Fifteen studies (n=4,989) were included in the review, of which 14 were RCTs (n=4,924).
The method of randomisation was unclear in several studies, as was the issue of allocation concealment in all but 4 studies. All but 2 (single-blind) studies were double-blind. Three studies stated the reasons for drop-outs and in 3 studies the number of drop-outs exceeded 10%.
Studies assessing gingivitis used several different outcome measures and showed diverse results. Six studies of SnF2 dentifrices were pooled; these showed a statistically significant reduction in gingivitis compared with control (gingival index WMD -0.15, 95% CI: -0.20, -0.11; I-squared 91.1%). Two studies of SnF2 dentifrices also showed a statistically significant reduction in the severity of gingivitis (gingivitis severity index WMD -0.21, 95% CI: -0.27, -0.14; I-squared 80.1%). However, there was evidence of significant statistical heterogeneity in both pooled results.
Studies on plaque used several different outcome measures and reported diverse results. Four studies that assessed plaque formation using the Turesky index were pooled and showed a significant difference in favour of SnF2 dentifrices or gel in comparison with control (WMD -0.31, 95% CI: -0.54, -0.07; I-squared 91.7%). However, there was evidence of significant statistical heterogeneity and no differences were found when studies assessing the plaque index were pooled. The majority of studies showed a statistically significant increase in staining with different SnF2 formulations in comparison with NaF. There was insufficient data to perform a meta-analysis of SnF2 mouth rinse and combinations of dentifrice and mouth rinse.