RESUMO
PURPOSE: To conduct a clinical evaluation of calcium lactate and sodium fluoride mouthrinses in reducing sensitivity and efficacy of color change during in-office bleaching. METHODS: 75 participants were selected and divided into three groups (n= 25), according to the type of desensitizing treatment tested: calcium lactate mouthrinse prior to sodium fluoride mouthrinse before each bleaching session; daily mouthrinse with sodium fluoride; control (absence of mouthrinse). Each mouthrinse was used for 1 minute. Bleaching was performed following the same protocol in all groups, with 40% hydrogen peroxide (Opalescence Boost), in three 40-minute sessions, with a 48-hour interval between sessions. Clinical parameters such as sensitivity, gingival irritation and mouthrinse acceptability were assessed using Visual Analogue Scale (VAS) and clinical examination at two timepoints: baseline (before any treatment) and 48 hours after the end of treatment. The color was evaluated with a spectrophotometer (VITA Classical scale guide, 3D Master guide and CIEL*a*b*). The data were analyzed by generalized linear models and by one-way ANOVA. RESULTS: There was significant color change in all groups according to the VITA Classical scale guide (P< 0.001). There was no significant difference among the groups for ΔL*, Δa*, Δb* and ΔE over time (P> 0.05). The control group presented a significant increase in sensitivity (P= 0.008). The other groups showed no significant difference between initial and final timepoints (P> 0.05). No symptoms of gingival irritation were observed in any of the groups evaluated. All desensitizing treatments presented high acceptability. Bleaching treatment was effective, regardless of association with desensitizing treatments. No treatment prevented bleaching sensitivity, but the absence of a combined desensitizing treatment led to increased sensitivity. CLINICAL SIGNIFICANCE: Although bleaching sensitivity during in-office bleaching treatment cannot be avoided, daily fluoridated mouthrinse or calcium lactate used prior to fluoridated mouthrinse prevented its increase.