Evaluation of Double Layer Application Using a Universal Adhesive in the Quality of Cervical Lesions Restorations

The aim of this study will be to evaluate the effect of a double layer application of a universal adhesive system used as etch-and-rinse application mode in non-carious cervical lesions (NCCLs), on the 6- and 12-months clinical performance. Materials \& Methods: 144 restorations were randomly placed in 36 subjects (16 male and 20 female) according to the following groups (n=36): ER1 (one layer of Scotchbond Universal Plus adhesive applied as etch-and-rinse mode); ER2 (double layer of Scotchbond Universal Plus adhesive applied as etch-and-rinse mode); SEE1 (one layer of Scotchbond Universal Plus adhesive applied as selective enamel etching); SEE2 (double layer of Scotchbond Universal Plus adhesive applied as selective enamel etching). All groups were light-cured for 10s/1,000 mW/cm2 only after final layer. A resin composite will be placed by applying three increments and each one will be light cured for 20s/1,000 mW/cm2. The restorations will be finished immediately with fine diamond burs and polishers. The restorations will be evaluated at baseline and after 6- and 12-months by using the FDI criteria. The following outcomes will be evaluated: retention, marginal staining, marginal adaptation, post-operative sensitivity and recurrence of caries. The differences among the groups will be calculated using Friedman repeated measures analysis of variance rank (α = 0.05).