Pages 691-699, Language: EnglishSchmidlin, Patrick R. / Sener, Beatrice / Lutz, FelixObjective: This study evaluated the cleaning and polishing effect of a prophylaxis paste (Cleanic), two differently shaped abrasive-bristle brushes (Occlubrush normal cup and Occlubrush minipoint), and a nylon-bristle brush (Prophy brush) on a fine (Tetric Ceram) and a coarse hybrid resin composite (Tetric Condense) under standardized conditions. Method and materials: A total of 48 round specimens with a diameter of 17.2 mm (232.32 mm2) of a fine and a coarse hybrid resin composite were readied and fixed on scanning electron microscopic mounts. After a standardized polishing procedure, the mean surface roughness values were evaluated using five horizontal and five vertical measurements over an area of 1 X 3 mm. The gloss of each specimen was assessed with a spectrophotometer. Both hybrid resin composite groups were treated with one of the following instruments: a nylon-bristle brush (n = 8), a normal-cup abrasive-bristle brush, or a minipoint abrasive-bristle brush. The medium used was either water (control) or a prophylaxis paste. Surface roughness and gloss were measured after instrumentation times of 15, 30, 60, 90, and 120 seconds. For the evaluation of cleaning ability, another 48 total round specimens of fine and coarse hybrid resin composite were covered with a thin layer of black dispersion color and air dried for 24 hours. Specimens were treated with a nylon-bristle brush or an abrasive-bristle brush in combination with water or prophylaxis paste for 15, 30, 60, 90, and 120 seconds. At the beginning and after every treatment interval, the specimens were scanned, the images were digitized, and the percentage of cleaned surface was measured planimetrically. Results: The abrasive-bristle brush, used in combination with water, produced the best outcomes for cleaning ability, surface roughness, and gloss on resin composite restorations. Conclusion: There is no positive cumulative effect when an abrasive-bristle brush, with its cleaning and polishing effect, is used in conjunction with a prophylaxis paste. Abrasive-bristle brushes used with plain water are highly suitable for cleaning and polishing resin composite surfaces.