The dead pulp released some substances into dentine to stain it greyish black 坏死的牙髓释放物质渗入象牙质，牙齿渐变成灰黑色。
2.
Instead of a whiny turbine drill , he uses a flash of laser light to blast away dentin and enamel 他用的是一道激光而不是烦人的涡轮钻来清除象牙质和牙齿的珐琅质。
3.
Dissections of the canine and molar teeth demonstrate the structure of the enamel , dental pulp cavity . it is intended for middle schools 其中尖齿和磨齿作解剖，显示釉质、象牙质和牙髓腔内的神经、血管等的构造。
4.
Thirty weeks later two - millimeter - wide molar crowns emerged , complete with pulp chambers , root tips and bonelike layers of dentin and , in a first , enamel 30周后，冒出了两公厘宽的臼齿牙冠，具有牙髓腔、牙根的根尖、一层如骨骼般的象牙质，以及最基本的珐琅质。
5.
The permanent teeth may appear darker in colour when compared with the primary teeth because the enamel of the permanent teeth is more highly mineralized and more translucent than that of the primary teeth , allowing the underlying yellow - coloured dentine to show through 由于恒齿的珐琅质钙化得比较好，透光度也比较高，光线可以把珐琅质下层黄色的象牙质呈现出来，恒齿看起来也就比乳齿黄。不过，在某一些情况下，牙齿是会变色的。
