Flossing before brushing helps remove plaque and debris, thereby facilitating access and the protective action of the fluoride in toothpaste within the interdental spaces.

noli's read

This recommendation generates significant interest because the order of steps in our daily hygiene is often debated. A randomized controlled trial (RCT) published in 2018 in the Journal of Periodontology by the team of Mazhari scientifically confirms this approach. Researchers observed that using dental floss before brushing allows for significantly more effective plaque removal between teeth. Furthermore, this same study shows that this sequence promotes significantly higher fluoride retention in the interdental spaces, as prior cleaning clears access for the toothpaste. Although the American Dental Association (ADA) notes in its expert opinions that the most important factor remains the regularity of daily cleaning regardless of the order, the efficacy of this specific sequence is indeed validated by science.

the sources

No named source held this one up — that absence is part of the verdict.