This concise review presents two Cochrane Reviews undertaken to determine: (1) the relative effectiveness of fluoride toothpastes of different concentrations in preventing dental caries in children and adolescents; and (2) the relationship between the use of topical fluorides in young children and their risk of developing dental fluorosis. To determine the relative effectiveness of fluoride toothpastes of different concentrations, we undertook a network meta-analysis utilizing both direct and indirect comparisons from randomized controlled trials (RCTs). The review examining fluorosis included evidence from experimental and observational studies. The findings of the reviews confirm the benefits of using fluoride toothpaste, when compared with placebo, in preventing caries in children and adolescents, but only significantly for fluoride concentrations of 1000 ppm and above. The relative caries-preventive effects of fluoride toothpastes of different concentrations increase with higher fluoride concentration. However, there is weak, unreliable evidence that starting the use of fluoride toothpaste in children under 12 months of age may be associated with an increased risk of fluorosis. The decision of what fluoride levels to use for children under 6 years should be balanced between the risk of developing dental caries and that of mild fluorosis. © 2011 International & American Associations for Dental Research.