乳牙釉质混浊的偏光特点及其与龋齿易感性的研究

目的 从临床和实验研究两方面探讨乳牙釉质混浊对龋齿的易感性。方法 选择176名3-8岁的低出生体重儿和早产儿，分析乳牙釉质混浊与龋齿的相关性；将5颗自然脱落的釉质混浊乳前牙用于偏光显微镜的研究，发现其组织学特点，并探讨乳牙釉质混浊的发生机制。结果 临床研究发现乳牙釉质混浊与龋齿的发生显著相关；进一步的偏光显微镜研究的发现乳牙釉质混浊为表层下矿化缺陷，且矿化缺陷区域釉柱横纹加重。结论 乳牙釉质混浊因其表层下矿化缺陷增加了牙齿对龋的易感性，乳牙釉质混浊其发生为在牙齿矿化阶段的第三矿化期的中晚期出现全身或局紊乱所致。

A polarized light study on developmental enamel opacity of deciduous tooth and its susceptibility to dental caries

Objective From the clinical and experimental aspects, to study the susceptibility of dental enamel opacity to dental caries in the primary dentition. Methods One hundred and seventy-six children (aged 3-8) with histories of low birth weight and premature birth were studied on the relationship of dental enamel opacity to caries. Five exfoliated opacity anterior deciduous teeth were studied by the polarizing microscopy to find the histological characteristics and to probe into the pathogenesis of the enamel opacity.Results The prevalence of enamel opacity was significantly interrelated to prevalence of dental caries in those particular teeth. We also found the subsurface hypomineralized band and the obvious cross-striation of enamel rod in the enamel opacity.Conclusion The enamel opacity increases the susceptibility to caries.The enamel opacity results from local and general disorder occurred in the middle and /or advanced stage of the third enamel calcification process.