A Cochrane review included 17 studies (15 included in meta-analysis). Fluoride toothpaste was not significantly different from mouthrinse (pooled DMFS PF 0%; 95% CI, -18% to 19%; p = 0.94), or gel (pooled DMFS PF 0%; 95% CI, -21% to 21%; p = 1), or both gel and mouthrinse (pooled DMFS PF 1%; 95% CI, -13% to 14%; p = 0.94); heterogeneity was substantial. Results from the single trial comparing toothpaste with varnish (in deciduous teeth) were inconclusive (dfs PF 5%; CI not obtainable). The pooled results from the comparisons of fluoride varnish with mouthrinse was a non-significant difference favouring varnish (DMFS PF 10%; 95% CI, -12% to 32%; p = 0.40), but this result was not robust to sensitivity analysis performed, and heterogeneity was considerable. Results from the single trial comparing varnish with gel (14%, 95% CI, -12% to 40%; p = 0.30) and the single trial comparing gel with mouthrinse (-14% DMFS PF; 95% CI, -40% to 12%; p = 0.30) were inconclusive (favoured varnish and mouthrinse respectively).
Comment: The quality of evidence is downgraded by imprecise results (limited study size for each comparison).