Efficacy of In-office Bleaching Gel One Week After Mixing: A Randomized Clinical Trial

SUMMARY Objective: This randomized clinical trial aimed to evaluate the efficacy, risk and intensity of tooth sensitivity (TS) and gingival irritation (GI), and esthetic self-perception of in-office dental bleaching using a bleaching gel 1 week after mixing. Methods and Materials: Forty subjects underwent in-office bleaching with 40% hydrogen peroxide (Opalescence Boost PF, Ultradent). In a splitmouth design, each maxillary hemiarch received bleaching gel that was mixed during, or 1 week before, the treatment session. The bleaching procedure was performed in two sessions of 40 minutes with a 7-day interval. Tooth color was assessed before treatment, and 1 week, 2 weeks, and 1 month after the end of bleaching, using a digital spectrophotometer (Vita Easyshade; ΔE ab , ΔE 00 , and ΔWI D ) and subjective scales (Vita Classical and Vita Bleachedguide; ΔSGU). The risk and intensity of TS and GI were recorded using a Visual Analogue Scale (0-10). Esthetic self-perception was assessed using the Orofacial Esthetic Scale (0-10). Results: Satisfactory bleaching was achieved in both groups, with no significant differences for objective (ΔE ab , ΔE 00 , and ΔWI D ; p >0.72) or subjective (ΔSGU [shade guide units], p >0.84) color assessments. No significant differences were found in the risk and intensity of TS ( p =0.79; p =0.67) or GI ( p =1.0; p =0.85). Patients’ esthetic self-perceptions changed after the procedure ( p <0.009), mainly on the tooth color question ( p <0.001). Conclusion: In-office dental bleaching with Opalescence Boost PF 40% remained effective, without differences in risk and intensity of TS and GI, even 1 week after mixing.