Sealants versus fluoride varnish – which is better for preventing decay in children’s teeth?

ChildAlthough children and adolescents have healthier teeth today than in the past, tooth decay is still a problem among some individuals and populations, and it affects a large number of people around the world. Most decay in children and adolescents is concentrated on the biting surfaces of permanent back teeth. Preventive treatment options for tooth decay include tooth brushing with a fluoride toothpaste, use of fluoride supplements (e.g. fluoride tablets) and application of dental sealants and topical fluorides at dental clinics. Dental sealants are applied to form a physical barrier that prevents growth of bacteria and accumulation of food particles in the grooves of back teeth. Several sealant materials are available: The main types in use are resin-based sealants and glass ionomer cements. Fluoride varnishes are sticky pastes that are professionally applied to the teeth two to four times a year.

What was the research?

A systematic review of the evidence to find out whether dental sealants (or sealants together with fluoride varnishes) or fluoride varnishes are more effective for reducing tooth decay on biting surfaces of permanent back teeth in young people

Who conducted the research?

The research was conducted by a team led by Anneli Ahovuo-Saloranta from the Finnish Office for Health Technology Assessment (FinOHTA) on behalf of the Cochrane Oral Health Group. Helena Forss, Anne Hiiri, Anne Nordblad and Marjukka Makela were also on the team.

What evidence was included in the review?

Data was extracted from 8 randomised controlled trials. A total of 1,746 children aged 5 to 10 years participated in the trials, and were randomly assigned to receive dental sealant (or sealant together with fluoride varnish) or fluoride varnish applications.

What did the evidence say?

Some evidence suggests that applying resin-based sealants to the biting surfaces of permanent back teeth in children may reduce tooth decay in the permanent teeth of children by 3.7% over a two-year period, and by 29% over a nine-year period, when compared with fluoride varnish applications. Applying resin-based sealant together with fluoride varnish to the biting surfaces of the permanent back teeth may reduce tooth decay by 14.4% over a two-year period compared with fluoride varnish alone. Effects of applying glass ionomer sealants may be similar to those seen when fluoride varnish is applied, but evidence showing the similarity between interventions is of very low quality. Three studies reported that there were no associated adverse events from sealants or fluoride varnish applications were reported; the other studies did not mention adverse events.

How good was the evidence?

Available evidence is of low to very low quality because of the small number of included studies, and because of problems with the way in which studies were conducted. Further, most studies reported a relatively short follow-up time.

What are the implications for dentists and the general public?

Although evidence was found suggesting the superiority of resin-based fissure sealants over fluoride varnishes applied to prevent decay in permanent molars, and some evidence for benefit of resin-based sealant together with fluoride varnish over fluoride varnish alone, this evidence is of low quality. We conclude that current scarce data mean that it is not possible to reach conclusions about whether to apply sealants or fluoride varnishes on occlusal surfaces of permanent molars.

What should researchers look at in the future?

The number of included clinical trials was small, and more high-quality research is needed to compare the relative effectiveness of sealants versus fluoride varnishes for preventing dental decay on occlusal surfaces. With a split-mouth study design, the carry-over effect of fluoride varnish applications on the sealed teeth cannot be totally ruled out. Therefore, a parallel-group design would provide more reliable information on differences in effectiveness of sealants and fluoride varnishes. Proper documentation and description of study populations, intervention study designs, follow-up periods, drop-outs and outcomes as described in the CONSORT statement are recommended.


Ahovuo-Saloranta A, Forss H, Hiiri A, Nordblad A, Mäkelä M. Pit and fissure sealants versus fluoride varnishes for preventing dental decay in the permanent teeth of children and adolescents. Cochrane Database of Systematic Reviews 2016, Issue 1. Art. No.: CD003067. DOI: 10.1002/14651858.CD003067.pub4.

This post is an extended version of the review’s plain language summary, compiled by Anne Littlewood at the Cochrane Oral Health Group Editorial Base.