This study investigated the effects of oxygen inhibition and finishing/polishing procedures on the composite resin properties. One bulk-fill and two conventional composite resins (nanoparticle and microhybrid) were evaluated. Specimens were prepared using 4 surface treatments: control, no treatment; Gly, oxygen inhibition with glycerin; FP, finishing and polishing; Gly + FP, glycerin followed by finishing and polishing. The degree of conversion (DC) was measured using Fourier Transformed Infrared Spectroscopy (FTIR) immediately and after 15 days (n=5). Color stability (ΔEab, and ΔE00) and opacity were evaluated using a spectrophotometer after 15 days of immersion in coffee, using the CIELAB system (n=5). Data were analyzed by two-way ANOVA and Tukey tests (α=0.05) and opacity by two-way repeated-measures ANOVA. Glycerin usage increased significantly the DC however had no influence on the ΔEab, ΔE00 and, opacity values. Finishing and polishing reduced ΔEab and ΔE00 values, regardless of composite resins. Microhybrid showed higher opacity, followed by the nanoparticle and bulk fill, regardless of surface treatment. Post-polymerization polishing procedures resulted in lower conversion than using an oxygen inhibitor agent (Gly condition), but similar staining caused by coffee.

Orthodontic cements have been used to enhance retention between the band and the crown, however, unfavorable properties found in many of these cements may contribute to cement failure between band and crown's surface and leading to unsuccessful application of orthodontic forces. The aim of this study was to evaluate the shear strength of the Orthobite composite (FGM) using the Single Bond adhesive system (3M). The sample consisted of 30 bovine incisors divided in 2 groups (n=15). All teeth were submitted to prophylaxes with pumice stone and etching with phosphoric acid. In Group I the Orthobite was used conventionally. Group II was similar to Group I, however, the Single Bond adhesive system was applied after conditioning. The samples were stored in distilled water in incubator at 37 ºC for 24 h and submitted to the shear strength test at a speed of 0.5 mm/minute speed. Data were submitted to the Student T test (5 %). The results (MPa) showed no statistically significant differences between the groups, regardless of surface treatment. Thus, all groups exhibited adequate adhesive bond strength for clinical use.