Khraisat Ameen, Baqain Zaid H, Smadi Leena, Nomura Shuichi, Miyakawa Osamu, Elnasser Ziad
Department of Conservative Dentistry and Prosthodontics, Faculty of Dentistry, University of Jordan, Amman, Jordan.
Clin Implant Dent Relat Res. 2006;8(2):96-9. doi: 10.1111/j.1708-8208.2006.00006.x.
This in vitro study investigated the effect of lateral cyclic loading with different load positions and periods on abutment rotational displacement (RD) of external hexagon implant system.
Four groups of five implant assemblies each were used. Each assembly consisted of Brånemark System Mk IV implant (Nobel Biocare AB, Göteborg, Sweden), CeraOne abutment (Nobel Biocare AB), and a cement-retained casting. A cyclic load of 50 N was applied centrally and perpendicular to the long axis of the implant for groups A and B for 0.25 and 0.50 x 10(6) cycles, respectively, while for groups C and D, the same load was applied at 4-mm distance eccentrically for 0.25 and 0.50 x 10(6) cycles, respectively. The displacement was evaluated by hand drawing a longitudinal line across the implant-abutment interface. Before and after loading, the lateral distance between two reference points on the abutment and implant was measured under high resolution (x200) and the difference formed the RD value. The data were analyzed with one-way analysis of variance and compared with Tukey test (alpha=0.05).
Group D had the highest mean of RD value (55.00 +/- 1.871 microm), while group A had the lowest (2.800 +/- 0.837 microm). Groups A and B had a high statistically significant difference in RD values, as compared to groups C or D (p < .001). Moreover, group C had statistically significant difference from group D (p=.011). Conversely, no statistical significance was obtained when group A was compared with group B.
Within the limits of this in vitro study, the RD of the external hexagon joint components occurred significantly under eccentric lateral loading when compared to centric loading. The displacement increased significantly with longer period of eccentric lateral loading.
本体外研究探讨了不同加载位置和加载周期的侧向循环加载对外六角种植体系统基台旋转位移（RD）的影响。
使用四组，每组五个种植体组件。每个组件由Brånemark系统Mk IV种植体（诺贝尔生物保健公司，瑞典哥德堡）、CeraOne基台（诺贝尔生物保健公司）和一个粘结固位铸件组成。A组和B组分别在种植体长轴中心垂直施加50 N的循环载荷，循环次数分别为0.25×10⁶次和0.50×10⁶次，而C组和D组在距中心4 mm处偏心施加相同载荷，循环次数分别为0.25×10⁶次和0.50×10⁶次。通过在种植体-基台界面手绘一条纵线来评估位移。加载前后，在高分辨率（x200）下测量基台和种植体上两个参考点之间的侧向距离，差值即为RD值。数据采用单因素方差分析，并与Tukey检验进行比较（α = 0.05）。
D组的RD值均值最高（55.00±1.871μm），而A组最低（2.800±0.837μm）。与C组或D组相比，A组和B组的RD值在统计学上有高度显著差异（p <.001）。此外，C组与D组有统计学显著差异（p = 0.011）。相反，A组与B组比较时未获得统计学显著性。
在本体外研究的范围内，与中心加载相比，外六角连接部件在偏心侧向加载下显著发生RD。偏心侧向加载时间越长，位移显著增加。
