To evaluate the influence of light on bleaching efficacy and tooth sensitivity during in-office vital bleaching.
We performed a literature search using Medline, EMBASE and Cochrane Central up to September 2011.
randomised controlled trials (RCTs) or quasi-RCTs comparing the
light-activated bleaching system with non-activation bleaching system
were included. Reports without clinical data concerning bleaching
efficacy or tooth sensitivity were excluded.
studies were included in the meta-analysis. A light-activated system
produced better immediate bleaching effects than a non-light system when
lower concentrations of hydrogen peroxide (15–20% HP) were used (mean
difference [MD], −1.78; 95% confidence interval [CI]: [−2.30, −1.26]; P<0.00001).
When high concentrations of HP (25–35%) were employed, there was no
difference in the immediate bleaching effect (MD, −0.39; 95% CI: [−1.15,
0.37]; P=0.32) or short-term bleaching effect (MD, 0.25; 95% CI: [−0.47, 0.96]; P=0.50)
between the light-activated system and the non-light system. However,
the light-activated system produced a higher percentage of tooth
sensitivity (odds ratio [OR], 3.53; 95% CI: [1.37, 9.10]; P=0.009) than the non-light system during in-office bleaching.
increases the risk of tooth sensitivity during in-office bleaching, and
light may not improve the bleaching effect when high concentrations of
HP (25–35%) are employed. Therefore, dentists should use the
light-activated system with great caution or avoid its use altogether.
Further rigorous studies are, however, needed to explore the advantages
of this light-activated system when lower concentrations of HP (15–20%)