Evaluation of the effectiveness of acid resistance using hydroxyapatite granules

Abstract

The purpose of this study was to evaluate acid resistance using HA granules. HA granule samples were divided into the following four groups: (1) HA granules reacted with APF. (2) HA granules irradiated with Nd:YAG laser. (3) HA granules reacted APF and irradiated with Nd:YAG laser. (4) Control: HA granules reacted with saline. Reacted specimens were immersed in acetic acid–sodium acetate buffer solution. Each aliquot was centrifuged. The calcium content of the supernatant was then measured using the ortho-cresolphthalein complexion method. The fluoride content was measured using an ion meter. The calcium flow rates of groups (1) and (3) were both significantly lower than groups (2) and (4). The calcium flow rates of the APF group and the APF and laser irradiation group were both significantly lower than those of the laser irradiation group and control group (ANOVA, p<0.01). The fluoride flow rate of the APF and laser irradiation group was significantly lower than the APF-only treatment group (Mann–Whitney U-test, p<0.05). APF treatment and the combined use of APF and laser irradiation treatment appeared to be effective for acid resistance. This study model appears to be useful for the evaluation of acid resistance treatments.