The enamel layer of a tooth is made up of hydroxyapatite crystals, which form microscopic "rods". 牙齿最外层的牙釉质是由我们肉眼看不到的显微小管所组成的。
"enamel" glass, in bars, rods and tubes, unworked No sooner were the pieces of charcoal rubbed against the glass rod than electricity appeared on the rod. 搪瓷玻璃,呈棒状、条状和管状,未加工木炭块同玻璃一摩擦,棒上就带电。
In group ③, enamel rods were regularly arranged and highly mineralized and dentin had scattered foci of decalcification. 组釉柱排列整齐无脱矿,牙本质内有局灶性钙化减低区。
Cylindrical enamel blocks were drilled from fresh bovine incisors and imbedded in one end of plastic rods. 从新鲜的牛切牙上钻取圆柱形牙釉质块制作试样棒。