Effect of a cannabidiol-based mouthwash on dental enamel properties and biofilm control: an In situ study

Objectives This study evaluated the antibiofilm activity of experimental mouthwash containing different concentrations of cannabidiol (CBD) and the in situ effects on the physical and mechanical properties of dental enamel. Methods Bovine enamel fragments (6 × 6 × 2 mm) were mounted in intraoral appliances worn by 14 participants in a crossover design. Mouthwash containing CBD (0%, 0.01%, 0.05%, and 0.1%) and 0.12% chlorhexidine (CHX) were tested. Each experimental phase lasted 7 days, separated by washout periods. One side of the appliance was exposed to a cariogenic challenge (20% sucrose) prior to treatment. Surface roughness (Ra), microhardness (%KHN), and color change (ΔE00) were measured before and after treatments. Biofilm and yeast counts (log10 CFU) were quantified, and enamel surfaces were analyzed by scanning electron microscopy. Data were analyzed using two-way ANOVA with Bonferroni post hoc tests and Kruskal–Wallis with Dunn’s test ( P < 0.05). Results Sucrose did not significantly affect Ra ( P > 0.05), although CBD 0.1% showed higher roughness than CHX under sucrose exposure ( P < 0.05). No significant differences in %KHN were observed among treatments; however, sucrose reduced microhardness in the placebo and CBD 0.01% groups ( P < 0.05). CHX exhibited the highest ΔE00 values ( P < 0.05). Biofilm formation was similar among CHX, CBD 0.05%, and CBD 0.1% ( P > 0.05), while CHX showed lower yeast counts than CBD 0.01% and CBD 0.1% ( P < 0.05). Conclusion CBD 0.05% demonstrated potential for biofilm control without adversely affecting enamel properties. Clinical relevance This study provides evidence supporting a natural compound–based mouthwash as a clinically viable alternative to chlorhexidine, showing similar efficacy and no associated adverse effects under the conditions tested.