Comparison of Flexural Strength of Different CAD/CAM PMMA‐Based Polymers

Abstract Purpose To compare the flexural strength of different computer‐aided design/computer‐aided manufacturing (CAD/CAM) poly(methyl methacrylate)‐based (PMMA) polymers and conventional interim resin materials after thermocycling. Materials and Methods Rectangular‐shaped specimens (n = 15, for each material) (25 × 2 × 2 mm 3 ) were fabricated from 3 CAD/CAM PMMA‐based polymers (Telio CAD [T]; M‐PM‐Disc [M]; Polident–PMMA [P]), 1 bis‐acrylate composite resin (Protemp 4 [PT]), and 1 conventional PMMA (ArtConcept Artegral Dentine [C]) according to ISO 10477:2004 Standards (Dentistry‐Polymer‐Based Crown and Bridge Materials). The specimens were subjected to 10,000 thermocycles (5 to 55°C). Three‐point flexural strength of the specimens was tested in a universal testing machine at a 1.0 mm/min crosshead speed, and the flexural strength data (σ) were calculated (MPa). The flexural strength values were statistically analyzed using 1‐way ANOVA, and Tukey HSD post‐hoc test for multiple comparisons (α = 0.05). Results Flexural strength values ranged between 66.1 ± 13.1 and 131.9 ± 19.8 MPa. There were significant differences among the flexural strengths of tested materials, except for between T and P CAD/CAM PMMA‐based polymers ( p > 0.05). CAD/CAM PMMA‐based polymer M had the highest flexural strength and conventional PMMA had the lowest ( p < 0.05). CAD/CAM PMMA‐based T and P polymers had significantly higher flexural strength than the bis‐acrylate composite resin ( p < 0.05), and conventional PMMA ( p < 0.0001), and significantly lower flexural strength compared to CAD/CAM PMMA‐based M ( p < 0.05). Conclusions The flexural strength of CAD/CAM PMMA‐based polymers was greater than the flexural strength of bis‐acrylate composite resin, which had a greater flexural strength compared to conventional PMMA resin.