Fig. 6From: Effect of roughness and acidic medium on wear behavior of dental resin compositeThe duration of running-in period for the resin composites with different Ra in distilled water: a 1.60 ± 0.23 μm; b 0.50 ± 0.04 μm; c 0.14 ± 0.02 μm; d 0.05 ± 0.004 μm. The gray shadow indicates the running-in stage and the white part indicates the steady stageBack to article page