Evaluation of Load-bearing Capacity of Interim Fixed Partial Dentures Reinforced with Glass Fibers: An In Vitro Study.

AIM: To compare the load-bearing capacity of three and four-unit fixed partial denture (FPD) with two different designs of pontics reinforced with industrial glass fibers at two different positions of the FPD. MATERIALS AND METHODS: A total of 64 samples were made with Bis-acryl composite temporary material and reinforced with industrial glass fibers (E-glass). The specimens were divided into eight groups (groups I-VIII) depending on the number of units, type of pontic design and area of placement of fibers. A universal testing machine was used to evaluate and compare the load-bearing capacity of the specimens. The evaluated data were statistically analyzed using one-way ANOVA and Bonferroni post hoc tests (p ≤ 0.05). RESULTS: Three-unit interim FPD and modified ridge lap pontic design showed greater load-bearing capacity after reinforcement with glass fibers than a four-unit interim FPD and hygienic pontic design, respectively. Fiber placement at the occlusal plus connector area as well as the cervical plus connector area had comparable results. CONCLUSION: Industrial glass fibers (E-glass) could be used as a cheaper alternative but clinical performance and their safety are yet to be evaluated. CLINICAL SIGNIFICANCE: Reinforcement with industrial-grade glass fibers can be a cheaper option for increasing the load-bearing capacity of interim partial dentures, but it needs to be studied in vivo through further studies.

Evaluation of Bond Strength of Cantilever Resin-retained Bridge Designs: An In Vitro Study.

AIM: The aim of the study was to compare the bond strength of three cantilever resin-bonded bridge (RBB) designs cemented with resin cements. MATERIALS AND METHODS: Twenty-four extracted human mandibular canines with eight teeth per group were used in this study to evaluate the bond strength of cantilever resin-retained bridge designs of the mesh, perforated, and combination of mesh and perforated luted to the prepared lingual surface of canine teeth using resin cement. Debonding was done using Instron universal testing machine by applying load on the mid-buccal region of the pontic and the obtained values were evaluated. The data was analyzed statistically. RESULTS: The mean shear bond strengths of mesh, perforated, and combination of mesh and perforated are 0.88 ± 0.31 MPa, 0.81 ± 0.31 MPa, and 0.93 ± 0.32 MPa. However, there is no significant differences in the statistical analysis that were performed using a one-factor analysis of variant (ANOVA) test (p = 0.744). CONCLUSION: Within the limitation of this study for cantilever resin-retained bridge designs, the combination of mesh and perforated design showed greater mean shear bond values when compared with the mesh design and perforated designs. This shows equal in vitro performance to the gold standard designs (group A is mesh design and group B is perforated design). CLINICAL SIGNIFICANCE: The new design which is the combination of mesh and perforated shows equal in vitro performance to the gold standard designs. Thus, their use in clinical situation can bring better result in concern to cantilever resin-retained prosthesis.