A randomized double-blind clinical trial comparing the efficacy, longevity and tolerability of two carbamide peroxide concentrations used for at-home vital bleaching

The aim of this double-blind randomized clinical trial was to verify the efficacy, longevity and tolerability of two carbamide peroxide concentrations used in at home vital bleaching. Ninety-two volunteers with shade mean C1 or darker for the six maxillary anterior teeth were randomized into two groups (n= 46) according to bleaching carbamide peroxide concentration: 10% (CP10) or 16% (CP16). Participants were instructed to use the whitening agent in a tray for two hours/day during three weeks. Shade evaluations were done with a value-oriented shade guide and a digital spectrophotometer at baseline and, at one week, 6 and 12 months after bleaching treatment. Tooth sensitivity was measured daily using a scale ranging from 0 (no sensitivity) to 4 (severe sensitivity). At 6 and 12-month follow-up periods, a questionnaire was applied including questions related to alimentary habits and oral hygiene aiming to verify if these factors could influence the durability of the bleaching treatment. One-week post-bleaching, both carbamide peroxide concentrations resulted in teeth significantly lighter than at baseline (p 0.1). The group treated with CP16 related more tooth sensitivity during the first (p= 0.02) and third (p= 0.01) weeks of treatment than the CP10 group. However, no major difference was observed (p= 0.09) when the degree of tooth sensitivity between groups was compared. After 12-month follow-up, both concentrations resulted in tooth significantly lighter than baseline for all color parameters (p 0.1). O PC16 relatou mais sensibilidade dentária durante a primeira (p= 0.02) e terceira (p= 0.01) semanas de tratamento. No entanto, não foi observada diferença entre os grupos quanto ao grau de sensibilidade relatada (p= 0.09). Após 12 meses de acompanhamento, pacientes tratados com PC10 ou PC16 permaneceram com dentes significativamente mais claros que o baseline para todos os parâmetros de cor (p 0.5). Ambas as concentrações de peróxido de carbamida testadas foram bem toleradas e, embora se tenha observado uma pequena regressão da cor para o PC16, o efeito clareador permaneceu satisfatório após 12 meses de acompanhament