Characterization of the mechanical properties of CAD/CAM polymers for interim fixed restorations.

This study investigated some mechanical properties of five CAD/CAM materials used for the fabrication of provisional restorations and tooth segments for digitally fabricated dentures. The CAD/CAM blocks were sectioned into bars for flexural strength and elastic modulus testing (n=80), and for surface microhardness (n=80). Half of the specimens were water-stored for 30 days while the other half was dry-stored. Additional specimens were prepared for bond strength (n=40). A 2-way analysis of variance (ANOVA) was conducted to detect the effect of material and water storage (α=0.05). Statistical software (IBM SPSS Statistics v21; IBM) was used for conducting all analyses. Material type and storage significantly affected the flexural strength, flexural modulus and microhardness (p<0.001). The type of material did not have a significant effect on bond strength (p>0.05). The tested materials showed variation in their flexural properties and surface microhardness whereas their bonding properties with resin luting cement were similar.