Fatigue of Dental Implants

描述（由申请人提供）：虽然牙种植体尚未成为无牙患者的标准护理，但这种治疗选择的使用正在迅速增加。从1983年到2002年，美国的种植体数量增加了十倍，2002年向北美牙医出售的种植体产品价值1.5亿美元。在没有植入物的情况下，无牙症给美国公民带来了严重的健康问题。如果没有牙齿或种植体将负荷转移到牙槽骨，患者会经历骨吸收，在一年内下颌高度平均下降4mm。有研究表明，通过适当的治疗，实现稳定的生物整合不再是限制种植体寿命的主要因素。由于机械因素导致的假体或假体支撑的疲劳断裂是更普遍的失败原因。据报道，种植体直径、假体胶结方法、种植体-基台连接设计对基台螺钉松动和骨折有显著影响。很明显，牙科种植体社区将受益于种植体设计的系统比较，但如果没有更有效的疲劳测试方法，这样的研究是不可行的。以下具体目标是围绕我们的中心目标，开发一种有效的方法来测试牙科种植体的可靠性：1)将有限元应力分析结果与物理标本上观察到的骨折起源联系起来。2)验证步进应力法估算种植体机械可靠性随时间变化的准确性。3)确定一个加速度因子，以便在不同循环频率下收集的疲劳数据之间进行转换。通俗地说，这个项目将使未来的研究人员能够用更快的方法改进牙科产品。

DESCRIPTION (provided by applicant): Although dental implants are not yet the standard of care for edentulous patients, the use of this treatment option is rapidly increasing. The number of implants placed in the US increased by a factor of ten from 1983 to 2002 with $150 million of implant products sold to North American dentists in 2002. In the absence of implant placement, edentulism poses a serious health concern for US citizens. Without a tooth or implant to transfer loading to the alveolar bone, patients experience bone resorption with an average decrease of 4 mm in mandibular height within one year. It has been suggested that with proper treatment, achieving stable biointegration is no longer the primary factor limiting the lifetimes of implants. Fatigue fracture of the implant or the prostheses supported by the implant due to mechanical factors is a more prevalent cause of failure. Implant body diameter, prosthesis cementation method, and implant-abutment connection design have all been reported to significantly affect abutment screw loosening and fracture. It is clear that the dental implant community would benefit from systemic comparisons of implant designs, but such studies are not feasible without more efficient fatigue testing methods. The following specific aims are focused around our central goal of developing an efficient method for testing reliability of dental implants: 1) Correlate the results of finite element stress analysis to the fracture origin observed on physical specimens. 2) Verify the accuracy of step-stress method for estimating the mechanical reliability of dental implants over time. 3) Determine an acceleration factor to allow conversion between fatigue data collected at different cyclic frequencies. In lay terms, this project will enable future researchers to improve dental products by faster methods.