Factors influencing the effectiveness of sealants--a meta-analysis.

Meta-analysis of published studies was applied to analyze the effectiveness of fissure sealants in preventing dental caries. Studies were identified by a MEDLINE search, supplemented by a hand search of the references in the articles recovered. All articles were assessed on the basis of quality, and were combined with the Mantel-Haenszel method. The prevented fraction in the exposed population (PF) was estimated using pooled relative risk. Heterogeneity of the effect and publication bias were also analyzed. Twenty-four studies were included in the meta-analysis. The overall effectiveness of autopolymerized fissure sealants was 71.36% (95% confidence interval 69.69-72.94%). Effectiveness in preventing caries decreased with time, and increased when drinking water was fluoridated (82.69% vs 72.28%). Heterogeneity was significant in most cases, and was further studied with multiple linear regression analysis. It is concluded that autopolymerizing sealants should be used. More research is needed to compare the effectiveness of dental hygienists and dentists in applying sealants.