Papers by Dr. Marwa Beleidy
Egyptian Dental Journal /Egyptian Dental Journal, Jul 1, 2024
Egyptian Dental Journal
Purpose: To evaluate Well-Root ST and Expoxidin Duo sealers' contact angle, dentinal tubule penet... more Purpose: To evaluate Well-Root ST and Expoxidin Duo sealers' contact angle, dentinal tubule penetration, and their impact on fiber post-bond strength. Materials and Methods: Fifty-eight maxillary central incisor teeth were collected and decoronated. Ten teeth were longitudinally split into 20 segments and treated with bioceramic (Well-Root ST) and epoxy resin-based (Epoxidin Duo) sealers (n=10 per group) to evaluate the contact angle. Forty-eight teeth were divided into two groups (n=24) based on the same sealers used for obturation. Both obturated teeth groups were subdivided into two subgroups based on the evaluating test; 14 specimens were assessed for dentinal tubule penetration using a scanning electron microscope (SEM), and 10 specimens were restored with fiber posts and cross-sectioned to evaluate the push-out bond strength using a universal testing machine. Failure mode was determined for pushed-out slices under a SEM. Independent t-test was used to compare two different groups. One-Way ANOVA and Tukey's Post Hoc tests were used for multiple comparisons. P < 0.05 was the significance level. Results: Epoxidin Duo group showed a significantly higher contact angle (56.78 ± 0.68 o) than Well-Root ST group (53.25 ± 0.25 o). Well-Root ST group showed significantly higher dentinal tubule penetration (10.40 ± 1.05 µm) than Epoxidin Duo group (7.61 ± 1.08 µm). Both groups showed a non-significant push-out bond strength difference. Conclusions: Bioceramic sealer showed higher wettability and dentinal tubule penetration than epoxy resin-based sealer. However, both sealers affected the fiber post-bond strength at various regions throughout the root canal length without influencing the total bond strength.
Egyptian dental journal, Jul 1, 2019
Statement of the problem: The wide use of digital dentistry in fixed prosthodontics using 3D prin... more Statement of the problem: The wide use of digital dentistry in fixed prosthodontics using 3D printers and CAD/CAM in fabricating crowns and partial fixed dental prosthesis created a need for more information about their marginal gap and internal fit. Purpose: This study aimed to evaluate the effect of fabrication technique using CAD/CAM manufactured and heat pressed lithium dislicate crowns made from milled wax and 3D printed resin patterns on their marginal gap and internal fit. Material & Methods: A total of 50 prepared mandibular first molar resin models were used and divided into two main groups according to their fabrication phase: Patterns group and fully fabricated crowns group. Patterns group was subdivided into milled wax patterns (W) (n=10) and 3D printed resin patterns (P) (n=10). Fully fabricated crowns group was subdivided according to fabrication technique of lithium disilicate crowns into: Machinable ceramics (M), using IPS e-max CAD blocks (n=10), Pressable ceramics (Pw), using IPS e-max press ingots following wax milling (n=10) and Pressable ceramics (Pp), using IPS e-max press ingots following 3D resin printing (n=10). All patterns and ceramic crowns were cemented with Rely-X self-adhesive resin cement. Marginal and internal adaptations were measured using SEM at 300 × magnification. Kruskal-Wallis and Wilcoxon signed-rank tests were applied to compare between the groups. Data were presented as median and range values. The significance level was set at P ≤ 0.05. Results: P group showed a significant higher median total marginal gap of 111.4 μm (80.8-139.7) than W group of 51.3 μm (45.1-57.8) before heat pressing. While M group showed the significant highest median marginal gap of 138.4 μm (83.4-191.8) and no significant difference between heat pressed groups (Pw and Pp) (P ≤ .05). Regarding changes after heat pressing, Pw group showed no significant decrease, while Pp group showed a significant decrease in median total marginal gap. For internal fit, there was no significant difference between the pattern groups (2780) Marwa Beleidy and Ahmed Ziada E.D.J. Vol. 65, No. 3 (W and P) before heat pressing (P ≤ .05). After heat pressing, Pp group showed the significantly highest median gap of 195 μm (138.9-441.5) with no significant difference between M and Pw groups (P ≤ .05). Pw group showed a significant decrease in median gap, and Pp group showed no significant decrease after pressing (P ≤ .05). Conclusions: Heat pressed lithium disilicate glass ceramic crowns produced from CAD/CAM waxing or resin 3D printing techniques resulted in better marginal and fit accuracy than CAD/CAM. 3D printed resin patterns yielded internal fit values higher than other groups, but with promising clinical acceptability.
Egyptian Dental Journal
Purpose: Due to a lack of data on their wear behavior, the study aimed to analyze the twobody wea... more Purpose: Due to a lack of data on their wear behavior, the study aimed to analyze the twobody wear rate of two different composite veneered computer-aided design/computer-aided manufacturing (CAD/CAM) polyetheretherketone (PEEK) posterior crowns after wear simulation using 3D surface deviation. Materials and Methods: Twenty duplicated epoxy resin models of prepared mandibular first molar to receive an all-ceramic crown were fabricated. Twenty CAD/CAM PEEK substructures were manufactured and divided according to the veneering technique into two groups (n=10); group (H): CAD/CAM High Impact Polymer Composite (HIPC) veneered PEEK substructures, and group (C): Conventional Crea.lign composite veneered PEEK substructures (control). The specimens underwent thermal and mechanical loading (49N, 5/55˚C; 120,000 chewing cycles) as antagonized by steatite ceramic balls. 3D surface deviation analysis using a 3D dental scanner and Geomagic Design X software was applied before and after chewing simulation to determine the volumetric wear loss (mm 3). Data were statistically analyzed with the Mann-Whitney U test to compare the two groups. The significance level was set at p≤0.05.
Journal of Prosthodontics
Egyptian dental journal, 2021
Statement of problem:Veneered polyetheretherketone(PEEK) is a recent alternative choice for fixed... more 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...
Purpose: The purpose of the study was to evaluate the fracture resistance of CAD/CAM fabricated m... more Purpose: The purpose of the study was to evaluate the fracture resistance of CAD/CAM fabricated monolithic zirconia FDPs with differently designed split pontics under simulating ageing conditions. Methods: A total of 21 FDPs with split pontics were constructed over 21 dental epoxy resin casts representing missing mandibular first molar with a second premolar abutment of 0° angulation and a tilted second molar abutment of 25° angulation. The FDPs were divided into three groups (n=7) according to the split pontic design; Group (K): Keyhole, Group (B): Bone, Group (R): Relief cut. The cemented FDPs were subjected to thermocycling and mechanical loading in a chewing simulator equivalent to one-year clinical service. Fracture resistance of aged specimens was measured by a universal testing machine and followed by fracture mode detection by scanning electron microscope. One-way ANOVA and Bonferroni post-hoc tests were utilized to compare among groups. The significance level was set at P ≤...
Egyptian Dental Journal
Statement of problem: Veneered polyether ether ketone (PEEK) is a recent alternative choice for f... more Statement of problem: Veneered polyether ether ketone (PEEK) is a recent alternative choice for fixed dental prostheses. There is a lack of data about the effect of composite veneering techniques of CAD/CAM PEEK cores on the marginal accuracy and fracture resistance of such restorations. Purpose: To investigate the different composite veneering techniques of CAD/CAM PEEK cores influence on the marginal accuracy and fracture resistance of posterior crowns. Methods: Twenty duplicated epoxy resin dies of a prepared mandibular first molar to receive a ceramic crown were fabricated. 20 CAD/CAM PEEK cores were fabricated and divided into two groups (n=10) based on the veneering technique; group (A): HIPC veneered PEEK cores and group (B): nanohybrid crea.lign composite veneered PEEK cores (control group). Marginal gap was evaluated at 4 equidistant points on each crown by a digital microscope before and after ageing equivalent to clinical 6 months service. The fracture load was assessed after ageing. The data were statistically analyzed using one-way ANOVA, pair-wise Tukey's post-hoc and Student's t-tests to reveal the significance between groups (P ≤ 0.05). Results: The marginal gap was significant between before (59.638±5.91 µm and 58.587±7.74 µm) and after ageing (79.167±11.62 µm and 72.222±6.53 µm) for A and B groups respectively (p=0.0019/0.0039<0.05). ANOVA test showed a significant difference between groups before and after ageing (p= 0.0002<0.05) which was not detected by Tukey's test (p>0.05). B group showed a significant higher fracture resistance mean value (1674±224.8 N) than A group (1294±282 N) (p=0.0164<0.05). Conclusions: The marginal gap and fracture load values recorded by posterior crowns fabricated from CAD/CAM PEEK cores veneered with HIPC or nanohybrid composite were all within the clinically acceptable range.
Egyptian Dental Journal
Purpose: This randomized clinical study was to assess cordless techniques compared to conventiona... more Purpose: This randomized clinical study was to assess cordless techniques compared to conventional cords in gingival displacement and effect on periodontal health. Material and Methods: Forty participants having a premolar abutment were elected following inclusion criteria and allocated by using parallel randomization into four groups (n=10) for gingival retraction either with Ultrapak, GingiTrac, Traxodent or NoCord. By single-blinded operator, the horizontal gingival displacement as a primary outcome was measured on pre-and post-retraction polyether impressions utilizing a stereomicroscope. As secondary outcomes, the placement time and bleeding after removal were noted. The periodontal parameters; plaque index, gingival index (GI), and probing depth (PD) were recorded pre-operative, 1-and 7-days post-operative. Results: There was a non-significant gingival displacement difference among groups (P=.282) and a significant difference within each group. GI elevated in all groups after one day as Traxodent exhibited the highest value (p<.001). After seven days, it returned to a non-significant value compared to the baseline except for GingiTrac and Traxodent which were significantly higher (p<.001). PD of Ultrapak and GingiTrac were non-significant in all-time hiatuses, while Traxodent and NoCord revealed a significance. After seven days, Traxodent showed higher PD than the baseline (p<.001). Ultrapak induced maximal bleeding (50%), while NoCord showed no bleeding. Conclusion: Cordless retraction systems showed similar horizontal gingival displacement compared to conventional cords. NoCord can be considered an alternative retraction system, providing an effortless placement, good gingival displacement and no bleeding. All techniques induced an interim gingival inflammation; Traxodent showed the highest level. GingiTrac and Traxodent demonstrated delaying recovery.
Egyptian Dental Journal
Purpose: The purpose of the study was to evaluate the fracture resistance of CAD/CAM fabricated m... more Purpose: The purpose of the study was to evaluate the fracture resistance of CAD/CAM fabricated monolithic zirconia FDPs with differently designed split pontics under simulating ageing conditions. Methods: A total of 21 FDPs with split pontics were constructed over 21 dental epoxy resin casts representing missing mandibular first molar with a second premolar abutment of 0° angulation and a tilted second molar abutment of 25° angulation. The FDPs were divided into three groups (n=7) according to the split pontic design; Group (K): Keyhole, Group (B): Bone, Group (R): Relief cut. The cemented FDPs were subjected to thermocycling and mechanical loading in a chewing simulator equivalent to one-year clinical service. Fracture resistance of aged specimens was measured by a universal testing machine and followed by fracture mode detection by scanning electron microscope. One-way ANOVA and Bonferroni post-hoc tests were utilized to compare among groups. The significance level was set at P ≤ 0.05. Results: There was a statistically significant difference among groups (P-value <0.001, Effect size =0.852). Pair-wise comparisons among the groups revealed that group (K) showed the statistically significantly highest mean fracture resistance (2148.6 ± 193 N), and followed by group (R) (1605.4 ± 286.2 N). While group (B) showed statistically significantly lowest mean fracture resistance (1027.6 ± 91.8 N). Conclusions: The tested different split pontic designs of monolithic zirconia FDPs for tilted molar abutments demonstrated acceptable fracture load values.
Journal of Indian Prosthodontic Society
Background : Marginal discrepancies in implant-supported prosthesis are inevitable, despite caref... more Background : Marginal discrepancies in implant-supported prosthesis are inevitable, despite careful waxing, investing, and casting procedures. The choice of metal also affects these discrepancies. Materials and Methods : A total of 48 frameworks were fabricated: 16 ...
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Papers by Dr. Marwa Beleidy