In-process assessment of dental cutting of a leucite-reinforced glass-ceramic.
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.
Song
Xiao-Fei
XF
School of Mechanical Engineering, Tianjin University, Tianjin 300072, China.
Yin
Ling
L
Han
Yi-Gang
YG