Finishing and polishing systems influence the roughness and color stability of acrylic and bis-acryl composite resins

Background: To evaluate the effect of different finishing and polishing systems on the surface roughness and color changes of bis-acryl (Protemp 4 - 3M ESPE- St. Paul, USA; Structur 3 - Voco, Cuxhaven, Germany) and chemically activated acrylic materials (Duralay - Reliance, SP, Brazil).

Material and methods: Specimens (10 x 2 mm) thick were prepared for each material. The specimens were subjected to polishing and finishing procedures with aluminum oxide discs (Diamond Master - FGM, Joinville, Santa Catarina, Brazil) and spiral rubber disks (Sof-Lex - 3M ESPE, Germany). The control did not receive any polishing and finishing procedures. Surface roughness and color measurement values were obtained after the finishing and polishing procedures and immediately after 30 days of storage in water, coffee, and red wine. Data for each material were analyzed by One-Way ANOVA (p<0.05).

Results: The polishing with aluminum oxide discs was able to affect the initial surface roughness values of chemically activated acrylic material (p<0.05). After immersion in staining solutions, lower ∆E values were only observed for the bis-acryl composite resins compared to the control group (p<0.05).

Conclusions: The finishing and polishing systems influenced the surface roughness and color stability of the materials tested. The chemically activated acrylic resin showed lower surface roughness and higher color stability than the bis-acryl materials. Key words:Acrylic resin, bis-acryl resin, provisional restoration.