Comparison of two stylus methods for measuring surface texture

Objectives: The purpose of this study was to evaluate and compare two “stylus” methods for measuring surface texture of dental tissues and materials Methods: The two styli chosen were a contact diamond stylus and a non-contact focussed laser stylus attached to the same measuring apparatus. Results: These indicate that there are significant differences between those obtained from surface texture measurements using a non-contact laser stylus and a diamond contact stylus method despite being mounted in the same profilometer. This is valid for both the test specimens of known surface texture, provided by the manufacturers, and for a “real world” simulation using contoured and finished Dicor ceramic blocks. The only significant agreement between the two styli was found for the R a parameter. This should not be used alone to describe the roughness of a surface because the parameter is not sensitive to profile shape. Owing to the properties of the stylus used it is essential that the limitations of surface profilometry be recognised. Significance: Caution should be exercised when comparing the results of surface texture studies of dental hard tissues and restorative materials using varying types of stylus attached to a surface profilometer.