Friction behavior of dental porcelain with different leucite particle sizes

The effect of leucite particle size on the friction behavior of dental ceramics was investigated using a ball-on-disc tribometer. The experimental loads were 20, 30 and 40 N and the tests were conducted unlubricated and under the lubrication of an artificial-saliva. Dental ceramics with different leucite particle sizes, i.e. 0.5 +/- 0.2, 1.2 +/- 0.3 and 5 +/- 2 mu m, were prepared by sintering the mixture of a low temperature frit and leucite powders with different average particle sizes (0.4, 1 and 5 mu m). The results showed that the leucite particle size, experimental load and lubrication media had not significant effects on the steady-state friction coefficient of the samples. However, the evolution of the friction coefficient was different, which could be generally classified into two categories, i.e. with and without an abrupt increase in the friction curve. The changes in experimental condition and leucite particle size were attributed to such difference.