RESUMO
OBJECTIVES: To compare the risk and intensity of tooth sensitivity (TS) as well the effectiveness of at-home bleaching using two carbamide peroxide bleaching gels, specifically a novel polymeric nanoparticle gel (experimental) and a commercial gel (Opalescence PF, Ultradent, South Jordan, Utah, USA), applied at two application times. METHODS: This multicenter, triple-blind, and split-mouth randomized controlled trial was conducted on 80 healthy adults with canine teeth that were shade A2 or darker. The participants all used the experimental and the control gels on one side of a tray, depending on the group to which they were allocated, for 30 or 60 minutes per day over four weeks. The absolute risk and intensity of TS were assessed daily using the five-point Numeric Rating Scale and the 0-10 Visual Analogue Scale. Color change was evaluated with shade guide units (ΔSGU) and a digital spectrophotometer (ΔEab, ΔE00, and ΔWid) at baseline and 30 days postbleaching. The risk and intensity of TS was evaluated by the McNemar and the Wilcoxon signed-rank tests, respectively. Color change (ΔSGU, ΔEab, ΔE00, and ΔWid) was evaluated by Mann-Whitney and paired t-tests (α=0.05). RESULTS: No differences in the risk and intensity of TS were observed based on the bleaching gels used and the times of application (p>0.05). Thirty days after bleaching, there was no significant difference in color change, in terms of the bleaching gels used or the application times (p>0.05). CONCLUSION: The novel carbamide peroxide polymeric nanoparticles gel, when applied for 30 or 60 minutes, produced effective color change and a low rate of tooth sensitivity, as compared to the control group.
Assuntos
Sensibilidade da Dentina , Nanopartículas , Clareadores Dentários , Clareamento Dental , Peróxido de Carbamida , Géis , Humanos , Peróxido de Hidrogênio , Clareadores Dentários/uso terapêutico , Resultado do TratamentoRESUMO
PURPOSE: To evaluate the effect of bur roughness on bond strength values and conditioner pattern of two-step self-etch adhesives applied on sclerotic dentin. METHODS: The roots of 48 bovine incisors were removed and the crowns were divided into four groups: the control group (CO) teeth were left untreated or the teeth were slightly roughened with coarse-, medium-, or fine-grit diamond burs. Next, the teeth were subdivided and Clearfil SE Bond (CSE) and Adper SE Bond (ASE) were applied according to the manufacturers' instructions. Composite resin (Opallis) buildups were incrementally constructed on the bonded surfaces. After storage for 24 hours in distilled water at 37°C, the teeth were sectioned into sticks (area of 0.8 mm(2)). The sticks were stressed until failure by tensile forces (0.5 mm/min). Additionally, eight bovine teeth were treated as previously described, and after adhesive application, the surface was rinsed off and examined by scanning electron microscopy to measure the relative number of open tubules (OT). Data (MPa) were analyzed by two-way analysis of variance and Tukey test (p=0.05). RESULTS: CO showed the highest bond strength values (p<0.05). As regards OT, the lowest mean was observed for CO (p<0.05) and the highest was found after application of CSE or ASE (p<0.05).