We searched randomized controlled trials, meta-analysis and systematic reviews from OVID-EBM Reviews which included ACP Journal Club, The Cochrane Library, and MEDLINE（1991 to 2005 ） to evaluate clinical effectiveness of pit and fissure sealants for caries. The resultsshowed that pit and fissure sealants were recommended to prevent caries of the occlusal surface. The effectiveness varied between the two types of sealants, in general, flowable resin composite had a more satisfactory retention than glass ionomer composite. Acid etch was helpful for less microleakage and more satisfactory retention. Mechanical air-abrasion with acid etch may have the best border seal, However, we were not sure of the effectiveness of Er：YAG laser, technique of dental drill preparation and splicing. More high quality clinical trials on pit and fissure sealants are still needed.
Objective To evaluate the efficacy of the light cured flowable composite resin and the light cured pit and fissure sealant in the prevention of dental caries in children. Methods EMbase, CBM, The Cochrane Library, PubMed, Web of Science, CNKI, WanFang Data and VIP databases were searched from inception to January 1st, 2017 for randomized controlled trials (RCTs) or quasi-RCTs about the application of the light cured flowable composite resin and the light cured pit and fissure sealants. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then, the RevMan 5.3 software was applied to conduct meta-analysis. Results A total of 13 studies were included. The results of meta-analysis showed that the complete retention rate of the light cured flowable composite resin group was higher than that of the light cured pit and fissure sealant group (6 months: RR=1.03, 95%CI 1.00 to 1.06, P=0.03; 12 months: RR=1.09, 95%CI 1.04 to 1.13, P=0.000 3; 24 months: RR=1.22, 95%CI 1.13 to 1.31, P<0.000 01). The incidence of caries of the light cured flowable composite resin group was lower than that of the light cured pit and fissure sealant group (12 months: Peto OR=0.30, 95%CI 0.16 to 0.56,P=0.000 2; 24 months: Peto OR=0.44, 95%CI 0.31 to 0.63, P<0.000 01). Conclusion The light cured flowable composite resin is superior to the light cured pit and fissure sealant in the complete retention and caries prevention. The above conclusions are needed to be verified by more high-quality clinical studies because of the limitation of the quality and follow-up time of studies.