Low quality evidence for effectiveness of fluoridated milk.

DATA SOURCES: The Cochrane Oral Health Groups Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, the U.S. National Institutes of Health Trials Register and WHO International Clinical Trials Registry. STUDY SELECTION: Randomised controlled trials with an intervention and follow-up period of at least two years, comparing fluoridated milk with non-fluoridated milk. DATA EXTRACTION AND SYNTHESIS: Two reviewers independently extracted data and assessed risk of bias with the Cochrane risk of bias tool. RESULTS: Only one unpublished trial was included. It involved 180 children aged three years at study commencement and was considered to be at high risk of bias. After three years permanent teeth had a caries reduction (mean difference (MD) -0.13, 95% CI -0.24 to -0.02) and primary teeth a caries reduction (MD -1.14, 95% CI -1.86 to -0.42). For primary teeth this is a substantial reduction, equivalent to a prevented fraction of 31%. For permanent teeth,the disease level was very low in the study, resulting in a small absolute effect size. CONCLUSIONS: There is low quality evidence to suggest fluoridated milk may be beneficial to schoolchildren, contributing to a substantial reduction in dental caries in primary teeth. Due to the low quality of the evidence, further research is likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. There was only one relatively small study, which had important methodological limitations on the data for the effectiveness in reducing caries. Furthermore, there was no information about the potential harms of the intervention. Additional RCTs of high quality are needed before we can draw definitive conclusions about the benefits of milk fluoridation.