Effects of hydroxyapatite-containing dentifrice on remineralization of caries-like lesions : in vitro pH cycling study using supernatant of dentifrice preparation

Objective: to compare the effects of a dentifrice containing nano-hydroxyapatite (nHA) with a fluoride dentifrice on the remineralization of artificial enamel caries-like lesions using a pH cycling model. Methods: Sound extracted third molars with artificial lesions, 100-120孠deep, were cut into sections 100-150孠thick. Each specimen was studied using polarized light microscopy and microradiography to evaluate the lesion depth (LD) and the mineral content of the lesions before and after 10 days pH cycle. Each cycle involved three hours of demineralization twice a day with two hours remineralization in between. One minute treatments with the selected products were performed thrice daily, before the first demineralization and before and after the second demineralization. Thirty-three sections were randomly divided into three groups for exposure to the different test dentifrices. Results: Different subscript letters indicate a difference among groups (p<0.001, ANOVA and SNK). Conclusion: Based on the data obtained from this pH cycling model, using supernatant preparations of dentifrices, the dentifrice that contained 10% nHA showed similar healing efficacy when compared with the dentifrice that contained 950ppm NaF. Group Dentifrice LD (孩ᓄ Before After % change ᓄ1 950ppm NaF