根管治疗后邻(牙合)面缺损前磨牙修复方式的生物力学研究

目的 从生物力学角度比较不同方法修复根管治疗后邻面缺损前磨牙的效果，并探讨最佳的修复方案。方法 收集完整离体前磨牙10对，每对牙分别接受不同的处理，试验组制备根管治疗及邻面缺损洞型模型，对照组为同名完整离体牙。研究金属烤瓷全冠修复和桩冠修复后的力学问题。采用横梁加载速度1.00 mm/min缓慢匀速加载于与牙体长轴成45 °颊尖舌斜面中点，测试破坏载荷，用SPSS10.0软件包进行配对分析。结果 金属烤瓷全冠修复时，患牙的抗折能力不能达到完整离体牙水平；桩冠修复后，患牙的抗折能力高于完整离体牙水平。结论 从生物力学角度而言，根管治疗后邻面缺损前磨牙的最佳修复方法是桩冠修复。

Biomechanical Study of Restorations of Medial-occlusal Cavities of Endodontically Treated Premolars

Objective To compare the different restorations of endodontically treated premolars, and to choose the best method. Methods 10 pairs of symmetry maxillary first premolars were collected from 10 patients, and randomly divided into 2 groups. Every pair received different treatment accordingly. The test group was set up the medial-occlusal cavities model under the same standard. The 10 pairs teeth were test by instron 4302 universal test machine in speed of 1.00 mm/min until broken up and the top load was recorded. The load angle was 45 degree to the long axis of the teeth, as the load was pointed to the middle of the lingual surface on the buccal cusp. The records were analyzed by paired samples t test. Results Based on the medial-occlusal cavities, the fracture strength of the full crowned teeth was lower than the full natural teeth, and the fracture strength of the post-crowned teeth was higher than the full natural teeth. Conclusion From the point of biomechanics, the different trauma of the endodontically treated teeth fits to different restorations. The medial-occlusion cavities fit the post-crown restoration mostly.