牙体缺损是口腔临床上的一种常见现象 ,主要是由龋病及外伤引起。一般牙体缺损 ,可采用充填术或酸蚀 ,光敏树脂直接修复。对于牙体严重缺损的修复 ,如何增强固位力、抗力 ,人们从混凝土中的钢筋得到启发 ,于 185 5年 dwinell提出了加钉的概念 [1] ,后逐渐完善 ,特别是近三十多 Dental defects are a common clinical condition in the oral cavity, mainly caused by dental caries and trauma. General dental defects, filling or etching can be used, the direct repair of photosensitive resin. For the restoration of serious dental defects, how to enhance the retention force, resistance, people from the steel in the concrete to be inspired in 185 5 dwinell put forward the concept of nail [1], and then gradually improved, especially nearly more than 30