Fatigue of Dental Implants

描述(申请人提供)：虽然种植体还不是无牙患者的标准护理，但这种治疗方案的使用正在迅速增加。从1983年到2002年，美国的植入物数量增加了10倍，2002年向北美牙医销售了1.5亿美元的植入物产品。在没有种植体植入的情况下，无牙本质对美国公民的健康构成了严重的担忧。在没有牙齿或种植体将负荷转移到牙槽骨的情况下，患者会经历骨吸收，下颌高度在一年内平均下降4 mm。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，种植体或由种植体支撑的假体的疲劳断裂是更常见的失败原因。据报道，种植体直径、假体粘接方法和种植体-基台连接设计都对基牙螺钉松动和断裂有显著影响。很明显，种植体社区将从种植体设计的系统比较中受益，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。围绕我们开发一种测试牙种植体可靠性的有效方法的中心目标，我们集中了以下具体目标：1)将有限元应力分析的结果与在物理样品上观察到的断裂来源相关联。2)验证逐步应力法估计种植体随时间变化的机械可靠性的准确性。3)确定允许在不同循环频率下采集的疲劳数据之间进行转换的加速系数。就外行而言，该项目将使未来的研究人员能够以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.