Flexural properties of denture base resins subjected to long-term water immersion

Abstract

Objective. The aim of this study was to investigate the flexural properties of denture base resins subjected to long-term water immersion. Materials and methods. Four denture base resins (one conventional heat-processed, one microwave energy-processed and two pour-type autopolymerizing) were selected for this study. The specimens of each denture base material tested were fabricated according to the manufacturers' instructions (n = 10). The flexural properties of the denture base resins were measured according to ISO 20795-1. The ultimate flexural strength, the flexural strength at the proportional limit and the elastic modulus of the specimens were evaluated. Results. The ultimate flexural strengths of the heat-processed resin and the two pour-type autopolymerizing resins significantly decreased after 6 months water immersion. The flexural strength at the proportional limit of the heat-processed resin significantly decreased after 6 months water immersion, but the microwave energy-processed denture base resin and two pour-type autopolymerizing resins did not change after 6 months water immersion. The elastic moduli of the heat-processed resin, the microwave energy-processed denture base resin and one pour-type autopolymerizing resin significantly increased after 6 months water immersion. Conclusion. The flexural properties of denture base resins significantly changed after long-term water immersion.