用扫描电镜观察了正常牙的人工劈裂面和隐裂牙的劈裂面,发现隐裂牙的中央窝沟长而深,下方的釉质有脱矿现象.窝沟底下方的牙本质有陈旧裂面,牙本质小管断裂方向不一致,也有脱矿现象。本文认为以上变化是隐裂牙的内在致病因素;在致裂因素作用下产生的,导致隐裂发生。 Scanning electron microscope was used to observe the artificial cleavage surface of normal tooth and the cleavage surface of the cracked tooth and found that the central fossa of the fissured tooth had long and deep enamel demineralization. Fracture, dentinal tubule fracture direction is inconsistent, but also demineralization. This paper considers that the above changes are the intrinsic risk factors of the cracked tooth, which are produced under the action of the fissile factor, resulting in the occurrence of the fissure.