Little is known about the effect of specimen preparation and testing protocols on the micro-shear bond strength (μSBS) results. To evaluate whether variations in polyethylene rod use affect (μSBS)). Human dentin disks were randomly distributed into six groups (n = 5): polyethylene tube (3 levels) and adhesive system (2 levels). In Group 1, polyethylene tubes filled with polymerized composite) were placed on adhesive covered surfaces. Tubes were removed 24 h after water storage, leaving the rods only. In Group 2, the same procedure was performed; however, tubes were kept in place during testing. In Group 3, composite rods without tubes were placed on adhesive covered dentin. In all groups, adhesives were photoactivated after positioning filled tubes/rods on adhesive covered surfaces. Specimens were tested under shear mode and the data subjected to a two-way ANOVA and Tukey's tests. Groups 1 and 2 resulted in statistically similar mean μSBS (P > 0.05); however, a greater number of pretest failures were observed for Group 1. Higher μSBS values were detected for Group 3, irrespective of adhesive system used (P < 0.05). Removing the polyethylene tube before composite rod is placed on dentin affects μSBS values.

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Objective: This study was aimed at comparing the bleaching efficacy and bleaching sensitivity (BS) of two higher-concentration in-office bleaching gels (37% carbamide peroxide [CP] and 38% hydrogen peroxide [HP]) applied under two conditions: alone or in association with sonic activation.Methods: Fifty-six volunteers were randomly assigned in the split-mouth design into the following groups: CP, CP with sonic activation (CPS), HP, and HP with sonic activation (HPS). Two in-office bleaching sessions were performed. Color was evaluated using Vita Classical, Vita Bleachedguide, and digital spectrophotometer at baseline and at 30 days post-bleaching. Absolute risk and intensity of BS were recorded using two pain scales. All data were evaluated statistically (color changes [t test], BS [Chi-square and McNemar test], and BS intensity [VAS; t test; NRS; Wilcoxon; α = 0.05]).Results: Significant and higher whitening was observed for HP when compared with CP (p < 0.04). However, higher BS intensity was observed in the former (p < 0.001).No significant difference was observed in whitening effect or BS when the HP or CP bleaching gels were agitated (sonic application) compared with when they were not (p > 0.05). Conclusion:The 37% CP gel demonstrated lower bleaching efficacy and lower BS compared with the 38% HP bleaching gel. The whitening effect was not influenced by the use of sonic activation.

<p><strong>Case report</strong>: Even if directly veneering discolored anterior teeth with composite is quite widespread, proper reproduction of their natural appearance requires much from the professional. Comprehensive management, from planning to finishing and polishing, of a severely discolored upper central incisor through its directly<strong> </strong>veneering is critically reported. <strong>Relevance</strong>: Direct composite laminate veneers are, indeed, a viable treatment option to correct esthetic abnormalities involving most of the labial surface of anterior teeth. This relative conservative therapy, since accurately performed by the well qualified dentist, will assign the patient esthetic, functional and emotional rehabilitation, culminating in a harmonious and pleasant smile.<strong></strong></p>

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