In-office whitening: An investigation of the effect of light activation

Objective: Tooth whitening is increasing in popularity and treatment regimes are increasingly becoming more complicated and sophisticated. The use of light activation of in-office whitening agents has been recommended but little research to substantiate its benefits exists. The aim of this study was to determine if light activation changes the outcome of treatment in terms of whitening effect and whether it increases levels of sensitivity. Materials and Methods: Twenty two subjects were randomly allocated to two groups. Group A underwent in-office bleaching with a 25% hydrogen peroxide gel with light activation followed by two weeks home bleaching with 10% carbamide peroxide (Zoom, Culver City, California, USA). Subjects in Group B followed the same protocol but without light activation of the gel. The colour of the six anterior teeth was evaluated, with a value ordered shade guide, pre-treatment and 1 and 2 weeks post in-office bleaching. In addition sensitivity was assessed at the same visits using a visual analogue scale. Results: Immediately post treatment Group A had a mean shade improvement of (3.84) and Group B (3.4). At 1 and 2 weeks post treatment the mean shade improvements were 6.92 and 6.64 and 8.01 and 7.98 respectively. Immediately post treatment Group A had a mean sensitivity of 0.45 and Group 2 had a mean sensitivity of 2.36. At the 1 and 2 weeks review the mean sensitivity was 2.36 and 3.45 and 2.55 and 3.00 respectively. At all time points there was no significant difference in colour change or levels of sensitivity (p>0.05). Conclusions: Within the limitations of this study it can be concluded that the adjunctive use of light activation of the in-office bleaching system tested did not improve the clinical outcome in terms of the whitening achieved. In addition it did not increase the level of sensitivity recorded.