Effect of mouthrinse with low pH on the surface microhardness of artificial carious enamel / 대한구강보건학회지

ABSTRACT

OBJECTIVES: The aim of the present study was to evaluate the effect of fluoride mouthrinse with low pH on the surface microhardness of artificial incipient carious enamel. METHODS: Firstly, the concentration of sodium fluoride and pH values were measured in commercially available mouthrinse. Secondly, DOCTOR Clean & Fresh(R) (Jang In Pharm, co., LTD. KOREA) with 0.02% sodium fluoride and pH value below pH 4.0 was selected as the experimental group, 0.02% sodium as the positive control group and distilled water as the negative control group. Enamel samples of n vine teeth (n=36) were divided into the three groups respectively and treated with the mouthrinse solutions for 3 and 20 minutes. The surface microhardness (Vickers hardness number, VHN) was measured with microhardness tester before and after the treatments. RESULTS: The average pH of DOCTOR Clean & Fresh(R) was 3.45+/-0.00, and it was acidic enough to cause tooth erosion. The difference of surface microhardness (DeltaVHN) before and after the 20 minute treatment was statistically significant among the groups: DOCTOR Clean & Fresh(R) (12.77+/-2.25 DeltaVHN), distilled water (0.24+/-0.75 DeltaVHN), 0.02% sodium fluoride solution (-0.62+/-1.62 DeltaVHN) (P<0.05). The DOCTOR Clean & Fresh(R) group with low pH showed greater changes on the surface microhardness of the carious enamel than those of other groups (P<0.05). CONCLUSIONS: It is suggested that the mouthrinse with low pH can reduce the surface microhardness of incipient carious enamel.