RESUMEN
PURPOSE: To study the surface roughness of early carious lesions which were treated with resin infiltration and polished with different materials, and to provide reference for selection of appropriate polishing system. METHODS: Fifty-four labial surface specimens of mandibular incisors were created out of bovine teeth. They were randomly divided into 6 groups. One group was sound enamel group. Another group was early enamel carious group. Other specimens were treated with a partially saturated acidic buffer solution for preparation of initial artificial enamel caries. These initial artificial enamel caries were treated with resin infiltration. Then they were randomly divided into 4 groups according to polishing or not and type of polishing tool (rubber cups, polishing discs, HiLuster polishers). The surface roughness of specimens in all groups were measured with Form Talysurf PGI 800. Arithmetical mean deviation of the assessed profile (Ra) and the maximum height of the profile(Rz) were used as measurement parameter. SPSS 17.0 software package was used for data analysis. RESULTS: Comparison of sound enamel surfaces and early carious surfaces revealed no significant difference in surface roughness(P>0.05), but the mean value of the latter one was higher. After infiltration, the roughness of surfaces without polishing was significantly higher than that of early carious surfaces(P<0.05). After infiltration and polishing with different tools, there was no significant difference in surface roughness of every two groups (P>0.05). The roughness of polishing groups after infiltration was significantly smaller than that of group without polished after infiltration (P<0.05). Comparison of polishing surfaces after infiltration and early carious surfaces revealed no significant difference in surface roughness (P>0.05). CONCLUSIONS: After early caries being treated with infiltration technique, the roughness of teeth surfaces increases significantly. Those surfaces should be polished. Rubber cup and polishing discs with smaller granularity are more effective and reasonable as the surface polishing materials.