Changes in plaque and gingivitis levels after tooth bleaching: A systematic review

The primary aim of this systematic review was to evaluate the effect of external tooth-bleaching products on plaque indices and to compare it to a placebo or a negative control.

A protocol was developed aimed to answer the next focused question: What is the effect of tooth bleaching compared to no treatment or a placebo, in subjects without periodontitis aged ≥18 years in the levels of plaque and gingivitis? Two electronic databases were used as sources in the search for studies satisfying the inclusion criteria: (a) The National Library of Medicine (MEDLINE via PubMed); (b) Cochrane Central Register of Controlled Trials.

Only randomized controlled trials were included. The initial search found 382 potential publications. Seven of them were finally included, and six were used in the meta-analyses. The use of bleaching products showed higher reductions in plaque (n = 6; standardized mean difference [SMD] = 0.47; 95% confidence interval [CI] = 0.06, 0.88; P < 0.001) and gingivitis indices (n = 4; SMD = 0.47; 95% CI = 0.22, 0.73; P < 0.001), when compared to a control group (no treatment or placebo).

External tooth bleaching is associated with statistically significant short-term reductions in plaque and gingivitis indices. However, no data were available to evaluate long-term effects.