Study on the surface properties of different commercially available CAD/CAM materials for implant-supported restorations

Abstract

To determine if there are any differences in surface characteristics (surface roughness and contact angle) among different CAD/CAM materials indicated for fabricating implant-supported restorations, following all the material preparation protocols provided by the manufacturer. One-hundred forty-four specimens were divided into six groups: RBC (resin-based composite), PMMA (polymethyl methacrylate), PEEK (polyether ether ketone), ZP (zirconia polished), ZG (zirconia glazed) and CoCr4 (CoCr4 alloy). The experimental part included surface roughness (SR) and contact angle of water (WCA) analyses, fulfilled with atomic force microscopy (AFM) and scanning electron microscopy (SEM) view of surface topography. The data were analyzed using Kruskal-Wallis test with a Dunn's post hoc analysis, the correlation between measurements was tested using Spearman's rank correlation coefficient and all data were presented as mean ± SD. ZG specimens were significantly rougher compared to other groups (p ≤ 0.05). The WCA measurements revealed significantly lower mean values in ZG group (p ≤ 0.05), contrary to PEEK and CoCr4, where significantly higher mean values were observed, compared to other groups (p ≤ 0.05). There exist a moderate negative correlation between the SR and WCA (ρ = 0.41). AFM 3D and SEM 2D images presented more or less heterogeneous surface of all materials. There were statistically significant differences in surface roughness and contact angle among tested material groups. Moderate negative correlation was found between surface roughness and contact angle of tested material groups. The study gives us a better understanding of influence of physicochemical characteristics of investigated materials on their surface properties and provides useful knowledge for future researches in a view of material's behavior under in vivo conditions, when it comes to a question of features related to surface quality, such as microbial adhesion, corrosion, wear, biocompatibility and esthetics.