Color change of vital teeth exposed to bleaching performed with and without supplementary light

Abstract 

Objectives

The aim of this clinical study was to evaluate tooth color change after exposure to 25% hydrogen peroxide in-office tooth whitening system, with and without supplementary light exposure.

Methods

Twenty subjects were treated with two separate 45-min exposures of bleach, with and without light using an opposing-arch design. Visual and instrumental color measurements were obtained from eighty teeth before bleaching and seven days after treatment using two different shade guides, Vitapan Classical (VC), Vita Bleachedguide 3D-Master (BG) and an intraoral spectrophotometer. Data were analyzed using ANOVA, paired t-test, and Wilcoxon signed rank tests at the 0.05 level of significance.

Results

Instrumental method revealed significant difference in color between treatment with light and without light after seven days (p<0.05). No differences were visually detected between treatment with light and without light using the VC (p=0.56). However, a significant difference was recorded using the BG (p<0.01). Instrumental measurements of color change were in better accordance with visual findings using the BG guide (R²=0.60) rather than the VC (R²=0.20).

Conclusions

Within the limitations of this study, the treatment with supplementary light showed significantly greater bleaching-dependent changes in color compared to treatment without light when assessed using instrumental methods. The same was determined for the visual method with Vita Bleachedguide 3D-Master. No significant difference in color change with respect to light exposure was detected for the Vitapan Classical.

Keywords: Tooth bleaching, Tooth whitening, Bleaching light, Whitening lamp, Tooth color, Dental shade guide, Power bleaching, In-office bleaching