The Biaxial Flexural Strength and Weibull Analysis of Polished and Glazed CAD/CAM Polymethylmethacrylate Provisional Material..

Abstract

Aim: To assess the influence of polishing and glazing treatments on the flexural strength of Polymethylmethacrylate (PMMA) provisional material.Methods: Twenty-four PMMA discs (10 mm diameter x 2 mm thickness) were sliced from Yamahachi blank (Aichi, Japan). Then discs were divided according to the surface finish treatment into (n=8 in each); Group A: As milled with no surface finish, Group P: Polished, and Group G: Glazed. Polishing and glazing were performed following the manufacturer’s instructions. All discs experienced 5000 cycles of thermocycling between 5 ± 2°C and 55 ± 2°C. Biaxial flexural strength test was carried out using a universal testing machine and the mode of failure was recorded by the same observer. Data was analyzed using one-way ANOVA followed by Tukey’s post hoc test. Weibull distribution parameters were estimated using the maximum likelihood method.Results: Flexure strength results showed that there was no significant difference between different groups. The highest strength value was found in Group A (139.89±33.07) (MPa) and the lowest value was found in Group G (115.24±21.39) (MPa). Group G had the highest Weibull modulus. Conclusions: Neither polishing nor glazing had an influence on the flexural strength of CAD/CAM milled PMMA provisional material.