Evaluation of flexural strength of Zirconia using three different connector designs: An in vitro study

Abstract

Aim: The aim of this study is to evaluate the flexural strength of zirconia using three different connector designs under vertical and oblique loads. Setting and Design: Invitro - analytical study. Materials and Methods: For simulating zirconia fixed partial prosthesis, a specimen with three octagonal cylinders connected with each other was designed. Each face of the octagon was 3.75 mm ± 0.1 mm, and the total width was 9 mm ± 0.1 mm with a standard connector area of 10 mm 2 at cross-section. Three different connector designs, i.e., round, oval, and triangular were milled. Universal testing machine was used to test flexural strength with vertical and oblique forces. Statistical Analysis Used: Intergroup comparison of flexural strength was made using Descriptive statistics (1) one-way ANOVA, Bonferroni's post hoc test (2) Kruskal–Wallis test. The confidence interval was set at 95%, P < 0.05 was considered statistically significant for both the tests. Results: The highest flexural strength was observed in the triangle connector with vertical forces and lowest with oblique forces. Conclusions: Triangle connector design proved to be better than round and oval connectors on the application of vertical loads. Round connector design proved to be better than triangle and oval connector on application of oblique loads.

Comparative Analysis of the Structural Weights of Fixed Prostheses of Zirconium Dioxide, Metal Ceramic, PMMA and 3DPP Printing Resin—Mechanical Implications

“…Schmitter et al, in their prospective cohort study, evaluated the two-year clinical performance of extended tooth-supported zirconia, recommending 9 mm 2 as the minimum size for connectors in the cross-sections of the FDPs [61]. They also concluded that triangular connectors presented greater resistance to bending from vertical forces, while circular connectors presented better results against oblique loads [62]. Therefore, the importance of the connector design as a factor in the predictability of FDPs is clear [63].…”