Influence of a novel pH-cycling model using dental microcosm biofilm on the remineralizing efficacy of fluoride in early carious lesions

Objectives To evaluate the remineralizing efficacy of fluoride in early carious lesions using a novel microbial pH-cycling model that combines the chemical pH-cycling model with dental microcosm biofilms. Materials and methods Artificial carious lesions were formed in 48 bovine incisors. The chemical and microbial pH-cycling models were applied to 24 specimens, respectively; the latter was applied after formation of dental microcosm biofilms for 6 days, based on the human saliva inoculation. The pH-cycling schedule was repeated for 12 days. All specimens were evaluated for fluorescence loss (Delta F) using quantitative light-induced fluorescence-digital before and after the pH-cycling. Specimen biofilms were further analyzed for red/green values (R/G ratios) and colony-forming units (CFUs). One-way analysis of variance and Tukey's post hoc analysis were used to analyze change in fluorescence loss (Delta Delta F) according to the pH-cycling model and treatment. Results When the chemical pH-cycling and microbial pH-cycling models were used, Delta Delta F was 1.36 (p = 0.008) and 1.17 (p > 0.05) times higher, respectively, in the fluoride-treated group than that in the distilled water-treated group. In the microbial pH-cycling model, R/G ratios and CFU counts of biofilms were not significantly different between treatments (p > 0.05). Conclusions No significant difference was observed in the remineralizing efficacy of fluoride according to the presence of dental biofilms covering early carious lesions.

Automated summary

The study evaluated the remineralizing efficacy of fluoride in early carious lesions using a novel microbial pH-cycling model. Results showed that fluoride treatment led to significantly higher ΔΔF values in both the chemical and microbial pH-cycling models compared to distilled water treatment, while there was no significant difference in the impact on biofilms in the microbial pH-cycling model.