目的:观察不同类型种植体-天然牙联合可摘义齿修复Kennedy I类牙列缺损时不同部位的应力和位移.方法:建立16个种植体-天然牙联合可摘义齿修复下颌Kennedy I类牙列缺损的三维有限元模型,在垂直加载条件下比较不同类型(ITI Straumann 和NOBEL ReplaceTMTapered)种植体周围骨组织、基牙牙周膜、基托下黏膜的应力以及基托下黏膜组织的位移变化情况.结果:不论种植体类型,种植体颈部皮质骨为应力集中区域,种植体周围皮质骨内部的最大应力随着种植体长度和直径的增加而减小,基牙牙周膜及基托下黏膜组织的最大应力和位移量无明显变化.同类型种植体直径增加时周围皮质骨最大应力的减小比长度增加时显著;不同类型种植体中,相同长度(6～10 mm变化区间)的直径为4.1 mm(或3.3 mm)的ITIStraumann 种植体周围皮质骨应力低于直径为4.3 mm(或3.5 mm)的NOBEL ReplaceTM Tapered种植体.结论:种植体外形、直径和长度的变化不会影响基牙牙周膜及基托下黏膜组织的应力分布;同类型种植体中,相对于长度而言,更应重视种植体直径的选择;不同类型种植体的外形可能比直径对种植体周围皮质骨应力的影响更大.%Objective: To study the stress distribution and displacement of mandibular free-end removable partial denture with different types of implants.Methods: 16 three-dimensional finite element models of implant-tooth-supporting Kennedy Class Ⅰ removable partial denture were created.Effects of different types of implants( ITI Straumann(R) and NOBEL ReplaceTM Tapered) were evaluated under vertical loading.The variation of displacement of periodontium under saddle and the stress of the bone around implants, the periodontal membrane of abutments and the residual ridge was analysed and compared among the type of implant.Results: No matter how the parameter of implants altered, the stresses within implants concentrated at the cervical cortical bone around implants.Maximum stress within cortical bone around the implant decreased with the increasing of diameter of the same type of implant, but the maximum stress and displacement of abutments and periodontium under saddle had no significant differences among the implant types.With the same variation of length(from 6 mm to 10 mm) , maximum stresses within cortical bone around ITI Straumann(R) implants with the diameter of 4.1 mm( or 3.3 mm) were lower than NOBEL ReplaceTM Tapered implants with 4.3 mm( or 3.5 mm).Conclusion: The stress distribution of periodontal membrane of abutments and periodontinm under saddle were not affected by implant shape, length and diameter; more attention should be paid to diameter than to length for the choices among the same type of implant; shape may have more influence than diameter upon the peri-implant stress among different types of implants.
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