The trial was biased because it lacks the double-blind procedure necessary to achieve credible results. To be truly representative, this trial should have included data from respondents who used only fluoride-free toothpaste. I believe the credibility of fluoride as a dental therapy, whether applied externally, used as a gel, or ingested in drinking water, is seriously questionable. There is also the risk of overdose causing dental fluorosis. It's well within the bounds of probability that low-caries incidence has far more to do with parental supervision of childrens' tooth brushing and good oral hygiene than the nature of the toothpaste used. The mechanics of disciplined regular cleaning is more important than the media employed.