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

Abstract

Objective This study evaluated the flexural strengths of reinforced denture base resins subjected to long-term water immersion.

Materials and methods Acrylic denture base resin reinforced with metal wire or glass fiber-reinforced composite (FRC), and without reinforcement were tested. Bar-shaped specimens were fabricated. Half of the specimens were stored in 37 °C distilled water for 50 hours (h), the other half were stored in 37 °C distilled water for 180 days (d) before testing. Ten specimens were fabricated per group for each reinforcement/water immersion period combination. The ultimate flexural strength and flexural strength at the proportional limit of reinforced denture base resin were tested.

Results The 180 d bulk specimen possessed significantly lower ultimate flexural strength compared with the 50 h bulk specimen (p < 0.05). The ultimate flexural strength of the 50 h metal, 50 h FRC, 180 d metal and the 180 d FRC reinforcement specimens were not significantly different from each other (p > 0.05). The 180 d bulk specimen had a significantly lower flexural strength at the proportional limit compared to the 50 h bulk specimen. The 180 d reinforced specimens of metal and FRC were not significantly different from each of the 50 h specimens.

Conclusion The flexural strengths of a reinforced denture base resin did not change after long-term water immersion.

Keywords:

• Flexural strength at the proportional limit
• glass fiber-reinforced composite
• metal wire
• ultimate flexural strength

Acknowledgements

The authors would like to thank the GC Corporation for supplying some of the materials used in this project.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.