摘要
目的研究自然牙根支持和种植基牙支持覆盖义齿在咀嚼过程中其周围骨皮质应力的差异，为改善种植覆盖义齿的修复效果提供依据。方法借助于ＣＴ扫描与计算机辅助设计手段，用三维有限元方法比较自然牙根支持式与种植牙支持式覆盖义齿在采用不同固位装置，不同咬合力状态下，支持组织应力分布的差异。结果①无论自然牙根支持式还是种植牙支持式覆盖义齿，在采用杆卡或按扣式附着体时，骨组织应力分布虽有不同，但这种不同与咬合力方向作用的结果相比是小的。在相同载荷下，２０°斜向加载时基牙周围骨皮质层最大应力值是垂直加载的２２～３倍。②种植基牙支持式覆盖义齿在两种不同上部结构设计，４种不同载荷条件下，基牙颈部周围骨质皮层最大应力值是自然牙支持式覆盖义齿的２５倍～４倍。结论为减少种植基牙周围骨皮质应力峰值，预防压力性骨吸收的产生，种植覆盖义齿设计时，应避免产生过大的侧方咬合力。同时。
Objective To investigate the stress distribution around the bone tissue of overdenture supported by teeth roots or implants in the process of mastication which may assist to improve the design of the dentures.Methods By means of CT scan, CAD and a three distribution finite element methods to study the stress distribution of the supporting tissue of overdenture supported by roots or implants when various attachment retentive apparatus and various bite forces were applied.Results No matter overdenture supported by roots or implants the stress distribution on bone tissue are difference between the bar and stud attachments, However these difference were minor compared with the difference caused by the direction of force. The stress value of cortical bone around the roots or implants with twenty degree oblique force is 2.2～3 times higher than that with vertical force. Overdenture supported by implants produced 2.5～4 times higher stress in the cortical bone around than that of overdenture supported by roots when various superstructures or various loads were applied.Conclusion It must consider to reduce the stress peaks and provent bone resorption by increasing the number of implants and using the force breaking design of implant super strcture when the overdenture were supported with implants only.
出处
《中华口腔医学杂志》
CAS
CSCD
北大核心
1998年第5期303-305,共3页
Chinese Journal of Stomatology
基金
军队青年科研基金
