A systematic review of the evidence on flossing indicates that professional flossing performed in first-grade children on school days reduced caries risk by 40%.
A systematic review of the evidence on flossing indicates that professional flossing performed in first-grade children on school days reduced caries risk by 40%. This benefit was identified in predominantly the primary teeth in children who, it is assumed, had comparatively poor oral hygiene and minimal exposure to fluoride. When professional flossing was performed on a three-monthly basis, there was no evidence of a benefit, suggesting that infrequent flossing may be ineffective when it comes to caries control. When flossing was self-performed by young adolescents, even under supervision on school days, there was also no evidence of benefit, which may be due to the presence of fluorides, poor flossing techniques, or other reasons. No evidence on the effectiveness of floss in adults or under real-world clinical conditions could be identified. In particular, there was no evidence that flossing is effective in the presence of topical fluorides.
Of the six trials that evaluated the effect of flossing on interproximal caries risk, two trials reported that professional flossing reduced caries risk (Wright et al., 1979, 1980). The strengths of these two studies include the large observed relative risk reduction of 40%, the statistical significance of the combined results, and the possibility that flossing benefits were underestimated because there was no professional flossing performed on weekends and the extended summer break, and, possibly, because parental flossing of control teeth diluted the professional flossing effect. Weaknesses include that both studies were not truly independent, since they were conducted by the same investigators, that financial support may have biased study findings (Wright et al., 1980), that minimal data were available on oral hygiene and fluoride exposure, and that a difference of 54 caries lesions in two studies combined is a small number on which to base universal flossing recommendations. If the benefits of flossing clustered within mouths more than we estimated, or if the baseline randomization was biased, the statistical significance of a flossing benefit could come into question.
.
