Efficacy and Adverse Effects of Whitening Dentifrices Compared With Other Products: A Systematic Review and Meta-analysis.

Whitening dentifrices (WDs) are widespread and accessible worldwide, claiming to whiten teeth. Therefore, this systematic review aimed to assess the extrinsic stain removal (ESR), the whitening potential, and the adverse effects of WDs. Randomized controlled trials comparing WDs with regular dentifrices (RDs) and other home-based whitening products were searched at NCBI-PubMed, Cochrane-CENTRAL, EBSCO-Host, and clinicaltrials.gov. The studies were screened and had data extracted by two independent researchers. Eligible studies presented outcomes of ESR, color change, and adverse effects, with no restriction of publication date. Data were meta-analyzed using RevMan 5.3, and the level of evidence was rated according to GRADE criteria. Eleven studies (n=1962) assessed reduction of stain area and intensity through Lobene Stain index, with a mean difference (MD) of -0.33 ([-0.41;-0.25]; p=0.00001) and -0.34 ([-0.44;-0.25]; p=0.00001), respectively. When the modified Lobene Stain index was used (six studies; n=2576), MD was -0.42 ([-0.58;-0.25]; p=0.00001) and -0.30 ([-0.39;-0.21]; p=0.00001), respectively. Mean color change through shade guide tabs (three studies; n=1322) was -1.80 ([-2.33;-1.26]; p=0.00001). All differences were in favor of the WDs, which also produced a risk of adverse effects (RR=1.74; [1.20, 2.52]; p=0.003; four studies; n=1322). The comparison of WDs with paint-on gel (two studies; n=58) yielded similar efficacy and adverse effects (p>0.05), whereas the comparison of WDs with white strips (two studies; n=87) yielded higher efficacy of the latter (p=0.00001) and similar adverse effects (p=0.52). The quality of evidence varied from low to moderate. WDs are more effective in reducing extrinsic stain and producing a whitening-like effect in teeth than RDs, although they also produce more adverse effects. Whitening efficacy of WDs is similar to paint-on gel and lower than white strips. Higher-quality evidence demands larger, well-conducted, independent studies.