Confocal Laser Microscopic Analysis of Biofilm on Newer Feldspar Ceramic

Purpose: This study evaluated the surface roughness, hydrophobicity and in situ dental biofilm associated with microfilled feldspar ceramics submitted to the different finishing and polishing procedures. Methods and Materials: Samples were made according to the manufacturer's instructions and allocated to groups as follows: glaze (G1); glaze and diamond bur (G2); glaze, diamond bur and rubber tips (G3) and glaze, diamond bur, rubber tips and felt disks impregnated with a fine-aluminum oxide particle based paste (G4). Roughness was evaluated with a roughness analyzer (R-a). Hydrophobicity was determined by the contact angle of deionized water on samples. Biofilm was evaluated eight hours after formation in the oral environment using confocal laser-scanning microscopy (CLSM) and scanning-electron microscopy (SEM). Results: Significant differences were found related to roughness (G1<G4<G3<G2). G1 presented the highest hydrophobicity. G1 and G4 presented the lowest mean thickness and biovolume of biofilm when compared to G2 and G3, both of which were similar. Isolated cocci were verified in G1 and G4 using SEM, while G2 and G3 presented bacteria aggregates. Conclusion: Polishing with rubber points followed by felt disks impregnated with a fine-aluminum oxide particle resulted in biofilm formation similar to that present with a glazed ceramic surface, even though the surface is still rougher and more hydrophobic.