【作者】 彭建辉；

【导师】 王玉果； 宋晓菲；

【作者基本信息】 天津大学 ， 机械工程， 2012， 硕士

【摘要】 牙科切割器械高速调磨陶瓷修复体过程中产生的热量不仅会对陶瓷修复体造成热损伤,使之不能达到预期寿命的标准,还会对患者造成痛苦。本文在国家自然科学基金的资助下,研究了高速电动牙科手机和金刚石车针磨削牙科陶瓷进程中的磨削力学性能、温度场等问题,主要工作和结果如下:(1)利用高速电动手机替代传统的空气涡轮手机,结合动态的牙科磨削实验,测量了不同磨削参数下电动手机磨削牙科陶瓷磨削力信号,观测了表面质量,揭示了磨削参数对于电动手机性能参数的影响及其变化规律。(2)搭建了测量磨削温度的实验平台,使用红外热像仪对电动手机高速磨削过程中的磨削表面温度进行测量,揭示了磨削过程中磨削参数对磨削温度的影响。研究结果表明,去除深度对电动手机调磨过程中表面磨削温度的影响最大,并且随着去除深度的增加,磨削温度随之增加。(3)借助有限元方法,构造适当的磨削热模型,建立了电动牙科手机高速调磨牙科陶瓷时的温度场的数值仿真模型。利用该模型,研究了去除深度与进给速度对牙科调磨过程中的表面温度、形变及应力的分布。研究结果表明,在磨削区内的温度和应力最大,最大变形出现在磨削区的边缘处。最后,通过与实验数据的对比,验证了数值仿真模型的合理性与有效性。上述结果不仅为电动手机口腔调磨过程中产生的热现象提供了理论和实验依据,而且为临床上牙科医生合理地进行牙科调磨手术提供了积极的指导作用。更多还原

【Abstract】 In dental grinding of bioceramic restorations using dental high-speed handpiece, the machining-induced thermal problems could not be ignored, because that the high temperature in dental grinding of ceramics would not only bring pains to patients, but also cause damage in ceramic restorations resulting in a reduction in strength and lifetime of the restiorations. In this dissertation, the important process parameters related with force and temperature during the in vitro dental grinding of bioceramics using a high-speed electric handpiece and diamond burs were investigated with the help of the National Natural Science Foundation of China. The following work and the results are drawn:(1) First author used high-speed electric handpiece to replace the traditional air-turbine handpiece, and then measured and analyzed the grinding force signal in the progress of grinding dental ceramics using an electric handpiece and diamond burs. Surface roughness and morphology were observed by a stylus profilometer and scanning electron microscope. At last, author investigated grinding forces and surface quality under different grinding parameters, and assessed the grinding performance of the electric handpiece.(2) Grinding forces and grinding temperature when using an electric handpiece to grind dental ceramics were measured by a piezoelectric force dynamometer and a thermal infrared imager. Then analyzed the grinding temperature under the different grinding parameters with single factor analysis method, the result would provide the dentists with positive suggestions to reduce the pain and heat damage.(3) The temperature field in grinding dental ceramics was numerical analyzed using finite element analysis methd, and important influential factors were analyzed.The experimental temperature and simulated temperature were compared and the result were consistent. It indicates that the heat source simulation was correct. The above results provide theoretical and experimental basis to proper intraoral dental grinding of ceramic restorations.更多还原