Influência da aplicação do selante de superfície e desafio erosivo na alteração de cor de uma resina composta submetida ao manchamento artificial

Abstract

The purpose of this study was to evaluate the influence of the erosive challenge (DR) and the surface sealant application (SS) in the color change (CR) on a composite resin (RC) submitted to artificial coffee staining (CF). Forty-eight specimens (8mmX1mm) were prepared with composite resin and surface sealant, with and without erosive challenge. The groups division follow as (n=12): Group 1- RC+SS DR CR CF CR; Group 2- RC+SS CRCFCR; Group 3- RC DR CR SS CFCR; Group 4- RCCRSSCFCR. Groups 1 and 3 received erosive challenge for 5 days using hydrochloric acid (HCl 0.01 M, 150 mL/cycle, produced in a specific laboratory and replaced with each new exposure) at room temperature, for 2 minutes each 4 immersions per day. The surface sealant was applied immediately after the specimen preparation in the groups 1 and 2, and after the first color measurement in the groups 3 and 4. After immersion in coffee solution during 14 days, specimens have had a new color measurement using spectrophotometer (X-Rite Color 962. Danaher Corporation) performed according to CIEL*a*b* color system. The results showed that for ∆E, the groups 1 (21,01) and 2 (23,10) presented lower values than G3 (27,76) and G4 (26,57), respectively, while for ∆L the opposite happened (G1= - 16,84; G2= -17,72; G3= -22,62; G4= -21,22). In the analysis of ∆a and ∆b, a significant difference was found in ∆b of G1 (10,7) only, presenting a lower value. Opacity remained stable for all groups. The resin luminosity decreased and the color variation increased when the sealant was applied after the erosive cycling and storage.