Whitening dentifrice and tooth surface discoloration: a systematic review and meta-analysis

Objective: The aim of this systematic review was to assess the effect of a whitening dentifrice (WDF) relative to a regular dentifrice (RDF) on the reduction of natural extrinsic tooth surface discoloration (ETD). Materials and metods: The MEDLINE-PubMed, Cochrane-CENTRAL and EBSCO-Dentistry and Oral Sciences databases were searched, up to April 2017. The inclusion criteria were as follows:(randomized)controlled clinical trials, healthy subjects ≥18 years of age, studies comparing WDF with RDF, a follow-up period of at least 6 weeks and studies scoring ETD as the stain area/extent, stain intensity or a composite score. Studies using an induced staining model were excluded. Results: Independent screening of 851 unique papers resulted in 21 eligible publications, which included 32 comparisons. The descriptive analysis illustrated that the majority of comparisons showed a significant effect on ETD, in favour of WDF over RDF. The meta-analysis substantiated this observation and revealed that the difference of means (diffM) comparing WDF and RDF was a reduction for stain area of -0.44 [(95% CI: -0.55; -0.339) (P<.00001)] according to the original Lobene Stain Index; this result is in favour of the WDF. For the modified Lobene Stain Index, the diffM was -0.41 [(95% CI: -0.71; -0.10) (P=.009)]. For overall stain intensity, the diffM was -0.35 [(95% CI: -0.44; -0.25) (P<.00001)], and the composite score was -0.39 [(95% CI: -0.57; -0.21) (P<.0001)] and -0.54 [(95% CI: -0.66; -0.43) (P<.00001)]. Subgroup analysis differentiating between products that contained added chemical antidiscoloration agents showed a similar pattern. Conclusion: In this review, nearly all dentifrices that are specifically formulated for tooth whitening were shown to have a beneficial effect in reducing ETD, irrespective of whether or not a chemical discoloration agent was added.