三单位全瓷固定桥破坏机理及过程的数值模拟

Numerical simulation of failure process of three-unit all-ceramic fixed partial denture

针对全瓷桥修复体在临床易发生崩瓷、折裂破坏以及其破坏过程和机理仍不十分明确等问题,采用真实破裂过程分析RFPA2D系统,模拟了静载荷条件下三单位氧化锆全瓷桥底冠的破坏过程,分析了其破坏机理.应力指纹图和主应力分布图显示全瓷桥的破坏模式属于拉破坏且裂纹最初萌生于全瓷桥连接体下部.对比数值模拟的破坏模式和已有的试验结果,发现二者破坏模式十分吻合.RFPA2D能够全程逐步自动追踪全瓷固定桥折裂全过程,该项研究可作为试验研究、临床观察研究、全瓷固定桥抗折裂破坏能力研究的一种重要补充手段.

In order to clarify the fracture mechanisms and failure process of three-unit all-ceramic fixed partial denture（FPD） in clinic,the RFPA^2D（Realistic Failure Process Analysis） system was used to simulate the failure process of three-unit zirconia fixed partial denture framework in the static loading condition,and the corresponding failure mechanism was analyzed.The stress fringe pattern and principal stress distribution figure reveals that the failure mode of all-ceramic fixed partial denture belongs to tensile failure and the crack initiate at the bottom of the all-ceramic fixed partial denture connector.The failure mode obtained using the numerical simulation is well consistent with the previous experimental result.The RFPA^ 2D can trace the fracture process of all-ceramic fixed partial denture automatically and step-by-step.The present research can be taken as an important complement for both experimental and clinical studies of stress distribution as well as the fracture resistance study for all-ceramic fixed partial denture.