Results of this study should reassure dentists that nightguard vital bleaching is a safe, effective, and predictable method to lighten teeth. The whitening effect lasted up to 47 months in 82% of the patients, with no adverse side effects reported at the end of the study.

Among the 20 participants whose data were analyzed, it was found that a 16% carbamide peroxide whitening solution (Nite White Classic), when used as described in this study, can be effective in nightguard vital bleaching with no statistical differences in gingival index, plaque index, nonmarginal gingival index, nongingival oral mucosa changes, tooth vitality, or tooth sensitivity, compared with a 10% whitening solution (Nite White Classic). More gingival irritation was experienced with 16% carbamide peroxide. Additionally, 20% of the participants in this study self-reported sensitivity when wearing their treatment tray without any solution, and 36% of the participants reported sensitivity to the placebo solution.

This in vivo study demonstrated that a 14-day regimen of NGVB using a 10% carbamide peroxide solution had minimal effect on the surface morphology of enamel and that the effects did not worsen over time.

Purpose:The purpose of this longitudinal whitening study was to determine the stability, posttreatment side effects, and patient satisfaction after 6 months of active treatment of tetracyclinestained teeth with 10% carbamide peroxide at 0 and 54 months post treatment. Materials and Methods:Twelve patients who completed the study (80%) were contacted and asked to participate in a survey concerning their whitening experience. Subjects were asked whether there had been any change in the shade of their teeth after treatment, and if they had experienced any side effects that they believed were treatment-related. Eight of the twelve patients underwent clinical examination.Results: Ten patients (83%) reported no obvious shade change or only a slight darkening not noticed by others. Two (17%) reported a slight darkening that is probably noticeable by other people, but no one reported moderate darkening or significant darkening back to original shade. All respondents (n = 12) denied having to have a crown or root canal that they believed was treatment-related. Examiners who compared preoperative and post-treatment photographs and Vita shade values were in agreement with the patients' perceptions of shade change. The degree of improvement was significant for both the immediate (0 mo) and the 54-month post-treatment comparison with the pretreatment shade (p < .005 and p c .01 respectively). CLINICAL SIGNIFICANCEResults of this nightguard vital bleaching study indicate that tetracycline-stained teeth can be whitened successfully using extended treatment time, and that shade stability may last at least 54 months after treatment. Patients who participated in this study were overwhelmingly positive about the procedure in terms of shade retention and lack of post-treatment side effects. ( J Estbet Dent 11:265-277,1999) on enamel surface. Am J Dent 1995; 8:29-32. 31. McGuckin RS, Babin JF, Meyer BJ. Alterations in human enamel surface morphology following vital bleaching. J Prosthet Dent 1992; 68:75+760. 32. Shannon H, Spencer P, Gross K, Tira D.Characterization of enamel exposed to 10% carbamide pexoxide blcaching agents. Quintessence Int 1993; 24:394.