Department of Restorative Dentistry, National Dental Centre, Republic of Singapore.
Int J Oral Maxillofac Implants. 2011 Jul-Aug;26(4):797-806.
Conical implant-abutment connections for platform switching have been recently introduced in implant systems. This study investigated the load fatigue performance of three conical abutment systems and their corresponding titanium and zirconia abutments.
Regular-diameter implants of the Ankylos (AK), PrimaConnex (PC), and Straumann (ST) systems were tested with their corresponding titanium (Ti) and zirconia (Zr) abutments tightened to the recommended torque (n = 5 implant-abutment assemblies per group). A rotational load fatigue machine applied a sinusoidally varying tensile-compressive 21 N load to specimens at a 45-degree angle, producing an effective bending moment of 35 Ncm at a frequency of 10 Hz. The number of cycles to failure was recorded, with the upper limit set at 5 million cycles. Results were evaluated through analyses of variance.
Except for the ST Zr group, which showed no failures in four samples and one failure just below the screw head, and the AK Ti group, in which one sample was preserved without fracture, all groups experienced failure of at least one of the components, whether the abutment screw only, the abutment, and/or the implant neck. There were significant differences between systems. There was no difference between systems for the Ti abutments, and the ST group was significantly different from the AK and PC groups for the Zr abutments.
Ti conical abutments appear to have poorer load fatigue performance compared with earlier studies of external-hexagon connections. The load fatigue performance of Zr conical abutments varied and seemed to be highly system dependent. Many of the fractures in both the Ti and Zr abutment groups occurred within the implant, and retrieval would pose a significant clinical challenge. The clinician should weigh the mechanical, biologic, and esthetic considerations before selection of any implant system, connection type, or abutment material.
最近在种植系统中引入了用于平台转移的锥形种植体-基台连接。本研究调查了三种锥形基台系统及其相应的钛和氧化锆基台的负载疲劳性能。
Ankylos（AK）、PrimaConnex（PC）和 Straumann（ST）系统的常规直径种植体与相应的钛（Ti）和氧化锆（Zr）基台一起测试，拧紧至推荐扭矩（每组 n = 5 个种植体-基台组件）。旋转负载疲劳机以 45 度角向试件施加正弦变化的拉伸-压缩 21 N 负载，在频率为 10 Hz 时产生 35 Ncm 的有效弯曲力矩。记录失效的循环次数，上限为 500 万次。结果通过方差分析进行评估。
除 ST Zr 组的四个样本中没有失效，一个样本在螺丝头下方失效，AK Ti 组中一个样本没有断裂外，所有组的至少一个组件都失效，无论是基台螺丝、基台和/或种植体颈部。系统之间存在显著差异。Ti 基台之间没有差异，Zr 基台方面，ST 组与 AK 和 PC 组之间存在显著差异。
Ti 锥形基台的负载疲劳性能似乎不如先前对外六角连接的研究。Zr 锥形基台的负载疲劳性能存在差异，似乎高度依赖于系统。Ti 和 Zr 基台组的许多断裂都发生在种植体内部，取出会带来重大的临床挑战。在选择任何种植系统、连接类型或基台材料之前，临床医生应权衡机械、生物和美学因素。
