SUMMARY: Purpose: The aim of this study was to investigate the staining behavior of demineralized enamel infiltrated by low-viscosity resin. Methods and Materials: Bovine enamel/dentin cylindrical samples (3 × 2 mm) were assigned into four groups (n=45) according to the enamel treatment: sound enamel (control), demineralization + artificial saliva, demineralization + daily application of 0.05% NaF, demineralization + resin infiltration (Icon, DMG). Artificial white spot lesions were produced in groups with demineralization. After the treatments, color was assessed by spectrophotometry, using the CIE L*a*b* system. The specimens (n=15) were then immersed in deionized water, red wine, or coffee for 10 minutes daily for eight days. Color was measured again, and the specimens were repolished with sandpaper discs. The final color was assessed. Data were analyzed by two-way analysis of variance and Tukey tests (α=0.05). A paired t-test was used for comparison between staining and repolishing conditions. Results: There were significant differences for surface treatment and dye after staining and repolishing. Immersion in wine and coffee resulted in significantly increased color alteration (ΔE) compared with water (p=0.001). The resin-infiltrated group exhibited the highest staining values (p=0.001). The repolishing procedures resulted in significantly decreased color change. Conclusion: The exposure of specimens to colored solutions resulted in significant color alteration. The demineralized enamel treated with resin infiltration showed significantly higher staining than all other tested groups; however, the repolishing of the specimens minimized the staining effect.

SUMMARY: Objectives: This study aimed to evaluate the bonding performance of a universal adhesive used according to self-etching or etch-and-rinse protocols in noncarious cervical lesions (NCCLs) and to compare the two protocols with their respective gold standard techniques. Methods and Materials: This randomized, double-blind clinical study enrolled 34 participants who met the inclusion criteria, 29 of whom returned after two years. They received 152 restorations bonded with one of the three adhesives (Scotchbond Universal Adhesive, Adper Single Bond 2, or Clearfil SE Bond) and one of the two bonding techniques tested. The NCCLs were restored with nanocomposite resin (Filtek Supreme). Final contours were done with a fine diamond rotary instrument and polished with rubber points. The restorations were evaluated using the FDI World Dental Federation criteria at baseline (seven days after the restoration procedure), 6, 12, and 24 months. Descriptive statistics, Kruskal-Wallis, Friedman analysis of variance, and least significant difference tests were performed. Results: No statistically significant differences were found in esthetics or the functional and biological evaluated criteria among the adhesive systems and techniques. Conclusions: The Scotchbond Universal system behaved similarly to the conventional etch-and-rinse or self-etching systems in all the adhesion strategies in the evaluated periods.