An in vitro atomic force microscopic study of commercially available dental luting materials

Objective: The aim of this in vitro study was to compare the surface roughness parameters of four different types of dental luting agents used for cementation of implant restorations. Method and materials: Five specimens (8 mm high and 1 mm thick) of each cement were made using metal ring steelless molds. Atomic Force Microscope was employed to analyze different surface texture parameters of the materials. Bearing ratio analysis was used to calculate the potential microgap size between the cement and implant material and to calculate the depth of the valleys on the cement surface, while power spectral density (PSD) measurements were performed to measure the percentage of the surface prone to bacterial adhesion. Results: Glass ionomer cement showed significantly lower value of average surface roughness then the other groups of the materials (P LT 0.05) which was in line with the results of Bearing ratio analysis. On the other side, PSD analysis showed that zinc phosphate cement experience the lowest percentage of the surface which promote bacterial colonization. Conclusion: Glas ionomer cements present the surface roughness parameters that are less favorable for bacterial adhesion than that of zinc phosphate, resin-modified glass ionomer and resin cements. Microsc. Res. Tech. 76:924-930, 2013. (c) 2013 Wiley Periodicals, Inc