The effect of nano-sized carbonate apatite on remineralization of artificial caries-Like Lesions

Objectives: The purpose of this study was to evaluate the remineralization effects of nano-sized carbonate apatite (n-CAP) paste and to compare it with casein phosphopeptide amorphous-calcium phosphate (CPP-ACP) paste. Methods: The bovine enamel specimens formed artificial caries were randomly divided into 4 groups: (1) 0% n-CAP (negative control group), (2) 5% n-CAP (first experimental group), (3) 10% n-CAP (second experimental group), (4) Tooth MousseTM (TM, positive control group) containing 10% CPP-ACP. We compared the remineralization effects of n-CAP and CPP-ACP on early caries lesions using the pH-cycling model for 14 days. All specimens were evaluated surface hardness by Vickers Hardness Number (VHN) at before and after pH-cycling. The degree of mineral loss (volume% mineral) was measured as ΔZ (total mineral loss) using the Knoop Hardness Number (KHN) to determine the remineralization effect by lesion depth. Scanning Electron Microscope (SEM) to examine the features of remineralization on the specimen surface. The results were analyzed with one-way ANOVA using SPSS 12.0 statistical package program (SPSS Inc, USA). Results: On observing changes in the surface microhardness, 5% n-CAP group had much higher ΔVHN (23.16±9.99) than did the other groups. On measuring the mineral loss by depth of enamel lesions, TM groups exhibited lower ΔZ, total mineral loss (1014.9±342.8) from KHN than the other groups. The features of the enamel surfaces were observed using SEM. The surface of 10% n-CAP group was not only covered with nano-sized particles but also regular and flat. On the other hand, the surface of TM group was irregular. Conclusion: 5% n-CAP had the effect of remineralization on the enamel surface layer, so it is possible to use n-CAP for remineralization of dental erosion.ope