Although children and adolescents have healthier teeth than in the past, tooth decay (also known as caries) is a problem in some people and places. Most tooth decay in young people occurs on the biting surfaces of back teeth. Tooth decay prevention includes brushing, fluoride supplements (such as tablets), fluoride directly applied to the teeth and dental sealants. Dental sealants aim to prevent bacteria growth that promote tooth decay in grooves of back teeth. Sealants are applied by dentists or dental care team members. The main types used are resin-based sealants and glass ionomer cements.
What was the research?
A systematic review of the evidence to find out whether sealants can prevent tooth decay in permanent teeth, and to look at the effects of different types of sealants.
Who conducted the research?
The research was conducted by a team led by Anneli Ahovuo-Saloranta from the University of Tampere , on behalf of Cochrane Oral Health. Helena Forss, Tanya Walsh, Anne Nordblad, Marjukka Makela and Helen V Worthington were also on the team.
What evidence was included in the review?
38 randomised controlled trials that involved 7,924 young people aged 5 to 16 years were included. A variety of dental sealants was used to prevent tooth decay. Young people in the studies represented the general population. The review includes studies available from a search of the literature up to 3 August 2016. We assessed all studies as being at high risk of bias because the dental professionals who are measuring the outcomes can see whether or not sealant has been used.
What did the evidence say?
Fifteen studies compared resin-based sealants to no sealants and found that children who had sealant applied to their back teeth were less likely to have tooth decay in their back teeth than children with no sealant. We were able to combine data from seven of these studies (including two published since 2010), which involved children who were aged from 5 to 10 years when the sealants were applied. This showed that if 40% of back teeth develop decay over 24 months, using sealant reduces this to 6%. Similar benefits for resin-based sealants were shown up to four years. The effect appeared to persist when measured up to nine years, but there was less evidence. Results were inconclusive when glass ionomer-based sealant was compared with no sealant and when one type of sealant material was compared with another. Four studies assessed possible problems from using sealants; none were reported.
How good was the evidence?
We found moderate-quality evidence that resin-based sealant is more effective than no sealant for preventing tooth decay, reducing it by between 11% and 51% more than in children without sealant (measured two years after application). ‘Moderate quality’ means we are reasonably certain of this finding, although it is possible that future research could change it. Most of the studies included in this analysis were carried out in the 1970s. We are not able to draw conclusions about the other comparisons included in our review as the available evidence is very low quality. More studies with long follow-up times are needed.
What are the implications for dentists and the general public?
Resin-based sealants applied to occlusal surfaces of permanent molars reduced caries when compared to no sealant. The effectiveness of glass ionomer sealant and the relative effectiveness of different types of sealants has yet to be established.
What should researchers look at in the future?
Trials with long follow-up times are needed to research the effectiveness of sealing procedures related to different caries prevalence levels. Long-term follow-up studies are needed, especially because caries progression rates in permanent teeth in the future are difficult to predict. Future studies should report characteristics of study populations in terms of risk factors likely to predict caries development. This will help to better determine the applicability of the evidence to different populations and settings, especially where background prevalence is not known. More research is also needed to clarify the relative effectiveness of different sealant material types (representing materials with clearly different chemical compounds). Head-to-head comparisons should preferably be studied in controlled settings including a trial arm without sealing. Intervention study designs should be in keeping with the Consolidated Standards of Reporting Trials (CONSORT) statement (www.consort-statement.org).
Ahovuo-Saloranta A, Forss H, Walsh T, Nordblad A, Mäkelä M, Worthington HV. Pit and fissure sealants for preventing dental decay in permanent teeth. Cochrane Database of Systematic Reviews 2017, Issue 7. Art. No.: CD001830. DOI: 10.1002/14651858.CD001830.pub5.
This post is an extended version of the review’s plain language summary, compiled by Anne Littlewood at the Cochrane Oral Health’s Editorial Base.