Home-based chemically-induced whitening of teeth in adults

Comparison of efficacy of tray-delivered carbamide and hydrogen peroxide for at-home bleaching: a systematic review and meta-analysis

“…This means that only methodologically sound studies should be included in a meta-analysis in a practice called "best evidence synthesis" [20]. Although we have performed subgroup analyses with studies classified as at "low" risk of bias and "unclear/high" risk of bias, the main conclusions should be based only in the studies classified as at "low" risk of bias in regard to randomization and allocation concealment, opposed to earlier studies that based their conclusions on all included studies regardless of their risk of bias [13,21]. Although the inclusion of studies at "high" risk of bias did not change the overall conclusions of the present investigation, this type of inclusion tends to overestimate the effect size [42].…”

“…For the ΔE, which derive from objective numbers produced by a spectrophotometer, evaluator blinding was not considered a key domain. An earlier systematic review [13] also compared the effectiveness of at-home bleaching products for dental bleaching, but the authors included many different comparisons, which made it difficult to reach an overall conclusion for clinical practice. The authors concluded that most of the available dentist-supervised or over-the-counter bleaching products available in the market for at-home bleaching are effective, but this conclusion was based on studies classified as at "moderate" and at "high" risk of bias.…”

“…The full texts of these 29 studies were assessed to check if they were eligible. Among them, 16 were excluded due to the following reasons: (1) old systematic reviews [ [13,21]], (2) case series studies [ [22]], (3) placebocontrolled studies [ [23][24][25]], (4) studies that did not compare PC and PH products [ [26][27][28][29][30][31]], and (5) studies that did not employ a control tray-delivered CP product [32][33][34][35].…”

“…Carbamide peroxide breaks down into HP and urea, with the HP concentration being approximately one third of the original CP percentage. There are many carbamide peroxide bleaching systems on the market with concentrations ranging from 10 to 22 % [13]. Irrespective of the concentration, these bleaching gels are recommended for periods ranging from 8 (overnight) to 2 h daily [6,[13][14][15].…”

“…However, the literature is still controversial as to which product is actually the most effective one [16][17][18]. Although an earlier systematic review of the literature has already evaluated the effectiveness of at-home bleaching agents [13], this review was published 8 years ago. Additionally, they did not aim to investigate a narrow research question as several comparisons were done, making the clinical decision harder.…”