Enhancing antimicrobial properties of a resin-based material via incorporation of a powdered phytotherapeutic extract: an in vitro experimental study

Objectives: : This study aimed to evaluate the degree of conversion (DC), immediate enamel bond strength (IEBS), antimicrobial activity, and release of the active principle of a resin-based material (RBM) enriched with the powdered Schinopsis brasiliensis (Braúna) stem antibacterial extract. Methods: The RBM was enriched with 0, 1.25, 2.5, 5, 10, and 20 wt% powdered Braúna extract. The DC (n = 7) was assessed using micro-Raman spectroscopy. The IEBS (n = 7) was determined through the microshear test until failure, and failure modes were examined under a stereomicroscope. The antimicrobial activity (n = 15) was assessed by quantifying colony-forming units, and the release of the active principle was determined using ultra-high-performance liquid chromatography. One-way analysis of variance/Tukey and Kruskal-Wallis/Dunn tests were utilized to analyze the data (p < 0.05). Results: Materials with 10 wt% and 20 wt% extract showed the lowest DC statistically. However, for IEBS, there were no statistically significant differences among the different groups. All materials released the active principle, but only those with 20 wt% and 10 wt% extract could inhibit biofilm formation similarly to 0.12% chlorhexidine. Conclusions: Adding powdered Braúna extract between 10 wt% and 20 wt% is a promising alternative to provide an antimicrobial function to RBMs.