A Cochrane Review from 2004 evaluated fluoride for the prevention of demineralized white spot lesions (DWLs) during orthodontic treatment.54 This review included 15 trials with 723 participants and had less strength to their conclusions which were, "There is some evidence that the use of topical fluoride or fluoride-containing bonding materials during orthodontic treatment reduces the occurrence and severity of white spot lesions, however there is little evidence as to which method or combination of methods to deliver the fluoride is the most effective. Based on current best practice in other areas of dentistry, for which there is evidence, we recommend that patients with fixed braces rinse daily with a 0.05% sodium fluoride mouthrinse. More high quality, clinical research is required into the different modes of delivering fluoride to the orthodontic patient." An update to the 2004 review was published in 2013 that included an additional three studies and 458 participants.55 In the updated review, the authors “found some moderate evidence that fluoride varnish applied every six weeks at the time of orthodontic review during treatment is effective, but this finding is based on a single study. Further adequately powered, double-blind, randomized controlled trials are required to determine the best means of preventing DWLs in patients undergoing orthodontic treatment and the most accurate means of assessing compliance with treatment and possible adverse effects. Future studies should follow up participants beyond the end of orthodontic treatment to determine the effect of DWLs on participant satisfaction with treatment.” Although the level of evidence as to which fluoride therapy is best to use during orthodontic treatments, it is clear that fluoride therapy is an essential component of successful treatment.