Tribological behavior evaluation of dental fluorapatite glass ceramic

Abstract

Fluorapatite glass ceramics have been widely used in dental restoration because of its excellent esthetics, biocompatibility, and mechanical performance. However, its tribological behavior has not been intensively studied. In this paper, SiO2–Al2O3–K2O–CaO–P2O5 system fluorapatite glass ceramic was prepared by a melt-quench route, and the tribological behavior of the material was investigated in the dry and saliva environments. Effect of saliva and initial surface topology on the friction and wear was evaluated. The results showed that glass ceramics containing a quantity of rod-like fluorapatite crystals with a mean length of 369 nm were obtained. The Vickers hardness of the material was 637 HV. The friction coefficient and wear volume in saliva environment were obviously larger than dry friction because of the increase of adhesion between the two contact surfaces and acid erosion induced by saliva. The wear mechanism in saliva environment is combination of adhesive wear and erosion wear. Friction coefficient and wear volume at the early stage became larger with the increase of initial surface roughness of glass ceramic under dry friction; therefore, smooth surface of the fluorapatite glass ceramic is beneficial to improve the friction and wear performance.