One-year follow-up comparing at-home bleaching systems outcomes and the impact on patient's satisfaction: Randomized clinical trial.

OBJECTIVE: To compare at-home systems with reduced daily time of use (10% hydrogen peroxide [HP] gel with prefilled (PT) or customized trays (CT), and 10% carbamide peroxide [CP] gel), with the conventional nightguard vital bleaching (10% CP). Bleaching efficacy, adverse effects, and patient's satisfaction were evaluated. METHODS: Sixty participants were randomly divided into treatments (14 days): Opalescence GO (OGO)-10%HP PT-30 min, White Class-10%HP CT-30 min, Opalescence PF-10%CP CT-2 h, and Opalescence PF-10%CP CT-8 h. Color difference (visual and spectrophotometer), tooth sensitivity (visual analogue scale), gingival condition (Löe index), enamel mineralization (laser fluorescence), and patients' satisfaction (questionnaire) were assessed. Statistical tests were applied (5%). RESULTS: After 1 year, color difference was similar for the groups (p > 0.05). All groups showed similar sensitivity risk (p > 0.05). The intensity of sensitivity and gingival irritation was mild for all gels, but higher for OGO. Fluorescence after bleaching remained similar to those of sound enamel. All participants were satisfied with treatments. CONCLUSIONS: All systems produced similar bleaching efficacy, which was maintained after 1 year. Patients were satisfied with bleaching outcomes. Tooth sensitivity occurred in all groups, but with overall mild intensity. No relevant gingival irritation and enamel demineralization was observed. CLINICAL SIGNIFICANCE: Bleaching with 10% HP gels in prefilled and CTs represent efficacious alternative for tooth color change, with patients' acceptance similar to conventional 10% CP. Patients must be warned about the mild sensitivity and gingival irritation potential, mainly with PTs.

Hydrogen peroxide degradation of bleaching systems with different trays: Randomized clinical trial.

PURPOSE: This crossover study evaluated the hydrogen (HP) and carbamide (CP) peroxide degradation of bleaching gels in prefilled (PT) and customized trays (CT). METHODS: Volunteers were randomly allocated to treatments (n=10) : PT-HP/OGO (Opalescence GO-10%); CT-HP/WTC (White Class-10%) or CT-CP/OPF (Opalescence PF-10%). Gel samples were collected from the upper and lower trays in each period (baseline, 15, 30, 50 and 120 minutes). HP concentration was determined with the potassium permanganate titration method. Degradation was calculated based on initial concentration of gels. Repeated measures two-way ANOVA and Tukey's test (5%) were applied. RESULTS: Bleaching gels exhibited exponential degradation over time. In 30 minutes, no significant differences in degradation among them were detected (P= 0.13). After 2 hours, lower degradation of CT-CP/OPF (61.85±10.65), compared with hydrogen peroxide in PT and CT (71.55±8.24 and 78.69±9.33, respectively) was observed. The gels showed higher degradation rate in lower trays than in upper trays in all evaluated times. In general, the bleaching gels in lower trays degraded more than in upper trays. The carbamide peroxide gel presented lower degradation than hydrogen peroxide after 2 hours. The degradation of the 10% hydrogen peroxide gel used in prefilled trays was higher than the one in customized trays after 30 minutes, but after 120 minutes, the degradation rate was similar for both. CLINICAL SIGNIFICANCE: Bleaching gels degraded faster in lower arches than in upper arches. The degradation process was faster in the first 15 minutes of use and depended on the gel's composition, time of use, and tray position in the dental arches.