"O"型圈附着体义齿与套筒冠义齿对基牙牙根应力分布的研究

目的　分析比较“O”型圈附着体覆盖义齿与套筒冠覆盖义齿的基牙牙根应力分布特点。方法　应用三维有限元应力分析方法研究了“O”型圈附着体覆盖义齿与套筒冠覆盖义齿的基牙牙根应力分布特点。结果　垂直载荷下 ,桩核型“O”型圈覆盖义齿基牙牙根内综合应力峰值较套筒冠覆盖义齿牙根内应力峰值下降了 6 6 .7% ,应力分布更均匀 ,斜向载荷下 ,两种覆盖义齿的基牙牙根内应力峰值均较垂直载荷时高 ,但应力分布规律与垂直载荷类似。结论　“O”型圈覆盖义齿可以缓冲传递到基牙及粘骨膜的牙合力并使应力峰值降低 ,有利于口腔软硬组织的健康。尤其适用于需要利用残根作为基牙及基牙牙周健康欠佳的患者。

A comparative study of stress distribution between O-ring coping attachment overdenture and telescopic overdenture in a mandible with 3-D finite element method

Objective To evaluate and compare str es s distribution in a mandible between O-ring coping attachmets overdenture and te lescopic overdenture.Methods Three dimensional finite element method was appli ed and the models were loaded vertically and obliquely.Results The tooth root stress peak of O-ring coping attac hmets overdenture was decreased 66.7% compared to telescopic overdenture and the root stress distrbution in O-ring coping attachmets overdenture was more unifor m under vertical loads.The tooth root stress peaks of two kinds of dentures unde r oblique loads were both higher than those under vertical loads.Conclusion O-ring coping attachmets overdenture could buf fer bite forces transferred to tooth root and alleviate stress peaks.It is more beneficial to abutment than telescopic overdenture under the same conditions and especially applicable for patients who have to make stump as abutment.