Light activation does not improve efficacy of tooth whitening
medwireNews: The use of light activation does not appear to enhance the effectiveness of tooth whitening, but is associated with greater sensitivity immediately after treatment, results of a clinical study show.
The study involved 22 patients who were due to undergo in-surgery tooth whitening with 25% hydrogen peroxide gel followed by 2 weeks of home treatment with 10% carbamide peroxide gel.
Half of the patients were randomly assigned to receive light activation at a wavelength of 400-500 nm during in-surgery bleaching. There were no other differences in treatment between the groups.
The study's primary outcome was the efficacy of tooth whitening, assessed by determining the change in color of the six maxillary anterior teeth on a shade guide at the end of whitening versus baseline.
Reporting their findings in the Journal of Dentistry, Paul Brunton (University of Leeds, UK) and team say that patients in both groups showed a clinically significant change in tooth color between baseline and 2 weeks following the end of home treatment.
In the group that received light activation, mean tooth color shade changed from 11.86 at baseline to 8.03 immediately after in-surgery treatment, with further reductions to 4.94 at 1 week and 3.85 at 2 weeks after home treatment.
In the group that did not receive light activation, mean tooth color shade changed from 11.70 at baseline to 8.28, 5.04, and 3.72 at the same three time points, respectively. None of the between-group differences were significant.
A secondary outcome was tooth sensitivity, determined by self-assessment using a visual analog scale. This measure was comparable between the groups at all time points except immediately after in-surgery treatment. At this point, sensitivity scores were significantly higher among patients who received light-activation than in those who did not, at 2.36 versus 0.45.
By 2 weeks after home treatment, sensitivity had increased and was comparable between the groups, at 3.00 with light versus 2.55 without light activation.
Noting that sensitivity is a recognized complication of tooth whitening with peroxide, Brunton et al conclude that their results represent "a valuable addition to the evidence base for tooth whitening."
By Joanna Lyford, Senior medwireNews Reporter