Comparative tribological study of two prosthetic dental materials: Zirconia and Vita enamic

The purpose of this study was to compare the tribological behaviour of two commercial prosthetic materials – Zirconia and a polymer infiltrated ceramic (PIC) commercially known as VITA ENAMIC – when tested against human molars/premolars. Samples of both materials were prepared and their hardness, wettability and topography were characterised. Antagonist teeth samples were prepared by cutting human molars/premolars to obtain isolated cusps. A wear test was performed during 306,000 chewing cycles, corresponding to 1.5 year of mastication, using a simulator with artificial saliva as lubricant. The wear mechanisms were analysed by scanning electron microscopy (SEM), the dental wear loss was determined by volume calculation using 3D scans of the cusps, and the prosthetic material loss by 2D profilometry analysis. Contrarily to VITA, no wear was found in Zirconia. No correlation was found between dental wear and the used counter-face, showing that dental wear is not influenced by the counter-face hardness when opposing surfaces with similar roughness are used.