This is the most recent update of this very significant Cochrane review on sealants for dental caries prevention in the permanent teeth of young people. This review was first reported in 19991 and most recently updated in 2008.2 As with the previous reviews this one assessed caries prevention, the effectiveness of differing materials, and sealant retention. In addition it examined the use of sealants on approximal surfaces for caries prevention but not lesion infiltration or caries arrest. Although no trials on approximal sealing for caries prevention were actually included in the results. The rigour of the reporting has improved but this does make the review less accessible.

In total 34 trials were included in the review. As with the previous reviews there was strong evidence for the effectiveness of resin sealants (12 trials). After 48-54 months, the retention of resin sealants was in general 70%. Based on the results of six studies with a caries incidence in the molar teeth of 40%, the application of resin sealants would reduce this to 6% developing caries. It should be remembered that the vast majority of trials examine the effect of a one time application of sealant but in clinical practice sealants should be maintained and repaired if defective; if maintained the effectiveness would be even higher.

Glass ionomer sealants had much poorer retention, but perhaps due to the low caries incidence in the populations studied, it was not possible for the review to make firm recommendations as to the effectiveness of glass ionomer in general and compared to resin sealants, in particular. However, given the number of studies supporting resin, this must remain the first choice material, with glass ionomer being reserved for use as an interim sealant when co-operation levels or tooth eruption status makes achieving adequate isolation difficult. No adverse effects were reported in the two trials that reported this issue.

In conclusion this review confirms the effectiveness of resin sealants. There is a need for more trials looking at the effectiveness of differing materials, especially glass ionomers, perhaps focussing on their use in less than ideal situations, because we already know resins work when isolation is not an issue.