WEAR MECHANISM OF A DENTAL GLASS-CERAMIC

Wear tests were conducted on a mica-containing glass-ceramic designed for use in dental restoration of occlusal surfaces. In these tests, an alumina ball was slid against a glass-ceramic disk in laboratory air atmosphere. The friction coefficient was monitored during the tests an d the wear rates were determined from profile traces obtained on the w ear tracks after the tests were completed. The wear surfaces were exam ined in a scanning electron microscope to determine the wear mechanism . It was concluded that wear primarily occurs by a microfracture proce ss along the mica-glass interface. Since the size and volume fraction of the mica plates is expected to control the microfracture process, w ear could be controlled by altering the microstructure of this materia l.