Effect of Streptococcus mutans on the flexural strength of resin-based restorative materials

Abstract

Background: There are a limited number of studies about the effects of microbial aging on the mechanical properties of restorative materials. Therefore, this study aimed to evaluate the effect of simulated aging with Streptococcus mutans on the flexural strength of different resin-based materials.Materials and Methods: This experimental study was performed on the blocks of different types of restorative materials including composite resin, giomer, and a resin-modified glass ionomer (RMGI). Moreover, three types of aging, such as 30-day storage in distilled water, S. mutans, and germ-free culture medium, were used in this study. The three-point bending flexural strength of the specimens before and after aging was measured according to the International Organization for Standardization-4049 standard. Data were analyzed by two-way ANOVA and post hoc Tukey's tests. A P 0.05). Furthermore, no significant difference was observed between S. mutans-based aging and distilled water aging regarding RMGI (P = 0.75).Conclusion: It can be concluded that aging by S. mutans reduced the flexural strength in all three restorative materials.

Keywords

• aging
• flexural strength
• streptococcus mutans