Objectives . The purpose of this study was to evaluate the change of gloss for nanocomposite resins by toothbrushing.
Materials and methods . Nine different composite resins were filled into acrylic resin mold and light cured under slide glass (control surface). Gloss was measured using Novo-curve™ glossmeter (Rhopoint, U.K.). Then composite surface was polished with Enhance ® and Pogo ® (Dentsply/Caulk, Milford, DE, USA) as baseline. Brushing force was 250 g using a manual toothbrush (Braun oral B ® Indicator Plus) with toothpaste (NAME). Gloss measurements were performed after polishing and at 200, 400, 600, 800, 1000, 2000, and 3000 (6 month-final) manual stroke. Gloss retention was calculated with the following formula.
Gloss retention ( % ) = G final G baseline × 100