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 Ra 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.