Pages 490-495, Language: EnglishKrejci, Ivo / Lutz, Felix / Boretti, RosemarieObjective: The search for the ideal polishing agent for resin composite materials is still ongoing. A new polishing brush with abrasive bristles for polishing resin-based restorations was tested to determine if it polishes restorations, including those with concave surfaces, macrostructured occlusal surfaces, and textured surfaces, without destroying their delicate texture or microstructure. Method and materials: The polishing effectiveness and the ultimate destructive potential of these brushes were assessed quantitatively and subjectively in vitro. In addition, the durability of the brushes after repeated use and autoclaving was also evaluated. Results: The brushes were nondestructive to resin-based restoratives, enamel, dentin, and the restoration interface. They produced a shiny surface on resin-based restorative materials without destroying the surface texture. The abrasive brushes were autoclavable and demonstrated satisfactory durability, despite multiple heat sterilization cycles. Conclusion: These brushes can be considered to be key products to polish concave surfaces, anatomically shaped occlusal surfaces, and textured surfaces without damaging the surface characteristics.