Objective: to assess the remineralization ability of Nanometer Hydroxyapatite and Nanometer Calcium phosphate to human enamel caries. Methods:15 freshly-exstracted single canal teeth were splited medially into two parts buccolingually.30 specimens in all, with early artificial caries lesion ,were distributed randomly into three groups.A group : remineralization of toothpaste containing Nanometer Hydroxyapatite powder; B group: remineralization of toothpaste containing Nanometer Calcium phosphate powder; C group: toothpaste only (ten teeth in each group ). Microhardness of enamel surface of all the specimens were tested after remineralizing for 0daysA5daysA10days. Datas were statistically analyed using SPSS11.0software,The significance level was set at p<0.05. Results: Microhardness of specimens in groupAAB is significantly higher after remineralizating for 5days A10days( p<0.05).Highten of hardness in group C has no statistical difference.Change of hardness on 5days A10days:A>B>C ,( p<0.05). Conclusion:Nanometer Hydroxyapatite and Nanometer Calcium phosphate can faciliated remineralization of early artificial enamel-caries.The remineralization ability of Nanometer Hydroxyapatite is more significant than anometer Calcium phosphate in five days and in 10days.Comparingwith the chang of hardness in foregoing 5days,greater increase with toothpaste containing Nanometer Calcium phosphate powder was found in following 5days.
Key Words : Nanometer Hydroxyapatite Nanometer Calcium phosphate Remineralization Microhardness Correspondence: Niuweidong ,Dalian Medical University .(Tel:0411-84720029)