Confocal Laser Microscopic Analysis of Biofilm on Newer Feldspar Ceramic

Abstract

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 scanningelectron 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 Clinical RelevanceWhen the glazed surface of glass ceramics is submitted to chairside preparation, polishing with rubber points followed by felt disks impregnated with a fine-aluminum oxide particle appears be a good option to polish the surface of the glass ceramic, since this finishing-polishing method results in biofilm formation similar to the glazed ceramic surface. 44Operative Dentistry 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.

Performance of a novel polishing rubber wheel in improving surface roughness of feldspathic porcelain

“…The Ra values obtained in this study agreed well with the results of other reports on the roughness values of ceramic materials 1,6,8,19,22,35) . Compared to the roughness values of composite resins, ceramics show high Ra values because they are composed of ceramic crystals with no matrix substances in between, unlike composite resins 29,36,37) .…”

“…After adjustment of the interproximal and occlusal contacts and refinement of the contour and cervical margins, ceramic surfaces have traditionally been glazed to mask surface defects 1) , increase the mechanical properties such as the strength and fracture resistance of the porcelain [1][2][3] , prevent excessive wear of the opposing tooth surface 4) , and increase the longevity of the restored tooth. Glazing is also needed to minimize plaque accumulation 5,6) , improve soft tissue compatibility 6,7) , and increase surface luster and aesthetics.…”

Biofilm formation on different materials for tooth restoration: analysis of surface characteristics

“…When using SEM analysis, the biofilm is submitted to a fixation and dehydration process, which could alter its characteristics [15]. CLSM was used the present study, and thus, the biofilm could be evaluated without being submitted to fixation and dehydration, allowing the biofilm to maintain its original architecture [15].…”

“…To adjust the measurement software, it is necessary to identify the pixel in the first plane that represents the top of the material's surface not covered by biofilm. Biofilm structures can be quantified and subsequently analyzed statistically using an analysis of variance model [15,18,19]. The biovolume was defined as the number of biomass pixels in all images of a stack, multiplied by the voxel size {(pixel size) X 9 (pixel size) Y 9 (pixel size) Z} and divided by the substratum area of the image stack.…”

“…Surface free energy is another material property that is commonly related to biofilm formation. High surface free energy (hydrophilic) substrates exhibit more biofilm than low surface free energy (hydrophobic) substrates [14,15].…”