Dental caries: Do tooth sealants help in children and young people?

Using sealants on the molars (back teeth) can clearly reduce the risk of tooth decay.

The chewing surface of molars (back teeth) that have deep dents or grooves in them are particularly prone to tooth decay. This is because bacteria can easily get stuck inside the dents and grooves (fissures). Tooth decay, also called dental caries or cavities, is especially common in children and teenagers. One reason for this is because the protective enamel layer on their molars has not yet developed properly so these teeth are more vulnerable. If they eat too much sugary food and do not brush their teeth enough, their risk of tooth decay is higher.

To try to prevent tooth decay, dentists sometimes suggest using tooth sealants, particularly on permanent molars. In this painless procedure, the dentist covers the grooves on the surface of the teeth with a sealant, which is usually a resin (plastic) liquid. The aim is to stop bacteria from building up there. Various resin-based materials are used as sealants. Some of these release fluoride, whereas others do not. You can read more about what the procedure involves in our fact sheet (URL: http://www.informedhealthonline.org/index.191.en.html) .

Research on tooth sealants

Researchers from the Cochrane Collaboration wanted to find out how effective tooth sealants are. To do this, they systematically reviewed the results of trials. The researchers found 16 trials that tested modern forms of tooth sealants. The trials included children who were between about 5 and 16 years old. Some of the trials compared teeth that had sealants on them with teeth that did not – for example, by applying tooth sealants to the molars on one side of the children's mouths, but not the other. Ten of the trials compared different types of sealants with each other.

These trials showed that tooth sealants can work. After 4 to 5 years, compared to the “non-sealed” side, about half as many teeth on the “sealed” side of the children's mouths had cavities. One trial followed the children up for 9 years. In this trial, one group of children had tooth sealants applied to their teeth, and the other group did not. After 9 years, only 27% of the sealed teeth were affected by tooth decay, compared to 77% of the non-sealed teeth.

One of the keys to getting the most protection against tooth decay is that the sealants need to last as long as possible. After 1 year, 80 to 90% of the sealants were still in place. After 4 to 5 years, about 50 to 70% were still in place. Resin-based sealants lasted longer than so-called glass ionomer cement. In other words, sealants made from glass ionomer cement had to be re-applied more often.

It is not clear whether a particular material offers better protection against tooth decay than other materials if it stays intact. The trials did not look at adverse effects. The resins that are used nowadays are generally thought to be safe. Some people have had allergic reactions to them, but that is rare. It can be a good idea to have tooth sealants checked regularly by a dentist, to see whether the protective layer has worn away.


Author: Institute for Quality and Efficiency in Health Care (IQWiG)