Dentin bond strength evaluation between a conventional and universal adhesive using etch-and-rinse strategy

Aim: The aim of this study was to compare the microtensile bond strength (µTBS) and the characteristics of the adhesive interface of Scotchbond Universal - SU ­ etch-and-rise mode (3M ESPE) and Adper Scotchbond Multi-Purpose - MP (3M ESPE) to dentin over time. Methods: Class I cavity preparations were performed in 60 human molars that were randomly divided according to the dentin bonding system (DBS) used (n=30): (1) Acid conditioning + SU and (2) Acid conditioning + MP. For bonding strength (BS) analysis, 30 teeth (n = 15) were sectioned into sticks and submitted to the microtensile test in a universal testing machine after 24 hours and 12 months. The adhesive interface of the others 30 teeth was analyzed in a confocal microscope after 24 hours and 12 months. The data of µTBS were analyzed by two-way repeated measures ANOVA and Tukey's HSD (α = 0.05). Results: SU presented the lowest DBS compared to MP (p=0.000). Time did not influenced DBS for both adhesive systems (p=0.177). Confocal microscopy analysis showed no cracks between both adhesive systems tested. Conclusion: The results indicate that MP - µTBS showed a better performance compared to SU in total-etch mode

Color evaluation of white spot lesions treated with resin infiltration after water or grape juice storage

Aim: To evaluate the color stability of bovine enamel with artificial white spot lesions treated with resin infiltration (ICON) or remineralization with fluoride using two storage methods. Methods: Sixty incisors were submitted to artificial white spot lesion induced by demineralization-remineralization (DE-RE) cycling. Initial color was evaluated with CIE-Lab to measure ΔEab. Demineralized teeth were divided according to the treatment of the white spot lesion (n = 20): 1) Remineralization with 2% neutral fluoride gel for 4min (control); 2) ICON application following manufacturer's recommendations; and 3) ICON with decreased drying time after the application of ethanol. After 24h, color was evaluated and samples were subdivided (n = 10) according to storage: 1) distilled water for 1 month; 2) grape juice for 10min daily. After storage, color was evaluated. L*, a* and b* data were analyzed by one-way ANOVA and ∆Eab data by two-way ANOVA followed by Tukey's HSD (α = 0.05). Results: L* was affected by juice storage, and decreased when ICON was applied with decreased drying time after the ethanol application. The same behavior occurred with a* (increase with reduced drying time), while b* was not affected. For ∆Eab significant differences were observed between groups (p = 0.0219) and storage methods (p = 0.0007). There was no interaction effect (p = 0.1118). Remineralization with fluoride presented the lowest color changes after storage in water. Conclusion: Treatment of artificial carious lesions with resin infiltration presented greater color changes than fluoride remineralization after storage in both solutions in vitro