上切牙区双端悬臂梁种植固定桥的应力分析

目的：通过分析双端悬臂梁种植义齿修复上颌切牙区牙列缺损的种植体在不同加载条件下的周围骨应力分布及位移量,进而探讨临床修复的可行性。方法：应用CT断层扫描技术对上颌骨及上颌牙列的大致轮廓进行三维重建,后于上中切牙区植入种植体,完成牙冠修复并建立模型。通过三维有限元技术模拟载荷,比较不同加载条件下种植体的周围骨组织应力分布及位移量。结果：经统计学分析,种植体-骨界面的皮质骨唇侧、舌侧、近中、远中、根尖部五个部位应力值的差异有统计学意义（P〈0.001）,五个部位的位移量的差异也有统计学意义（P〈0.001）。模型在各种加载条件下的应力分布及位移量的特征大致相同,且变化趋势相似,种植体颈部及周围骨皮质为应力集中区。在各种不同的加载条件中,30°加载角度时种植体周围骨应力分布更为科学。结论：在适当的负重条件下,双端悬臂梁种植义齿是临床修复切牙区缺失可供选择的一种设计方案。

Stress analysis of partial implant-supported fixed dental prosthesis with cantilevers in maxillary incisor area

Objective： To investigate the stress distribution and displacement of the surrounding alveolar bones of the dental implants for the implant-supported fixed dental prostheses restoring missing maxillary incisors under different loading conditions. Methods： Three-dimensional structures of maxilla and maxillary dentition were reconstructed by using CT Scanning technology, and a finite element model was established after implants were placed and crown restorations were completed in the maxillary incisor area. The stress distributions and displacements of the surrounding alveolar bones of the implants under different loading conditions were compared and evaluated by using the established model to simulate occlusal force. Results： There was significant differences in stress distribution and displacement found under different loading force conditions. The alveolar bones surrounding the implant neck and cervical area were found to be the stress concentration zones, and 30 degree loading angle may allow an optimal stress distribution of the alveolar bones. Conclusion： Bilateral cantilever for implant-supported fixed prosthesis restoring missing maxillary incisors could be an advisable pattern under a certain appropriate loading.