The Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Biting force of patients rehabilitated with Precision Attachments Unilateral Removable Partial Denture57958721664210.21608/edj.2021.90416.1764ENHusseinElcharkawiProfessor and Chairman of Prosthodontics Dept. Faculty of Oral and Dental Medicine, Future University, and
Cairo University, Cairo, Egypt.0000-0002-2173-4033MOHAMEDABDALLAAssociate Professor of Prosthodontics Dept. Faculty of Oral and Dental Medicine, Future University, and Cairo
University, Cairo, Egypt.NadaKhourazatyAssociate Professor of Prosthodontics Dept. Faculty of Dentistry, Cairo University, Cairo, Egypt0000-0002-1006-5225Journal Article20210822Abstract:<br /> Statement of the problem: Analyzing occlusal force help understanding the efficiency of prosthesis. Purpose:Restoring unilateral; missing teeth was always a challenge to Prosthodontists. Precision attachment partial dentures provide solution for these problematic situations and provide patients with aesthetic and functional replacement of partial missing teeth and oral structures. This study was designed to analyze the post rehabilitation occlusal function of subjects treated with Precision Attachments Unilateral Removable Partial Denture PURPD, utilizing bite force sensor (the T scan system). <br /> Materials and Methods: Ten patients who have unilateral missing teeth (Kennedy class II) who received PURPD prostheses to reconstruct occlusal function were analyzed. The T scan III system was used to measure maximum occlusal force between PURPD side and the dentate side. <br /> Results: Subjects with precision attachment unilateral partial dentures PURPD demonstrated decreased significant occlusal force. <br /> Conclusion: Precision Attachment Unilateral Removable Partial Denture PURPD prosthesis induced less occlusal force compared to dentate side.https://edj.journals.ekb.eg/article_216642_ce8f271547d489a36b10ccc3ca4fc9c2.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101EFFECT OF DIFFERENT SURFACE TREATMENT PROTOCOLS ON THE RETENTION OF POSTERIOR PEEK CROWNS (A randomized invitro study)58959621664610.21608/edj.2021.90288.1767ENKareemAbdel MotalebMaster of Fixed Prosthodontics, Cairo UniversityHeshamKatamishProfessor at Fixed Prosthodontics Department, Faculty of Dentistry Cairo University0000-0003-3685-0827RehamElbastyAssociate Professor of Fixed Prosthodontics, Faculty of Dentistry Cairo University0000000326048830Journal Article20210823Aim:The purpose of this study is to evaluate the retention of PEEKbased posterior crowns after different surface treatment protocols(sandblasting using110micron alumina particles,acidetching using sulphuricacid and combined sandblasting and acidetching).Methodology:24extracted human natural molars that were mounted in epoxy blocks and they were prepared to receive PEEK copings that were divided into3groups.The first group was treated withsandblastingwith110micron alumina particles under 2bar,The second group was treated with98%sulphuric acid for60seconds then rinsed with running water for60seconds,The third group was treated with sandblasting and acid etching together then all copings were cemented to their corresponding teeth withRelyxUltimate clicker then after cementation all copings were subjected to a pull out test using aUniversal testing machine.After the mesurments the teeth were examined under digital microscope to detect the mode of failure.Results:For Sandblasted group the mean±SD values were(80.66±5.54N)with minimum value(59.31N) and maximum value(108.27N),while for Acid etched group the mean±SD values were(87.45±5.56N)with minimum value(81.96N)and maximum value(101.34N).Meanwhile the mean±SD values for Sandblasted and Acid etched group together were(92.43±5.51N)with minimum value(79.67N)and maximum value(106.19N).In accordance to the mode of failure In SB and AE treated group,the failure mode pattern was predominantly adhesive while minority was mixed.In SB+AE treated group samples showed equal%between adhesive and mixed failure mode patterns.There was no record for cohesive failure mode pattern in all groups.Conclusions:Within the limitation of this study;The surface treatment that was preformed by using sandblasting and sulphuric acid etching togethere showed the highest results in accordance to retention of the copings.The use of different surface treatment protocols gives a reliable results in accordance to retention.https://edj.journals.ekb.eg/article_216646_98c706c9556f7ec4e90cb4f2212a593f.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Influence of material type and preparation depth on the fracture resistance of endocrown restoration59760521664910.21608/edj.2021.92662.1770ENAbdallah MohamedEL-hosaryfixed prosthodontics, faculty of dentistry Mansoura universityWalidAl-ZordkAssociate Professor, Fixed Prosthodontics Dept., Faculty of Dentistry, Mansoura University, Mansoura, Egypt0000-0001-5140-7095AbdelreheemAbdelkaderAssistant Professor, Fixed Prothodontic, Faculty of Dentistry, Mansoura University0000-0001-5743-6962MohamedGhazyProfessor, Fixed Prosthodontics Department, Mansoura University, Mansoura, Egypt0000-0002-2396-6428Journal Article20210825Objectives: To assess the impact of intra-coronal preparation depth and restorative material on the fracture resistance of molar restored by endo-crown restoration. <br /> Materials and Methods: Forty root canal treated maxillary first molars were prepared for endo-crown restorations. Specimens were divided according to the pulpal extension depth and material type into four groups (n=10): teeth prepared with 3 mm pulpal extension and restored by PEEK (TP); teeth prepared with 3 mm pulpal extension and restored by zirconia (TZ); teeth prepared with 5 mm pulpal extension and restored by PEEK (FP); and teeth prepared with 5 mm pulpal extension and restored by zirconia (FZ). After fabrication of the restorations, each endo-crown was cemented to its corresponding tooth. All specimens were thermo-cycled (5,000 cycles - 5°C and 55°C). Each specimen was loaded till failure using universal testing machine, then the mode of failure was recorded. Two-way ANOVA and Tukey’s post-hoc tests were employed for data analysis (P< .05).<br /> Results: The highest fracture load was recorded with FP group (2578.3± 337 N) and the lowest value was recorded with TZ group (1511.42± 168 N). Two-way ANOVA test showed a significant difference among studied groups. Post hoc test showed significant differences between each pair of groups, except a non-significant difference (P = .787) between TZ and FZ groups. <br /> Conclusions: The fracture strength of molars restored with endo-crowns can enhanced by increasing the extension depth into pulp chamber. Moreover, PEEK is considered a promising material for endo-crowns.https://edj.journals.ekb.eg/article_216649_6ea39736bd70bb4317d6d39d2beabee0.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Mini implants versus conventional diameter implants for 4-implant-supported mandibular overdentures. One year randomized prospective clinical and radiographical study60761921665110.21608/edj.2022.93151.1771ENAmrEmarahLecturer, Department of Removable Prosthodontics, Faculty of Dentistry, Fayoum University, Fayoum, Egypt0009-0008-5856-6505MohammedHamedLecturer, Oral and Maxillofacial Surgery Department, Faculty of Dentistry, Beni-Suef University, EgyptInassAbuElmagdAssistant Professor, Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Fayoum University,
Fayoum, Egypt0000-0003-0737-1384ShahinazMohamedAssistant Professor, Department of Removable Prosthodontics, Faculty of Dentistry, Beni-Suef University, Egypt.0000-0003-4468-5307Journal Article20210829Abstract <br /> Purpose: This study implant to evaluate clinical and radiographic outcomes of mini-implants and conventional diameter implants used for 4-implant-supported mandibular overdentures after one year. <br /> Materials and methods: 12 edentulous patients with insufficient retention of their conventional mandibular dentures and reduced mandibular ridge width were assigned into 2 groups; group 1 (conventional implants group, control); received four conventional diameter implants using flap surgical approach, group 2 (mini-implant group): received four mini-implants in the interforaminal area of the mandible using flapless surgical approach. For both groups, implants were loaded immediately with mandibular overdentures via O-ring attachments. Plaque index, Gingival Index, probing depth, implant stability and marginal bone loss was assessed at baseline, 6 months and 12 months after overdenture insertion.<br /> Results: The survival rates were 95.9% and 91.7% for conventional implant and min-implants groups without difference between groups. For both groups, Plaque index, gingival index and implant stability did not differ significantly between observation times. Probing depth and marginal bone loss significantly increased with passage of time. Conventional diameter group showed significantly higher plaque, gingival indices, probing depth, implant stability and marginal bone loss than mini-implant group after six and 12 months. <br /> Conclusion: Within the limitation of this randomized trial, mini-implants may be a suitable alternative to conventional diameter implant in patients with reduced buccolingual bone thickness as it was associated with reduced Plaque index, Gingival Index, probing depth and marginal bone loss after one year. However, conventional diameter implants provided more implant stability than mini-implants.https://edj.journals.ekb.eg/article_216651_e99139c7afc05e89a8cd47fefa2bce0d.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Bone Loss Around Mandibular Implant Supported Overdentures. A Seven Year Follow Up.62163021665210.21608/edj.2021.89509.1738ENMOHAMEDABDALLAAss. Prof Prosthodontic Department Cairo UniversityNaglaaNassouhyAss. Prof Prosthodontic Department New Giza UniversityJournal Article20210807Introduction: The number of implants required to stabilize an overdenture has always been a question worth addressing, particularly when economic issues are of concern. Four implants have been used successfully to support a mandibular overdenture, however the type of attachment used may affect the outcome of implant survival and bone anatomy around the implants.<br /> Materials and methods: Eight patients were chosen. All patients were completely edentulous, with their maxillary arches restored with conventional dentures. The mandibular arch was restored with a metal reinforced acrylic resin overdenture supported by four implants.<br /> The implants were placed at the lateral and first premolar areas (Implant direct, Legacy II). Four patients received low profile attachments (Locator Abutment, Implant Direct, Legacy II) ( fig 1) and four patients received ball attachments (Ball Abutment, Implant Direct, Legacy II). Over the next 7 years annual bone measurements were taken by measuring from the implants apex to the level of the bone. implant stability was also checked and recorded by placing the smart peg and using ISQ measurements (Ostell).<br /> Results: using independent t test, bone loss around distal implants in both groups were significant especially in the locator group. The stability measurements showed no statistical significance over the course of 7 years.<br /> Conclusion:<br /> Long term follow up on mandibular overdentures supported by four solitary implants, regardless of the attachment, have shown good implant stability, however, significant bone loss around the most distal implants is to be expected.https://edj.journals.ekb.eg/article_216652_1d58732641b8499e475f0030e26bfdb6.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101PEEK Versus Metallic Framework For Extracoronal Attachment Mandibular Bilateral Distally Extended Removable Dental Prosthesis (RDP) Evaluation of Abutments Bone Height Changes and Patient Satisfaction. A Randomized Clinical Trial.63164521665310.21608/edj.2021.93903.1778ENNourhanRaghebLecturer, Department of Prosthodontics, Faculty of Oral &amp; Dental Medicine, Kafrelsheikh University, Kafr El-sheikh, EgyptMohamedElgamalLecturer, Prosthodontist, Department of removable Prosthodontics, Faculty of Dentistry, Mansoura University, Eldakahlia , Egypt.Journal Article20210901Purpose: to evaluate bone height changes around distal abutments (canines) with two different framework materials for extracoronal attachment mandibular bilateral distally extended removable dental prosthesis (RDP) and compare patient satisfaction .<br /> Materials and methods: <br /> <br /> Twenty-eight mandibular Kennedy class I partially edentulous patients with remaining 6 anterior teeth were selected. For all patients splinting of remaining anterior abutments by porcelain fused to metal crowns, the RDP frameworks were designed by CAD and printed into 3-D resin pattern. The patients were randomly divided into two groups. Patients in group I received extracoronal attachment RDP framework fabricated from milled BioHPP PEEK while patients in group II received extracoronal attachment RDP framework fabricated from Cobalt -Chromium (Co-Cr) material. Digital radiography was used for vertical bone loss (VBL) assessment around canines at insertion, 6 and 12 months. Patient satisfaction was measured after 6 months using visual analog scale (VAS). Statistical analysis was done by t-test and Mann-Whitney.<br /> Results: VBL significantly increased from T6 to T12 for both groups where (p=0.038 and 0.021) for PEEK and Co-Cr framework respectively. there was a significant difference in VBL between two groups at T12 only (p=0.012) where Co-Cr framework recorded significant higher VBL at T12 than PEEK. As for patients satisfaction, patients who received PEEK RDP frameworks were more satisfied as regards esthetic and comfort than patients who received Co-Cr RDP frameworks <br /> Conclusion: Extracoronal attachment RDPs with PEEK frameworks showed less VBL than those with Co-Cr frameworks. Patients with PEEK frameworks were more satisfied than patients with Co-Cr frameworkshttps://edj.journals.ekb.eg/article_216653_d274e99ececb2c862a1dc218c2f76c4c.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Effect of thermo-cycling on retentive forces of different esthetic thermoplastic clasp materials for removable partial denture. (In-vitro comparative study)64765821665510.21608/edj.2021.88151.1724ENEmanMohammedLecturer at Prosthodontic Department, Faculty of Oral and Dental Medicine, Zagazig University0000-0002-6239-4696MohammedEl SayedAssociate Professor, Removable Prosthodontics, Faculty of Dentistry Suez Canal UniversityJournal Article20210728Purpose: The objective of this in vitro study was to evaluate the effect of thermocycling on retentive forces of different esthetic thermoplastic partial denture clasp materials including, polyoxymethylene (Acetal), polyetheretherketon (PEEK) and monomer free semi-rigid microcrystalline polymer (karadent). <br /> Material and methods: 2 Testing models with 2 natural premolar teeth used to test the retentive force of three types of esthetic thermoplastic clasps (N=6) Acetal, PEEK and karadent. After Thermo-cycling, the retention force of the clasps was measured at the same cross head speed. The data were collected, tabulated and a statistically analyzed using SPSS v26 , Kruskal Wallis was used for comparing quantitative non-parametric data of more than two different groups, followed by post-hoc Dunkan’s while Wilcoxon signed rank was used to compare quantitative non-parametric data of two related groups. <br /> Results: PEEK group has recorded a high statistically significant difference in retention force mean values prior to thermo-cycling, P-value ≤0.001. Following thermo-cycling, reduced retention force mean values were found for all groups with non-significant difference between the groups and a significant difference within each group. For the percentage of changes, there was a significant difference between the groups with the least percentage of changes in the Acetal clasp group. p ≤ 0.05<br /> Conclusion: Within the limitations of this study, it was found that the thermoplastic resin clasps-showed a decreased retention values when exposed to thermo- cycling (2000 cycle) between (5 C-55 C) 30 seconds with significantly lower percentage of change for the Acetal than Peek and karadent esthetic clasp materials.https://edj.journals.ekb.eg/article_216655_aa10725723296b3d65d05ff076a6f1b3.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Comparison of Bond strength between acrylic based soft liner and two different denture bases (3Dprinted and conventional denture base).65966321665610.21608/edj.2021.94616.1784ENMohamed MahmoudDohiemlecturer of prosthodontics oral and dental medicine zagaig universityJournal Article20210906Introduction:<br /> Soft lines used in case of sore or atrophied mucosa, alleviate inflamed mucosa and for obturators<br /> after maxillofacial surgery. but These liners have several problems such as the loss of softness, <br /> porosity and poor tear strength, which is of the most serious problems with soft denture liners is <br /> the failure of adhesion between the soft denture liner and the denture 2 That may be lead to failure <br /> as a result.<br /> Material and methods:<br /> The samples were divided into two groups (n =40) according to the type of denture base materials:<br /> Group I: 3D printed denture base with Acrylic based soft liner (Acrostone Dental & <br /> Medical Supplies), Group II: heat cured acrylic denture base with Acrylic based soft liner <br /> (Acrostone Dental & Medical Supplies).<br /> The samples were tested by shear applied by tensile mode of force. samples were tested by<br /> (Instron) the universal testing machine at a crosshead speed of 40 mm/min until complete <br /> separation of soft-liner material from the acrylic plates. The maximum force at the point of failure <br /> leading to separation was recorded. <br /> Result:<br /> Bond strength in Group I (acrylic soft liner with conventional heat cured denture base) showed a statistically significant difference when compare to group II (the acrylic based soft liner to 3D printed denture base)Shows P value of 0.000*.<br /> CONCLUSION <br /> Based on our study findings of this in vitro study, 3Dprinted denture base with acrylic based soft liners had statistically significant lower tensile bond strength values to the conventional heat cured onehttps://edj.journals.ekb.eg/article_216656_90fec4152d05d2a4f2775466abf08233.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Effect of Er,Cr:YSGG LASER bio-modulation of osteotomy site on peri-implant crestal bone level in lower single fixed detachable prosthesis66567521666110.21608/edj.2021.94671.1785ENHeshamAlamAssociate Professor of Prosthodontics, Faculty of Oral and Dental Medicine, Future University, Cairo, EgyptMonaAboelnaggaAssociate Professor of Prosthodontics, Faculty of Dentistry, Ain Shams University, Egypt0000-0002-1891-5810AmanyElsayedAssistant professor of Oral & Maxillofacial Surgery, Faculty of Oral and Dental Medicine, Modern University for
Technology and InformationJournal Article20210907Objectives: This research was carried out to evaluate the effect of bio-modulation with Er,Cr:YSGG LASER on peri-implant crestal bone level changes in cases having edentulous mandible opposed with maxillary natural teeth rehabilitated with fixed detachable prosthesis constructed from BioHPP using CAD/CAM technology. Materials and Methods: This is a split mouth design study in which ten male patients exhibiting completely edentulous mandibular arch opposed by dentate maxillary arch were rehabilitated with fixed detachable lower single denture supported by six dental implants constructed from BioHPP Results: This study showed that there was a statistically significant increase in crestal bone height loss around the implants in both groups.Conclusion: Within the limitation of this study findings, it seems reasonable to suggest that patient compliance, control of occlusal load, primary implant stability, good oral hygiene and passive fit are important factors for the long term success of fixed detachable lower single denture designed by CAD/CAM rather than the additional use of low level laser therapy.https://edj.journals.ekb.eg/article_216661_52d758fe5806cebfdf1666ef813395dc.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Accuracy of fit of all on-four prosthesis constructed from 3D printing and milling technologies67768221666210.21608/edj.2021.95425.1788ENMohamed MahmoudDohiemlecturer of prosthodontics oral and dental medicine zagaig universityJournal Article20210911Introduction: Milled and 3D printed PMMA restorations are widely used in fabrication of all on-four prosthesis, as the traditional process needs many complicated steps. These steps may leads to inaccurate prostheses with poor fit.<br /> The aim of this study was to evaluate the accuracy of fit of CAD/CAM milled and 3D printed PMMA resin all on-four prosthesis.<br /> Material and methods: Eight patients rehabilited with all on-four implants supported prosthesis. Computer-guided surgical procedures were followed for insertion of the implants. Each patient received an immediate temporary resin all on-four prostheses. CAD (Computer Aided Designed) was used to design the prosthesis. Manufacturing CAM (Computer Aided Manufacture) of the prosthesis was carried out with two technologies. 3D printing and milling technologies were used to fabricate the resin prosthesis for each patient. The accuracy of fit of the two manufactured resin prosthesis was evaluated virtually using geomagic software.<br /> Results: The results shows a statistically significant difference of the milled group when compared with the 3D printed group. (p = < 0.000)<br /> Conclusion: Milled showed better fit than 3D printed restoration in resin temporary prosthesis for all on-four implant supported prosthesis.https://edj.journals.ekb.eg/article_216662_16c82566860cbc2ed533a9158b36745c.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Evaluation of Bone Height Changes in Three Implants Retained Mandibular Overdenture Using Three Different Attachment Design. A Randomized clinical trial.68369621666310.21608/edj.2021.80516.1675ENNouranAbdel NabiAssistant Professor, Prosthodontist, Department of Prosthodontics, Faculty of Oral & Dental Medicine, Cairo
University, Cairo, Egypt0000-0001-5558-2990NourhanRaghebLecturer, Prosthodontist, Department of Prosthodontics, Faculty of Oral & Dental Medicine, Kafr El-Shiekh
University, Kafr El-Shiekh, EgyptJournal Article20210613Introduction: The use of more than two implants for mandibular overdentures will improve the retention and stability. The aim of this randomized clinical trial was to compare bone height changes around three implant retained mandibular overdentures using ball, locator and telescopic attachment<br /> Materials and Methods: Twenty-four completely edentulous patients were seeking to install three implants in the edentulous mandible to improve retention of their complete dentures. Three implants were installed in the canine-premolar areas bilaterally and one in the midline. Three month healing period was allowed, and then patients were randomized using sealed envelopes into three groups; patients receiving ball attachments, patients receiving locator attachments and patients receiving telescopic attachments. Bone height changes were recorded using standardized peri-apical x-rays at the day of pick up, at 3, 6 and 12 months follow up. One Way ANOVA test was used followed by Tukey`s Post Hoc test for multiple comparisons. Two sided p values less than 0.05 was considered statistically significant.<br /> <br /> Results: At 6 and 12 month follow up the middle implant showed greater significant bone height changes than the right and left implants in all of the three groups. Ball attachment group showed a greater significant bone height changes when compared to the locator and telescopic attachment group at 6 and 12 month follow up.<br /> <br /> Conclusion: The implant installed in the mid line showed the greatest significant bone height changes and the ball attachment have experienced the greatest significant bone height changes after 12 month follow up period.https://edj.journals.ekb.eg/article_216663_5ccc6b508d7530a74eade6327dfbc343.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Peri-implant strains with ball and telescopic attachments for implant supported maxillary overdentures. An invitro strain gauge analysis69770621666410.21608/edj.2021.84705.1707ENAmrEmarahLecturer, Department of Removable Prosthodontics, Faculty of Dentistry, Fayoum University, Fayoum, Egypt0009-0008-5856-6505ShahinazMohamedAssistant Professor, Department of Removable Prosthodontics, Faculty of Dentistry, Beni-Suef University, Egypt.0000-0003-4468-5307Journal Article20210708Purpose: This invitro study evaluates peri-implant strains with ball and telescopic attachments for implant supported maxillary overdentures.<br /> Materials and methods: A model represent an edentulous maxillary ridge with 4 implants installed at both canine and second premolar areas was constructed. Experimental maxillary overdentures were fabricated and attached to the implants with rigid telescopic (TA, n=5), and ball (BA, n=5) attachments. Two strain gauges were bonded to the acrylic resin at buccal and palatal surfaces of each implant. Strains were measured during unilateral load application on the 1st molar region of the right (loading) side. Mann-Whitney test was used to compare microstrains between groups (TA, and BA), implant positions (canine and premolar implants) and strain gauge positions (buccal and palatal gauges on right and left sides). <br /> Results: For all strain gauge positions of canine and premolar implants, TA showed significant higher microstrain than BA. For both groups, palatal loading side showed the highest microstrain for canine implants, and buccal loading side showed the highest microstrain for premolar implants. For palatal gauges on both sides, canine implants recorded significant higher strain than premolar implants. For buccal gauges on both sides, premolar implants recorded significant higher strain than canine implants. <br /> Conclusion: Within limitation of this invitro study, it could be concluded that, ball attachments are recommended to retain maxillary implant overdenture than telescopic attachments as it were associated with reduced peri-implant strain.https://edj.journals.ekb.eg/article_216664_be5d60fde7475e4494e4c8b10edc9e6a.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Chewing efficiency and masseter muscle activity of conventional dentures, implant-supported overdentures, and fixed hybrid prostheses in patients with atrophied mandibles. A cross-over study70771821666510.21608/edj.2021.97939.1802ENMohamedElgamalLecturer of Prosthodontics Department, Faculty of Dentistry, Mansoura University, Mansoura, EgyptOsamaAskarLecturer of Prosthodontics Department, Faculty of Dentistry, Mansoura University, Mansoura, Egypt000000031249002XJournal Article20210925Purpose: This crossover study evaluated masticatory efficiency and masseter muscle activity of conventional dentures, implant-assisted overdentures, and fixed hybrid prostheses in patients with atrophied mandibles.<br /> Materials and methods: Twenty edentulous patients with mandibular ridge atrophy received mandibular and maxillary conventional dentures (control, CD). Following three months adaptation period, four parallel implants were installed in the interforaminal region. In a random method, bar overdentures (BOD) or fixed hybrid prosthesis (FHP) was constructed for each patient. Chewing efficiency (in terms of variance of the hue, VOH) was estimated utilizing chewing gum and ViewGum software program. EMG of masseter muscles (in terms of amplitude) was completed while clenching without food and clenching on soft and hard foods or without food. Measurements were performed three months after wearing the following prostheses: CD, BOD, and FHP.<br /> Results: BOD and FHP recorded significantly lower VOH than conventional dentures. No difference in VOH between BOD and FHP. The BOD and FHP exhibited significantly higher amplitude than the CD group. No significant differences amplitude between BOD and FHP prostheses were noted for all clenchings. Clenching on the hard food achieved the highest amplitude and clenching with no foods achieved the lowest amplitude.<br /> Conclusion: Within the scope of this trial, it could be concluded that both fixed hybrid prosthesis (FHP) and long bar overdentures (BOD) supported by 4 parallel interforaminal implants with distal cantilevers up to first molar teeth are recommended treatment modalities in patients with atrophied mandibular ridges as both improved chewing efficiency and EMG compared conventional denture.https://edj.journals.ekb.eg/article_216665_42cfb46a255f30b7d0a1f01e40bb6720.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Implant supported partial overdenture in esthetic zone (preliminary report)71973221666610.21608/edj.2021.98239.1804ENEhabElsaihAssociate Professor of Removable Prosthodontics, Faculty of Dentistry, Mansoura University0000-0003-1743-2873AhmedSalemAssociate Professor of Oral and Maxillofacial Surgery, Faculty of Dentistry, Mansoura University0000-0002-0839-9939BassantMowafeyLecturer of Diagnosis and Oral Radiology, Oral Medicine, Periodontology, Diagnosis and Oral Radiology
Department, Faculty of Dentistry, Mansoura University0000-0001-8539-0594Journal Article20210927Abstract:<br /> Purpose: <br /> This study aimed to investigate the implant-supported removable partial denture in the aesthetic zone with different attachments regarding the patient's opinion, and health of soft and hard tissue related to the implants.<br /> Materials and Methods: <br /> <br /> Eight subjects missing four/five maxillary anterior teeth were enrolled for this work in two groups according to the attachment used. Each patient had a removable prosthesis with attachment (positioner and ball) on two implants. Visual analog scale (VAS), marginal bone level, gingival index (GI), implant stability, and peri-implant propping depth (PD) were evaluated for all subjects in a scheduled 6 and 12 months follow-up.<br /> Results: <br /> VAS showed a significant difference indicating better patient acceptance to the implant-supported prosthesis and improved quality of life. No implant failure was recorded, and a mean marginal bone loss was 0.66±0.10 in group A and 0.70 ± 0.09 in group B. No statistically significant difference between groups in all study periods for gingival probing depth (PD) and implant stability. The gingival index (GI) showed a significant difference in ball attachment group B in the 12 months period. <br /> Conclusion: <br /> Within the limitation of this work, the removable partial overdenture can be used (when indicated) in the anterior region with anticipated success independent of the type of attachmentshttps://edj.journals.ekb.eg/article_216666_3c26ecab21898949715ebb9e0588255b.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Effect of Different Denture Base Materials on Normal Human Fibroblast Cell Line: An In Vitro Comparative Study73374121666710.21608/edj.2021.98360.1805ENBassemAbdelhameedLecturer, Department of Removable Prosthodontics, Faculty of Oral and Dental Medicine, Future University in
Egypt, Cairo, Egypt0000-0001-7074-9410Hala AhmedEl KammarAssociate professor of oral pathology, faculty of oral and dental medicine, future university ,cairo egypt0000-0002-1512-7624Journal Article20210927PMMA is the most commonly used denture base material, however some concerns regarding its biocompatibility have been heavily studied over the years. ACETAL and PEEK are more recently introduced denture base material alternatives which are believed to be more biocompatible than PMMA. Aim of the study: to evaluate and compare the short-term effects of PMMA, ACETAL and PEEK on human fibroblast cell line regarding cytotoxicity via direct contact. The assessment of cell cycle progression, cell death and ROS release were used as indicators. Materials and methods: WI-38 cell line was divided equally into four groups. Group I was the control group, for groups II, III and IV the WI-38 cells were cultured with PMMA, ACETAL and PEEK, respectively. The groups were all assessed by flowcytometry for cell cycle and cell death evaluation and ELISA for determining ROS after 4 days of culturing. Results: Pairwise analysis Bonferroni Method showed that highest mean values of total cell death, ROS levels and cell cycle arrest in the G2/M phase of the cell cycle was noted in group II (PMMA/WI38). Pearson`s correlation test (r test) showed that ROS levels correlated positively with total cell death and G2/M arrest. On the other hand, it correlated negatively with all the other parameters (G0/G1 and S). Conclusion: From the results of this study, we conclude that PEEK showed significantly superior biocompatibility compared to ACETAL and PMMA, from enough to justify its use as a denture base material in spite of its high price.https://edj.journals.ekb.eg/article_216667_114a1aaf5a13ad2dd6a63f6d69bb71e2.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Evaluation of the effect of adding zirconium or titanium oxide powder to heat cured acrylic resin on the fracture resistance of denture base of the mandibular implant supported overdenture. An invitro study74374821666810.21608/edj.2021.99085.1815ENAhmedFayyadAssociate Professor, Prosthodontic Department, Cairo University0000-0002-6713-2150Journal Article20211002Abstract<br /> Objectives: The objective of this study was to compare the fracture resistance of denture base of an implant supported mandibular overdenture when incorporating either 5% zirconium or titanium oxide powder to conventional heat cured acrylic resin. <br /> Materials and Methods: A completely edentulous mandibular model was used in this study with two implants installed bilaterally at the canine areas. The model was duplicated 15 times into dental stone according to the sample size calculation. The 15 models were divided into three groups, five model in each. In the first group an implant retained overdenture was constructed with conventional heat cured acrylic resin denture base. In group two the overdenture was constructed after adding 5 % zirconium powder to the conventional denture base material, while the denture base of the third group contained 5% titanium oxide powder added to the conventional denture base material. The universal testing machine was used to evaluate the fracture resistance of the three types of overdenture. The recorded data was collected, tabulated and statistically analyzed.<br /> Results: There was a statistically significant difference between the 3 types of denture bases regarding the fracture resistance where the highest mean value was recorded for the conventional acrylic denture base reinforced with 5% zirconium powder followed by that containing the titanium oxide powder while the conventional denture base showed the least values. <br /> Conclusion: Reinforcement of the conventional heat cured acrylic base material increased the fracture resistance of the denture base when used in mandibular overdenture cases retained with two implants.https://edj.journals.ekb.eg/article_216668_49db9f4a483211cffff97821da84efa3.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Evaluation of Internal Fit of CAD/CAM Implant Abutments with Hybrid and Internal Hex Connections Using Different Materials74976121874210.21608/edj.2021.100254.1824ENKhaledElbannaFixed Prosthodontics Division, Department of Oral and Maxillofacial Surgery and Diagnostic Sciences, Faculty of Dentistry, Umm Al-Qura University, KSA.AlaaAlqutubDepartment of Oral and Maxillofacial Surgery and Diagnostic Sciences, Faculty of Dentistry, Umm Al-Qura University, KSA.0000-0001-8585-5435ShereenKotb SalemFixed Prosthodontics, Faculty of Dentistry, October 6 University, Giza, Egypt0000-0002-6423-8259Journal Article20211013Objective: The aim of this study was to evaluate the internal fit of hybrid and internal hex connections using different materials. Materials&Methods: Forty abutments were divided into 2 groups according to connection type. Each group was subdivided into 4 subgroups according to material (Zr, Ti, Co-Cr and soft-milled Co-Cr-Mo). Internal fit was measured using replica technique. Results: All the samples had clinically acceptable gap values ≤150 µm where internal hex connection had narrower gap than conical connection. Zirconia was the material with lowest gap values, followed by titanium and soft-milled Co-Cr-Mo. Co-Cr had the largest gap distance. Conclusions: 1: Internal hex connection has better internal fit than hybrid connection with more consistent results among different materials. 2: Zirconia showed the best overall internal adaptation with consistent performance among the two connections used. 3: Low marginal gap distance of CAD/CAM conical abutments may not necessarily indicate proper seating of the abutments.https://edj.journals.ekb.eg/article_218742_f3bd3553fa7c026a8f34c53d2417aac0.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101FATIGUE RESISTANCE OF OCCLUSAL VENEERS CONSTRUCTED FROM DIFFERENT CAD/CAM MATERIALS WITH DIFFERENT OCCLUSAL THICKNESSES.76378121666910.21608/edj.2021.101261.1827ENAmiraElsharkawyAssociate Professor, Fixed Prosthodontics, Faculty of Dentistry, 6th of October University, Giza, EgyptJournal Article20211021Purpose: The purpose of the current study was to evaluate the effect of different CAD/CAM materials and different occlusal thicknesses on the fatigue resistance of occlusal veneers. Materials and Methods: Thirty intact maxillary molars were cut occlusally 4.0 mm above the cemento-enamel junction (CEJ). All teeth were dispersed into 3 main groups (n=10) rendering to the CAD/CAM materials tested; Lithium Disilicate (UP.Cad), Vita Suprinity (VS) and Vita Enamic (VE). Each group were further subdivided into 2 subgroups (n = 5) rendering to restoration thickness (1.0 and 1.5 mm). The restorations were adhesively bonded. Samples were subjected to step fatigue resistance test. Assessment of fracture mode was evaluated by Digital microscope. Scanning electron microscope (SEM) was used for fractographic analysis. Results: The highest fatigue resistance was recorded for VS followed by UP.CAD while the least mean value recorded with VE, the difference between groups was statistically significant (P= 0.0003<0.05) as indicated by two-way ANOVA. Occlusal veneers with 1.5 mm thickness recorded statistically significant higher fatigue resistance mean value than 1mm for all tested materials, (P= 0.0005<0.05) as indicated by two-way ANOVA. Most of the fractures were repairable patterns. Conclusions: The material type and occlusal thickness changes significantly affected the fatigue resistance of occlusal veneers. The fatigue resistance of the tested CAD/CAM materials seems promising also in 1.00mm occlusal thickness.https://edj.journals.ekb.eg/article_216669_1dc2844faeef427941e0749ab1bc115a.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101CAD/CAM Fabrication of a Patient-specific PEEK Implant for Marginal Mandibular Reconstruction: A Technical Report78378621667010.21608/edj.2021.101368.1828ENMohamedSaidLecturer, Prosthodontic Department, Faculty of Dentistry, Mansoura University, Egypt0000-0002-7466-5158MohamedShadyLecturer, Prosthodontic Department, Faculty of Dentistry, Mansoura University, EgyptMohamedElmetwallyAssistant Professor of Surgical Oncology, Faculty of Medicine, Mansoura University, EgyptMarcoYoussefResident of Surgical Oncology, Faculty of Medicine, Mansoura University, EgyptSalahHegazyProfessor, Prosthodontic Department, Faculty of Dentistry, Mansoura University, Egypt0000-0001-6581-4046Journal Article20211023Surgical reconstruction of mandibular defects is usually considered a challenge. This technique describes a workflow for CAD/CAM fabrication and insertion of PEEK implant for partial marginal resection of the mandibular angle bone for a 17-year-old young female diagnosed with low grade osteosarcoma. High resolution cone beam computed tomography scan was performed for digital planning. 3D rendering based on the DICOM data was performed using Ceramill Mind - software (Amann Girrbach AG), which produced a three-dimensional model of the mandible. The implant was first 3D designed on computer (Ceramill Mind - software), milled into wax and then finally produced using PEEK injection molding technique. The patients’ aesthetics and functions regarding speech, mastication, and normal opening without deviation were maintained as detected after 6-month follow-up. Combination between CAD/CAM and use of PEEK material in the reconstruction of mandibular defects could be a promising treatment option to restore the physiologic functions of the mandible.https://edj.journals.ekb.eg/article_216670_510d8fc54f7d0544e617e5be7dfba398.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Zirconia versus cobalt chromium meshwork reinforcement of implant-assisted mandibular overdenture78779421667110.21608/edj.2021.101402.1829ENMohamed AhmedAlkhodaryAssociate professor, department of prosthodontics, faculty of dentistry, Alexandria university, Egypt.0000-0003-2736-3672Journal Article20211017Introduction <br /> This work aimed at testing the mechanical behavior of non-metallic enforcement of an implant-assisted mandibular overdenture denture base with a zirconium meshwork and compared its behavior to that of cobalt chromium meshwork under fatigue cyclic loading and fracture resistance. <br /> Materials and Methods<br /> Thirty completely edentulous models in which 2 laboratory implant analogues were secured in the position of the teeth 33 and 43 with ball abutments were used, 10 overdentures of group I had cobalt-chromium meshwork reinforcement of 1mm thickness, group II had 10 overdentures reinforced with 0.5 mm zirconia framework, and group III had 10 dentures with 1 mm zirconia reinforcing framework, the 3 groups were subjected to fatigue cyclic loading and fracture testing.<br /> Results<br /> Group I did not show complete fracture, only cracks in the denture base. group II showed complete fracture of its samples, and only 6 samples of group III showed complete fracture with cracks in the remaining 4. There were significant differences between groups I and II, groups I and III, and groups II and III where the fracture load was significantly greatest for group I, followed by group III, and finally group II.<br /> Conclusion<br /> The Co-Cr meshworks provided the strongest reinforcement of the overdenture bases as compared to zirconia frameworks. The 1 mm thickness zirconia meshwork was more resistant to fracture than the 0.5 mm zirconia framework, but weaker than the Co-Cr framework, however, its recorded resistance to fatigue cyclic loading and fracture was thought to provide an acceptable clinical service lifetime.https://edj.journals.ekb.eg/article_216671_01605f2f39cc630670ad1a83bafa5cb7.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Early Loading of Short and Standard-Length Dental Implants Retaining Mandibular Kennedy Class I Removable Partial Dentures79580621667210.21608/edj.2021.101408.1830ENMohamed AhmedAlkhodaryAssociate professor, department of prosthodontics, faculty of dentistry, Alexandria university, Egypt.0000-0003-2736-3672Abeer MohamedEtteshConsultant of oral and maxillofacial surgery, outpatient clinics, Alexandria University, EGYPT.Journal Article20211017Introduction<br /> This study clinically evaluated early loaded short dental implants compared to early long dental implants assisting mandibular Kennedy Class I IARPDS with the implants placed once at the position of the missing first molar once at the position of the missing second molar.<br /> Materials and methods<br /> Twenty male patients, 30 to 60 years old, participated in this study and were blindly divided into 2 groups. The 10 patients of group I received one short one placed in the mandibular right edentulous space at the site of the missing first molar, and a long implant placed in the left distal extension space at the site of the missing first molar. Group II was made of the same number of patients but with the implants placed at the sites of the missing second molars. After one year of the IARPD loading the implants were evaluated for plaque index, pocket depth, mobility, vertical bone loss, and bone density profile. <br /> Results<br /> No significant differences were detected in plaque index, probing depth, mobility, or vertical bone loss between the implants in the two groups, however, group I implants had more bone density profile than group II implants, especially long implants as compared to short implants.<br /> <br /> Conclusion<br /> The long and short implants placed at the location of the missing first molars had more bone density profile values than those placed at the place of the missing second molars, and in both cases long implants showed better bone density profile than short implants.https://edj.journals.ekb.eg/article_216672_313c37a2a57ab1c93f79bd9afad217c1.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Biocompatibility of conventional acrylic resin versus modified with titanium dioxide nanoparticles in maxillofacial prosthesis. A parallel randomized control trial80781521667310.21608/edj.2021.101483.1832ENNohaAligamaleldinAssistant Professor, Prosthodontic Department, Faculty of Dentistry, Cairo University0000-0002-0155-8896NancyElsherbiniAssociate Professor Prosthodontic Department, Faculty of Dentistry, Cairo university, Cairo, Egypt0000-0003-4553-9092Journal Article20211017Statement of the problem: Biocompatibility of the maxillary obturators, is one of the most important bases for excellent prognosis.<br /> The modified acrylic resin with titanium dioxide nanoparticles has been shown to be an efficient form of poly (methyl methacrylate) resin for the fabrication of dentures.<br /> Objective: The aim of this study is to evaluate the biocompatibility of the obturator constructed with the modified acrylic resin compared to the conventional one.<br /> Materials and Methods: Fourteen patients with acquired maxillary defect were selected to participate in this study, the patients were divided randomly into two groups. Group I patients received obturators constructed from the conventional (poly methyl methacrylate) acrylic resin, Group II patients received obturators constructed from (poly methyl methacrylate) acrylic resin modified by the addition of titanium dioxide nanoparticles. Three swabs were taken from each patient (one from the fitting surface of the obturator facing the defect and the two others were obtained from the nasal and palatal surfaces of the defect) these swabs at 3 months and 6 months after insertion. The results were collected, tabulated and statistically analyzed.<br /> Results: As regard the incidence of bacteria harbored in the defect there was an increase in the bacterial count throughout the follow up period in both groups. The increase was statistically significant in group 1 while was non-significant in group 2.<br /> Conclusion: The use of modified acrylic resin with titanium dioxide nanoparticles in obturators construction obviously improved its biocompatibilityhttps://edj.journals.ekb.eg/article_216673_0e2370f2b63e5a6b9e578768924ce7b9.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Gold alloy metal clip versus nylon plastic clips of stress-free implant (SFI) bar used for immediately loaded 4-implant assisted mandibular overdentures. One-year randomized trial evaluating marginal bone loss and patient satisfaction.81783021667410.21608/edj.2021.101726.1835ENWaleedMaryodAssociate Professor, MSA University0000-0001-8964-6243EngySalamLecturer, Oral Radiology Department, Faculty of Dentistry, Fayoum University0000-0001-5320-5331GhadaAlkaranfillyLecturer, Biomaterial Department, Faculty of Dentistry, Fayoum University, EgyptJournal Article20211018Purpose: the aim of this randomized trial was to evaluate marginal bone loss and patient satisfaction with gold alloy metal clip versus nylon plastic clips of stress-free implant (SFI) bar used for immediately loaded 4-implant assisted mandibular overdentures.<br /> Materials and methods: Eight edentulous patients with unsatisfactory experience of retention and stability of mandibular conventional dentures. Implant were connected with SFI bars then immediately loaded by E-clip (Elitor gold metal alloy) retained overdentures (group 1) or T-clip (titanium housings with replaceable nylon clips) retained overdentures (group 2). Marginal bone loss was measured after 6 and 12 months of insertion. Patient satisfaction was evaluated <br /> Results: For both groups marginal bone loss significantly increased from 6 months to 12 months after insertion. Group 1 recorded significant higher marginal bone loss in group 2 at 6 and 12 months after insertion. Regarding VAS, Group 1 recorded significant lower scores (i.e. high patient satisfaction) of satisfaction compared to normal teeth, the retention of the overdenture, the stability of the overdenture, and comfort with chewing with overdenture than group 2. Regarding OHIP-14, Group 1 recorded significant lower scores of comfort on eating, unsatisfaction with food, interruption of meal and difficulty in function well (i.e. high patient satisfaction) than group 2. No significant difference in other questions of VAS or OHIP-14 was noted between groups. <br /> Conclusion: Within the limitations of this study, E-clip (Gold alloy metal clip) was recommended for SFI bar when used for immediately loaded 4-implant assisted mandibular overdentureshttps://edj.journals.ekb.eg/article_216674_357859f869c4f4eaac6367b88845e5aa.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101In vitro retention overall pull-off force of telescopic crowns made from two different materials at three taper angles83183821667510.21608/edj.2021.102891.1841ENLamisEnabaDepartment Removable Prosthetics, Faculty of Dentistry, Misr International University, Cairo0000-0001-9001-7559Journal Article20211026<strong>Objective: </strong>The objective of the study is to measure the in vitro retention overall pull-off force of telescopic crowns made from two different materials and with different taper angles.<br /> <strong>Materials and methods: </strong>The telescopic crowns were digitally fabricated from two materials, Polyether-ether ketone (PEEK) disc and graphene-nano reinforced acrylic disc (GN) at three taper angles (0˚, 1˚ & 2˚). Retention force for each specimen was measured 20 times in a pull off- Test, the machine was set to a crosshead speed 50 mm/min applying tension mode of force up to crown dislodgement. Twenty cycles of insertion and removal were performed for each sample and then the retention force was computed and recorded using computer software. Statistical analysis was carried out using Two-way analysis of variance (ANOVA) to explore the effect of different materials and degree of taper on the retention load. Independent sample t-test was conducted to explore the difference between materials.<br /> <strong>Results: </strong>The retention force of 2 ° taper showed a statistically significant lower value than 0° and 1° tapers. The specimens of the PEEK groups showed significantly higher initial retentive force values than (GN) groups.<br /> <strong>Conclusions: </strong>Telescopic crowns fabricated from PEEK milled material showed better retention force than the GN milled material. Increasing the degree of taper angle of the telescopic crown above 1° could jeopardize the resultant retention. However, long-term clinical studies are still recommendedhttps://edj.journals.ekb.eg/article_216675_1a695ff5cc1449119087e11d884f9db1.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101FRACTOGRAPHIC ANALYSIS OF MONOLITHIC AND BILAYERED ZIRCONIA AFTER THERMO-MECHANICAL FATIGUE AND FRACTURE STRENGTH TEST83984521667710.21608/edj.2021.103069.1842ENAbdulmoeinAlzhairiMsc, Fixed Prosthodontics, Faculty of Dentistry, MAS University, Cairo, Egypt0009-0005-6711-8542AhmedHamdyProfessor, Professor of Fixed Prosthodontics, Faculty of Dentistry, MSA University,Cairo, Egypt.FaisalHamzaAssistant Professor, Fixed Prosthodontics, Faculty of Dentistry, MSA University, Cairo, EgyptJournal Article20211027Objective: To study the fracture pattern of different zirconia restorations. <br /> Materials and Methods: A first upper premolar sound natural tooth was prepared and duplicated into epoxy resin die. Twenty-one full coverage crowns were fabricated and divided into three groups according to type of ceramic material.; super high translucent monolithic zirconia (Zolid fx) group (A), super translucent monolithic zirconia (STML Katana) group (B), and zirconia core (Ceramill zi) with hand-layered veneering porcelain (Vita VM9) group (C). Crowns were cemented with self-adhesive resin cement. All samples were first subjected to thermal cycling (5o-55oC/10,000 cycle) and then to chewing simulator (240,000 cycles, 50N). After fracture resistance test, fractographic method was used to analyze the fractured samples. <br /> Results: the fracture origin of all studied groups was similar with crack origin located at occlusal surface (cone crack). Crack origins were indicated with mirror regions with appearing lines of hackle.<br /> Conclusion: the fracture origin was found to be dependent on the fracture resistance technique rather than the material itself. <br /> Keywords: fractographic analysis, zirconia, artificial aging.https://edj.journals.ekb.eg/article_216677_e9c82e580d75f511c5db33d8ca7db813.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Evaluation of the fracture resistance of three different implant supported overdenture base materials84785221667810.21608/edj.2021.103829.1847ENNadaEl KhourazatyAssociate Professor Prosthodontics, Faculty of Oral and Dental Medicine, Cairo University0000000210065225Journal Article20211101Objectives: The objective of this study was to evaluate and compare the effect of incorporating 5% zirconium powder to conventional acrylic resin and injection molded thermoplastic resin denture bases regarding the fracture resistance. <br /> Materials and Methods: The study was performed on acrylic models of a completely edentulous mandibular arch with two implants installed bilaterally at the canine areas. Fifteen duplicates of the model were done on which fabrication of three types of dentures was carried out. Group 1 conventional acrylic resin heat cured PMMA, group 2 conventional acrylic resin heat cured PMMA + 5% zirconium powder and group 3 thermopress flexible polymeric +5 zirconium powder. Fracture test was done using the universal testing machine. The load required to fracture the denture bases was recorded in Newton. The data was collected and tabulated for statistical analysis.<br /> Results: There was a statistically significant difference between the 3 types of denture bases regarding the fracture resistance in which the highest mean value of 4941.20 was recorded with the conventional acrylic denture base reinforced with 5% zirconium powder followed by bre.flex flexible therompress polyamide reinforced with ZrO2 then the conventional acrylic resin which presented the lowest mean value of 1336.00.<br /> Conclusion: The fracture resistance of the conventional acrylic resin denture base after reinforcement was the highest amongst the tested materials which renders it as a good alternative to conventional acrylic denture base for construction of mandibular implant supported over denture.<br /> Acrylic resins denture base; over denture; denture fracture; mechanical properties; fracture resistancehttps://edj.journals.ekb.eg/article_216678_3e61d36f10f71aac1f324d17eb17529b.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Treatment protocol for temporomandibular joint derangement using an anterior repositioning splint with modification (one year prospective study).85387321667910.21608/edj.2021.105020.1857ENEhabElsaihAssociate professor of removable prosthodontics, Department of removable Prosthodontics, Faculty of Dentistry,
Mansoura University.0000-0003-1743-2873BassantMowafeyAssociate professor of diagnosis and oral radiology, Oral medicine, periodontology, diagnosis and oral radiology
department, Faculty of Dentistry, Mansoura University0000-0001-8539-0594FatmaAtaLecturer of diagnosis and oral radiology, Oral medicine, periodontology, diagnosis and oral radiology department, Faculty of Dentistry, Mansoura University.AhmedSalemAssociate Professor of Oral and Maxillofacial Surgery, Faculty of Dentistry, Mansoura University0000-0002-0839-9939Journal Article20211108Purpose: <br /> To study the patient with temporomandibular joint derangement concerning the subjective response and clinical outcome and to a modified splint treatment protocol.<br /> Materials and Methods: <br /> 12 patients included with disc displacement with reduction (DDwR). The treatment protocol was initiated using an anterior repositioning splint (ARS) for 3 months and later completed with ARS modification into a stabilizing splint (SS) for the next 9 months. Follow-up was made over one year (6 weeks, 12 weeks, and 1-year intervals). The follow-up included the patient's self-evaluation, clinical examination, and MRI. <br /> Results: <br /> In comparison to the base-line a significant improvement was recorded in the tested parameters; A) in 12 weeks follow up, the subjective data were; the pain frequency (0.41±0.51), the pain degree (0.25±0.45), the modified pain by chewing, movement, para-function, and other parameters were 0.08±0.28, 0.25±0.45, 0.25±0.45, and 0.16±0.38 respectively. B) in 6 & 12 weeks follow-ups the clinical parameters were; MCPS 0.58±0.51, and 0.25±0.45, the MYS 0.58±0.51, 0.25±0.45, the MD 1.91±0.66, 0.58 ±0.51, C) the VAS scores, the mandibular movement range in the maximum opening, protrusive and both lateral directions, and the Helkimo's disability index scores, D) in 3& 12 months follow-ups the complete disc recapture diagnosed by MRI were 66% and 83% respectively.<br /> Conclusion: <br /> There is a positive impact of the ARS on all criteria of patient subjective and clinical outcomes. The improvement continued after splint modification for the successive 9 months.<br /> Within the limitation of this study, and upon literature comparison, this treatment protocol is recommended in DDwR cases.https://edj.journals.ekb.eg/article_216679_4b0eb9d86d816600a085b51fbb36d1ee.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Shear Bond Strength of Various dental Ceramics Treated with two Techniques of Surface Treatment after Thermocycling87588321668010.21608/edj.2021.105777.1865ENRaiesa MohamedHashemFixed prosthodontics department, faculty of dentistry,minia university, Egypt0000-0002-3034-2883Journal Article20211203ABSTRACT<br /> Aim: The goal of this work was to compare the shear bond strength of various ceramics bonded to tooth structure following thermocycling using a traditional vs a simplified Surface Treatment approach.<br /> Materials and methods : Thirty removed human mandibular molar teeth were separated into three groups (10 samples each) based on the kind of ceramic material employed (zirconia reinforcing lithium silicate (celtra), Polymer infiltrated glass ceramic (hybrid ceramic) (vita enamic), and lithium disilicate ceramic (vita enamic) (Emax). Each group was divided into two categories based on the surface treatment process (5 samples each) The classic approach (hydrofluoric acid with silane coupling agent) was used in Subgroup I, whereas the simplified method was applied by using Monobond Etch & Prime in Subgroup II. Shear bond strength tests were carried out using universal testing machine. The data was obtained, processed, and statistically analysed.<br /> Results: It was found that a non-significant higher SBS mean values recorded for conventional technique (12.57±0.51 MPa) than simplified technique (11.41±0.36) in Emax group. Regarding Vita Enamic there was significantly higher SBS mean values recorded for the simplified technique (10.83±0.17) using MEP than conventional technique (8.24±0.46) (HF+S). While Celtra duo, revealed significantly higher SBS mean values recorded for conventional technique (11.46±0.51) than simplified technique (7.32±0.75).<br /> Conclusion: Vita Enamic showed better results using Monobond Etch & Prime surface treatment than HF acid and silane. While For Emax and celtra due HF acid and silane has shown better results.<br /> Keywords: Surface treatment, Ceramics, , Shear bond strength, Simplified technique.https://edj.journals.ekb.eg/article_216680_c303265dd6f12b15450ee0c80f35d0a9.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Prosthetic complications in immediately loaded All-on-Four mandibular prosthesis using titanium wire reinforcement versus non reinforced temporary framework. A Randomized Clinical Trial88589221668110.21608/edj.2021.106662.1872ENAhmedFayyadAssociate Professor, Prosthodontic Department, Cairo University0000-0002-6713-2150Journal Article20211117Abstract:<br /> Objectives: The objective of this study was to evaluate the prosthetic complications resulting from the treatments performed with the All-on-Four concept either with splinted or un-splinted implants using the novel OT bridge system <br /> Materials and Methods: This study was conducted on twelve edentulous patient aged from 60 to 70 years. An upper and lower removable complete denture were constructed for each eligible patient. CBCT scan was done for all patients. All patients received 4 implants to support an “all-on-four” fixed mandibular prosthesis. The patients were randomly divided into two equal groups. The first group patients received an immediately loaded all-on-four prosthesis with un-splinted abutments. While the second group patients received an immediately loaded all on four mandibular prosthesis where the abutments were splinted together with titanium wire. Immediate loading was performed for all patients. Prosthetic complications were evaluated for the prosthesis in a 6-month period.<br /> Results: In this study the overall prosthetic complications for those patients treated with splinted or un-splinted all on four technique was as follows: for Group I (un-splinted implants), total incidence of patients showed at least one Prosthetic complication were 12 (100%) patients, while 4 (33.3%) patients showed at least one Prosthetic complications in (Group II).<br /> Conclusion: From this study it can be concluded that the All-on-four concept with immediate loading is a procedure that is viable and could be helpful in completely edentulous patients. However, it can predispose the patient to some prosthetic complications specially when the implants are un- splinted with titanium wireshttps://edj.journals.ekb.eg/article_216681_ec1e6e34bf534e93ce77b819904a6786.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Bonding performance of self adhesive flowable composite to dentin pretreated with four different natural matrix metalloproteinases inhibitors89391421668210.21608/edj.2021.107161.1878ENDinaEl- RefaiAssociate Professor Biomaterials, Faculty of Dentistry, Ain Shams University, Cairo, Egypt0000-0002-2578-0766Journal Article20211121Objective: The study attempted to assess the effect of application of four natural matrix metalloproteinases inhibitors (proanthocyanidin, quercetin, chlorogenic acid and hesperidin); as dentin pre-treatment agents; on the shear bond strength of Vertise Flow self adhesive flowable composite to dentin.<br /> Materials and methods: The study included five groups: Group I (control): Dentin was etched and the composite was applied without pre-treatment. Group II: Etched dentin was pre-treated with 2% proanthocyanidin prior to composite application. Group III: 2% quercetin solution was used. Group IV: 2 % chlorogenic acid was used. Group V: 2 % hesperidin solution was used. <br /> Shear bond strength of 40 specimens in each group was measured; 20 specimens were tested at 24 hours, and other 20 specimens were tested after thermocycling.<br /> Failure mode was analyzed according to Adhesive Remnant Index scoring system.<br /> Scanning electron microscopic imaging for the composite/ dentin adhesive junction was performed. <br /> Results: Shear bond strength testing after thermocycling revealed that group II recorded the highest value among all groups, whereas group IV recorded the least value.<br /> Concerning the failure mode; the majority of specimens of groups I and IV recorded score (1). Concerning groups II, III and V, the majority of specimens registered score (2). Conclusions: Proanthocyanidin can be considered a highly potent matrix metalloproteinases inhibitor to enhance and promote a satisfactory bonding stability of flowable composite to dentin, followed by quercetin and hesperidin. However, application of chlorogenic acid is not recommended.https://edj.journals.ekb.eg/article_216682_d281df52dd83e9d30739254584bf2278.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101The Effect Of Silver Versus Titanium Dioxide Nanoparticles On Poly methylmethacrylate Denture Base Material91592121668310.21608/edj.2022.111973.1919ENYasmineThabetAssociate Professor, Oral and Maxillofacial Prosthodontics department, Faculty of Dentistry, Ain Shams University,
Cairo, Egypt.DinaMoustafaAssistant Lecturer of Microbiology and Immunology department, Faculty of Dentistry, The British University in
Egypt.SaraEl ShafeiLecturer, Oral and Maxillofacial Prosthodontics department, Faculty of Dentistry, The British University in
Egypt, Cairo, Egypt0000-0002-5060-8941Journal Article20211219Abstract<br /> Materials and methods:<br /> Three groups of heat cured acrylic resin specimens were prepared; the first was Group C made of conventional heat cured acrylic resin, the second group was Group Ag where the acrylic resin specimens were incorporated with 5% Silver nanoparticles, and the third group Ti had its specimens incorporated with 5% Titanium oxide nanoparticles.<br /> The specimens were tested for microbial colonization using direct culture and serial dilution methods. The specimens were then further tested for surface roughness.<br /> Results:<br /> There were higher bacterial counts in specimens of group C (control) 51.12±4.7198 than those with Ag nanoparticles 32.44±2.7701 and TiO2 nanoparticles 31.92±2.2159. The difference was statistically significant between the control group (C) and the Ag nanoparticles group and between the control group and the TiO2 nanoparticles group. However, there was a statistically non-significant difference between the Ag nanoparticles group and TiO2 nanoparticles group. Statistical analysis by ANOVA for repeated measures showed statistically non-significant difference between the three groups regarding the surface roughness. <br /> <br /> Conclusions:<br /> • Ag and TiO2 nanoparticles had a similar antimicrobial effect when added to PMMA. <br /> • The addition of 5% of Ag and TiO2 nanoparticles has not affected the surface roughness of PMMA.https://edj.journals.ekb.eg/article_216683_16036782b04dc7eaa793db391c8179c0.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Peri-implant marginal bone loss and oral health-related quality of life in patients treated by mini-implant-retained mandibular overdentures with different occlusal schemes (lingualized, monoplane and bilateral balanced): A randomized clinical trial92393621668410.21608/edj.2022.113140.1930ENImanEl-asfahaniAssociate Professor, Removable Prosthodontics Department, Faculty of Dentistry Minia University, Egypt0000-0003-0952-9544EmanHelalResearcher, Fixed & Removable Prosthodontics Department, Oral & Dental Research Institute, Cairo, EgyptJournal Article20211226Purpose: To evaluate the peri-implant marginal bone loss and oral health-related quality of life in patients receiving mini-implant-retained mandibular overdentures with different occlusal schemes.<br /> Materials and methods: Twenty-one completely edentulous patients were selected. All patients received complete dentures before the surgical procedures, The patients were randomly divided into three groups according to the occlusal scheme. Group I: complete dentures with lingualized occlusal scheme, Group II : complete dentures with Monoplane occlusal scheme, Group III : complete dentures with bilateral balanced occlusal scheme. Four mini implants were inserted and loaded in each patient in mandible intraforminally. The peri-implant marginal bone loss and oral health-related Quality of Life were evaluated at implant loading (baseline or zero month), six and twelve months after implant loading .<br /> Results: No significant difference in the peri-implant marginal bone loss was found between Group I, II and III in the 0-6 follow-up period, while at the 0-12 follow-up period significant difference was found. No significant difference was obtained between total OHIP-EDENT scores in the three groups at baseline and 6-months follow up visits, while at the 12-months follow up visit, significant difference was found .<br /> Conclusion: Within the limitations of this study, it can be concluded that in mini-implant retained mandibular overdentures, lingualized and monoplane occlusal schemes may provide better results in the peri-implant marginal bone loss aspect compared to bilateral balanced occlusal scheme. Furthermore, in patients’ oral health-related Quality of Life aspect, lingualized occlusal scheme may be superior to monoplane and bilateral balanced occlusal schemes.https://edj.journals.ekb.eg/article_216684_4b1f251f27e6cbd29be3ad31ce0513cd.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Dynamic fatigue resistance and marginal leakage of endocrowns fabricated with two different CAD/CAM ceramic materials.93794721668510.21608/edj.2022.110841.1907ENMohamedMohamedAssociate Professor, Fixed Prosthodontics Department, Faculty of Dental Surgery, Ahram Canadian University0000-0003-2140-906XHanaaNassarLecturer, Fixed Prosthodontics Department, Faculty of Dental Surgery, Ahram Canadian University0000-0002-0246-9748Journal Article20211212Aim: To assess the effect of two CAD/CAM monolithic restorative materials on the fracture resistance of endocrowns subjected to dynamic fatigue loading and surface pre-treatment on microleakage.<br /> <br /> Materials and Methods: Twenty-eight freshly extracted human mandibular first molars were endodontically treated and prepared for endocrown restorations. Samples were randomly divided into two groups (n=14) ; lithium disilicate (IPS E-max CAD) and resin hybrid ceramic (SHOFU Block HC). CAD/CAM endocrown restorations were fabricated, surface treated, and cemented with dual-cured adhesive resin cement. Thermocycling was done. Each group was then subdivided into two equal subgroups (n=7) according to the type of test used in the study; dynamic fatigue test and microleakage test. <br /> Results: Shoufu (SH) group recorded a higher significant difference in the mean value of dynamic fatigue failure load and cycles than E.max CAD (LD) group with mean value as indicated by the student t-test (P<0.05). While the LD group recorded a higher significant difference mean value of leakage than the SH group's mean value. There was an inverse correlation between microleakage and dynamic fatigue failure load of the tested groups as indicated by Pearson linear correlation.<br /> Conclusions: Endocrowns made of resin-hybrid ceramic showed higher dynamic fatigue resistance load and lower microleakage compared with that made of lithium disilicate glass-ceramic. Shofu HC Hybrid CAD/CAM blocks can be considered as a promising alternative material to lithium disilicate blocks in the restoration of endocrowns.https://edj.journals.ekb.eg/article_216685_3318b9a011130c9d8306ac005146b1e6.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101The Effect of Aging upon Retentive Characteristics of Two Different Stud Attachments In vitro Study94995421668910.21608/edj.2022.109753.1895ENKhaledAbdelwahabAssociate Professor, Department of Prosthodontics, Cairo University, New Giza UniversityJournal Article20211206Aim: <br /> In Vitro study was conducted to compare the retention of CM LOC and locator attachment systems in retaining mandibular overdenture upon simulation of insertion-removal cycles.<br /> Materials Abd methods:<br /> Ten complete dentures were fabricated on a Stone model representing a completely edentulous mandible that was obtained by making an impression for an edentulous patient. The stone model was duplicated using laboratory addition silicone after placing single implant analogue in the Medline using a dental surveyor. Then the mold was duplicated using epoxy resin. The prefabricated dentures were divided into two groups. Group was set to receive the CM LOC attachment and the other group was set to receive the ball attachment. Using a universal testing machine, the retention was measured at base line, 500, 1000, 1500, and 2000 insertion and removal cycles using ROBOTA chewing simulator, which represents (o,3,6,9,12) month; Considering that the patient will remove the denture 4 to 5 times a day<br /> Results:<br /> There was a statistically significant difference between the two types of attachments. The CM LOC attachment showed a higher statistically significant mean difference when compared to locator attachment after 1000 cycles (9 months). It was concluded that CM LOC appeared to have a favorable retention over the locator attachment in the first year with less serviceability.<br /> <br /><br />https://edj.journals.ekb.eg/article_216689_5f52a0fdcc376a794b1253e3daf896ae.pdfThe Egyptian Dental Association (EDA)Egyptian Dental Journal0070-948468120220101Assessment of primary stability and bone density of maxillary implant overdenture following Osseo densification concept.95596321669010.21608/edj.2022.109760.1896ENKhaledAbdelwahabAssociate Professor, Department of Prosthodontics, Cairo University, New Giza UniversityAlaaNawwarLecturer of Oral and Maxillofacial Radiology, Faculty of Dentistry, Cairo University000000015481135NadaEl KhourazatyAssociate professor of Prosthodontics, Faculty of Dentistry Cairo University0000-0002-1006-5225Journal Article20211206Abstract<br /> Objectives: To evaluate the effect of osseodensification concept using Densah bur on implant primary stability and peri-mplant bone density in maxillary implant overdenture. Materials and Methods: Ten completely edentulous patients were selected and two implants were inserted in the maxilla for each patient in a split mouth study design; one implant with the conventional drilling system and one implant with the Densah bur drilling system. Implant primary stability was assessed using ostell device at the time of implant placement and at prosthetic rehabilitation phase (4m). Bone density around the implants was measured using CBCT at 3,6,12 months intervals. Results: significant difference was found regarding Osstell values as well as bone density measurements between both groups throughout the study period Conclusions: Within the limitation of this study, Densah drilling burs that adopt the osseodensification concept have displayed more primary stability compared to the conventional drilling protocol in terms of primary stability as well as bone density for delayed loaded implants used to retain and support maxillary overdentures. <br /> Key words: implants, primary stability, osseodensification, bone density, overdenture.https://edj.journals.ekb.eg/article_216690_cac612a5722d93569aab729619ecb0aa.pdf