Light augments tooth whitening with peroxide

Background. The authors tested the adjunctive use of light with a 15 percent peroxide gel as a single-visit, in-office tooth whitening system. Methods. Subjects (N = 87) with stained (> shade D4, Vita Zahn-fabrik, Bad Sackingen, Germany) anterior teeth were randomly assigned to test (peroxide and light), peroxide control (peroxide gel) or light control (placebo gel and light) groups and were tested for one hour. The researchers evaluated tooth shade, color and subject response at baseline and post-treatment and at three and six months posttreatment. Results. The initial shade unit reduction, of combined light and peroxide treatment (8.4) was greatest compared with that of peroxide alone (5.9) and of light alone (4.9). Approximately 88 percent of these effects persisted for six months. Lightness was increased and yellowness decreased to a significantly greater extent in the test group than in either control. These findings were corroborated by subject evaluation. One week after treatment, moderate to greatly increased tooth sensitivity occurred in 20 percent of test subjects, 21.7 percent of peroxide control subjects and non of the light control subjects. Neither tooth sensitivity nor gingival redness was present at the three- and six-month visits. Conclusions. Peroxide and light treatment significantly lightened the color of teeth to a greater extent than did peroxide or light alone, with a low and transient incidence of tooth sensitivity. Clinical Implications. Light can increase the tooth-whitening effect of peroxide, thereby increasing the effectiveness of tooth-whitening procedures.