乳牙牙釉质钙含量、分布与患龋状况的关系

目的 研究乳牙牙釉质中钙元素的含量及分布，探讨其与患龋状况的关系。方法 运用扫描电镜和能谱仪测定38颗正常的下颌乳中切牙横剖面不同部位、不同深度的牙釉质钙元素含量，并以标本所在个体的龋患状况分组，进行统计学分析。结果 牙釉质外层钙含量大于中层、内层有高度统计学意义。牙釉质钙含量均值在无龋组、患龋低危组、高危组间的差异无统计学意义。有龋组牙釉质的近中侧、唇侧钙含量值与dft呈低度负相关关系。正常乳牙牙釉质中钙的分布呈非均质状态，由外至内其含量呈依次降低趋势；正常下颌乳中切牙的牙釉质钙含量值不能很好地反映个体的龋患状况。结论 在宿主因素方面，牙釉质钙含量的差异可能不是龋发生的主要因素。

Correlation between the Content and Distribution of Ca in Enamel of Deciduous Teeth and Caries Status

Purpose To study the content and distribution of Ca in enamel of deciduous teeth and its correlation with caries status in children. Methods Crown s cross sections from 38 deciduous mandibular central incisors were investigated by SEM and EDX. We compared the Ca content in different caries status groups, different positions, different depths, and analyzed the correlation between the Ca content and caries status with statistics. Results The Ca content decreased from outer layer, middle layer to inner layer in enamel,and there was a significant statistical difference between the former and the later two. There was a low negative correlation between the Ca content of enamel in mesial side,labial side and dft respectively. No statistical difference was found in the Ca content of enamel among three caries status groups. The distribution of Ca in normal enamel was asymmetric. The Ca content showed a decrease tendency from the outer layer to the inner layer in enamel. The Ca content of enamel has little correlation with caries status. Conclusions Difference of Ca content of enamel may not the major factor of cariogenesis in terms of the host.