纳米羟基磷灰石对邻面去釉后再矿化的效果

Remineralization effect of nanohydroxyapatite on adjacent glazed surfaces

目的探讨质量分数为10%的纳米羟基磷灰石悬浮液对邻面去釉后再矿化的效果,为临床使用纳米羟基磷灰石预防邻面去釉后牙釉质脱矿提供基础参考。方法收集新鲜拔除的前磨牙40颗,邻面去釉并用砂条抛光处理后自牙冠冠状面切开,每颗牙齿制成两个标本,共80个,随机分成4组,分别为空白组、多乐氟组、护牙素组、10%纳米羟基磷灰石组。经体外pH循环30 d后,应用显微硬度仪对去釉面处理前后分别进行检测,扫描电镜观察并用X线能谱仪分析釉质表面元素。结果实验后4组邻面去釉标本显微硬度值,空白组为(128.18±6.89)kg/mm2、多乐氟组为(216.75±9.87)kg/mm2、护牙素组为(198.88±4.76)kg/mm2、10%纳米羟基磷灰石组为(218.44±7.88)kg/mm2,4组间差异有统计学意义(F=189.14,P<0.001);两两比较发现,多乐氟组和10%纳米羟基磷灰石组差异无统计学意义(P>0.05),而其余各组间差异均有统计学意义(P<0.05)。钙磷比值空白组(1.39±0.08)、多乐氟组(1.70±0.11)、护牙素组(1.54±0.12)、10%纳米羟基磷灰石组(1.71±0.14)间差异有统计学意义(F=10.539,P <0.001);两两比较发现,实验后多乐氟组与10%纳米羟基磷灰石组间差异无统计学意义(P>0.05),而其余各组间差异均有统计学意义(P<0.05)。结论多乐氟、护牙素、10%纳米羟基磷灰石对去釉后的牙釉质再矿化均有良好的促进作用,10%纳米羟基磷灰石的再矿化作用与多乐氟相当。

Objective To investigate the effect of a nanohydroxyapatite suspension with a 10%mass fraction on enamel demineralization after adjacent enamel removal and to provide a reference for the clinical use of nanohydroxyap-atite to prevent enamel demineralization after adjacent enamel removal.Methods Forty fresh extracted premolars were incised from the coronal surface of the crown after glazing and polishing with sand strips.Each tooth was made into two specimens.Eighty teeth were randomly divided into four groups:a blank group,a dolofluoride group,a dental mousse group and a 10%nanohydroxyapatite group.After 30 days of pH cycling in vitro,a microhardness tester was used to de-tect the enamel surface elements before and after deglazing treatment.Scanning electron microscopy(SEM)and X-ray energy dispersive spectrometry(EDS)were used to analyze the enamel surface elements.Results After the experi-ment,the microhardness values of the adjacent glazed specimens of the four groups were(128.18±6.89)kg/mm^2 in the blank group,(216.75±9.87)kg/mm^2 in the dolefluoride group,(198.88±4.76)kg/mm2 in the dental care group and(218.44±7.88)kg/mm2 in the 10%nanohydroxyapatite group,which were significantly different(F=189.14,P<0.001).The LSD-t test showed that there was no significant difference between the dolefluoride group and the 10%nanohydroxyapatite group(P<0.05),but the differences between the other groups were statistically significant(P>0.05).There were significant differences in the Ca/P ratio among the blank group(1.39±0.08),the dolefluoride group(1.70±0.11),the dental care group(1.54±0.12)and the 10%nanohydroxyapatite group(1.71±0.14)(F=10.539,P<0.001).There was no significant difference between the dolefluoride group and the nanohydroxyapatite group after the experi-ment(P>0.05),but there were significant differences among the other groups(P<0.05).Conclusion Dolerofluoride,dental protector and 10%nanohydroxyapatite can promote remineralization of enamel after enamel removal.The remin-eralization induced by 10%nanohydroxyapatite is similar to that induced by dolerofluoride.