Smoothness provided by a one-step finishing and polishing system and its maintenance after 12-month aging.

Purpose: To evaluate the smoothness provided by a one-step finishing and polishing system and its maintenance after hydrothermal aging and brushing of a nanofilled resin composite.

Methods: 96 samples of the nanofilled composite Filtek Z350 XT were fabricated, which, after initial average roughness (Ra) analysis, were randomly distributed into three groups, according to the selected finishing and polishing system. The multi-step systems Sof-Lex (aluminum oxide discs) and Jiffy (bullet-shaped abrasive rubbers), and the one-step system OneGloss (bullet-shaped abrasive rubber) were used.