Six studies were included. The authors stated that they included an estimated 384 patients, 840 teeth and 1,090 surfaces (none of the studies appeared to report all three of these units). Four RCTs (approximately 140 patients) and one prospective and one retrospective cohort study were included. All studies were rated as fair on the validity assessment. One study had a high loss to follow up and three studies did not have blinded outcome assessment.
Caries progression in sealed lesions (median annualised progression rate 5 per cent) was lower than in unsealed lesions (median annualised progression rate 16.1 per cent). Sealing caries lesions reduced the likelihood of lesion progression by more than 70 per cent (summary prevented fraction was 73.2%, 95% CI 59.8 to 82.2 assuming perfect correlation between teeth or 75 per cent, 95% CI 67.1 to 81.1 assuming no correlation between teeth).
When only the RCTs were analysed, the summary prevented fraction remained above 70 per cent (four studies: summary prevented fraction 71.2%, 95% CI: 50.3, 83.3 assuming a correlation of 1). When only non-cavitated lesions were considered the median annualised progression rates for sealed lesions was 2.6% compared with 12.6% in unsealed lesions.
There was no evidence of statistical heterogeneity for any outcomes.