Enhancing Removable Partial Denture Hygiene: Investigating Mucolytic Agents and Biocides for Disrupting Biofilms and...

To evaluate the antibiofilm action of 2.5 mg/mL peracetic acid (PA), 0.5 mg/mL cetylpyridinium chloride (CPC), and 160 mg/mL N-acetylcysteine (NAC) against multispecies biofilm of Streptococcus mutans, Staphylococcus aureus, Candida albicans, and Candida glabrata developed on surfaces of heat-polymerizing acrylic resin (AR) and cobalt-chromium (Co-Cr) alloy.

A multispecies biofilm was grown on the surface of AR and Co-Cr specimens (Ø 12 × 3 mm). After biofilm maturation, the specimens were immersed in experimental solutions and evaluated through biofilm viability (CFU; n = 9), biofilm metabolic activity (XTT; n = 9), biofilm-covered areas (live/dead; n = 2), effects on the extracellular polymeric substance (EPS; n = 2), and biofilm morphology (n = 1). Data were analyzed by ANOVA and Tukey post-hoc test or Kruskal-Wallis followed by Dunn post-hoc test (α = .05).

Overall, all evaluated solutions impacted biofilm viability. PA presented wider activity by reducing CFU of all microorganisms on both surfaces, XTT (P < .001) and live/dead (P < .001). NAC had a notorious effect in reducing the viability of bacteria without affecting the yeasts. NAC reduced XTT on AR (P = .006) and Co-Cr (P = .003) but did not reduce the aggregated biofilm layer. CPC had a distinct effect, being most effective in reducing CFU on AR compared to the Co-Cr surface. However, it did not influence XTT or the amount of residual aggregated biofilm.

PA provided the greatest antibiofilm action, while CPC and NAC showed intermediate action. Nonetheless, no solution was able to completely remove the biofilm adhered to the surfaces of heat-polymerizing AR and Co-Cr alloy.