Evaluation of the Solvent Evaporation Time of Universal Adhesives in the Quality of Cervical Lesions Restorations

The aim of this study will be to evaluate the effect of prolonging solvent evaporation time on the 6- and 12-months clinical performance of two universal adhesive systems used as selective enamel etch (SEE). Methods: 140 restorations will be randomly placed in 35 subjects according to the following groups: SUP5 (Scotchbond Universal Plus evaporated for 5 s); SUP25 (Scotchbond Universal Plus evaporated for 25 s); GBU5 (Gluma Bond Universal evaporated for 5 s); GBU25 (Gluma Bond Universal evaporated for 25 s). Resin composite will be placed incrementally and light-cured. The restorations will be evaluated at baseline, after a week, 6 and 12 months using the FDI and USPHS criteria. Statistical analyses will be performed using appropriate tests (α = 0.05).

This is a four-arm, double-blind, randomized controlled clinical trial. Experimental group 1: 35 non-carious cervical lesions (NCCL) will receive composite resin restorations using an alcohol- and water-based solvent universal adhesive (Scotchbond Universal Plus; 3M) in the selective enamel etching strategy with evaporation of solvent for 25 seconds. Experimental group 2: 35 non-carious cervical lesions (NCCL) will receive composite resin restorations using an acetone-based universal solvent adhesive (Gluma Universal Bond; Kulzer) in the selective enamel etching strategy with solvent evaporation for 25 seconds. Control group 1: 35 non-carious cervical lesions (NCCL) will receive composite resin restorations, using an alcohol- and water-based universal solvent adhesive (Scotchbond Universal Plus; 3M), in the selective enamel etching strategy, with evaporation of solvent for 5 seconds. Control group 2: 35 non-carious cervical lesions (NCCL) will receive composite resin restorations, using an acetone-based universal solvent adhesive (Gluma Universal Bond; Kulzer), in the strategy of selective enamel etching, with solvent evaporation for 5 seconds. LCNCs will be randomized to universal adhesive usage and flash-off time. All groups will be light-cured with a light-curing device (SmartLite Focus, Dentsply) with a light intensity of 855 mW/cm² for 20 seconds. Operators will restore the cervical area by applying three increments of resin (Opallis, FGM Prod. Odont.Ltda, Joinville, SC, Brazil). Each increment will light cure for 10 s at 1200 mW/cm2 (Radii Cal, SDI, Victoria, Australia). Restorations will be finished immediately with fine diamond burs (#3195F and #3195FF, KG Sorensen, Barueri, SP, Brazil) and polished with discs and polishing gums (Soflex, 3 M ESPE, St. Paul, MN, EE. UU.).