Comparison of methods for measuring surface roughness of ceramic.

The aim of this investigation was to compare two methods of assessing the surface texture of finished dental ceramic; a laser reflectivity method (LSR) and a contact stylus tracing method. Identical ceramic blocks (Dicor MGC) were finished using a variety of techniques and devices, and the surface texture characterized by LSR and contact stylus tracing to enable comparisons to be made between the two methods. The results indicate that there is little correlation between the two measuring methods. Therefore, laser reflectivity should not be exclusively used to measure the surface texture of contoured and finished ceramic materials. The development of sophisticated surface characterization parameters suggest that the surface characteristics of dental restorations and other related surfaces should be described using more than one surface measurement parameter. Surface parameters should be chosen which can both quantify surface roughness and provide information on the shape of the surface under investigation.