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72672}, abstract = {Objectives: To characterize the bonding interfaces of a calcium silicate-based restorative material (Biodentine) and CPP/ACP-modified glass ionomer with dentine. Also, this study was designed to evaluate the influence of dentine-surface treatment with poly acrylic acid on the bonding of both materials to dentine.Methods: Sixty caries-free human molars were used in this study. Specimens were randomly divided into three groups according to type of restorative material used (n=20); calcium silicate-based (Biodentine, Septodont, France), conventional GIC Fuji VII-EP, GC Corporation, Tokyo, Japan) or CPP/ACP-modified glass ionomer (Fuji VII-EP, GC Corporation, Tokyo, Japan). Each group was divided into 2 sub-groups relative to the dentine surface treatment method (n=10); the dentine in control group was left without treatment, while the dentine surface in test groups was conditioned with poly acrylic acid (PAA) for 10s prior to the application of restorative. In each subgroup,5 specimens were double-labeled with fluorescein and rhodamine-B dyes then observed under a confocal laser scanning microscopy (CLSM). While the remaining 5 specimens were observed under scanning electron microscopy (SEM) then subjected to EDX elemental analysis.Results: CLSM micrographs showed that the mineral rich zone (MRZ) was obvious in non-conditioned Biodentine groups compared to conditioned groups. Both GICs groups exhibited obvious ion-exchange zones. In the non-conditioned Biodentine groups, polygonal crystal deposition was noticed beneath the hybrid layer. These findings were confirmed by the outcome of micromorphological analysis of restoration/tooth interface using SEM.Conclusions: Calcium silicate-based restorative material has a great affinity to exchange ions with tooth substrate and to bond chemically with dentine. The results of this study showed that calcium silicate-based restorative material (Biodentine) can be applied directly on dentine surface without any pre-surface treatment.}, keywords = {Bioactive restorations,Biodentine,Calcium Silicate,CPP/ACP,Glass Ionomer,Confocal Laser Scanning Microscopy}, url = {https://edj.journals.ekb.eg/article_72672.html}, eprint = {https://edj.journals.ekb.eg/article_72672_5307b0bd528fe422bb8806c6e16e082c.pdf} } @article { author = {Hadhoud, Fahd}, title = {Cone beam computed tomography assessment of canal transportation, centering ability, and radius change of two single file systems in curved root canals}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2739-2747}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72654}, abstract = {Objective: assessment the canal transportation and centering ability of two single file systems (Reciproc and Neoniti) in  curved mesiobuccal (MB) root canal of natural lower first molars, by cone beam computed tomography (CBCT) scanning. Methods: Forty non-calcified Mesio-buccal root canals with complete formed root and apical curvature of 20-45o and Radius ≤ 15mm were chosen from extracted human lower first molars. The samples were divided based on the instrument (n=20) into two main groups group I (Reciproc R 25/08) and group II (Neoniti R 25/08). Each group has another subdivided based on the motion into (n=10) Subgroup A: reciprocation motion Subgroup B: full rotation motion. The apical transportation, centering ability and radius change were measured by pre- and post-instrumentation CBCT scans by superimposing in four section (2, 4, 6 and 8 mm from apical foramen). Values were recorded, tabulated for each group and statistically analyzed. Results: The ability of instruments to remain centered in prepared canals at 2and 4 mm levels was higher in Neoniti reciprocation in MD dimension. The centering ratio at 6 and 8 mm level and in BL dimension were not significantly different between the tested subgroups. The change of the radius values and percentage produced no significant difference. Conclusion: Both Neoniti and Reciproc systems haven’t significant difference in canal transportation, centering ability and change in curvature radius expect when using reciprocation motion Neoniti produced significantly better results than Reciproc especially in the apical third.}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72654.html}, eprint = {https://edj.journals.ekb.eg/article_72654_147e04ff857d9faa85c735249a36b1a9.pdf} } @article { author = {Haridy, Mohamed and Ahmed, Hend and Hamza, Nermeen}, title = {Effect of different enamel surface preparations on the micro-tensile bond strength of resin composite to bleached enamel}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2749-2762}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72655}, abstract = {Aim: This study was carried out to investigate the effect of different enamel surface treatments on micro-tensile bond strength of resin composite to bleached enamelMaterials and methods: 56 human premolars were used in this study. Teeth were divided into two main groups group 1: unbleached enamel (10 teeth) while group 2: bleached enamel (40 teeth). Then group 2 was subdivided into 4 subgroups (10 each) according the enamel surface treatment employed after bleaching and before bonding to composite either no treatment, grinding with diamond stone to remove 0.5mm of the surface, air abrasion using the air abrasion system (AquaCare-Velopex International) and combination of grinding and air abrasion. Each subgroup as well as the control group was further divided into two classes (5 each) according to the aging time either 24 hours or 3 months. Another six specimens were used as representative for the enamel surface topography after treatments for scanning electron microscopy SEM testing. Specimens of group 2 were polished and mounted in an acrylic block (five teeth in each block) with slight lingual inclination from their long axis to facilitate bleaching and light application. For in office bleaching, Philips ZOOM in-office light-activated bleaching gel was used in this study. After the in-office bleaching, teeth were subjected to at home bleaching using Night White ACP system for successive 7 days. The bleached teeth were divided into four subgroups according the enamel surface treatment employed after bleaching and before bonding as mentioned before. All enamel specimens either unbleached (control) or bleached and prepared specimens were bonded to Filtek Universal Restorative composite (3M ESPE, St Paul, MN, USA) using Single Bond universal adhesive (3M ESPE, St Paul, MN, USA). For immediate subgroups and classes, the specimens were stored in distilled water for only 24h after resin composite bonding. While for the three-month classes, the specimens were stored for three months in distilled water at room temperature. For micro-tensile bond strength test, specimens were longitudinally cut into a series of 1 mm thick slabs by means of a water-cooled diamond blade of thickness 0.5 mm in a low speed micro-slicing machine. By rotating the specimen 90o and sectioning it again lengthwise (five cuts), four sticks of about 1 mm2}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72655.html}, eprint = {https://edj.journals.ekb.eg/article_72655_2afda0d829dce296bc4ca24917dc6da7.pdf} } @article { author = {Saadoon, Mahmoud and Kataia, Mohamed and abdellaatif, Amr and Awad, Samah}, title = {Clinical versus radiographic success of necrotic primary molars treated by Lesion Sterilization and Tissue Repair. A randomized controlled trial}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2763-2767}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72674}, abstract = {The success and failure after treatment of necrotic primary molars causes a hassle to clinicians. This study aims to study the difference between clinical success and radiographic success after treatment using Lesion Sterilization and Tissue Repair technique. The study was conducted on 41 subjects in each group, all subjects were treated by LSTR technique. At the end of the study despite of radiographic failure in 21%from group A & 4% from group B. Molars were clinically successful with absence of pain, swelling, mobility, fistula formation, and were maintained functioning till the end of the study. }, keywords = {}, url = {https://edj.journals.ekb.eg/article_72674.html}, eprint = {https://edj.journals.ekb.eg/article_72674_b9a73190be24fa7de9c6e9010a839ad7.pdf} } @article { author = {Anous, Weaam and Al-Ashry, Salma and Ali, Magdy and Kataia, Mohamed}, title = {Incidence of Postoperative Pain After Using Different Kinematic Cutting Motion in Multiple Versus Single File Concept}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2769-2777}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72656}, abstract = {Aim: Evaluate pain after using rotary instrument with different cutting motion and different number of instruments in vital mandibular teeth. Materials and Methods: Thirty-two patient with vital mandibular first molar was selected for this study. The root canal treatment was done in single visit. The patients were asked to follow general instructions and to sign a printed informed consent that explains the aim of the study and obligates the patient to fill a pain diary before the treatment, after 3 hours after finishing of the treatment, 24 hours, 48 hours, 7 days. Root canals were mechanically prepared using the different techniques (8 vital teeth in each group). Group 1: The ProTaper Next files. Group 2:  A primary reciprocating WaveOne Gold file. Group 3: A small reciprocating WaveOne Gold was used in reciprocating motion followed by primary reciprocating wave one gold file. Group 4: One shape rotary file. Obturation was carried out using the manufacture recommended gutta percha by selection of a master cone corresponding to the size of the master apical file. All canals were obturated using an epoxy resin-based sealer.Results: Pre-operatively; there was no statistically significant difference between the four groups. Immediately post-operative; wave One gold (Primary) group showed the statistically significantly highest mean pain score. After 3 hours; wave One gold (Small and Primary) group showed the statistically significantly highest mean pain score. After 24 hours. 48 hours as well as 7 days; all groups showed no pain.Conclusion: Reciprocating files showed more pain than rotation files.}, keywords = {Rotary instrument,reciprocating instrument,Postoperative Pain}, url = {https://edj.journals.ekb.eg/article_72656.html}, eprint = {https://edj.journals.ekb.eg/article_72656_0a274ad2f79be9637ee694abaefc46e8.pdf} } @article { author = {Beleidy, Marwa and Ziada, Ahmed}, title = {Scanning electron microscope evaluation of the marginal gap and internal fit of additive versus subtractive fabrication techniques for posterior lithium disilicate crowns}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2779-2793}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72676}, abstract = {Statement of the problem: The wide use of digital dentistry in fixed prosthodontics using 3D printers and CAD/CAM in fabricating crowns and partial fixed dental prosthesis created a need for more information about their marginal gap and internal fit.Purpose: This study aimed to evaluate the effect of fabrication technique using CAD/CAM manufactured and heat pressed lithium dislicate crowns made from milled wax and 3D printed resin patterns on their marginal gap and internal fit.Material & Methods: A total of 50 prepared mandibular first molar resin models were used and divided into two main groups according to their fabrication phase: Patterns group and fully fabricated crowns group. Patterns group was subdivided into milled wax patterns (W) (n=10) and 3D printed resin patterns (P) (n=10). Fully fabricated crowns group was subdivided according to fabrication technique of lithium disilicate crowns into: Machinable ceramics (M), using IPS e-max CAD blocks (n=10), Pressable ceramics (Pw), using IPS e-max press ingots following wax milling (n=10) and Pressable ceramics (Pp), using IPS e-max press ingots following 3D resin printing (n=10). All patterns and ceramic crowns were cemented with Rely-X self-adhesive resin cement. Marginal and internal adaptations were measured using SEM at 300 × magnification. Kruskal-Wallis and Wilcoxon signed-rank tests were applied to compare between the groups. Data were presented as median and range values. The significance level was set at P ≤ 0.05.Results: P group showed a significant higher median total marginal gap of 111.4 μm (80.8-139.7) than W group of 51.3 μm (45.1-57.8) before heat pressing. While M group showed the significant highest median marginal gap of 138.4 μm (83.4-191.8) and no significant difference between heat pressed groups (Pw and Pp) (P ≤ .05). Regarding changes after heat pressing, Pw group showed no significant decrease, while Pp group showed a significant decrease in median total marginal gap. For internal fit, there was no significant difference between the pattern groups (W and P) before heat pressing (P ≤ .05). After heat pressing, Pp group showed the significantly highest median gap of 195 μm (138.9-441.5) with no significant difference between M and Pw groups (P ≤ .05). Pw group showed a significant decrease in median gap, and Pp group showed no significant decrease after pressing (P ≤ .05). Conclusions: Heat pressed lithium disilicate glass ceramic crowns produced from CAD/CAM waxing or resin 3D printing techniques resulted in better marginal and fit accuracy than CAD/CAM. 3D printed resin patterns yielded internal fit values higher than other groups, but with promising clinical acceptability.Clinical implications: Both the additive and subtractive production for patterning phase before heat pressing allow clinical acceptability in terms of marginal and internal adaptation when a single unit posterior ceramic lithium disilicate crown is fabricated.}, keywords = {3D printing,CAD/CAM,Heat pressed,Marginal gap and Internal fit}, url = {https://edj.journals.ekb.eg/article_72676.html}, eprint = {https://edj.journals.ekb.eg/article_72676_9bda2e1e4431575b776ed82dc907cb07.pdf} } @article { author = {Rabie, Mohamed and Hassan, Hayam and Elshaboury, Elham}, title = {Cleanliness Efficacy of Neolix and Silk Rotary Systems in Root Canal Retreatment}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2795-2800}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72657}, abstract = {Aim: Comparing the cleanliness efficacy of Neolix and Silk nickel-titanium rotary systems used in root canal retreatment with and without Carvene solvent. Method: Forty extracted maxillary anterior teeth having single root canal were collected. Root canals were prepared and obturated with size 40 gutta-percha and Guttaflow bioseal, bioactive sealer. The root canals were distributed into two groups stated to the method of obturating material removal using (Neolix and Silk file systems). Further the groups were subdivided into two subgroups by using Carvene as a solvent or not. Roots were separated in bacco-lingual direction into two equal halves then cleanliness was analyzed using Stereomicroscope at the cervical, middle and apical regions. Results: Neolix system recorded higher cleanliness than Silk file system. Treatment with no-solvent recorded higher cleanliness than with using Carvene. Cervical region recorded the highest cleanliness followed by middle then apical region. Conclusion: Neolix file system without using solvent were more efficient for removing root canal obturating materials.}, keywords = {Neolix,Silk,Carvene,retreatment,Stereomicroscope}, url = {https://edj.journals.ekb.eg/article_72657.html}, eprint = {https://edj.journals.ekb.eg/article_72657_f3a8ae73a6b9955cccb04cd89341fdda.pdf} } @article { author = {ElEmbaby, Abeer}, title = {IMPACT OF NATURAL CROSS-LINKING AGENTS ON DENTIN BONDING}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2801-2811}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72658}, abstract = {Collagen is the most important structure of the hybrid layer, and chemical alteration to its structure could be gainful during bonding procedures. Aim: To evaluate the influence of two natural cross-linking agents (pomegranate peel extract [PP], and Apple peel extract [AP]) compared to chlorohexidine 2% [CHX on the shear bond strength (SBS) of sound and demineralized dentin before and after aging.Materials and Methods: 160 sound human premolars were collected and their occlusal surfaces were ground flat to expose dentin. Eighty teeth were submitted to cariogenic challenge by pH cycling to induce demineralized dentin [DD] after those teeth were randomly divided according to the dentin treatment protocol: chlorohexidine 2 % solution (CHX solution, Consepsis, Ultradent USA), pomegranate peel extract 10% solution (PP, Naturalin Bio-Resources Co., Ltd, Lu-Valley Enterprise Square. Changsha, City. Hunan Province. China), apples peel extract 10% solution (AP, Naturalin Bio-Resources Co., Ltd, Lu-Valley Enterprise Square. Changsha, City. Hunan Province. China) and the control group without any treatment. Then each group was further subdivided into two subgroups the first one was evaluated after 24 hours water storage and the second one after six months of water storage. Data were statistically analyzed by repeated measures Analysis of Variance (ANOVA) to study the effect of material, substrate, storage and their interaction on shear bond strength. Bonferroni’s post-hoc test was used for pair-wise comparisons when the ANOVA test is significant. The significance level was set at P ≤ 0.05. The interaction between the tested variables had a statistically significant effect on mean shear bond strength. PP scored the statistically highest mean shear bond strength. There was no statistically significant difference between CHX and AP; both showed lower mean values. While the control showed the lowest.Conclusion: Chemical alteration to the dentin matrix endorsed by PP and AP lead to enhance in the shear bond strength. The application of natural collagen cross-linkers during bonding procedures may be an innovative approach to enhance dentin bond strength properties}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72658.html}, eprint = {https://edj.journals.ekb.eg/article_72658_6fa4df36d4ef478ee1a0d845e00e2118.pdf} } @article { author = {El-Sherief, Samia and Rabie, Mohamed and Negm, Ahmed}, title = {Marginal Adaptation of a new Formulation of MTA Material used as Root-End Filling: A Scanning Electron Microscopy (SEM) Study}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2813-2819}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72659}, abstract = {Introduction Achieving a hermetic apical seal is mandatory to prevent ingress of any microorganisms or periapical fluids into the root canal system. Therefore it is essential to develop new materials having favorable physical, chemical and biological properties. Aim the purpose of this study was to use scanning electron microscopy to compare the marginal adaptation of new formulation of MTA (Harvard MTA), MTA flow and glass ionomer as root end filling materials using ultrasonic root-end preparation. Methodology Thirty-nine extracted single rooted human teeth were prepared using Protaper Next file system (Dentsply/Sirona) and filled with gutta-percha and MTA fillapex sealer (MTA Fillapex; Angelus, Londrina, Brazil) and obturated using cold lateral compaction technique. The apical 3 mm of the roots were sectioned perpendicular to the long axis of the roots. A 3-mm depth root-end cavity was prepared with ultrasonic tips powered by an Enac ultrasonic device. The teeth were randomly allocated into three groups of 13 teeth each according to filling materials tested. Group I the samples were filled with Harvard MTA (Universal, Handmix, Germany, Harvard), Group II filled with MTA Flow (Ultradent Products Inc., South Jordan,UT, USA), group III filled with glass ionomer (Fuji II, GC gold label 2, GC International, Japan). Using SEM the distance between the tested materials and the surrounding dentin was measured at different points.Results According to the results of Kruskal-Wallis, there was significant difference between the three experimental groups at P value 0.01. The Man Whitney test was used for two-by-two comparison of the groups which revealed no statistical significant difference between MTA flow and MTA Harvard group however; there was statistically significant difference in Glass Ionomer group. Conclusion SEM results showed the presence of gaps in the root-end filling materials in all groups. MTA flow has the best marginal adaptation followed by MTA Harvard while the Glass Ionomer showed the least marginal adaptation.}, keywords = {Root-end filling materials,Mineral trioxide aggregate,Glass Ionomer,marginal adaptation,SEM}, url = {https://edj.journals.ekb.eg/article_72659.html}, eprint = {https://edj.journals.ekb.eg/article_72659_da276f930103cc413a527df7dc50c721.pdf} } @article { author = {EL-Wassefy, Noha and Ghorab, sayed}, title = {Shear bond strength of two veneering composite resins to a modified polyetheretherketone (PEEK) material: Influence of surface pretreatments and thermocycling}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2821-2830}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72677}, abstract = {Objective: To research the influence of different surface pretreatment and thermocycling on shear bond strength (SBS) between veneering resins and a modified polyetheretherketone (PEEK) material.Materials and Methods: (PEEK) specimens were machined and allocated into Four pretreatment groups, Group A; no treatment, Group B; etching with 98% sulfuric acid for 1 min, Group C; air abrasion with 50 µm Al2O3, and Group D; air abrasion with 110 µmAl2O3. Surface roughness (Ra) was determined by a profilometer. Surface morphology of specimens was scanned by a Scanning Electron Microscope. Specimens were treated with Visio.link bond, divided into two subgroups; one veneered with SR Nexco and the other with Crea.lign composites. SBS was tested immediately and after thermocycling. Data were statistically analyzed using ANOVA and Tukey HSD, α = 0.05.Results: Air abrasion with 110 µm alumina significantly increased the surface roughness (P<0.001). The highest shear bond strength values were observed for sulfuric acid etched group. Specimens veneered with CreaLign showed non-significant higher SBS values than those veneered with SR Nexco (P>0.05). After thermocycling, all tested groups revealed significant improvement in SBS (p<0.001). Conclusions: A modified PEEK material strengthened with 20% submicron ceramic fillers, could be treated by etching with 98% sulfuric acid for 1 min, to enhance bond strength to veneering composites and was found to have significant improvement in bond strength after thermocycling.}, keywords = {Surface roughness,PEEK,Shear bond strength,thermocycling}, url = {https://edj.journals.ekb.eg/article_72677.html}, eprint = {https://edj.journals.ekb.eg/article_72677_3768848173b3496d4d654c4072351997.pdf} } @article { author = {Mohsen, Bassem and Hashem, Shereen}, title = {Polymethyl Methacrylate v.s Cayanoacrylate for Denture Teeth Rebonding}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2831-2835}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72679}, abstract = {Debonded/detached denture teeth is a very common cause for denture failures. Chairside repairs using Polymethylmethacrylate (PMMA) is a technique sensitive and difficult procedure. An alternative adhesive that was quickly recognized was the Cyanoacrylate (CA). CA are solvent free adhesives that cure rapidly when pressed into a thin film between two surfaces. Apart from that, they have clinical applications in medicine, especially as tissue adhesives and sealing materials. Materials and methods: Specimens consisted of acrylic teeth bonded to acrylic denture base. The specimens were divided into two groups; group I for testing bond strength using PMMA and group II for testing bond strength using CA. Results: The lowest mean MPa was seen in group 2 and the difference in MPa between this group and group 1 was significant. Conclusion: Even though CA appears to be the easier option, its` bond strength for teeth rebonding to denture base is less than that of PMMA.}, keywords = {Polymethylmethacrylate, Cyanoacrylate, denture teeth, debonding Abbreviations: Polymethylmethacrylate: PMMA,Cyanoacrylate: CA,Megapascal: MPa,Ridge-lap surface area: RLSA}, url = {https://edj.journals.ekb.eg/article_72679.html}, eprint = {https://edj.journals.ekb.eg/article_72679_95484996b808f2c615cb4c4bfb66d97e.pdf} } @article { author = {Mosallam, Rania and Haridy, Mohamed}, title = {Fracture Strength of Endodontically Treated Teeth Restored with Endocrown restorations with /without Resin Composite Base Materials – An in vitro study}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2837-2848}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72680}, abstract = {Objective: To compare the effect of using resin composite base materials on fracture strength of endodontically treated premolar teeth restored with endocrown restorations. Materials and Methods: A total of 60 sound maxillary first premolars with standardized MOD cavities with endodontic treatment were selected for this study, except for intact control. They were randomly divided into six groups (n=10); G1: sound premolars ( negative control); G2: unrestored teeth (positive control); G3: MOD cavities with endocrown restorations. G4: MOD cavities with nanohybrid composite base and endocrown ; G5: MOD cavities with sonicfill bulk fill composite base and endocrown ; G6: MOD cavities with bulk fill flowable composite base and endocrown. Vita Enamic hybrid ceramic was used to fabricate the overlay restorations. All samples were subjected to thermocycling between 5Cº to 55Cº in water bath for a total of 2000 cycle with 10 seconds dwell time. Then specimens were individually mounted on a computer-controlled material testing machine (Instron 3345) with a load cell of 5 kN and the maximum load to produce fracture in Newton (N) was recorded. Statistical analysis: Analysis of variance (ANOVA) and Kolmogorov Smirnov and Shapiro-Wilk tests was performed .Results: Fracture strength of restored teeth was increased compared to unrestored teeth. The fracture strength of G6 (bulk fill flowable) was significantly higher than the fracture strength of G5,G4,G3 and not significantly different from G1( intact teeth). Conclusion: The use of resin composite base material significantly increased the fracture strength of endodontically treated premolars with endocrown restorations.}, keywords = {Endocrown, Overlay,resin composite,Fracture strength}, url = {https://edj.journals.ekb.eg/article_72680.html}, eprint = {https://edj.journals.ekb.eg/article_72680_c67f7fdb14904d05f938c50b03d785e6.pdf} } @article { author = {Shoeib, Ahmed and Shaker, Maie and Abdeen, Reem and El-Segai, Azza}, title = {Evaluation of silver and copper oxide NANOPARTICLES release from different prosthetic materials incorporated with nanoparticles}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2849-2855}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72681}, abstract = {The purpose of this study was to evaluate the amount of released of silver and copper oxide nanoparticles when they were incorporated in heat cured acrylic resin denture, chemical cured soft liner, and cream type adhesive.Material and methods: A total number of 240 samples were prepared, 80 denture base samples, 80 liner, and 80 adhesives, and 10 samples from each material were free from nanoparticles that act as a control. The remaining samples were divided into two groups: (Group I) contained denture base, liner and adhesive samples modified with copper-oxide nanoparticles concentration by (0.1%, 0.3%, and 0.5%, 10 sample each), and (Group II) has the same number of samples but modified with same silver nanoparticles concentrations. The samples were placed in distilled water for one week and the amount of release was measured by spectrophotometer. The recordings data were analyzed using Two-way repeated measures Analysis of Variance (ANOVA) to compare between the three groups as well as to study the effect of time within each group. Bonferroni’s post-hoc test was used for pair-wise comparisons. P< 0.05 was considered.Results: Release was higher in denture adhesive followed by denture liner and denture base respectively in the two groups. The amount of release increased with increasing nanoparticles concentration in denture base and adhesive but not in denture liner. There was no significant difference between Group I, and Group II.Conclusion: Nanoparticle release was affected by the type of prosthetic material, nanoparticle concentration, but not nanoparticles type.}, keywords = {Nanodentistry,silver nanoparticles,copper oxide nanoparticles,denture base,denture liner,denture adhesive}, url = {https://edj.journals.ekb.eg/article_72681.html}, eprint = {https://edj.journals.ekb.eg/article_72681_4713f6761a5fabfbc42933ea0a14cbbf.pdf} } @article { author = {Salem, Shereen}, title = {Wear and Microhardness of Three Different Types of CAD/CAM Ceramic Materials}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2857-2866}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72682}, abstract = {Objective: Wear and microhardness of three different types of CAD/CAM ceramics against enamel as an occlusal antagonist were studied. Also, microhardness was evaluated. Materials and Methods: The three tested ceramics were: Vita Enamic (polymer-infiltrated ceramic), IPS e.max CAD (lithium disilicate ceramic) and Celtra Duo (Zirconia reinforced lithium silicate ceramic). The occlusal antagonists were extracted teeth. Thirty samples were constructed divided into 3 groups according to the type of ceramic used (10 samples each). Then each group was subdivided into 2 subgroups (5 samples each), The first subgroups underwent a microhardness test while the other subgroups were first weighed then subjected to wear test and finally re-weighed again before being subjected to microhardness test. Results: The results showed a significant difference in weight loss due to wear between Vita Enamic and both IPS e.max CAD and Celtra Duo. There was also a significant difference for the antagonist tooth structure as regard both weight and height loss between Vita Enamic and both IPS e.max CAD and Celtra Duo. Microhardness results showed a significant difference between Vita Enamic and both IPS e.max CAD and Celtra Duo as regard microhardness without and after wear. For all the tested ceramics, there was no significant difference as regard microhardness without and after wear test. Also, there was no significant difference as regard wear and microhardness between IPS e.max CAD and Celtra Duo.Conclusions: Vita Enamic showed the worst wear behavior and the least abrasiveness to enamel while, IPS e.max CAD and Celtra Duo showed comparable wear behavior and abrasiveness to enamel. Also, ceramic microhardness was not affected by wear for the three tested ceramics.}, keywords = {Polymer-infiltrated ceramic,Lithium disilicate ceramic,Zirconia reinforced lithium silicate ceramic,Wear,Microhardness}, url = {https://edj.journals.ekb.eg/article_72682.html}, eprint = {https://edj.journals.ekb.eg/article_72682_57613813b97dbf42852ecb82fc9fe675.pdf} } @article { author = {Hadhoud, Fahd and Abdel-Kader, Karim}, title = {Comparative evaluation of the tissue dissolution capability of 3% of sodium hypochlorite, 5%pomegranate, and 5%miswak}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2867-2873}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72683}, abstract = {Objective: This study aimed to evaluate of the tissue dissolution capability of 3% of sodium hypochlorite, 5%pomegranate, and 5% miswak.Methods: 45 freshly extracted premolar teeth were used. The teeth were grouped into three groups (n=15) Group I: The pulp tissue was immersed in 3% sodium hypochlorite irrigating solution. Group II: The pulp tissue were immersed in Punicagranatum (5%pomegranate) Nano particles irrigating solution. Group III: The pulp tissue were immersed in Salvadorapersica (5%miswak) Nano particles irrigating solution. The pulp tissue obtained was inserted into a small plastic test tube and 10ml of the irrigating solution were added to it and stored for 15 min. The ultrasonic tip were inserted inside the tube with irrigating solution and allowed to work for 1 minute to achieve proper agitation. After 15 min the solution was filtered through absorbing filter paper for 3 min to remove any excess moisture and left the sample to dry. Then the weight of the residual pulp tissue was measured and the difference between the initial and final weight was used to calculate the weight loss that were represent the dissolving power of each solution.Results: The highest value of dissolution percentage was found in Sodium hypochlorite group (98%), followed by Pomegranate group (78.3%). while the least value was found in Miswak group (66.8%). p= ≤0.001.Conclusion: On contrary of miswak, Pomegranate gives promising results in relation to NaOCl in terms of tissue dissolving capacity.}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72683.html}, eprint = {https://edj.journals.ekb.eg/article_72683_48b3b75ae791cc0b09b1cb8df083bcd3.pdf} } @article { author = {Murad, Noha}, title = {Effect of HF acid etching duration on surface roughness of newly introduced glass ceramic material}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2875-2887}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72684}, abstract = {Purpose: The aim of this in-vitro study will be directed to evaluating the effect of different hydrofluoric acid etching durations on the surface roughness of lithium silicate based glass ceramics obsidian and e-max, microstructure changes also color difference.Materials and methods: Eighty disc samples were grouped according to material type into two groups; obsidian group(n=40) and e-max group(n=40), each group was subdivided into four groups according the duration of hydrofluoric acid (HF) application into: Subgroup I (control) (n=10) without surface treatment. Subgroup II, (n=10) 20 seconds Subgroup III, (n=10): 40 seconds. Subgroup IV, (n=10): 60 seconds. All surface treated samples will be subjected to: Surface roughness examination, Surface topographic analysis using SEM and profilometer, and color differenceResults: the surface roughness test revealed that; the highest mean value was recorded in 60 second etch, followed by 40 sec etch then 20 second etch; with the least value recorded in control (no etch). ANOVA test revealed that the difference between etching subgroups was statistically significant (p<0.0001). Also higher mean value was recorded in E-max with statistically significant difference (p=0.014). Effect of etching time on color the highest mean value was recorded in 60 second etch, followed by 40 sec etch then 20 second etch,; with the least value recorded in control (no etch). ANOVA test revealed that the difference between etching time was statistically significant (p<0.0001).Also a higher mean value was recorded in E-max with statistically significant difference (p<0.0001),Conclusion E-max group showed higher means of surface roughness test and color difference rather than obsidian. Also 60 second etch showed the highest mean values of surface roughness test and color difference followed by 40 second etch followed by 40 second etch.}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72684.html}, eprint = {https://edj.journals.ekb.eg/article_72684_cbba88e94709ab367c821931c7ae3df6.pdf} } @article { author = {Saad, Nermeen and Zohdy, Maged}, title = {Effect of occlusal-convergence and resin cement on retention of cubic-zirconia based crowns}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2889-2897}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72685}, abstract = {Purpose. The purpose of this study was to evaluate the retention of cubic zirconia crowns with two occlusal convergence preparations and cementation with two resin cements. Materials and methods. 28 dies were divided according to the convergence angles into two main groups. Group (1): 20° (n=14) Group (2): 12° (n=14) Each group was subdivided according to resin cement used into two subgroups. Subgroup A: RelyX Unicem (3M/ESPE, USA) (n=7) Subgroup B: Panavia v5 with clearfil primer plus (Kurary, Japan) (n=7) Two stainless steel master dies were prepared by a milling machine to simulate all ceramic full coverage crown preparation of a maxillary premolar. Each Steel die was machined with height 5.5 mm and two planes occlusal reduction with palatal cusp bevel. The external diameter of the cylinder was 7.5 mm. one die was prepared with 12˚ and the other with 20˚ occlusal convergence angle. Impressions of the main master dies were taken and poured using a non-shrink epoxy resin material. The crowns were cemented. Instron universal testing machine was used to test the retention. The cemented crowns were pulled off along the path of insertion with a crosshead speed of 0.5 mm/minute. The forces required for dislodgment of the crowns were recorded in N. Data were statistically analyzed using one-way ANOVA and many comparisons were made using .Tukey’s test at pResults. Retention of the zirconia crowns was significantly affected by the occlusal convergence and by the type of resin cement. Self-etching resin cement showed a higher significant result in comparison to self-adhesive. Retention values with occlusal convergence 12° was highly significant with both cementsConclusions. The Retention of cubic zirconia ceramics varied significantly depending on the type of resin cement and degree of occlusal convergence of the preparation.}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72685.html}, eprint = {https://edj.journals.ekb.eg/article_72685_32b284b4e1341dd3baa58b0af02de2eb.pdf} } @article { author = {Osman, Maha}, title = {Effect of thermo-cycling on micro-tensile bond strength of bulkfill resin composite using recent universal adhesive}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2899-2910}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72686}, abstract = {Statement of the problem: bonding performance of newly launched universal adhesive recommended by the manufacturer to be used with sonically activated bulkfill resin composite need further investigation. Materials and Methods: A total of 40 non carious human molar teeth were extracted and collected from diabetic patients for this study. The selected teeth were divided into two main groups, 20 teeth each, according to adhesive used (A). In group (A1), the adhesive system was universal one step self- etch adhesive (OptiBond Universal), while in group (A2), two steps universal self etch primer adhesive (OptiBond XTR) was applied. Each group was subdivided into two subgroups, 10 teeth each, according to whether thermocycling was carried out or not (T). Where (T0) class denotes the teeth that were not subjected to thermocycling and (T1) class denotes the teeth that were subjected to thermocycling. (SonicFill 2 bulkfill resin composite) restorative material was used with both adhesives. The teeth stored in distilled water for 24 hours before the rod specimens were prepared for the microtensile bond strength test. Two rods from each tooth were obtained. Half of the specimens of each group were subjected to theromcycling testing at 5oC± 2oC to 55oC± 2oC for 500 cycles. Microtensile bond strength test was carried out using a universal testing machine. Results: showed that the mean microtensile bond strength of one step universal self-etch adhesive (OptiBond Universal) had statistically significantly higher value than the self-etch primer (OptiBond XTR) either with thermocycling or without thermocycling at (P <0.001). The mean microtensile bond strength of one step universal self etch adhesive had statistically significantly higher value without thermocycling than with thermocycling at (P <0.001). The microtensile bond strength test with the two steps universal self-etch primer (OptiBond XTR) adhesive showed that there was no statistically significant difference between mean microtensile bond strength either with or without thermocycling (P = 0.067). Conclusion: The (SonicFill2) resin composite one of the recently used bulkfill resin composite restorative material performed higher bond strength with one step universal self etch adhesive more than with two steps universal self-etch primer adhesive when applied to the dentin substrate. However concerning bond stability, the SonicFill2 resin composite restorative material showed higher bond stability after thermocycling with two steps universal self etch primer more than with one step universal self etch adhesive.}, keywords = {universal adhesives,Sonically applied resin composite,Micro-tensile,thermocycling}, url = {https://edj.journals.ekb.eg/article_72686.html}, eprint = {https://edj.journals.ekb.eg/article_72686_a39d475431bb0d27517c599489f96d26.pdf} } @article { author = {Nossair, Shereen}, title = {The effect of thickness and degree of translucency on the final color of lithium disilicate veneers}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2911-2920}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72687}, abstract = {Statement of problem: Achieving lighter final shades of A1 and BL1 with lithium disilicate veneers and the impact of different lithium disilicate translucencies and thickness on the final color is unclear. Aim: The aim of this in vitro study was to investigate the effect of different translucencies and thicknesses of lithium disilicate on the final shade of veneers. Materials and methods: Eighty lithium disilicate specimens were fabricated from two translucencies of lithium disilicate blocks(IPS e.max CAD blocks, Ivoclar Vivadent); HT high translucency(HT) and low translucency (LT), in two different shades; A1 and BL1, and with 4 different thicknesses; 0.3mm, 0.5mm, 0.7mm, and 0.9mm. The discs were placed on an A3 shade composite substrate with a 0.1 mm translucent resin cement. ΔE values were recorded to determine color differences between the specimens and the standard A1 and BL1 color parameters. ΔE values were directly recorded with a handheld spectrophotometer (Easyshade Advance) The ΔE values were compared with an acceptability threshold (ΔE=3.7). Two-way ANOVA, and the Bonferroni test were used to analyze data (α=.05). Results: The changes in both thickness and translucency showed high significance. For A1 shade, the 0.9 mm LT showed the least mean ΔE value while the highest mean value was obtained by 0.9 mm HT. For BL1 shade, The 0.9 mm HT samples showed the least mean ΔE value while the highest mean value was obtained by 0.3 mm LT samples.Conclusions: The thickness and the translucency of lithium disilicate affected its final color. A minimum of 0.5 mm thickness of LT lithium disilicate was able to produce a clinically acceptable A1 shade. Achieving BL1 final shade was not possible with both HT lithium disilicate and LT lithium disilicate in thicknesses up to 0.9mm.}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72687.html}, eprint = {https://edj.journals.ekb.eg/article_72687_ee25cf039e05a4b1db6f6d94ba99fa1c.pdf} } @article { author = {Salaheldin, Mai and Sherif, Ashraf and Mohammed, Ahmed and Nossair, Shereen}, title = {Comparison of accuracy of restorations generated through digital images of two extra oral scanners}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2921-2929}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72688}, abstract = {Statement of problem: With the advancement of digital technology, extraoral digital scanners have become popular among dental laboratories and dentists. The literature concerning accuracy of restorations fabricated from digital images of extraoral scanners is non conclusive.Aim: The the aim of the study is to compare the accuracy of single crowns generated from CAD/CAM Systems using digital images of two extra-oral scanners. Materials and Methods: Twenty 3D printed dies were scanned using the investigated extraoral scanners (InEos X5 and Ceramill map 400). The digital images were used to produce a 3D virtual crown design on the systems’ respective CAD softwares. Crowns were milled of lithium disilicate blocks. The milled crowns were divided into two groups according to the type of CAD/CAM system used; Group I/M (Cerec system: In Eos X5 and MCX5) and Group C/C (Amanngirbach System: Ceramill map 400 and Ceramill motion2), 10 crowns each. The marginal gap distance between the crown and the 3D printed resin die was measured using a digital microscope and replica technique was used to measure the internal gap between the crowns and their respective 3D printed resin dies. Results: Group I/M demonstrated statistically significant smaller median marginal gap distance 95 μm while Group C/C demonstrated a median marginal gap distance of 113 μm. The was no statistically significant difference between both systems with regards to internal fitness. The accuracy of crowns of both systems was within clinically acceptable range.Conclusions: Crowns generated from CEREC system (In Eos X5/ MCX5) showed better marginal accuracy than AmannGirrbach system. (Ceramill map 400 / Ceramill motion 2). Both systems produced marginal accuracy and internal fitness within the clinically accepted range.}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72688.html}, eprint = {https://edj.journals.ekb.eg/article_72688_9c46ab6c00a88f90dcafd9ddc8ed15f9.pdf} } @article { author = {Gomaa, Amira}, title = {Strains Induced in CAD/CAM Milled Mandibular Implant Retained Overdentures In vivo Strain Gauge Analysis}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2931-2944}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72689}, abstract = {Purpose: The introduction of computer-aided design/computer-aided manufacturing (CAD/CAM) technology to the field of removable prosthodontics has recently made it possible to fabricate complete dentures using prepolymerized polymethyl methacrylate (PMMA) blocks that are claimed to have better mechanical properties. However, little was published concerning the clinical deformation of CAD/CAM PMMA. The purpose of this study was thus to compare the clinical deformation of CAD/CAM processed PMMA and conventionally processed heat-cured PMMA implant retained mandibular overdenture bases.Materials and Methods: Thoroughly selected ten completely edentulous patients have received two dental implants in the lower canine region. Two duplicate mandibular overdentures were constructed using CAD/CAM milled PMMA and conventionally constructed heat-cured PMMA. Self cure acrylic resin was used to pick up the attachments to the fitting surface of the mandibular overdenture base. Six linear strain gauges were attached to the lingual side of the polished surface of both overdenture bases to measure strains induced during maximal clenching and gum chewing.Results: Higher strain values were recorded with the conventionally constructed heat-cured PMMA overdentures compared to CAD/CAM constructed PMMA overdentures. The recorded strains were mainly compressive at the midline while the strains at implant sites were tensile. Higher strains were recorded during clenching compared to gum chewing in both assessed overdentures. Conclusion: CAD/CAM constructed PMMA implant-retained mandibular overdenture exhibits less denture deformation during function compared to conventionally constructed heat-cured PMMA overdenture.}, keywords = {CAD/CAM dentures,PMMA resin,Strain,deformation,denture base,Implant,overdenture}, url = {https://edj.journals.ekb.eg/article_72689.html}, eprint = {https://edj.journals.ekb.eg/article_72689_46f28fc887bbf79eae0cc63c3b21a37f.pdf} } @article { author = {Salah El-Din, Amr and Osama, Ahmed}, title = {The Effect of using different locator attachments with a different retention value on the bone height changes in Implant Supported class I removable Mandibular partial Overdenture, A Radiographic Evaluation}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2945-2954}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72690}, abstract = {Purpose: The aim of this study was to evaluate the effect of using different locator attachments with a different retention value and ball and socket attachment on the bone height changes in Implant Supported class I removable Mandibular partial Overdenture.Introduction: The use of osseointegrate dental implants is one of the most successful treatment options to solve the problem of distal extension cases. A critical factor affecting the success of an implant is the manner in which mechanical stresses are transferred from the implant to the bone. One of the factors which affect the amount of force transmitted to the implant is the choice of the attachment. The Locator attachment system is a self-aligning and has dual retention, supplied in different colors; with a different retention value (white, orange and blue). The white housing has light retention, the orange housing has standard retention, and the blue has high retention while the ball and socket attachments consist of a titanium male unit and an easily replaceable rubber ring female unit that is retained in a metal retainer ring. The question is which of the various Locator attachment system used to retain mandibular partial overdenture affect the magnitude of stresses transmitted to the implants thus affecting the bone height changes around the implants.Material and methods: Twelve class I mandibular partially edentulous patients with opposing full dentate maxillary arch were selected from the from the Outpatient clinic, Prosthodontic Department, Faculty of Dentistry, Ain shams University. For all the patients extra and intraoral examinations were done associated with the proper laboratory investigations. Acrylic temporary partial denture was made for all the patients, the partial denture was duplicated into clear acrylic resin model then the model was scanned using CBCT machine and the DICOM data was processed to obtain STL file for the model. The digital image was performed and the virtual implant was placed in the most optimal position at the first molar area according to the surgical and prosthetic design. Conventional implant fixture were surgically inserted so that the top level of fixture needs to be located 0.5mm below the marginal crestal bone level, After three month from implant insertion, each patient was recalled For the insertion of super structure. The selected cases were randomly divided into three equal groups; Group I received an implant Supported class I removable Mandibular partial Overdenture with white locator attachment Group II received a Implant Supported class I removable Mandibular partial Overdenture with an orange locator attachment and Group III received an implant Supported class I removable Mandibular partial Overdenture with a ball and socket attachment.CBCT was used to evaluate the bone height changes around each implant at time of partial over denture insertion, 6months and 12 months from partial over denture insertion.Results: The results show that in all groups the bone loss appeared to be within acceptable limits in the groups during follow up period(less than1 mm during first year) but with significant differences in the bone height changes around the implant between both locator attachments and ball and socket attachment while the results show no significant difference between white and orange locator but the orange locator show higher bone resorption than the white locator.Conclusion: The current study concluded that locator attachments with different retention value provides better preservation of crestal bone than ball and socket stud attachment , where the white locator attachment show transmits less stress to the abutment resulting in reducing the amount of bone loss around the implants than orange locator when used in implant supported class I mandibular partial over denture}, keywords = {Implant overdenture,ball and socket attachments,locator attachments,white locator,orange locator,CBCT,crestal bone resorption}, url = {https://edj.journals.ekb.eg/article_72690.html}, eprint = {https://edj.journals.ekb.eg/article_72690_25c55b8bcc4bc86e0de532e63ce1d841.pdf} } @article { author = {Zidan, Ahmed}, title = {Effect of chitosan on resin-dentin interface durability: A 2 year in-vitro study}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2955-2965}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72691}, abstract = {Aim: The aim of the current study was to evaluate immediate and long-term bonding effectiveness of chitosan-treated dentin, bonded using 2-step etch-and-rinse dental adhesive, after 2 years of ageing.Materials & Methods: Microtensile bond strength test and nanoleakage examination of resin-dentin interfaces, created by Adper Single Bond 2 with or without chitosan pre-treatment, were performed after 24 h, 12 mos and 24 mos of water storage. Stiffness of demineralized dentin sticks treated with chitosan for 1 or 10 min was evaluated. Matrix metalloproteinases (MMPs) activity was also assessed by measuring the amount of hydroxyproline release, indicating collagen degradation by MMPs, after chitosan treatment for 1 or 10 min. Data were collected, tabulated and statistically analysed.Results: Chitosan treatment of acid-etched dentin, before adhesive application, resulted in microtensile bond strength values which are significantly higher (40.7± 1.7 MPa and 37.2±1.9 MPa respectively) and nanoleakage values (56.5±3.8% and 62±3.6 % respectively) that are significantly lower than the untreated control group at 12 mos and 24 mos storage periods (P ≤ 0.05). The stiffness of demineralized dentin increased significantly after 1 min chitosan application (12.6±1.8 MPa) and further increased after 10 min chitosan application (22.4± 2.2 MPa). Hydroxyproline released decreased significantly (P-value <0.001) when completely demineralized dentin was treated with chitosan for 1 min (1.1 µg/mg dentin) with further significant decrease when chitosan was used for 10 min (0.8 µg/mg dentin). Conclusion: Chitosan treatment of acid-etched dentin, before adhesive application, was effective in improving durability of resin-dentin bonded interfaces. Clinical Significance: Despite of the great advances that have occurred in the field of adhesive dentistry, still, biodegradation of resin-dentin bonds over time continues to jeopardize the durability and success of resin composite restorations.}, keywords = {Chitosan,etch-and-rinse adhesive,Dentin,microtensile bond strength,Nanoleakage,Stiffness,hydroxyproline release}, url = {https://edj.journals.ekb.eg/article_72691.html}, eprint = {https://edj.journals.ekb.eg/article_72691_b7b7926d9dbeb18f966d2c7b61ee8092.pdf} } @article { author = {Azer, Amir and Shahin, Heidar}, title = {FIT OF LASER SINTERED METAL RESTORATIONS: A SYSTEMATIC REVIEW}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2967-2980}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72692}, abstract = {Objective: The aim of this study is to review all the published in vitro research on the fit of laser sintered metal copings compared to other fabrication techniques.Materials and Methods: A comprehensive electronic search was performed through Google Scholar to combine the following key words: ‘3D printing’, ‘rapid prototyping’, ‘laser sintering’, ‘direct metal laser sintering’, ‘laser melting’, ‘metal coping’, ‘cobalt chromium coping’, ‘metal crown’, ‘cobalt chromium crown’, ‘internal fit’ and ‘marginal fit’. The search was limited to articles written in English. In addition, a manual search was also conducted through articles and reference lists retrieved from the electronic search and peer reviewed journals.Results: A total of 284 articles were retrieved and only 17 met the specified inclusion criteria for the review. The selected articles had assessed marginal and ⁄ or internal fit of laser sintered metal copings against other fabrication techniques.Conclusions: Laser sintered metal copings have a good marginal and internal fit within the clinically acceptable range suggested in the literature. Laser sintering procedure provides an efficient and rapid method for digitally designing and manufacturing complex metal structures for crowns and FPDs.}, keywords = {3D printing- laser sintering- metal coping- internal fit – marginal fit}, url = {https://edj.journals.ekb.eg/article_72692.html}, eprint = {https://edj.journals.ekb.eg/article_72692_dc7131931e51eac47cf03c415b45e04f.pdf} } @article { author = {Gomaa, Amira}, title = {Chewing and Bite Force Efficiency of Innovative Implant Assisted Overdentures}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2981-2992}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72693}, abstract = {Introduction: Computer-aided technology is an innovative method for fabrication of removable prosthodontics. Thus, more prospective clinical trials are necessary to validate this technology. Purpose: The purpose of this study was to evaluate the impact of computer-aided design and computer-aided manufacturing (CAD-CAM) milling technique of prepolymerized Poly Ether Ether Ketone (PEEK) and Poly methyl methacrylate (PMMA) implant assisted overdentures on the chewing efficiency and bite force compared to the conventionally fabricated heat cured acrylic resin overdentures. Materials and Methods: Ten completely edentulous patients with persistent complaint of poor retention and stability of their mandibular complete dentures were selected. Each participant received four dental implants in the anterior mandible. Three identical overdentures were constructed for each patient. According to the processing technique and denture base material, the processed overdentures were classified into three groups. Group I: comprised CAD/CAM milled PEEK overdentures. Group II: comprised CAD/CAM milled PMMA overdentures. Group III: comprised conventional heat cured acrylic resin overdentures. Chewing efficiency of all overdenture groups in terms of measuring the unmixed chewing gum fraction was assessed using two-colour mixing ability test. Biting force was also assessed by a bite force transducer. All assessments were carried out three months after overdenture insertion of each type .Results: Chewing efficiency and biting force increased significantly with the CAD-CAM milled PEEK and CAD-CAM milled PMMA overdentures compared to the conventionally processed heat cured overdentures. However, no statistically significant difference was detected in the chewing efficiency and biting force when PEEK and PMMA overdentures were used. Conclusions: The CAD-CAM fabricated overdentures provided increased chewing efficiency and better biting force compared to conventionally processed heat cured overdentures.}, keywords = {CAD/CAM dentures,PEEK resin,prepolymerized PMMA resin,bite force,chewing efficiency,Implant overdenture}, url = {https://edj.journals.ekb.eg/article_72693.html}, eprint = {https://edj.journals.ekb.eg/article_72693_fdcd62076f9fe6e9a0c737a4af1ed364.pdf} } @article { author = {Alsofi, Loai}, title = {CYTOTOXICITY OF REGULAR AND FAST SET BIOCRAMIC MATERIALS}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2993-2997}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72694}, abstract = {Aim: To compare the cytotoxic effect of regular and fast set Root Repair Materials using oral epithelial cells (OEC).Materials and methods: The cytotoxicity of the two forms was tested against OEC cells using Sulfo-rhodamine B (SRB) assay. The cells were exposed to the test compound for 72 hrs. Results: Both fast and regular set root repair materials showed a considerable cytotoxicity against OEC cells with IC50 of 3.0 and 3.4 μg/ml, respectively. Despite their moderate cytotoxic effect, the resistant fraction was relatively high for Fast and regular root repair composites (R-values equal 35.6% and 32.2%, respectively). Conclusions: Both fast and regular set of EndoSequence Root Repair Materials have a considerable cytotoxicity against OEC cells. Despite their moderate cytotoxic effect against the cells the resistant fraction was relatively high for both.}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72694.html}, eprint = {https://edj.journals.ekb.eg/article_72694_b4b1fa34f15963bcf1a44ccc550e9adc.pdf} } @article { author = {Hamama, Hamdi}, title = {Effect of Dentine Surface Treatment on Bonding of Bioactive RMGI-based Restorative Material to Dentine}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {2999-3006}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72695}, abstract = {Objectives: To evaluate the effect of different dentine surface treatment methods on bonding of bioactive RMGI-based restorative material to dentineMethods: A total number of 25 caries-free human permanent molars were used as the bonding substrate. The occlusal enamel was removed using a low-speed diamond saw (Isomet, Buehler, USA). The selected molars were divided into 5 groups (n=5) according to the dentine surface treatment method used; saline (control), 10% citric acid (10s),17% EDTA (10s), 37% Phosphoric acid (10s) or polyacrylic acid (10s). Then, restorative material was placed to cover the exposed dentine surface following the manufacturer instructions. The hybrid/hybrid-like layer was observed using environmental field emission scanning electron microscopy E-FESEM operated in secondary electron/ back -scattered detection modes. Furthermore, the tooth/restoration interface was subjected to an elemental analysis using Energy Dispersive X-ray (EDX) and EDX mapping.Results: The micromorphological analysis of tooth/restoration interface showed that bioactive RMGI-based restorative material (Activa) exhibited good hybridization with dentine following surface treatment with 10% citric acid, as well as, saline. The outcome of elemental analysis showed that 10% citric acid did not adversely affect the calcium content of dentine in comparison with surface treatment using phosphoric acid. Conclusions: Water plays a great role in bonding of bioactive restorative materials to dentine. These materials can directly bond to dentine after rinsing of the surface with saline. Although, bioactive RMGI restorative material manufacturer recommends conditioning the dentine with phosphoric acid prior to insertion of materials, it is highly advisable and more conservative to use 10% citric acid.}, keywords = {Bioactive restorations,RMGIC,EDX,Micromorphological Analysis Tooth/restoration interface}, url = {https://edj.journals.ekb.eg/article_72695.html}, eprint = {https://edj.journals.ekb.eg/article_72695_36579ab7dfffb757c986f47ae428567e.pdf} } @article { author = {Hany, Carl and Taymour, Maha}, title = {Marginal Integrity of Glass Ceramic Laminate Veneers Produced Through Different CAD/CAM Milling Protocols: In-Vitro Study}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {3007-3018}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72696}, abstract = {Statement of the problem: The conservative nature of the labial ceramic veneers necessitates minimum amount of tooth reduction with thin peripheral margins. Since construction time of restorations is becoming a determinant factor together with accuracy, the effect of three different CAD/CAM milling protocols that depend on the time factor deserves to be assessed.Purpose: The purpose of this investigation was to evaluate the effect of three different CAD/CAM milling protocols; namely normal, fast, and two-step milling on the peripheral marginal accuracy of glass-ceramic laminate veneers.Materials and Methods: A maxillary central incisor acrylic tooth was chosen to serve as a die for veneer construction. Acrylic tooth preparation was done to receive incisal feather edge design for the ceramic veneer. A total of thirty laminate veneer restorations were constructed from IPS e.max CAD glass ceramic using the CAD/CAM technology with three different milling protocols. The veneers were divided into the following groups according to the selected milling protocol; Group 1: Ten veneers constructed using the normal milling protocol, Group 2: Ten veneers constructed using the fast milling protocol, Group 3: Ten veneers constructed using the two-step milling protocol. The milled veneers were subjected to crystallization process according to manufacturer’s instructions then they were checked on their corresponding die for proper adaptation and seating. For proper assessment of the vertical marginal gap, the veneers were fixed on the master die using one drop of adhesive placed centrally to stabilize the veneers in their place during the measuring procedure. The vertical marginal gap distance of each ceramic was measured using a stereomicroscope at magnification X45. The measurements were done along the peripheral circumference for all the veneer margins (mesial, distal, cervical and incisal). Measurement at each point was repeated five times. A digital image analysis system was used for assessing and evaluating vertical marginal gap width. The mean vertical marginal gap distance was calculated and then tabulated for the statistical analysis of the data. Results: Effect of milling protocol: The two-step milling protocol showed the statistically significant lowest mean marginal gap distance (33.2 ± 6.3 μm) while both the normal and fast milling protocols showed the statistically significant highest mean marginal gap distances with no statistically significant difference between them. (40 ± 7.5 μm and 41.2 ± 4.9 μm respectively) Effect of surface: The cervical surface recorded the statistically significant lowest mean marginal gap distance (34 ± 6.5 μm) while the distal surface recorded the highest mean marginal gap distance (41.6 ± 8.6 μm) with non-statistically significant difference from incisal (37.2 ± 4.6 μm) and mesial surface (39.7 ± 6.4 μm).Conclusions: Within the limitations of this in-vitro study, the following conclusions were drawn: 1) Marginal discrepancy of all groups fell within the clinically acceptable value, thus the three milling protocols can be safely used. 2)Veneers fabricated using the two-step milling protocol exhibited the least marginal discrepancy among other experimental groups, thus it can be used as the protocol of preference if restoration accuracy is of utmost importance. 3) Since there was no significant difference between normal and fast milling protocols regarding marginal discrepancy, therefore fast milling can be recommended for veneer fabrication if chairside time is of prime importance in some cases. 4) Cervical marginal discrepancy was found to have the least value compared to other surfaces}, keywords = {}, url = {https://edj.journals.ekb.eg/article_72696.html}, eprint = {https://edj.journals.ekb.eg/article_72696_cf55531f7dcd94c702865ad6ad2f6b4f.pdf} } @article { author = {Elkhodary, Noha and abo-Shahba, Mostafa}, title = {Evaluation of internal fit, marginal integrity and fatigue resistance of E-max CAD crowns on two different preparation designs for maxillary anterior teeth. An Invitro study}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {3019-3029}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72697}, abstract = {Statement of the problem: Preservation of the cingulum in anterior teeth have been recommended however with recent ceramic restorations its contribution to internal adaptation and fatigue resistance needs further study.Objective: The purpose of this in-vitro study was to evaluate the internal fit, marginal integrity and the fatigue resistance of E-max CAD crowns on two preparation designs for maxillary anterior teeth.Material and methods: Twenty defect free human maxillary central incisors were prepared to receive E-max CAD ceramic crowns. 10 samples were prepared with parallel labiolingual wall (anatomic) group A and 10 samples were prepared with elimination of the cingulum (non-anatomic) group B. Scanning was done using powder free Identica hybrid scanner (Medit 02855] 23, Inchon-ro 22-gil, Seongbuk-gu, Seoul, Korea), designing was made by Exocad software version 2016 (Exocad Gmbh Julius-Reiber-Strabe 37, 64293 Darmstadt, Germany) then the restoration was milled by Roland DWX-510 milling machine (15363 barranca Parkway Irvine, California 92618) from E-max CAD blocks (LT) (Ivoclar Vivadent AG, 9494 Schaan, Princiability of Liechtenstein). Internal fit, marginal adaptation was measured before cementation using replica technique on prepared tooth using stereomicroscope. Duplication of the preparation was made in order to get epoxy resin dies for crown cementation, then restorations were cemented on the corresponding epoxy resin die and marginal adaptation was reevaluated under stereomicroscope. Specimens were then subjected to thermomechanical aging using four stations multimodal ROBOTA chewing simulator (Model ACH-09075DC-T, AD-TECH TECHNOLOGY CO., LTD., GERMANY) followed by fatigue resistance measurement using universal testing machine (Model 3345; Instron Industrial Products, Norwood, MA, USA). Results: It was found that group B recorded statistically significant (P<0.05) higher marginal gap mean value (29.7±3.97 µm) than group A (25.39±3.24 µm) as indicated by unpaired t-test before cementation while after cementation it was found that group B recorded statistically non-significant (P>0.05) higher marginal gap mean value (37.15±5.34 µm) than group A (34.2±4.84 µm). while for the internal adaptation it was found that group A recorded statistically significant higher internal gap mean value (91.93±17.41 µm) than group B (57.97±14.08 µm). It was found that Group B recorded statistically non-significant higher fatigue resistance mean value (1130.58±31.53N) than Group A (1114.84±45.04N). Conclusion: Different preparation designs affect the marginal adaptation of the restoration which was statistically significant only before cementation. The non-anatomic group (B) showed statistically significant lower internal gap than anatomic group (A). While there was no significant difference in the fatigue resistance of both groups after thermocyclic loading.}, keywords = {E-max CAD,internal fit,Fatigue Resistance,Marginal integrity,Preparation design}, url = {https://edj.journals.ekb.eg/article_72697.html}, eprint = {https://edj.journals.ekb.eg/article_72697_3298b8e990b078e07a70fe1ec853f70c.pdf} } @article { author = {Al-Madi, Ebtissam and Al-Harbi, Alaa and Al-Obeid, Alaa and Al-Aqil, Fatin and Al-Saleh, Samar and Alobaida, Mohamed}, title = {The Awareness of Barodontalgia among dental students}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {3031-3036}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72699}, abstract = {Objective: Barodontalgia is dental pain provoked by atmospheric pressure changes. The incidence is high in the Arabian Gulf region (34% in divers and pilots). The aim of the study was to measure students’ knowledge about barodontalgia. Methods: 1110 questionnaires consisting of knowledge of barodontalgia (definition, diagnosis, treatment, and prevention) were distributed among dental students in three dental schools in Saudi Arabia. Results: The response rate was 75%. Only 22.2% were aware of the correct definition of barodontalgia. Most students did not know the correct answers to questions about Barodontalgia (57-70%). 80.4% of the students indicated that they did not have any formal education in relation to barodontalgia. 3.2% of students were exposed to a case of barodontalgia during their clinical studies. Most of the students (82%) were interested to know more about barodontalgia.Conclusion: There is low awareness of Barodontalgia among students. Dental curricula should include knowledge of this phenomenon.}, keywords = {Barodontalgia,Dental Undergraduate Students,Dental Curriculum,Dental Pain}, url = {https://edj.journals.ekb.eg/article_72699.html}, eprint = {https://edj.journals.ekb.eg/article_72699_d53ce7045816aa26e7e3e67af352b2be.pdf} } @article { author = {Abd El Hamid, Hajer}, title = {COMPARATIVE STUDY BETWEEN PROTAPER NEXT AND 2 SHAPE Ni-Ti ROTARY FILES ON MAINTANENCE OF CANAL CURVATURE USING RADIOVISIOGRAPHY (RVG) (AN IN VITRO STUDY)}, journal = {Egyptian Dental Journal}, volume = {65}, number = {Issue 3 - July (Fixed Prosthodontics, Dental Materials, Conservative Dentistry & Endodontics)}, pages = {3037-3044}, year = {2019}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2019.72700}, abstract = {Background: The main objective of the root canal preparation is to develop a continuous taper from coronal to apical with maintaining the original shape and curvature of the canal. During continuous development and manufacturing of nickel-titanium (Ni-Ti) alloys, there was a significant improvement of quality of rotary files to maintain the original root canal curvature with predictable results with less changes and iatrogenic damage.Aim: The aim of this study was to evaluate and compare the maintenance of canal curvature using ProTaper Next and 2 Shape rotary Ni-Ti file system in shaping the apical third of the root canal using RadioVisoGraphy (RVG) on curved root canals.Materials and Methods: Sixty extracted human permanent mandibular molar with mature apices and 30°–40° apical root curvature were collected and divided into two groups thirty teeth in each ; Group I : canals prepared using 2Shape NiTi rotary file system; Group II: canals prepared using ProTaper Next (PTN) rotary Ni-Ti file system. All samples were radiographed before and after preparation using RVG. The data collected were evaluated using the Student t-test. Results: It was observed that Group I (2Shape) showed maintenance of canal curvature and lower percentage changes in canal curvature as compared to Group II (ProTaper Next) with no significant differences between the two groups Conclusion: It was concluded that 2Shape rotary Ni-Ti system maintain the original canal curvature in comparison to ProTaper next rotary file system in curved root canal.}, keywords = {Maintenance of canal curvature,RadioVisoGraphy (RVG),ProTaper Next nickel-titanium rotary files,2 Shape rotary Ni-Ti files}, url = {https://edj.journals.ekb.eg/article_72700.html}, eprint = {https://edj.journals.ekb.eg/article_72700_45ba3e73ddb68287e9ef3ccab12f4851.pdf} }