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目的：分析人造全冠牙体预备不同设计对微渗漏的影响．方法：采用三维有限元分析法，分析三单位全冠固定桥同时轴向加载１５０Ｎ，在不同锥度，不同高度，不同颈缘设计条件下，不同粘固剂所受的应力大小及其分布．共建立１４个有限元计算模型，锥度分别为０°，６°，１２°，２５°；高度分别为４，５及６ｍｍ；颈缘设计分别为９０°肩台和１３５°凹面形；粘固剂分别为磷酸锌粘固剂，玻璃离子粘固剂和复合树脂．结果：随着锥度的增大和高度的降低，粘固剂所受的平均应力值增大；不同颈缘设计对粘固剂总应力影响不大，对颈缘所受应力影响较大；在同等条件下，磷酸锌粘固剂所受应力最大，其次是复合树脂，玻璃离子粘固剂所受应力最小．结论：在牙体预备锥度较大，高度较低的情况下，不宜选择１３５°凹面设计和磷酸锌作为粘固剂．
Objective: To analyze the effect of different designs of artificial total crown on microleakage. Methods: Three-dimensional finite element analysis was used to analyze the stress distribution and the stress distribution of different cements under the condition of different taper, different height and different cervical margin design. A total of 14 finite element models were established with tapers of 0 °, 6 °, 12 ° and 25 °, respectively, with heights of 4, 5 and 6 mm respectively. The neck margin design was 90 ° shoulder and 135 ° concave, respectively Agents were zinc phosphate cement, glass ionomer cement and composite resin. Results: With the increase of taper and the decrease of height, the average stress value of cements increased; different neck design had little effect on the total stress of cement, but had a greater impact on the stress of the neck; Under the conditions of zinc phosphate cement under the maximum stress, followed by the composite resin, glass ionomer cement suffered the least stress. CONCLUSION: In the condition of larger tooth preparation and lower height, it is not appropriate to choose 135 ° concave design and zinc phosphate as the cement.