The purpose of this study was to investigate the effects of porcelain finishing techniques on the adherence of Streptococcus sobrinus. The finishing. lures (Unglazed, self-glazing, mechanical polishing, mechanical polishing + glazing, and glazing) were tested using an in vitro assay. The results exhibited that greatest amount of dry weight and the colony count of plaque occurred on the mechanical polished surfaces. However, the smallest amount of plaque occurred on the glazed porcelain surfaces.