Effect of surface roughness of porcelain on adhesion of bacteria and their synthesizing glucans

Statement of problem. In some instances of porcelain restoration, refinishing is inevitable. In terms of plaque accumulation on porcelain, refinishing could be a substitute method for glazing. Purpose. This study compared the amount of adhesion of plaque components (bacterial cells and glucans) on porcelain disks with various degrees of surface roughness to assess the effects of surface roughness on the amount of plaque accumulation. Material and methods. Radiolabeled cell suspensions were incubated with porcelain disks for 3, 8, and 24 hours at 37 degrees C, and the amounts of adhered cells and glucans were measured by using a liquid scintillation method. Results. The amount of cells and glucans adhered on porcelain increased with incubation time. The sur face roughness value and the amount of plaque adhesion decreased with the increase in polishing level. However, the greatest amount of plaque was adhered on glazed surfaces, although their surfaces were smoother than the surfaces polished with 120- or 600-grit abrasive papers. Conclusion. With the exception of glazed surfaces, a positive correlation between surface roughness and the amount of plaque accumulation was observed. Repolishing with a diamond paste would not induce problems of plaque accumulation, compared with an intact glazed surface.