Development of an Experimental Dentifrice with Hydroxyapatite Nanoparticles and High Fluoride Concentration to Manage Root Dentin Demineralization.

Abstract

BackgroundHigh-fluoride dentifrice is used to manage root caries, but there is no evidence whether its association with nanohydroxyapatite could provide an additional protection for root caries. Therefore, this study aimed to develop and evaluate the effect of an experimental dentifrice with high fluoride (F−) concentration and nanohydroxyapatite (nano-HA) on root dentin demineralization.Materials and MethodsAfter formulation of dentifrices, root dentin specimens were randomly assigned to six groups (n = 10) using different dentifrice treatments: placebo; nano-HA without F−; 1,100 µg F−/g; 1,100 µg F−/g + nano-HA; 5,000 µg F−/g; and 5,000 µg F−/g + nano-HA. A pH cycling model was performed for 10 days, in which treatments were performed twice a day. After that period, the longitudinal hardness was evaluated and the area of demineralization (ΔS) was calculated. The formulated dentifrices were evaluated for primary stability, cytotoxicity, and other technical parameters. Two-way ANOVA and Tukey’s test with p set at 5% were used for data analysis.ResultsThe experimental dentifrices were stable and had no cytotoxicity. Regarding dentin demineralization, the placebo group significantly increased ΔS compared to all other treatment groups (p<0.001). The dentifrices containing 5,000 µg F−/g, regardless of the presence of nano-HA, led to a smaller lesion area in relation to the other treatments (p<0.001).ConclusionThe findings of this study suggest that nano-HA reduced dentin demineralization, and dentifrice with 5,000 µg F−/g dentifrices, regardless of the presence of nano-HA, showed a greater reduction in root dentin demineralization.