Browsing by Author "Nagy, Mohamed M"

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    Inflammatory response and immunohistochemical characterization of experimental calcium silicate-based perforation repair material
    (Wiely, 08/03/2022) Okasha, Hend ; Abu-Seida, Ashraf M; Hashem, Ahmed A; El Ashry, Salma H; Nagy, Mohamed M
    This study compares the immunohistochemical reaction of a new experimental tricalcium silicate perforation repair material to mineral trioxide aggregate (MTA) and Biodentine. A total of 162 mature premolar teeth from 12 dogs were divided into three experimental groups (n = 54 teeth each) according to the evaluation period: 1, 2 and 3 months. Each group was further divided into two equal sub- groups (n = 27 teeth each) according to the time of repair: immediate repair and delayed repair. Each subgroup wassubdivided according to the material used into three experimental subdivisions (n = 8 teeth each): MTA, Biodentine (Septodont) and experimental material, and two control subdivisions: positive control (n = 2 teeth) and negative control (one tooth). Under general anaesthesia, access cavity was done. Cleaning and shaping were performed using ProTaper universal rotary instruments. The canals were obturated using cold lateral compaction technique with Gutta percha and Adseal sealer. Furcation perforations were created then randomly sealed using the three materials either immediately or after one month (delayed repair). Inflammatory cell count and immunohistochemical analysis of osteopontin-positive area fraction were digitally analysed using the ImageJ soft- ware. Delayed furcal perforation repair showed significantly higher inflamma- tory cell count than immediate repair. No significant difference in inflammatory cell count and immunohistochemical analysis was detected between the three tested materials. The immunohistochemical analysis revealed the highest im- munopositive area fraction in the 3-month evaluation period. The experimental tricalcium silicate cement performed similarly to Biodentine and MTA regarding the osteopontin expression during perforation repair, suggesting it is a suitable alternative with favourable handling characters.
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    Stress analysis of over-denture abutments treated with two obturation techniques
    (University Library System, University of Pittsburgh, 8/18/2021) Elsherbini, Ahmed N; Nagy, Mohamed M; Elsherbini, Nancy N
    Aim: Evaluation of stresses induced on over-denture abutments endodonticaly treated with two different obturation techniques. Materials and Methods: 4 pesudo-realistic models were fabricated with two remaining canines as abutments. One canine was treated with lateral obturation technique and the other with vertical obturation. An over-denture was fabricated on the model. Then strain gauges were attached on the coronal one third of the root buccally and lingually. 50 N were applied on the middle of the model using universal testing machine and readings were collected. Results: From the collected data the lateral obturation showed 85.25±104.901 μ∈ and the vertical obturation showed 4.875±3.555 μ∈ with significance difference of P<0.05 between the groups. Conclusion: It can be concluded that the abutments treated with vertical obturation techniques reduced the stresses induced to the supporting structures when compared with the lateral condensation technique. © 2021 University Library System, University of Pittsburgh. All rights reserved.