Smooth surface caries 光镜下分四层: 透明层 釉质 translucent zone 透明层 暗层 层 dark zone 病损体部 病损体部 牙本 body of the lesion 层 表层 surface zone Department of Oral Pathology, Shandong University 8 http://1.51.214.13Department of Oral Pathology, Shandong University 8 http://1.51.214.13 光镜下分四层: 透明层 translucent zone 暗 层 dark zone 病损体部 body of the lesion 表 层 surface zone