Song Xiao-Fei, Yin Ling, Han Yi-Gang
School of Mechanical Engineering, Tianjin University, Tianjin 300072, China.
Med Eng Phys. 2009 Mar;31(2):214-20. doi: 10.1016/j.medengphy.2008.07.010. Epub 2008 Aug 30.
This paper reports an in-process assessment of the dental cutting of a leucite-reinforced glass-ceramic with a high-speed dental handpiece under clinical operating conditions. The dental cutting was performed using a computer-controlled 2-degrees-of-freedom (2-DOF) testing regime and a coarse diamond bur of 106-125 microm grit size. Dynamic forces were monitored during the cutting process using a piezoelectric force dynamometer and a data acquisition system in both time and frequency domains. Bur speeds were found to decrease with the depth of cut and with the feed rate, by a maximum of 10.5% from the free-running speed of 322.2 krpm (1 krpm=1,000 rpm) to 288.4 krpm at the highest feed rate of 60mm/min and depth of cut of 50 microm. Both the tangential and normal forces increased with the depth of cut and the feed rate, in the ranges of 0.24-1.77 N and 0.60-2.93 N respectively. The torque increased with the depth of cut and feed rate. The specific cutting energy generally decreased with the depth of cut or the feed rate with the exception of a small-scale fluctuation at the higher depth of cut and feed rate. The dental cutting characteristics for the leucite glass-ceramic were similar to those for the feldspathic porcelain but had higher magnitudes.
本文报道了在临床操作条件下，使用高速牙科手机对白榴石增强微晶玻璃进行牙科切割的过程评估。牙科切割采用计算机控制的两自由度（2-DOF）测试方式，使用粒度为106 - 125微米的粗金刚石车针。在切割过程中，使用压电测力计和数据采集系统在时域和频域监测动态力。发现车针速度随着切割深度和进给速度的增加而降低，在最高进给速度60mm/min和切割深度50微米时，从自由运行速度322.2 krpm（1 krpm = 1,000 rpm）最大降低10.5%至288.4 krpm。切向力和法向力均随着切割深度和进给速度的增加而增加，分别在0.24 - 1.77 N和0.60 - 2.93 N范围内。扭矩随着切割深度和进给速度的增加而增加。除了在较高切割深度和进给速度时有小幅度波动外，比切削能通常随着切割深度或进给速度的增加而降低。白榴石微晶玻璃的牙科切割特性与长石质瓷相似，但数值更高。
