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

## TL;DR

This study found that S-PRG-based dental materials did not offer better protection against tooth decay or biofilm formation compared to traditional materials in a simulated oral environment.

## Contribution

The study provides empirical evidence that S-PRG-based materials do not significantly outperform conventional ones in cariogenic conditions.

## Key findings

- No significant differences in biofilm volume or microbial counts were observed between S-PRG and conventional materials.
- Microhardness and FTIR analysis showed similar demineralization patterns across all tested materials.
- S-PRG-based materials did not demonstrate superior protection against cariogenic challenges.

## Abstract

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).

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).

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).

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.

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.

The online version contains supplementary material available at 10.1007/s00784-025-06731-5.