Clinical Relevance Conventional multistep resin cements presented higher adhesive performance to dentin than simplified self-adhesive cements, which is an important criterion for indirect restoration prognosis. SUMMARY This study aimed to conduct a systematic review of the literature on laboratory studies assessing bonding performance to dentin of conventional and self-adhesive resin cements, in cementing indirect restorations. This review was reported according to the PRISMA Statement. Of a total of 518 studies, 36 were screened full text and reviewed according to exclusion criteria. Nineteen papers were included in the systematic review and meta-analyses, according to the following inclusion criteria: studies that evaluated the bond strength to dentin of indirect restorations cemented with dual conventional or self-adhesive resin cements and those that presented bond strength data in MPa as an outcome. Statistical analyses were conducted using Rev-Man 5.1. Comparisons were performed with random effects models at 5% significance level. A global analysis comparing conventional and self-adhesive cements and three subgroup analyses comparing immediate and long-term results were performed. Global analysis showed a difference between groups, with conventional resin cements presenting higher bond strength results than self-adhesive resin cements, in immediate and long-term time periods (both p =0.03). Immediate and longterm bond strength results were different for self-adhesive cements, favoring immediate bond strength ( p =0.03), but immediate and long-term bond strength results for conventional resin cements were not different ( p =0.06). Medium or high risk of bias was found in all studies. Conventional multistep resin cements showed superior overall adhesive performance compared with simplified self-adhesive resin cements when used to cement indirect restorations to dentin.

SUMMARY The purpose of this study was to evaluate the ability of three resin composite systems to mask a severely discolored background by the application of a layering technique through CIELAB and CIEDE2000 analysis. Ninety 1.5-mm-thick disc specimens were produced from three different resin composite restoration systems: IPS Empress Direct (Ivoclar Vivadent), Charisma Diamond (Heraeus Kulzer), and Filtek Z350 XT (3M-ESPE). The specimens were divided into groups according to the restoration system and the resin composite shade combination used for the layering technique (enamel, body, and dentin shades). Color measurements were performed by a reflectance spectrophotometer (SP60, EX-Rite) against a C4 shade background and an inherent color background, which simulates a severely discolored background and a tooth surface with no discoloration, respectively. The total color difference between both color measurements was calculated by CIELAB (ΔE* ab ) and CIEDE2000 (ΔE 00 ) formulas. The mean ΔE ab * and ΔE 00 values were analyzed by analysis of variance (general linear models) and Tukey's post hoc tests (α=0.05). Three groups presented clinically acceptable color difference values (ΔE*≦3.46 and ΔE 00 ≦2.25): 1.5 mm dentin, 1.0 mm dentin/0.5 mm body, and 1.0 mm dentin/0.5 mm enamel; ie, all the groups from the Z350 XT restoration system. The resin composite layering technique is an effective way to mask severely discolored backgrounds. The Filtek Z350 XT system was the only restoration system capable of masking the C4 background.