O objetivo deste estudo foi avaliar o efeito da aplicação de clorexidina (CRX) em dentina condicionada na retenção de restaurações confeccionadas em lesões cervicais não-cariosas (LCNC) após 6 meses. Ensaio clínico randomizado triplo cego do tipo boca dividida foi conduzido. Pacientes (n=42) com no mínimo duas LCNC foram incluídos. LCNC foram randomizadas em dois grupos: controle (solução placebo) ou grupo teste (aplicação de CRX 2% por 60 s após o condicionamento e antes da aplicação do adesivo). Restaurações Classe V (n=169) foram realizadas com adesivo de condicionamento ácido total e resina composta, por 10 operadores treinados. Um examinador calibrado avaliou as restaurações após 1 semana (base) e 6 meses usando os critérios da FDI. O desfecho primário foi retenção das restaurações. A análise dos fatores associados à falha das restaurações foi conduzida com Teste Exato de Fisher (α=0,05). Após 6 meses de acompanhamento, 3,4% (IC 95% 1,3-7,3) das restaurações falharam. Não houve diferença estatística entre os grupos CRX e controle (p=0,920). Com relação às variáveis das cavidades, cavidades mais profundas (p=0,024), largas (p=0,004) e em formato de cunha (p=0,033) falharam mais. Ambos os tratamentos (CRX e controle) proporcionaram performance clínica aceitável das restaurações. O uso de CRX como coadjuvante na adesão à dentina não influenciou a retenção das restaurações Classe V após 6 meses de acompanhamento.

This study aimed to evaluate the effect of chlorhexidine (CHX) application on etched dentin on the 6-month retention of restorations placed on non-carious cervical lesions (NCCLs). A randomized controlled split-mouth and triple blind trial was carried out. Patients (n=42) with at least two non-carious cervical lesions were included. NCCLs were randomly assigned to two groups: control (placebo solution) or test group (2% CHX solution for 60 s after acid etching and before the adhesive application). Class V restorations (n=169) were performed with an etch-and-rinse adhesive system and composite resin by 10 trained operators. A calibrated examiner evaluated the restorations at 1 week (baseline) and at 6 months using the FDI criteria. The primary outcome was retention of the restorations. The analysis of factors associated to failure of restorations was carried out by Fisher's exact test (α=0.05). After 6 months of follow-up, 3.4% (CI 95% 1.3-7.3) of the restorations failed. There was no statistically significant difference between control and CHX (p=0.920). Regarding the cavity variables, deeper (p=0.04), wider (p=0.004) and wedge-shaped (p=0.033) cavities failed more. Both treatments provided acceptable clinical performance of the restorations. The use of CHX as a adjuvant in dentin adhesion did not influence the retention of Class V restorations after 6 months of follow-up.

Tooth discoloration is commonly found in the dental clinic and tooth bleaching has been considered the preferred esthetic alternative, being more conservative, safe and with predictable results. Supervised home-use of 10% Carbamide Peroxide (CP) bleaching with custom-trays is the most common bleaching procedure dispensed by dentists to their patients. The good results obtained with this technique stimulated the flourishing of new products and techniques. Over-the-counter (OTC) bleaching products appeared as a low-cost alternative to bleach discolored teeth without dentist supervision. Different OTC products are available in supermarkets, drug stores or on the Internet, including rinses, paint-on brushes, toothpastes, chewing guns, dental floss, and whitening strips. There is lack of clinical evidence regarding the safety and effectiveness of these products, being most of the studies supported by the manufacturers'. Basically, toothpastes, chewing gums, and dental floss are removal agents of superficial stains. Rinses and paint-on brushes with low levels of hydrogen peroxide have some whitening effect, but without clinical relevance. Strips present similar esthetic results and side-effects, compared to bleaching with 10% CP using trays; however, the studies have financial support from the manufacturers and were based on short term evaluations. Legislation varies widely in different countries regarding OTC dental bleaching. Concerns have appeared due to the potential abusive use of these self-medication agents, especially in young patients, with potential harmful results. Dentists should be acquainted with this kind of products to be able to inform their patients. In conclusion, there is a need for independent clinical trials to provide sufficient evidence regarding the use of OTC bleaching products.