EFFECT OF DIFFERENT FINISHING/POLISHING SYSTEMS ON SURFACE GLOSS AND ROUGHNESS OF COMPOSITES WITH DIFFERENT POLYMERIZATION TIME

Aim: the objective of this in vitro study was to evaluate the effec- tiveness of different finishing and polishing (F/P) systems by the analysis of surface gloss and roughness of single- and mul- ti-shade composites, polymerized for either 40 or 80 seconds. Methods: a total of 240 composite blocks (14 x 5 x 4 mm) were produced and divided into 3 groups (n = 80): one mul- ti-shade (Harmonize, Kerr) and two single-shade composites (Vittra APS Unique, FGM and Omnichroma, Tokuyama). Each group was further divided into 4 subgroups (n = 20) finished and polished using OptiDisc (Kerr), Enhance PoGo (Dentsp- ly), or Twist Dia (Kuraray), plus an untreated control group. A further subdivision (n = 10) was based on polymerization time (40” or 80”) of the blocks. Surface gloss was measured using a tailored 60° incidence angle glossmeter, while roughness was evaluated using a rugosimeter. Results: all F/P systems increased gloss and reduced roughness compared to the untreated control group. Twist Dia produced the smoothest and glossiest surfaces (p <0.001). Gloss and roughness values appeared to be more effective in the single-shade groups when polymerized for 40 seconds (p <0.001), whereas in the 80 seconds subgroups the effect of F/P systems appeared variable and dependent on the specific combination of materials and protocols. Conclusions: data showed that the choice of the F/P sys- tem and the composite material is fundamental to optimizing the esthetic and surface characteristics of direct restorations.