No abstract

No abstract

No abstract

No abstract

The aim of the present study was to evaluate the influence of several experimental pretreatment crosslinker solutions on the resin polymer–dentine interface created using a representative universal adhesive system, by means of microtensile bond strength testing (μTBS), nanomechanical properties and ultramorphology confocal laser scanning microscopy (CLSM). Five experimental solutions containing different flavonoids were applied as dentine pretreatment after acid etching. A control pretreatment group containing no flavonoid was also employed. A representative modern universal adhesive was then applied, followed by a 3 mm thick composite built up. Specimens were sectioned into sticks and submitted to a μTBS test or nanoindentation analysis along the interface (24 h or 25,000 thermocycles). The ultramorphology of the polymer–resin interface was also evaluated using CLSM. The results were analyzed using two-way ANOVA and Bonferroni’s post hoc test (α = 0.05). All flavonoids improved short- and long-term μTBS values (p < 0.01), while only some specific such solutions improved the nanomechanical properties (p < 0.05) and preserved the structural morphology of the interface after aging. Pretreatment of acid-etched dentine using specific flavonoid-containing solutions may be a promising approach to improve both the nanomechanical properties and the durability of modern universal adhesive systems.

1 2 3 4 5 6 7This work " a r i z e s the results obtained after the evaluation of the electric properties plus physical and chemical characteristics of seven samples of polymeric insulators (organic, EPDM type) under natural aging at 115 kV operation voltage. The seven samples were obtained, from one to seven years insulators in normal service, respectively. First, the samples were subjected to some tests to venfy the electrical characteristics. After that, the same samples were subjected to the physical and chemical tests. The results of the tests (electrical and physicalchemical), show important differences between the first sample (only one year in Senice) and the last sample (seven years in service), also a family of curves indicating the loss of electrical properties vs years in service was obtained. With these curves, the rest of service life of the samples was estimated maintaining the same field conditions. The criteria used for these evaluations were based on the critical values considered for the analyzed variables.

SUMMARY Objectives This double-blind, randomized clinical trial evaluated the influence of dentin moisture on postoperative sensitivity (POS), as well as, on clinical performance in posterior bulk-fill composite restorations, using a universal adhesive, until 12 months after clinical service. Methods and Materials In accordance with a split-mouth design, 45 patients received posterior restorations, restored with a bulk-fill resin composite (Filtek Bulk Fill, 3M Oral Care) and a universal adhesive used in etch-and-rinse mode (SBU; Single Bond Universal Adhesive), which were applied on dry or moist dentin, with a cavity depth of at least 3 mm. Three operators placed 90 Class I/Class II restorations. Patients were evaluated for spontaneous and stimulated POS in the baseline, and after 48 hours, 7 days, and at 6 and 12 months. In addition, secondary parameters (marginal discoloration, marginal adaptation, fracture, and recurrent caries) were evaluated by World Dental Federation (FDI) criteria after 7 days and at 6 and 12 months. Statistical analyzes were performed using the Chi-square, Fisher exact, Friedman, Kruskall–Wallis, and Mann–Whitney tests (α=0.05). Results No significant spontaneous and stimulated POS was observed when SBU was applied in dry and moist dentin (p&gt;0.05). A significant and higher risk of spontaneous POS (20.0%; 95%CI 10.9–33.82 for dry dentin and 22.22%; 95%CI 12.54–36.27 for moist dentin) occurred up to 48 hours after restoration placement for the dry and moist dentin groups (p&lt;0.02). However, the POS intensity was mild up to 48 hours with no significant difference between dry and moist dentin groups (p&gt;0.79). When secondary parameters were evaluated, no significant differences between the groups were observed. Conclusion Dentin moisture did not influence POS in posterior bulk-fill composite restorations when associated with a universal adhesive applied in etch-and-rinse mode.

No abstract