@article { author = {Asaad, Rasha and Salem, Shereen}, title = {Wear, Microhardness and Fracture Toughness of Different CAD/CAM Ceramics}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {485-495}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.45103.1287}, abstract = {Objective: To evaluate wear of three CAD/CAM ceramics (Lithium Disilicate, Zirconia reinforced-lithium silicate, Zirconia-based) and their opposing enamel antagonist in addition to their microhardness & fracture toughness. Materials and Methods: Thirty rectangular shaped samples (12 x 14 x 2 mm)were fabricated and divided into three groups according to the type of ceramic used (10 samples each):Group(IP): IPS e.max CAD, Group(VS):Vita Suprinity and Group(BZ): BruxZir. Each group was divided into two sub-groups (5 samples each) according to the testing procedure. The first sub-groups were subjected to microhardness and fracture toughness tests, while the second sub-groups were first weighed then subjected to wear test and finally re-weighed again before being subjected to microhardness and fracture toughness tests. Results: Wear results showed a significant difference in weight loss of tested ceramics and the antagonist tooth structure between (BZ) and both (IP) & (VS) . Microhardness of the three ceramics were significantly different in each sub-group regardless of wear test. Regarding fracture toughness, there was a significant difference between (BZ) and both (IP) & (VS) in both sub-groups. For all tested ceramics, both sub-groups (without wear and after wear) were not statistically significantly different regarding microhardness and fracture toughness. Conclusions: BruxZir showed the best wear behavior and the worst abrasiveness to enamel. Microhardness and fracture toughness were the highest for zirconia-based ceramic but both parameters were not affected by thermo-mechanical aging of wear test for the three tested ceramics.}, keywords = {Wear,Microhardness,Fracture Toughness,CAD/CAM,Ceramics}, url = {https://edj.journals.ekb.eg/article_143980.html}, eprint = {https://edj.journals.ekb.eg/article_143980_05711243d3f4907f875cf3ff02617291.pdf} } @article { author = {Ziada, Ahmed and Beleidy, Marwa}, title = {Effect of Artificially Accelerated Ageing and Different Mouth Rinses on Color Stability of Veneered PEEK Crowns}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {497-507}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.42708.1263}, abstract = {Statement of problem:Veneered polyetheretherketone(PEEK) is a recent alternative choice for fixed dental prostheses.There is a lack of data about the color stability of different veneering composite techniques of CAD/CAM PEEK cores. Purpose:To verify the effect of thermocycling and different mouth rinses on color stability of CAD/CAM composite versus conventional nanohybrid composite veneered PEEK crowns. Methods:Forty-two duplicated epoxy resin dies of prepared mandibular first molar to receive ceramic crown were fabricated.42 CAD/CAM PEEK cores were fabricated and divided into two groups(n=21)based on the veneering technique;group(C):nanohybrid crea.lign composite veneered PEEK cores and group(H):HIPC veneered PEEK cores. Each group was subdivided based on mouth rinse into 3 groups(n=7):Listerine-alcohol free, Hexitol and Distilled water.The color at baseline, after thermocycling equivalent to clinical 6 months service and 1-week immersion in mouth rinses were measured utilizing a spectrophotometer.The data were statistically analyzed using ANOVA,pair-wise Tukey’s post-hoc and student t-tests to reveal the significance between groups(P ≤ 0.05). Results:All specimens showed visually unperceptible color differences after thermocycling and immersing in mouth rinses(∆E*<3.3).Based on material,C group showed a statistically significant higher color change values than H group.ANOVA test revealed that the highest color change was for Hexitol followed by Listerine then distilled water(p=<0.0001<0.05).Tukey’s post-hoc test showed non-significant difference between Hexitol and Listerine.The interaction between the effect of mouth rinses and type of veneering composite materials was statistically non-significant for C group while significant for H group(P>0.05). Conclusions:Although visually nonperceptible,HIPC or nanohybrid composite veneered PEEK crowns showed a color difference after thermocycling and immersion in different mouth rinses.}, keywords = {HIPC,nano-hybrid composite,PEEK,CAD/CAM,color stability and mouth rinse}, url = {https://edj.journals.ekb.eg/article_143982.html}, eprint = {https://edj.journals.ekb.eg/article_143982_dd50a5e2c4f7fdce59ae1d7667c60b34.pdf} } @article { author = {Hussein, Ghada and Morsi, Tarek and Afifi, Dina}, title = {Shear Bond Strength of Aged Monolithic Zirconia Veneers Using Different Types of Bonding agent}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {509-518}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.46161.1290}, abstract = {Objective: The purpose of this study was to evaluate the effect of MDP containing resin cement and surface treatment of Translucent zirconia and Ultra translucent zirconia on shear bond strength. Material & Methods: Eighty zirconia discs were constructed . Samples were divided into two groups: Group I: Translucent zirconia samples (n=20) Gro up II: Ultra translucent zirconia samples (n=20) Each group will be subdivided into 2 subgroups according to the surface treatment Subgroup A: Samples will be treated with air abrasion Sub group B: Samples will be left untreated. Each sub group will be further subdivided into 2 subgroups according to bond type: Subgroup 1: samples cemented with MDP containing bond (Universal bond). Subgroup 2: samples cemented with non MDP containing bond (Adper single bon II). All tested samples were subjected to Shear bond strength test.Deboneded samples were examined under the scan electron microscope to determine their mode of failure.Data were statistically analyzed and recorded. Results: Regarding the effect of ceramic material and resin cement :For MDP containing resin cement, translucent zirconia had a significantly higher value than ultra translucent zirconia. While for Non-MDP containing resin cement there was no significant difference between both materials. Regarding the effect of surface treatment and resin cement for both treated and untreated samples, MDP containing resin cement had a significantly higher value than Non-MDP containing resin cement. Conclusion: the use of phosphate monomer luting cements on freshly air-abraded zirconia as the simplest and most effective way for zirconia cementation procedure.}, keywords = {Zirconia,Veneers,MDP}, url = {https://edj.journals.ekb.eg/article_143983.html}, eprint = {https://edj.journals.ekb.eg/article_143983_6bd4c260440ef302aea23ecfaa1a5788.pdf} } @article { author = {Zahran, Mohammed and Sabbahi, Dania}, title = {Development and Implementation of Evidence-based Dentistry Teaching Module at Saudi Arabian University}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {519-530}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.46192.1291}, abstract = {Aim: to describe the module followed to help undergraduate students in applying the EBD-related skills to develop an evidence-based report at Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia (KAUFD). Method: The paper explains the procedures undertaken to teach the students at the last year of the dental program at KAUFD. A brief description of the module was provided, starting for the preparation and including all steps required to produce the evidence-based report to answer certain clinically relevant questions. At the end of the module, students were invited to anonymously fill out a questionnaire to evaluate the module. Responses to the questionnaire from 2015-16 and 2019-20 were summarized using descriptive statistics. Chi-square or Fisher’s exact tests were used to compare the students’ responses from the two academic years at significant level of 0.05. Results: Majority of students found the module objectives and expectations clear, were satisfied with the module organization and felt that it was intellectually challenging. More than 80% of respondents stated that they are confidents in applying the EBD concept to answer any clinical question. Overall, majority of the students found the topics were clinically relevant, the assignment were useful, and deadlines were reasonable. Students were highly satisfied with their experience with the assigned tutor in regard to all evaluated aspects. Conclusion: This study supports the effectiveness of the EBD module that was incorporated into the undergraduate curriculum in improving the EBD-related knowledge and skills.}, keywords = {EBD module,teaching module,Dental Curriculum,evidence-based dentistry}, url = {https://edj.journals.ekb.eg/article_143984.html}, eprint = {https://edj.journals.ekb.eg/article_143984_4f10473a1b7a1b951b6ca44bd56ae864.pdf} } @article { author = {Eldessouky, Radwa and Ali, Khaled}, title = {Potential Toxicity Evaluation for a Nano-modified Veneering Ceramic System. Experimental Study in Dogs}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {531-536}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.43959.1275}, abstract = {Abstract Statement of problem: Although feldspathic porcelain is esthetic and biocompatible, it’s considered a weak point in zirconia restorations. Researches are necessary to improve its flexural strength without affecting biological properties. Purpose: to evaluate the possible toxic effects of incorporating ZrO2 Nanoparticles into conventional veneering ceramic system. Materials & Methods: Four veneering ceramic systems [Ex0, Ex5, Ex10&Ex20] were formulated by incorporating zirconia NPs into feldspathic powder [0%, 5%,10% & 20% wt.] respectively. Twenty dogs were grouped into 4 groups to receive the 4 experimental ceramic systems. The 3rd mandibular premolar for each dog was prepared for zirconia crowns. Impressions were taken for production of zirconia copings, veneered with experimental ceramics & delivered. After 3& 6months gingival specimens were collected& subjected to Real-time PCR test to assess genotoxicity of the 4 experimental veneering ceramics. Results: No genotoxicity was recorded for all groups in both 3& 6 months. However, appoptic genes recorded in Ex0: 0.64±0.01 &0.65±0.02, Ex5: 0.67±0.02& 0.67±0.01, Ex10:0.72±0.01&0.73±0.02 and in Ex20: 0.88±0.01& 0.89±0.01 compared to control (housekeeping gene) 0.96± 0.01 & 0.99±0.01 for3&6 months respectively. From clinical perspective; No local biological reactions were recorded. Conclusion: No genotoxic effect was recorded in all groups. whereas, appoptic genes expressed higher level in proportional to NPs ratio. Generally, a satisfactory soft tissue response was observed.}, keywords = {toxicity,Nano-modified,Veneering Ceramic}, url = {https://edj.journals.ekb.eg/article_143985.html}, eprint = {https://edj.journals.ekb.eg/article_143985_9310267fadf53ed971487cfd2dd23633.pdf} } @article { author = {Shaaban, Ahmed and M.Ammar, Mahmoud and abdelhamed, bassem}, title = {biological and mechanical effect of different types of attachments on supporting structures in implant retained mandibular overdenture a Randomized clinical study}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {537-546}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.43610.1269}, abstract = {Objective: To compare between implant retained overdenture with two different attachments by measuring : Retention. Bone changes by radiographic evaluation. Subjects and Methods: Eight completely edentulous patients were selected from the Outpatient Clinic of the Prosthodontic Department; Faculty of Dental medicine, Al Azhar University and classified into two equal groups. Each patient in two groups received two implants placed in the mandibular canine-premolar region bilaterally. Group (1): four patients received two implants using equator attachments. Group (2): four patients received two implants with using magnet attachments. and the study was randomized controlled trial with Calculated samples. type of randomization in that study was Block randomization and The out comes was assessor blinded as the investigators didn’t know the type of the attachment before measuring retention or amount bone resorption Results: Results revealed that, there was no statistically significant difference in bone loss between equator and magnet during the follow up period, and there were no statistically significant mean retention values in the two groups at base line and after 3 months. But 6 months; Magnet attachment showed statistically significantly lower mean retention values than Equator attachment. By time there was a statistically significant decrease in mean retention values of magnet rather than locator attachment. Conclusion: The use of equator and magnet attachments with two implant supported mandibular overdentures leads the same effect on crestal bone resorption. At the beginning the two attachment have the same retention quality by time magnet attachment loss some of its retention rather than locator attachment}, keywords = {Dental implants,overdenture,attachment,retention}, url = {https://edj.journals.ekb.eg/article_143987.html}, eprint = {https://edj.journals.ekb.eg/article_143987_3117203cda902f2240993f48b9f468d9.pdf} } @article { author = {Kandil, Mohamed and Sherief, Dalia}, title = {Marginal Adaptation, Compressive Strength, Water Sorption, Solubility and Ion Release of a Claimed Bioactive Restorative Material}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {547-561}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.42560.1256}, abstract = {Objectives: This study was conducted to investigate marginal adaptation, compressive strength, water sorption, solubility, fluoride and calcium release of a claimed bioactive restorative material (ACTIVA BioACTIVE Restorative) compared to glass ionomer (Fuji IX) and resin composite (SphereTEC). Materials and methods: ACTIVA was evaluated relative to Fuji IX and SphereTEC one. Marginal gap width was detected via scanning electron microscope before and after thermo-cycling. Compressive strength was tested using universal testing machine. For measuring water sorption and solubility, specimens were immersed in distilled water, subjected to drying cycles and weighed. Fluoride ion release was measured using ion-selective electrode while released calcium ions were detected using Atomic Absorption Spectrophotometer after 1, 14 and 28 days. Data analysis was performed using ANOVA, paired t-test and independent sample t-test. Results: Marginal gap was reduced in both ACTIVA and Fuji IX after thermocycling while it increased in SphereTEC one. After thermo-cycling, the marginal gap was larger in dentin compared to enamel. SphereTEC one showed the highest compressive strength mean value. Fuji IX represented the highest water sorption values, followed by ACTIVA which also exhibited the highest solubility. Fuji IX showed higher fluoride release than ACTIVA whose calcium release did not reach 1ppm. Conclusion: ACTIVA restoration can provide a potential marginal seal. Compressive strength was limited compared to resin composite. ACTIVA’s water sorption and solubility are within the acceptable range. However, its fluoride and calcium release was limited.}, keywords = {Bioactive restoration,marginal adaptation,Compressive strength,Calcium release,Fluoride release}, url = {https://edj.journals.ekb.eg/article_143988.html}, eprint = {https://edj.journals.ekb.eg/article_143988_422d65850944e0ae05e71dd2e895e376.pdf} } @article { author = {Elhelbawy, Nahla}, title = {Shade Matching of CAD/CAM Lithium Silicate Ceramics Veneered on Newly Introduced Foundation Material.}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {563-570}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.46823.1294}, abstract = {Statement of the problem: The emergence of Polyetheretherketone (PEEK) in prosthodontics and its use as a foundation for ceramic veenering restorations demand reassessment of shade match of final restoration. Purpose: This study aimed to investigate the use of different foundation materials on the color output of two CAD/CAM lithium silicate ceramics. Material and Methods: Rectangular plate specimens (60 sample) were prepared from CAD/ CAM generated all-ceramic materials of shade A2; IPS e.max (EM) CAD and Vita suprinity blocks (ZLS). A reflectance spectrophotometer used to measure the colour difference of ceramic samples before and after bonding to different foundation specimens; Zirconia (ZR), resin composite (RC), and PEEK; all of shade A2. The parameter of colour were measured via CIE L*a*b* (Commission Internationale de L’Eclairage) color system. Statistical analysis of data were done using two way ANOVA and the Tukey HSD test (α=0.05). Results:ANOVA revealed that ΔE values influenced significantly (P<.05) by the composition of ceramic material and different foundation materials used. However; the interaction was almost not statistically significant between the variables (p=.294). In comparison to ZR and RC assemblies, the foundation material; PEEK, revealed comparable color parameters when assembled with each of the tested veneering material. Conclusions: Zirconia reinforcement of CAD / CAM lithium silicate glass-ceramics decrease the impact of color variations on the various foundation materials used. The level of color acceptance varies between the ceramic and foundation materials tested. Compared to other widely used foundation materials (ZR and RC); PEEK displayed no different tendencies in color properties.}, keywords = {Lithium silicate ceramic,Color,PEEK,Foundation materials}, url = {https://edj.journals.ekb.eg/article_143990.html}, eprint = {https://edj.journals.ekb.eg/article_143990_d59e64ceb6bcb5cd9116489d81953c83.pdf} } @article { author = {Ibrahim, Wafaa and Elawady, Dina}, title = {Evaluation of masticatory muscle activity and survival rate of single implant-retained mandibular overdenture fabricated from thermoplastic versus conventional acrylic resin. A randomized controlled trial}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {571-581}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.46976.1295}, abstract = {Background: Electromyographic (EMG) activities of single implant-retained mandibular overdentures (MODs) has been dubious. Midline fracture of the denture is the most common complication related to Single implant-retained MODs. Thermoplastic polymethylmethacrylate (PMMA) acrylic resin achieves even distribution of forces and helps in absorption of impact forces which occurs during functional and parafunctional activities. Aim of the study: This clinical study aimed to investigate whether thermoplastic PMMA can improve the EMG activity and decrease the incidence of denture fracture in single implant- retained MODs. Materials and Methods: A randomized controlled trial was designed, where 28 completely edentulous patients (15 male, 13 female) were enrolled and randomly divided into two equal groups. Group I (control group) received single implant- retained MOD fabricated from conventional PMMA and group II received a single implant- retained MOD fabricated from thermoplastic PMMA acrylic resin. Patients’ muscle activity was evaluated at baseline and at 3, 6 and 12 months using EMG. The survival rate of MOD was evaluated by recording the incidence of mid-line fractures. Results: There was a significant improvement in the EMG activity of the masseter and temporalis muscle of the thermoplastic PMMA group in all the follow-up periods. There was a non-statistically significant difference in the MOD survival between groups. However, the decrease in fracture incidence was clinically significant in the thermoplastic PMMA acrylic MOD group. Conclusion: Within the limitation of this study, it was concluded that the fabrication of single implant-retained MODs from thermoplastic PMMA acrylic resins improves masticatory muscle activity and overdenture survival.}, keywords = {Masticatory muscle activity,single implant-retained mandibular overdenture,thermoplastic acrylic resin,conventional acrylic resin}, url = {https://edj.journals.ekb.eg/article_144025.html}, eprint = {https://edj.journals.ekb.eg/article_144025_ec018bf25bc5f6d666ea2b712ad10176.pdf} } @article { author = {Mansour, Fatema}, title = {Comparison of the Internal fit of conventional casting versus CAD wax (In-vitro Study)}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {583-587}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.40755.1227}, abstract = {Statement of Problem: The accuracy of internal fit for subtractive CAD-CAM systems used in the fabrication of metal coping is still unclear. Purpose: This in vitro study compared the internal fit of casting metal core using conventional wax versus CAD wax. Material and Methods: Twenty four resin specimen dies were randomly divided into two groups according to method of metal coping construction using conventional (C) or CAD (D) wax. The silicon replica technique evaluated the internal fit using stereomicroscope at ×24 magnification; the thickness of the silicon layer was measured at 20 reference points on each specimen. Parametric data of internal gap width was analyzed using one-way ANOVA. Results: Different techniques of wax construction showed insignificant difference in internal gap values between specimens made with conventional (C) (103.89±40.39) and CAD (D) waxing (104.10±39.96).However, there was a significant difference between internal gap values measured at different sites. Conclusions: Both construction techniques of casting were considered reliable in production within a clinically acceptable range regarding internal fit.}, keywords = {internal fit,Lost wax technique,CAD wax,Conventional casting,Silicon replica}, url = {https://edj.journals.ekb.eg/article_143992.html}, eprint = {https://edj.journals.ekb.eg/article_143992_297df024e5b6a562df1d961451a7a5fb.pdf} } @article { author = {Abdel Baseer, Sonal and Elcharkawi, Hussein and Dohiem, Mohamed}, title = {The Effect of Laser Grooved Implant Retained Overdenture on Bone Height Changes}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {589-596}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2021.47463.1308}, abstract = {ABSTRACT Purpose: The aim of the study was to evaluate the crestal bone height changes around laser grooved implants with mandibular overdenture. Materials and Methods: The study sample comprised of 10 completely edentulous male patients with age range between 40-60 years. In each patient, two laser grooved implants were placed in the interforaminal area. Implants were exposed after three months of healing, and ball abutments were used to retain the mandibular dentures. Crestal bone changes were evaluated using long cone paralleling technique after 0, 6 and 12 months. Data were collected, tabulated and statistically evaluated. Results: The results showed that mean change in marginal bone height throughout the 12 months follow-up period was 1.12 mm. T-test showed insignificant difference regarding effect of time on bone height changes from baseline to 6 months, from 6 months to 12 months, and from baseline to 12 m as P > 0.05, Conclusion: From the results of this study, it could be concluded that laser grooved implant retained overdenture showed minimal bone height changes after 1 year from prosthetic loading.}, keywords = {Prosthesis,overdenture,crestal bone,dental implants laser surface treatment}, url = {https://edj.journals.ekb.eg/article_143993.html}, eprint = {https://edj.journals.ekb.eg/article_143993_81abd53d327bdc82ba4da3fb0aa3e55e.pdf} } @article { author = {Elsayed, Shereen and Elbasty, Reham}, title = {Influence of Conventional Versus Digital Workflow on Marginal Fit and Fracture Resistance of Different Pressable Occlusal Veneers After Thermomechanical Fatigue Loading}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {597-613}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.46897.1311}, abstract = {Objectives: The aim of the study was to evaluate the marginal fit and fracture resistance after thermomechanical fatigue of two types of glass ceramic occlusal veneers constructed using two techniques for wax pattern. Methods: Thirty-two non-carious maxillary molars were used in this study. Teeth were prepared to receive all ceramic occlusal veneers. Prepared teeth were randomly divided into two equal groups according to the fabrication material of the occlusal veneer: Group I (e-max): pressable lithium disilicate glass ceramics. Group II (Celtra): pressable zirconia-reinforced lithium silicate glass ceramics. Each group was further subdivided into two equal subgroups according to the technique of construction of the wax pattern: Subgroup A (CAD/CAM): CAD/CAM technique. Subgroup B (Conventional): Conventional technique. Wax patterns were sprued, invested and heat pressed to produce the two types of ceramic occlusal veneers. All occlusal veneers were cemented to their corresponding teeth using adhesive resin cement. Thermomechanical aging was performed on all the samples. Vertical marginal gap distance measurement and fracture resistance testing were done. Results: The results of this study revealed that e.max (Conventional) recorded the highest vertical marginal gap mean values followed by Celtra (Conventional) then Celtra (CAD/CAM) while e.max (CAD/CAM) recorded the lowest mean values. It was found that e.max (conventional) recorded the highest fracture resistance mean values followed by Celtra (conventional) then e.max processed by (CAD/CAM) while Celtra processed by (CAD/CAM) recorded the lowest mean values. Conclusions: CAD/CAM constructed wax pattern presents a viable alternative option to conventional wax pattern. Celtra Press material revealed promising results.}, keywords = {Pressable ceramics,Celtra Press,IPS e-max press,Conventional wax pattern,CAD/CAM wax pattern}, url = {https://edj.journals.ekb.eg/article_143995.html}, eprint = {https://edj.journals.ekb.eg/article_143995_425a054b17f9c6201823b5d29b588b9d.pdf} } @article { author = {Rageh, Ahmed and Fahmy, Ahmed and El Khourazaty, Nada}, title = {COMPARISON BETWEEN THE EFFECTS OF THE PLATELET RICH FIBRIN (PRF) VERSUS XENOGRAFT ON PRIMARY STABILITY IN MANDIBULAR PREMOLARS IMMEDIATE IMPLANTS}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {615-623}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.44180.1277}, abstract = {Aim of the study: The aim of this study was to compare the regenerative potential of deproteinized bovine bone (xenograft) and platelet rich fibrin on implant primary stability in immediately placed mandibular premolar implants. MATERIAL AND METHODS: Twelve patients were selected from twenty five patients examined in the outpatient clinic of the implant clinic in Faculty Dentistry Cairo University The patients fulfilled the following criteria: Presence of non-restorable mandibular premolar tooth due to trauma, caries, root resorption, root fracture, endodontic or periodontal failure, Male or female patients between the ages of 30 to 50. And Patient with Sufficient bone volume, good oral hygiene and nonsmokers. Results: The results showed that the measurements of primary stability for immediately extracted sockets with PRF and implant placement were greater than that with the xenograft; there was a statistically significant difference between the PRF group and the control group regarding measurements of primary stability. The higher mean value was found in (PRF) group, while the lowest mean value was found in (Xenograft) group. Conclusion: From the results of the current study we can conclude that: PRF provides better primary implant stability than xenograft as space filling material. PRF is an effective material for management of jumping gap after immediately placed dental implants. Further studies are recommended for long term evaluation of PRFas space filling material.}, keywords = {Platelet rich fibrin,.> (PRF) VERSUS XENOGRAFT,.>ON PRIMARY STABILITY IN MANDIBULAR,.>}, url = {https://edj.journals.ekb.eg/article_143996.html}, eprint = {https://edj.journals.ekb.eg/article_143996_ce65bed5d92650b889014c7b24c85846.pdf} } @article { author = {Shaaban, Mahmoud and Fahmy, Ahmed and sherin, Nada}, title = {THE EFFECT OF PLATELET RICH FIBRIN ( PRF) VERSUS XENOGRAFT IN CLOSED SINUS LIFT WITH IMPLANT PLACEMENT ON IMPLANT STABILITY IN MAXILLARY POSTERIOR AREA Randomized Clinical Trial}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {625-634}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.47906.1315}, abstract = {Aim of the study: The aim of this study is to compare the effect of PRF versus xenograft on implant primary stability after closed sinus elevation in the maxillary posterior area . MATERIAL AND METHODS: Patients were divided in to two equal groups: Group A: closed sinus lifting by Osteotome using PRF as grafting material with implant placement in 8 partially edentulous patients. Group B: Closed sinus lifting by osteotome using xenograft as a grafting material with implant placement in 8 partially edentulous patients. After implant placement, Smart peg was placed on implant and Ostell is used to record ISQ. Implant stability was measured intraoperative and at week 2, 4, 6, 8 and 10 for both groups. The collected results were tabulated and statistically analyzed. Results: The study results showed that there was no statistically significant difference between (PRF) and (Xenograft) groups in ISQ reading. Conclusion: Maxillary sinus elevation by osteotome technique and using PRF or xenograft as a grafting material is a predictable and effective procedure for correcting limited bone resorption in posterior areas of the maxilla.}, keywords = {PLATELET RICH FIBRIN ( PRF) :,> VERSUS XENOGRAFT IN CLOSED SINUS :,> LIFT WITH IMPLANT PLACEMENT :,> ON IMPLANT STABILITY IN MAXILLARY POSTERIOR AREA :,>}, url = {https://edj.journals.ekb.eg/article_143997.html}, eprint = {https://edj.journals.ekb.eg/article_143997_5627348c6a7e06828547a29204bea5bd.pdf} } @article { author = {tammam, raafat}, title = {Clinical evaluation of monolithic Zirconia (5Y), Lithium Disilicate and modified PEEK CAD-CAM endocrown materials,3-year clinical prospective study}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {635-650}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.37997.1193}, abstract = {objective. to conclude clinically, if endocrowns are a dependable substitute to post-retained restorations for significantly broken endodontically treated teeth and which restorative materials are proficient customized for constructing endocrowns. Material and methods. The clinical study is an open label, parallel groups conducted randomly at Assiut University Dental Hospital. The trial involved a total of 40 patients. After providing signed informed consent, patients are enrolled and classified into three groups according to random number of the type of material (lithium disilicate, monolithic zirconia and modified PEEK material). Therapy distribution will be equalized (1:1:1). Endocrowns will be bonded by adhesive dual-cured luting resin composite. Medical assessments will be accomplished at zero, 6-M,12-M,18-M,24-M,30-M and at 36 months following handling according to modified US Public Health Service criteria with dual self-sufficient assessors. The criteria will be evaluated are the Marginal fit, Marginal discoloration, Anatomic contour, Surface texture, Color match). Entirely obtained data will be desperctively investigated and survival probabilities were calculated by indicated statistics by an independent statistician. Results: Afterward, an examination period of 3 years, endurance ratios were 94.87 %. one restoration replaced due to clinically improper failure and another after debonding rebonding again.Finally, the best material was lithium disilicate, translucent zirconia, and PEEK material respectively. Conclusions: Clinical relevance of translucent zirconia, lithium disilicate ceramic and modified PEEK materials are a proper restorative management choice for molar endocrown. But scheduled clinical longstanding documents should be scheduled.}, keywords = {clinical endocrown,Monolithic Zirconia,Lithium Disilicate,PEEK materials,CAD-CAM}, url = {https://edj.journals.ekb.eg/article_143999.html}, eprint = {https://edj.journals.ekb.eg/article_143999_d3386ff6b6de3f5c28f89a5b51621c83.pdf} } @article { author = {Shalabi, Mennatallah and Aziz, Essam and Nassouhy, Naglaa and Amin, Nermine}, title = {Comparative Study of Silicone-based Soft Liner Versus Versacryl Liner for Mandibular Complete Denture Cases (Randomized Clinical Trial)}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {651-660}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.44922.1285}, abstract = {A randomized clinical trial was carried out to compare between conventional silicone-based soft liner and Versacryl lining material for the relining of mandibular complete dentures in flat mandibular cases regarding oral health related quality of life and tissue keratinization index. Twenty-eight patients were distributed randomly into two groups (fourteen per group). After taking the relining impression for their existing mandibular dentures, the control group received conventional silicone based soft liner, while the intervention group received Versacryl lining material. Patients were evaluated at two weeks, two months and four months intervals. The results showed a significant difference between the two groups at two weeks and two months as the Versacryl relined dentures provided a better improvement in oral health related quality of life, while at four months there was no difference between the two groups. This study also showed a significant difference in parakeratization activity between the two groups at all follow up periods with the highest mean score in the Molloplast-B liner group.}, keywords = {complete denture,silicone-based soft liners,Oral health related quality of life,keratinization area percent}, url = {https://edj.journals.ekb.eg/article_144000.html}, eprint = {https://edj.journals.ekb.eg/article_144000_0fd8d77c2ad6e899e67a65ef88620b6c.pdf} } @article { author = {Abd ElHameed, Hala and Mohamed, Sara}, title = {Comparative laboratory evaluation of dimensional accuracy for 3D-printed complete maxillary denture}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {661-668}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.39414.1207}, abstract = {Purpose: The objective of the research was to investigate dimensional accuracy concerning denture teeth deviation and vertical dimensional changes for three-dimensional printed, monolithic dentures relative to heat-cured, acrylic resin dentures. Materials and methods: A waxed-up reference maxillary denture was constructed on an educational master cast, and then duplicated to produce ten simulated waxed-up dentures. The planned virtual denture was designed by subtracting the scanned cast from the scanned waxed-up denture with the cast. This virtual denture was considered as a reference and saved alone in 3D- Standard Tessellation Language (STL) format. From this reference (CAD maxillary denture) ten DLP dentures were fabricated. Each fabricated heat-cured, and 3D-printed denture was scanned separately, and the scanned data was saved in an STL file. Each STL file of scanned maxillary dentures was superimposed on a reference virtual maxillary denture to evaluate the degree of denture teeth deviation. An electronic digital caliper was used to measure the occlusal vertical dimension (OVD) of the waxed-up denture and after denture fabrication for both groups to evaluate the change in OVD. Results: A paired t-test was used to compare the recorded data between both groups. It was reported that the higher mean values for either denture teeth deviation or vertical dimensional changes after dentures fabrication were noticed in heat-cured acrylic resin dentures. These values were highly statistically significant between the tested groups for both items of investigations at p ≤ 0.01.}, keywords = {tooth movement,dimensional accuracy,complete denture,3D-printed dentures}, url = {https://edj.journals.ekb.eg/article_144002.html}, eprint = {https://edj.journals.ekb.eg/article_144002_b1bb05cf83c37723ddfe1ca313e17da0.pdf} } @article { author = {Shaaban Metwally, Ahmed and Fahmy, Ahmed and El Khourazaty, Nada}, title = {EFFECTS OF THE PLATELET-RICH FIBRIN (PRF) ON BONE DENSITY IN IMMEDIATE IMPLANT PLACEMENT AND LOADING IN ESTHETIC ZONE (A randomized Clinical Trial)}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {669-677}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.44290.1279}, abstract = {Aim of the study: The aim of this study is to evaluate the effect of PRF on bone density after immediate implant placement and loading in the esthetic zone. Introuduction: The present study was conducted to evaluate bone density using CBCT around immediately placed and loaded implants with the addition of PRF in the esthetic zone.The patients were selected from the out patient Dental Implant Clinic Faculty of Dentistry, Cairo University, based on inclusion and exlusion criteria. MATERIAL AND METHODS: Patients were divided in to two equal groups: Group A: Immediate implant placement and loading with PRF in jumping gap at site of unrestorable extracted teeth in esthetic zone. Group B: Immediate implant placement and loading without PRF in jumping gap at site of unrestorable extracted teeth in esthetic zone. After implant placement and loading CBCTs were taken at 0,3,6,9 month. Bone density was measured at 0, 3, 6, 9 month for both groups. The collected results were tabulated and statistically analyzed. Results: The results of this study showed that the PRF group had higher bone density and there was statistically significant difference between (PRF) and (no PRF) groups in bone density values in 3,6 and 9 months intervals.}, keywords = {THE PLATELET-RICH FIBRIN (PRF),> ON BONE DENSITY,>IN IMMEDIATE IMPLANT PLACEMENT,>}, url = {https://edj.journals.ekb.eg/article_144003.html}, eprint = {https://edj.journals.ekb.eg/article_144003_e727b8f2b5097c895e7caa42830d91c9.pdf} } @article { author = {Atia, Hamada}, title = {Evaluation of Color Change of Heat Cured Denture Base Material Incorporated with Novel Silver Nanoparticles Submitted to Accelerated Aging}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {679-688}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.49024.1327}, abstract = {Purpose:to investigate and compare the influences of adding different concentrations of colloidal forms silver nanoparticles on color changes of heat cured acrylic resin denture base material submitted to Accelerated aging. Methods: A total of 40 disc-shaped specimens were prepared from heat cured PMMA resins with different concentration of silver nanoparticles. A double beam ultra-violet visible spectrophotometer was used to obtain diffuse reflectance data at every 5nm between 400-700nm. The results were recorded using a computer color matching system (CCM) and tabulated for the statistical analysis of the color differences (ΔE) data. Comparisons between the different studied groups were analyzed using F-test (ANOVA) and Post Hoc test (Scheffe) for pair-wise comparisons. Significance of the obtained results was judged at the significance level of α = 0.05. Results: All groups of heat-cured acrylic resin with the addition of (NAg) groups II, III and IV were showed significant (ΔE) values more than group I at initial and at stage I, II of accelerated aging records. In stage III only group IV was showed significant (ΔE) values more than group I of the same stage. Therefore, group IV was showed significantly highest mean (ΔE) value followed by group III then group II (P < 0.05) in all accelerated aging stages but group I was showed significantly lowest mean (ΔE). Conclusion: The silver nanoparticles incorporation within the acrylic denture base material can change its color. The higher incorporation of silver nanoparticles with accelerated aging, the more color difference values (ΔE) of the acrylic resin denture.}, keywords = {silver nanoparticles,Color change,Acrylic resin denture,Accelerated aging}, url = {https://edj.journals.ekb.eg/article_144004.html}, eprint = {https://edj.journals.ekb.eg/article_144004_21ba763ab7e2b9dfaf0bf1e23f842ca6.pdf} } @article { author = {hasanin, ahmed and abo alfotouh, hamdi and Abdel Nabi, Nouran}, title = {Stress analysis of two different attachments for a single implant retained mandibular overdentures in the midline (In vitro study)}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {689-697}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.49329.1332}, abstract = {Abstract Objective: aiming to record the induced micro-strain around one installed implant in the midline of a completely edentulous mandible using strain gauges utilizing an implant retained overdenture with two different types of attachments Ball and CMLOC attachment. Materials and methods: An acrylic resin test resin test model representing a completely edentulous lower arch was used.. Duplication of the finished denture was carried out to be used as a surgical stent .A single implant installed in the midline. After the implant was installed in the acrylic resin cast, the ball attachment was screwed to the implant. The denture was prepared for the direct pick up procedure, the same procedure repeated for CM IOC attachment. Four strain gauges around were installed on all surfaces of implant to monitor the effect of the applied loads vertical on the two types of attachments. A vertically load applied of 100 N static load was applied by using universal testing machine at three different sites . Results : When the load applied on the right side and left side ,it was shown that the single implant retained overdenture with ball the attachment has shown higher microstrain than the CMLOC Conclusion: It can be concluded from this invitro study that the newly introduced attachment the CMLOC lends to show a better performance with regards to the micro-strains induced around the implants and also regarding improving the stability of the denture . On the other hand the ball attachments tends to show more micro-strain around the implants.}, keywords = {ball,attachments,CMLOC attachment}, url = {https://edj.journals.ekb.eg/article_144006.html}, eprint = {https://edj.journals.ekb.eg/article_144006_d1aa2c834a8b5706956a376107e4a6b3.pdf} } @article { author = {mohamed, shahinaz}, title = {Electromyographic evaluation of the masseter and temporalis muscles activity in patients with complete denture, implant supported and implant retained mandibular overdentures. a cross-over study}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {699-709}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2021.49747.1337}, abstract = {This study was conducted to compare the electromyographic [EMG] activity of both masseter and the anterior temporalis muscles in patients with: Conventional complete dentures, Implant supported overdentures without attachments and, Implant retained overdentures with locator attachments. Material and methods: Six completely edentulous male patients with atrophied mandibular ridges received upper and lower conventional complete denture. EMG activity were measured for both masseter and the anterior temporalis muscles during clenching without food, clenching hard (carrot) and soft (banana) foods. Measurements were made at time of denture insertion, one month and two months after. Two implants were installed in canine regions of the mandible. After osteointegration, healing abutments were connected and the mandibular denture were relined with hard acrylic resin. Measurements were repeated, then healing abutments were replaced with locator attachments, and measurements were repeated again. Results: The highest EMG activity/amplitude of masseter and temporalis muscles, were noted with locator overdentures, and the lowest values were observed with conventional dentures. There was no statistically difference in muscle activity between implant supported overdentures and complete dentures. For all groups, muscle activity for masseter and temporalis muscles increased with advance of time. For both groups, muscle activity was significantly higher during clenching of hard food than clenching without food or with soft food Conclusion: Within the scope of this study, implant retained overdentures are recommended for edentulous patients rather than conventional complete dentures or implant supported overdentures as it improves EMG activity/amplitude of masseter and temporalis muscles.}, keywords = {complete denture,dental implant,Overdentures,attachments,EMG activity}, url = {https://edj.journals.ekb.eg/article_144008.html}, eprint = {https://edj.journals.ekb.eg/article_144008_41c5f3b829c395104f5d7797b7fe9cb5.pdf} } @article { author = {eltorky, moaz and shakal, mahmoud and elshahawy, waleed and Kenawy, El-Refaie}, title = {Effect of Simulated Gastric Acid on Surface Roughness of Different Types of Dental Ceramics}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {711-716}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.49879.1339}, abstract = {Purpose: The purpose of this in vitro study was to evaluate the effect of simulated gastric acidity on surface roughness of different types of dental ceramics. Methods: Fifty specimens were divided according to type of the material into five groups (n=10), as follows: Partially stabilized zirconia (PSZ) (Prettaue),Fully stabilized zirconia (FSZ) (Prettaue Anterior), lithium disilicate ceramics (IPS. Emax), Zirconia-containing lithium silicate ceramics (ZLS) (Vita Suprinity) and Hybrid ceramics (Vita Enamic). Specimens were cut using a low-speed diamond saw (Isomet) into a rectangular shape with the following dimension: 12mm width x 14mm length x 1 mm thickness. Surface roughness was evaluated by optical profilometer. Each specimen was immersed in 5 ml of the simulated acid of ph 1.2 for 96 h in a37◦C incubator. Surface roughness of all tested groups was revaluated. One-way ANOVA was used to compare mean difference between groups. Paired t-test was used for comparing (before and after) roughness in each group. Results: There was significant difference (P=0.002) between all groups. There was increase in surface roughness for all materials tested, but it was non-significant (P>0.05) for Prettaue (P=0.607), Prettaue Anterior (P=0.273) and Vita Suprinty group (P=0.201). There was significant increase (P≤0. 05) for IPS. Emax group (P=0.007) and Vita Enamic groups (P=0.021). Prettaue Anterior group showed the least amount of surface roughness change (0.0006±0.002), while Vita Enamic group showed the highest surface roughness change (0.0100±0.011). Conclusions: The gastric acid significantly increased the surface roughness of hybrid ceramics and lithium disilicate ceramics}, keywords = {dental ceramics,roughness,Gastric Acid}, url = {https://edj.journals.ekb.eg/article_144009.html}, eprint = {https://edj.journals.ekb.eg/article_144009_a62700129e047b3d3fba99fd8f45e4ab.pdf} } @article { author = {Khairallah, Ahmed and Hamed, Mohammed}, title = {Biological and prosthetic complications of cantilevered and non-cantilevered fixed hybrid metal acrylic prostheses used for vertical and inclined implants in atrophied mandible. A randomized clinical trial.}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {717-728}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.52004.1380}, abstract = {Aim: This study aimed to evaluate biological and prosthetic complications of cantilevered and non-cantilevered fixed hybrid metal acrylic prostheses used for vertical and inclined implants in atrophied mandible. Materials and Methods: Eight completely edentulous individuals will be classified into 2 groups randomly: 1) Group I (cantilevered prosthesis, n=4): patients received 4 vertical implants parallel to each other’s in the interforaminal area and cantilevered metal acrylic prosthesis, 2) Group II (non-cantilevered prosthesis, n=4): patients received 4 implants (2 parallel anterior implants and 2 posterior implants inclined 30odistally) and non-cantilevered metal acrylic prosthesis. Biological and prosthetic complications were measured after one year from prosthesis insertion. Results: There was no significant difference in implant failure, implant survival, pain, swelling, abscess, fistula formation, peri-implantitis, peri-implant mucositis, bleeding on probing between groups. The non-cantilevered group showed significantly higher pocket depth than the cantilevered group. The cantilevered group showed significantly higher bone loss than the non-cantilevered group. There were no prosthesis fractures, cylinder fracture, abutment fracture, and prosthetic screw fracture occurred in both groups. There was no difference in teeth wear, teeth fracture, and gingival fracture between groups. The cantilevered group showed a significantly higher crown fracture, abutment screw, and prosthetic loosening than the non-cantilevered group. Conclusion: Both cantilevered and non-cantilevered fixed hybrid metal acrylic prostheses can be used successfully for vertical and inclined implants respectively in atrophied mandible with favorable biologic and prosthetic outcomes after one year.}, keywords = {cantilevered and non-cantilevered fixed hybrid metal acrylic prostheses,atrophied mandible,vertical and inclined implants,All in 4 concept}, url = {https://edj.journals.ekb.eg/article_144011.html}, eprint = {https://edj.journals.ekb.eg/article_144011_8d86dcaa88a225f0137166b44fe0fd23.pdf} } @article { author = {Aboushahba, Mostafa and Korayem, Ahmed and Younis, Sara}, title = {Effect of Preheating Cycles on Microshear Bond Strength of Nanohybrid Resin Composite Luted to CAD/CAM Ceramic}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {729-738}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.51897.1378}, abstract = {Objective: This study aimed to investigate the microshear bond strength of adhesive resin cement to Leucite-reinforced CAD/CAM ceramic and compare it with that of prewarmed nanohybrid resin composite. Materials and methods: Sixty Empress CAD ceramic plates were prepared. Each ceramic plate received five Tygon tube micro-cylinders filled with bonding agents creating 5 resinous micro-cylinders on each ceramic plate. In the first group (GpA), they were filled with resin cement, nanohybrid resin composite as a bonding agent was applied in the second group < br /> (GpB), after warming at 50℃, in the third group (GpC), two prewarming cycles were performed. Light-curing for 20seconds was applied. Micro-shear bond strength testing (μSBS) was performed using universal testing machine with a crosshead speed of 1 mm/min until failure occurred. The μSBS was calculated in MPa by dividing the load (Newton) over the respective surface area (mm 2 ).Data were tabulated and analyzed and showed normal distribution when checked using Kolmogorov–Smirnov test. One-way ANOVA used to compare between the tested groups for μSBS data followed by Tukey HSD post-hoc test for pairwise comparisons. Significant level was set at 5% (α=0.05). Results: One- way ANOVA showed a significant difference between tested groups (p < 0.001). Where heated composite (two prewarming cycle) showed the highest mSBS compared to other groups (p < 0.05). Nevertheless, heated composite (one prewarming cycle) showed an improved μSBS compared to resin cement group, but the increase was insignificant (p=0.081). Conclusion: pre-heated nanohybrid resin composites seem to be a potential alternative to resin cement to lute ceramic restorations.}, keywords = {Nanohybrid composite,resin cement,preheating,prewarming,leucite Ceramic}, url = {https://edj.journals.ekb.eg/article_144012.html}, eprint = {https://edj.journals.ekb.eg/article_144012_6b778ffa89527a4f1b4ad962ecfec8b5.pdf} } @article { author = {mohamed, shahinaz and Helmy, Mohamad}, title = {Peri-implant strain with locator and bar attachment during dislodging of maxillary implant overdenture. A comparative invitro study}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {739-746}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2021.52107.1383}, abstract = {Purpose: This study aimed to evaluate Peri-implant strain with locator and bar attachment during dislodging of maxillary implant overdenture Materials and methods: Four implants were inserted in completely edentulous acrylic maxillary model in canine and premolar areas. Experimental maxillary overdentures with 4 metal hooks were constructed and connected the implants with bar attachments (group I) or locator attachment (group 2). Two strain gauges were bonded at buccal and palatal surface of each implant. Micro strains were measured at buccal and palatal surface of canine and premolar implants during the vertical dislodging of the overdenture. Dislodging was made by chains connected at one end to the metal hooks and to a universal testing machine at the other end. Results: For canine and premolar implants, locator attachment showed significant higher microstrain values than bar attachments at buccal and palatal gauge positions. For bar group, no difference between buccal and palatal strain gauge positions was detected. However, for locator attachments, buccal strain gauges demonstrated significant higher strain than palatal gauges. For buccal and palatal strain gauges, canine implants showed higher strains than premolar implants for both groups Conclusion: Within the limitation of this in vitro study, could be concluded that bar attachments may be recommended to retain maxillary implant overdentures than locator attachments in terms of reduced peri-implant stresses that occur during the denture dislodgment which may lead to increased bone resorption around the implants.}, keywords = {Implant,attachments,Strain gauge,invitro study}, url = {https://edj.journals.ekb.eg/article_144014.html}, eprint = {https://edj.journals.ekb.eg/article_144014_e3e3204b17c3a35a5359d9090b5c8b49.pdf} } @article { author = {najjar, Mohamed shawkey and Baraka, Osama and Shoeib, Ahmad}, title = {Peel bond strength between a silicone-based soft liner and a heat-cured acrylic resin denture base reinforced with three concentrations of metal oxide nanoparticles}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {747-755}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2021.52325.1389}, abstract = {Purpose: To evaluate the effect of incorporation of 0.1%, 0.3%, and 0.5% concentrations of titanium oxide, aluminum oxide, and silica nanoparticles in the heat-cured acrylic resin denture base on the peel bond strength to a silicone denture liner. Methods: A total number of 100 heat-cured acrylic resin samples were prepared and classified into a control group and three groups according to the type of nanoparticle. Each group was classified into three subgroups according to the concentration of the nanoparticle (n=10). A Silicone based-soft liner was added over the acrylic resin specimens, and the peel bond strength was measured using the peeling bond strength test at an angle of 90°. Statistical analysis was done using a Two-way ANOVA test for interactions between peel bond strength and the different nanoparticle materials and their concentrations. Results: Two-way ANOVA showed that the three nanoparticles and different concentrations did not affect the peel bond strength. Conclusion: The nanoparticles in this study were not effective in increasing peel bond strength at the studied concentrations.}, keywords = {Nanoparticles,denture base,Heat cured,Peel bond strength,Silicon soft liner}, url = {https://edj.journals.ekb.eg/article_144015.html}, eprint = {https://edj.journals.ekb.eg/article_144015_f03c260ea14bb829baf8f79759bf2db7.pdf} } @article { author = {kamal, maha}, title = {Evaluation of Surface Micro-hardness and Fracture Toughness of Conventionally Constructed versus CAD/CAM Constructed Denture Base Materials- an In-Vitro Study.}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {757-765}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2020.52346.1390}, abstract = {The purpose of the current study was to evaluate surface micro-hardness and fracture toughness of Acetal Resin and Acrylic Resin (PMMA) constructed either by CAD/CAM milling method or by heat polymerized conventional method (lost wax method). Materials and methods: Twenty-eight specimens (fourteen of each material); Acetal Resin and Acrylic Resin were constructed in the form of discs of 2mm thickness and 10mm diameter. Discs were divided equally according to the denture base material into two groups, group I for Acetal Resin and group II for Acrylic Resin (PMMA). Each group was subdivided according to the way of construction into; sub-groups (n=7). Sub-groups Ia and IIa for CAD/CAM milled discs and sub-groups Ib, IIb for conventionally constructed discs. Microhardness was measured on sample surface by digital display Vickers Micro-hardness Tester. Fracture toughness was evaluated by axial loading by the indentation technique. Results: Group I (acetal resin group) recorded statistically significant higher microhardness mean values than group II (acrylic resin group). Moreover, group Ib (injection processed group) recorded statistically significant higher microhardness mean values than group IIb (conventionally processed group). Regarding fracture toughness there was statistically insignificant differences between all groups with higher mean values of group Ia,b (acetal resin groups). Conclusion: CAD/CAM constructed acetal resin and acrylic resin denture base materials presented superior mechanical properties than conventionally constructed ones and expected to be more durable denture bases. Key words: CAD/CAM, Acetal Resin. Acrylic Resin, microhardness, fracture toughness.}, keywords = {Key words: CAD/CAM,Acetal Resin. Acrylic Resin,Microhardness,Fracture Toughness}, url = {https://edj.journals.ekb.eg/article_144018.html}, eprint = {https://edj.journals.ekb.eg/article_144018_35b7c9cc0ac91dbe1b102d675ea1c46c.pdf} } @article { author = {Eltamimi, kawkb and Bayoumi, Dalia}, title = {Microtensile bond strength of zirconia nanofillers reinforced acrylic resin to denture teeth after thermocycling}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {767-774}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2021.52464.1394}, abstract = {Abstract Statement of problem: Addition of zirconium oxide nanofillers to PMMA had improved the mechanical properties of heat polymerized acrylic resin, but it’s effect on bond strength to acrylic teeth hadn’t been evaluated yet. Purpose: The purpose of the study was to evaluate the effect of Zirconium oxide (ZrO2) nanofillers powder with different concentrations (1.5%, 3%, 5%) on bond strength of resin denture base to acrylic teeth before and after thermocycling. Material and methods: Zirconium oxide nanoparticles powder were added to heat cured (PMMA) with different concentrations (0, 1.5% ,3%, 5%). The base surfaces of 16 molar acrylic teeth were flattened, and zirconia reinforced heat-polymerized acrylic resin was applied to them. Thereafter, bar specimens were produced for the microtensile bond strength testing either before or after thermocycling. Results: The results showed that 5% ZrO2 conc. recorded the highest value of microtensile bond strength. The lowest value was recorded in 1.5%, followed by 3%. Regarding thermocyling, the non-thermocycled groups always recorded higher values of microtensile bond strength either significant (1.5% & 5%) or insignificant (0% & 3%) than thermocycled ones at p < 0.05. Conclusions: Within the limitation of this study, it was concluded that reinforcement of acrylic denture base with zirconia nanofillers had significantly decreased bond strength with acrylic denture teeth in 1.5 % and 3% concentration; however, 5% had increased the bond strength values insignificantly. Thermocycling had reduced the bond strength in all concentrations.}, keywords = {Zirconium oxide nanofillers,microtensile bond strength,thermocyling,acrylic resin and acrylic denture teeth}, url = {https://edj.journals.ekb.eg/article_144021.html}, eprint = {https://edj.journals.ekb.eg/article_144021_c356b649196c34e599206a67539d082a.pdf} } @article { author = {Lamfon, Hanadi}, title = {DENTURE BIOFILM AND DENTUREASSOCIATED STOMATITIS, A LITERATURE REVIEW}, journal = {Egyptian Dental Journal}, volume = {67}, number = {Issue 1 - January (Fixed Prosthodontics, Removable Prosthodontics and Dental Materials)}, pages = {775-787}, year = {2021}, publisher = {The Egyptian Dental Association (EDA)}, issn = {0070-9484}, eissn = {2090-2360}, doi = {10.21608/edj.2021.53923.1413}, abstract = {Denture stomatitis is increased dramatically in the recent years, particularly in denture wearers. It is a common inflammatory reaction with multifactorial etiology that usually appears in the oral cavity as an erythematous reaction on the oral mucosa extends to the limits of the maxillary denture-bearing area. Candida albicans is regarded as the primary cause of denture-associated stomatitis owing to its high capability to adhere to oral tissues and denture surfaces in addition to biofilms formation. Candida species can interact with different microorganisms within the mouth resulting in a complex and mixed biofilm formation with an organized structure which is difficult to remove. The presence of bacteria in the acrylic biofilms resulted in increased pathogenicity and virulence of Candida biofilms making them more resistance to antifungal drugs. This article was introduced to highlight on the denture biofilm microbiota and its role in Candida albicans pathogenicity in addition to exploring the clinical manifestation, multifactorial etiology and management policies of Candida-associated denture stomatitis frequently faced in dental clinic.An online search of PubMed, Scopus, Science Direct, and Google Scholar was conducted using key words (Microbiota, Candida albicans, Denture stomatitis, Biofilm) from 1978 up to 2021. The management of denture stomatitis mainly depends on enhancement of oral hygiene processes, description of antifungal agents either topical or systemic, as well as disinfectants description. Recently, medical extracts that possess antimicrobial activity against oral pathogens was introduced as a safe and less side effects protocol for management of denture stomatitis.}, keywords = {Key words: Microbiota,Candida albicans,Denture Stomatitis,Biofilm}, url = {https://edj.journals.ekb.eg/article_144023.html}, eprint = {https://edj.journals.ekb.eg/article_144023_e8e4db3d3534e9452559e03190d8c6b7.pdf} }