Influence of S-PRG-based restorative and adhesive systems on biofilm formation and enamel demineralization in a simulated oral environment.

OBJECTIVE: This study aimed to evaluate the impact of bioactive restorative materials on biofilm formation and cariogenic processes using an in vitro dynamic cariogenic biofilm model simulated by a Multifunctional Oral Cavity Simulator. The experimental design included composite resins and adhesive systems containing S-PRG particles (Beautifil and FL-Bond II – Shofu), compared against a conventional composite (Filtek Z350XT – 3 M ESPE) and a conventional adhesive system (Clearfil SE Bond – Kuraray). METHODS: Samples were exposed to a controlled cariogenic environment and analyzed for colony-forming unit (CFU) counting, scanning electron microscopy (SEM), microhardness, and chemical modifications by Fourier-transform infrared spectroscopy (FTIR). One-way ANOVA and Tukey’s post hoc test was performed (α = 0.05). RESULTS: CFU counting and SEM analysis revealed no significant differences in biofilm volume or microbial counts among groups (P > 0.05), indicating no reduction with bioactive materials. FTIR analysis showed a marked reduction in phosphate and carbonate absorption peaks compared to sound enamel, indicating a similar demineralization pattern regardless of material. Microhardness analysis revealed no significant differences among materials (P > 0.05). CONCLUSION: Our findings did not reveal superior protection of bioactive materials containing S-PRG particles against cariogenic challenges. In this context, more robust clinical evidence is still needed to confirm the effectiveness of bioactive materials in enhancing restoration longevity and caries control. CLINICAL SIGNIFICANCE: Under dynamic cariogenic conditions, S-PRG-based materials performed similarly to conventional restoratives materials. These findings indicate that the purported bioactivity may not result in measurable clinical benefits.