Abstract Objectives This randomized, split-mouth, single-blinded trial assessed whether the use of reservoirs in at-home bleaching trays is equivalent to non-reservoir trays. Our choice of an equivalence trial was based on the expectation that a non-reservoir tray is sufficient to produce a color change. Secondary outcomes such as tooth sensitivity (TS) and gingival irritation (GI) were also assessed. Methodology Forty-six patients were selected with canines shade A2 or darker. In half of the patient’s arch, bleaching trays were made with reservoirs and the other half, without reservoirs. At-home bleaching was performed with carbamide peroxide (CP) 10% (3 h daily; 21 days). Color change was evaluated with a digital spectrophotometer (ΔE, ΔE00, and Whiteness Index) and shade guide units (ΔSGU) at baseline, during and one-month post-bleaching. TS and GI were assessed with a numeric scale (NRS) and a visual analog scale (VAS). Results After one month, the equivalence of reservoir and non-reservoir groups were observed in all color instruments (p>0.05). Fifteen and sixteen patients presented pain (absolute risk: 33% and 35%, 95%, confidence interval (CI) 21-46% and 23-49%) in the reservoir and non-reservoir side, respectively. The odds ratio for pain was 0.8 (95%CI 0.2-3.0) and the p-value was non-significant (p=1.0). TS intensity was similar between both groups in any of the pain scales (p>0.05). No difference in the GI was observed (p>0.05). Conclusions The protocol with reservoirs is equivalent in color change to the non-reservoir, although no superiority of the latter was observed in terms of reduced TS and GI with at-home 10% carbamide peroxide bleaching. Clinical Relevance The presence of reservoirs in a bleaching tray did not improve color change or affect tooth sensitivity and gingival irritation.

Resumo Para responder a seguinte questão de pesquisa através de uma revisão sistemática: "O risco e a intensidade de sensibilidade dentária (SD) e eficácia de clareamento são diferentes entre pacientes adultos que realizam clareamento caseiro usando moldeiras com reservatórios e aqueles que usam moldeiras sem reservatórios?”. Uma pesquisa abrangente foi realizada no MEDLINE via PubMed, Scopus, Web of Science, Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), Biblioteca Cochrane e literatura cinzenta, sem restrições. Os resumos da conferência anual da Associação Internacional para Pesquisa Dental além de estudos registrados ou em andamento também foram pesquisados. Dissertações e Teses foram pesquisados utilizando o Capes Journal Dissertações e Teses ProQuest. Apenas ensaios clínicos randomizados (ECR) foram incluídos. Usamos a ferramenta Risk of Bias (RoB) da Cochrane para avaliação de qualidade. Após a remoção de duplicatas, triagem de título e resumo e exame de texto completo, nove ECRs permaneceram para análises qualitativas. A grande maioria dos estudos não relatou o método de randomização, ocultação de alocação e cegamento do examinador durante a avaliação de cores. Dos nove estudos, oito estavam sob risco claro de viés. Em relação à mudança de cor, quatro estudos não relataram nenhuma mudança e dois relataram melhora na mudança de cor com reservatórios. Apenas quatro estudos registraram a sensibilidade dentária e não relataram diferenças significativas. Apenas um estudo relatou maior irritação gengival com reservatórios. A falta de relatórios de dados nos impediu de executar uma meta-análise. Outros ECR bem desenhados devem ser conduzidos para responder a esta questão de pesquisa. Até agora não há evidências que sustentem que reservatórios em moldeiras de clareamento melhorem a mudança de cor. PROSPERO - CRD42016037628

Abstract To answer the following focused question through a systematic review: “Are the risk and intensity of tooth sensitivity (TS) and bleaching efficacy different between adult patients who undergo at-home bleaching using trays with reservoirs and those who use trays without reservoirs?”. A comprehensive search was performed in the MEDLINE via PubMed, Scopus, Web of Science, Latin American and Caribbean Health Sciences Literature database, Brazilian Library in Dentistry, Cochrane Library, and grey literature without restrictions. Abstracts from conferences; unpublished and ongoing trial registries, dissertations and theses (ProQuest Dissertations and Periódicos Capes Theses databases) were searched. Only randomized clinical trials (RCTs) were included. We used the Risk of Bias tool (RoB) from the Cochrane Collaboration for quality assessment. After the removal of duplicates, title and abstract screening and full-text examination, nine RCTs remained for qualitative analyses. The great majority of the studies did not report the method of randomization, allocation concealment, and examiner blinding during color assessment. From the nine studies, eight were at unclear risk of bias. In regard to color change, four studies reported no change and two reported improved color change with reservoirs. Only four studies recorded tooth sensitivity and they reported no significant differences. Only one study reported greater gingival irritation with reservoirs. Lack of data reporting prevented us from running a meta-analysis. Further well-designed RCT should be conducted to answer this research question. So far there is not evidence to support that reservoirs in bleaching trays improve color change. PROSPERO - CRD42016037628

Resumo Objetivo Avaliar in vitro a capacidade de remoção de pigmentos ocasionados em resina composta após aplicação de peróxido de hidrogênio 35%. Material e método Confeccionaram-se 20 amostras de resina composta Opallis (FGM), cor A1, em matriz metálica circular. As amostras foram divididas em quatro grupos (n=5) dos seguintes agentes corantes: água destilada (controle), café, vinho tinto e Coca-Cola®. No manchamento, as amostras ficaram imersas nas soluções durante 72 horas, com troca diária das bebidas. Procedeu-se à aplicação do gel de peróxido de hidrogênio 35% (Whiteness HP Blue Calcium, FGM) em três sessões, sendo uma aplicação do gel por sessão, o qual permaneceu nas amostras durante 40 minutos. Medidas de cor foram feitas inicialmente, após manchamento, após aplicação do peróxido e por mais 21 dias, usando espectrofotômetro Vita Easyshade. Os dados foram submetidos à análise de variância de dois fatores (tempo vs. corante) e ao teste de Tukey, para o contraste das médias (α=0,05). Resultado Apresentaram alteração de cor (ΔE - média/desvio padrão de L*) o café (15,7 ± 2,0) e o vinho (15,2 ± 4,6), quando comparados à Coca-Cola® (4,8 ± 1,9). O peróxido de hidrogênio removeu a pigmentação das amostras, porém, para nenhum dos corantes, houve retorno à coloração inicial, principalmente no grupo manchado por café (12,9 ± 1,5); este mostrou diferença significativa quando comparado ao controle (1,6 ± 0,6), diferentemente do vinho (3,3 ± 0,6) e da Coca-Cola® (2,1 ± 0,9), que se aproximaram do grupo controle. Conclusão As soluções corantes pigmentaram a resina composta, principalmente o café. A aplicação do peróxido de hidrogênio 35% foi eficaz na remoção de pigmentos das amostras, porém, em nenhum dos grupos, com diferentes corantes, houve retorno à coloração inicial (p>0,005).

Abstract Objective Evaluate in vitro the ability to removal pigments of composite resin after application of hydrogen peroxide 35%. Material and method Concocted to-20 resin samples composed Opallis (FGM), A1 color, in circular metal matrix. The samples were divided into 4 groups (n = 5) the following coloring agents: distilled water (control), coffee, red wine and Coca-Cola®. In the staining, the samples were immersed in the solutions for 72 hours, with daily change of beverages. Proceeded to the application of 35% hydrogen peroxide gel (Whiteness HP Blue Calcium, FGM) in 3 sessions, one application of gel per session that remained in the samples for 40 minutes. Color measurements were made initially after staining after application of the peroxide and for 21 days using Vita Easyshade spectrophotometer. The data were submitted to two-way ANOVA and Tukey’s test (α = 0.05). Result Significant color change was observed in specimens after immersion in the solutions, except the control group. Hydrogen peroxide was capable of removing the stains, however the color did not return to the baseline in any of the staining groups, especially for the groups immersed in coffee. Conclusion Staining solutions can stain the composite resin. The application of 35% hydrogen peroxide can remove partially the staining, minimizing the color change produced by the staining solutions. However, the bleaching gel was not capable of removing all staining, especially for the coffee group.