【摘要】 目的：为了修复固位力差的冠斜折，重建■关系，增强修复体抵御■力的固位力。方法：采用自攻自断螺纹钉固位，光敏复合树脂充填，并对其固位力做模拟实验，分别制备３种不同的离体牙试件。用万能测试机测试不同受力时的剪切力大小，并结合物理和数学原理进行力学分析。结果：测试结果表明，固位钉角度不同、数量不同，其固位力也不同。固位钉平行牙体长轴打入与垂直断面打入两者固位力差异有高度显著性（Ｐ＜０．０１），单枚固位钉与三枚固位钉的固位力差异有高度显著性（Ｐ＜０．０１）。结论：固位钉的方向与牙体长轴一致时，剪切力较大，旋转力矩最小有利固位。三枚固位钉可提高修复体的稳定性。更多还原

【Abstract】 Objective: TO restore oblique fractured crowns that have bad retention forces, to establish occlusion relationship, to increase the force to resist the mastication. Methods: Done a simulated test for the retention force that retention with screw pins, restored with light curing resin. The tested aboral teeth were prepared for three different types. Test the shearing force of different moments with machine, and take a dynamics analysis with physics and maths principles. Results: The results proved that the retention forces are different with different angles and different numbers of retention pins. There is a highly significant difference between the pins insert into the teeth paralled to the teeth axis and pins insert into the teeth in a perpendicular angle(p<0.01 ). There is a highly signficant difference between a single and three retention pins(p<0.01 ). Conclusions: If the direction of the retention pin is paralled to the teeth axis, the stronger the shearing force, the less the moment of a rotation force. It was good for retention. Three retention pins could increase the retention force.更多还原