RESUMO
OBJECTIVE: To use the criteria set by the American Dental Association to evaluate the effectiveness of nightguard vital bleaching with 10% carbamide peroxide through a controlled randomized clinical trial. MATERIALS AND METHODS: Fifty volunteers allocated to either an experimental group(Opalescence PF 10%; OPA) or a control group (placebo; PLA) used a gel for 21 days. Observations of tooth colour were recorded at baseline, immediately after 3 weeks of use(day 21), and 30 days (day 30) and 6 months (day 180) after the treatment was finished. Colour was evaluated with the Vitapan classical shade guide and from the volunteers' degree of satisfaction. Tooth sensitivity and gingival bleeding were also assessed. RESULTS: The median increase in the lightness of the teeth in the OPA group was 3 units,based on the value-ordered Vitapan shade guide. This improvement in lightness was maintained for 6 months in 88% of this group. In the PLA group, 8% had a 2-unit reduction in tooth colour at day 21. Tooth sensitivity occurred in the OPA (36%) and PLA (8%)groups. Gingival bleeding was not associated with gel use. Volunteers' satisfaction was 92% for the OPA and 8% for the PLA group. CONCLUSIONS: With the protocol used, nightguard vital bleaching was an effective technique that had minimal and transient side effects that disappeared after treatment without causing sequelae or complications.
