Oral Implantology Research Group, Sir John Walsh Research Institute, School of Dentistry, University of Otago, Dunedin, New Zealand.
Clin Oral Implants Res. 2013 May;24(5):592-7. doi: 10.1111/j.1600-0501.2011.02411.x. Epub 2012 Jan 26.
Two fractured one-piece experimental (commercially unavailable) zirconia implants were analyzed using scanning electron microscope (SEM) analysis to identify failure origins and aid in understanding the failure mechanisms. Modifications to the zirconia implant design are suggested to minimize such fracture incidences.
Two zirconia implants fractured during the final torquing in the maxillary ridge using the prescribed hand torque wrench. The implants were subsequently retrieved and prepared for optical and SEM evaluation. Critical attention was given to the fractography (crack morphology) of the fractured implants to identify the fracture origin.
Events related to initiation and propagation of the crack front could be detected from the morphology of the fractured surfaces. Unfavorable torque and bending forces applied on the implant during surgical placement and the inherent flaws in the material may have resulted in crack initiation and implant failure.
Caution must be exercised when placing zirconia implants in dense bone sites. Modification of surgical protocols for the intended implant site may be necessary. Improvement in design features specific to zirconia implants, and strict quality control during manufacture is essential to minimize the likelihood of fracture.
使用扫描电子显微镜 (SEM) 分析对两个断裂的一体式实验（市售不可用）氧化锆植入物进行分析，以确定故障原因并帮助了解故障机制。建议对氧化锆植入物设计进行修改，以最大程度地减少此类骨折的发生。
两个氧化锆植入物在使用规定的手动扭矩扳手在上颌牙槽嵴最终扭紧过程中发生断裂。随后取出植入物并准备进行光学和 SEM 评估。特别注意断裂植入物的断口形貌，以确定断裂的起源。
从断裂表面的形态可以检测到与裂纹前缘的起始和扩展相关的事件。在手术放置过程中施加到植入物上的不利扭矩和弯曲力以及材料中的固有缺陷可能导致裂纹起始和植入物失效。
在致密骨部位放置氧化锆植入物时必须小心。可能需要修改针对预期植入物部位的手术方案。改善氧化锆植入物的设计特点，并在制造过程中进行严格的质量控制，对于最大限度地减少骨折的可能性至关重要。
