不同形态面固位螺钉对种植牙牙冠稳定性影响的有限元分析  

Three-dimentional finite element analysis of the effect of different shape of occlusal screws on stability of implant-supported crowns

作　　者：罗晨晨[1] 张振庭[2] 蒋向华[3] 

机构地区：[1]首都医科大学口腔医学院种植中心,北京100050 [2]首都医科大学口腔医学院特诊特需科,北京100050 [3]北京航空航天大学

出　　处：《北京口腔医学》2013年第2期95-98,共4页Beijing Journal of Stomatology

摘　　要：目的探讨2种不同形态的固位螺钉对修复体稳定性的影响。方法采用三维有限元分析法,对锥形螺钉与平头直角螺钉分别进行实验,计算在相同扭力(200Nmm)下所获得的预负荷值(即夹紧力)及其分布,以及拧紧力矩、防松力矩;在上述扭力下,分别给修复体施加150N和300N垂直向力,比较其预负荷值、拧紧力矩、防松力矩的分布与变化。结果在给予同样扭力(200Nmm)时平头直角螺钉能够获得更大的预负荷;拧紧力矩和防松力矩在螺纹处分布较多,而在螺钉头处分布较少;而锥形螺钉分布相反,力矩主要分布在螺钉头处。在受到150N垂直载荷时,预负荷均下降,其中平头直角螺钉保留的预负荷明显高于锥形螺钉。当受到300N的载荷时,2种螺钉损失的预负荷及力矩值都很大,平头直角螺钉剩余力矩仍然大于锥形螺钉。结论平头直角型面固位螺钉的稳定性优于锥形螺钉。较大载荷会降低修复体的稳定性。Objective To investigate the effect of different shape of occlusal screws on stability of implant- supported crowns. Methods Two forms of prosthetic retaining screws （ 7-degree conical head, flat head） were simulated by the 3-dimentional finite element analysis method. The preload （ F1 ） and torques （ Ta, Th） were caculated under the manufacturers＇ recommended torques （200Nmm）. After a vertical static occlusal load of 150N and 300N was given respectively, the preload （F1） and torques （Ta, Tb） were compared. Results Under the same torque （200Nmm） the flat head screw had a higher preload, and the torque distributed more to the screw thread. After a 150N vertical static load, the flat head screw still had the higher preload and torque. When the vertical load of 300N was exerted, both screws＇ preloads were decreased, and the flat head screw decreased less than the conical head. Conclusion The stability of fiat head screws was better than that of conical head screws.

关 键 词：牙种植 螺钉 松动 预负荷 三维有限元 

分 类 号：R783.6[医药卫生—口腔医学]