临床上对牙冠严重缺损,缺乏力学固位型的牙,进行充填治疗后,往往需做全冠修复,否则充填体易脱落,现对这类患牙根据牙体情况及缺损的大小,攻入1～4枚自攻自断螺纹固位钉(以下简称固位钉),以增强充填体的固位力,保存了一些残冠,免除了充填后的全冠修复。1　临床资料共收集我科199 Clinically on the serious dental crown defects, the lack of mechanical retention of teeth, filling treatment, often need to do full crown repair, or the filling body is easy to fall off, now the teeth of these teeth according to the size and size of the defect, attack Into 1 to 4 self-tapping self-retaining thread retention pin (hereinafter referred to as retention pin) to enhance the retention of the filling body, save some residual crown, eliminating the crown after filling repair. A total of clinical data collected in our department 199