['CENTRAL, Medline, Embase, Web of Science, LILACS and BBO databases, the Brazilian database of thesis and dissertations (Banco de Teses CAPES), a Brazilian register of ethically approved projects involving human beings (SISNEP) and two registers of ongoing trials (Current Controlled Trials and Clinical-Trials.gov). Reference lists were also scanned for relevant papers. Study authors were contacted for additional information.', 'Individual or cluster-randomised or quasi-randomised controlled trials conducted in children under seven were included.', 'Study selection and data abstraction were conducted by two reviewers independently. Risk of bias assessment was undertaken using the Cochrane Collaboration tool. Meta-analyses of prevented fractions (PF) were performed to assess the effect of fluoride toothpaste on the dmft and dmfs. Meta-analyses were also performed to obtain a pooled relative risk (RR) to assess the effect of fluoride toothpastes on the proportion of children developing caries.', 'Eight studies were included. When standard F toothpastes were compared to placebo or no intervention, significant caries reduction at surface (PF = 31%; 95% CI 18-43; 2644 participants in five studies), tooth (PF = 16%; 95% CI 8-25; 2555 participants in one study) and individual (RR = 0.86; 95% CI 0.81-0.93; 2806 participants in two studies) level were observed. Low F toothpastes were effective only at surface level (PF = 40%; 95% CI 5-75; 561 participants in two studies).'] Does limited evidence suggest standard fluoride toothpaste reduces caries potential in preschool children?