下颌桩核基牙式全口覆盖义齿基托及支持组织的应力分析

目的　分析下颌桩核基牙式全口覆盖义齿基托及其支持组织的应力分布状况 ,为临床工作提供实验依据和指导。方法　应用三维有限元法研究下颌桩核基牙式全口覆盖义齿基托及支持组织的应力分布特点 ,计算基托、黏膜、皮质骨的应力值并与自然基牙作对比分析。结果　基托在基牙周围有明显应力集中 ;双侧磨牙区牙槽嵴顶处的黏膜应力值相对较大 ;皮质骨主要承受压应力 ,在基牙周围有明显应力集中。结论　基托在基牙处易折裂 ;基牙周围皮质骨受力较大 ,易发生骨吸收 ;桩核对义齿基托及黏膜的应力分布无明显影响 ,对皮质骨的应力分布有一定影响

Stress analysis of the base of mandibular complete overdenture based on post-core abutment and its supporting tissues

Objective To study the stress distribution on the base of mandibular complete overdenture based on post-core abutment and its su pporting tissues, and to offer experimental foundation and guidance for clinic. Methods 3-D FEM was used to study the stress distribution on the base of mandibular complete overdenture based on post-core abutment and its supporting tissues, calculate the stress values of denture base, mucosality and cortex of bone, then we compared these values with those of natural abutment . Results Base plate of mandibular complete overdenture had stress concentration phenomenon at abutment zone. The stress value of mucosa on bilateral molar teeth alveolar ridge crest was relatively larger. Cortex of bon e mainly bore compressive stress; cortex of bone around the abutment had obvious stress concentration. Conclusion Denture base may fracture at abutment zone; cort ex of bone around abutment relatively bears more stress, so bone absorption may easily arise. Post-core has little influence on stress distribution of denture base and of mucosa ,while it does have some influence on that of cortex of bone.