What is an Appropriate Etching Time For Sealant Application on Permanent Molars? Results from a Meta-Analysis.

PURPOSE This meta-analysis investigated the influence of different acid etching times on the retention rate of pit-and-fissure sealants based on clinical trials with a minimum duration of two years. MATERIALS AND METHODS A literature search was carried out in electronic databases along with hand searching to identify clinical trials that evaluated pit-and-fissure sealants in permanent molars. From 1280 identified abstracts, 195 studies were selected for full-text analysis, and 28 studies with 36 test groups were included in this meta-analysis. Test groups with etching times of 15 (n = 3), 20 (n = 2), 30 (n = 10), 40 (n = 1) and 60 s (n = 20) were found. Incidence rates of pit-and-fissure sealant losses were modelled using negative binomial regression. RESULTS The regression analysis did not reveal a significant influence of etching time on the survival of pit-and-fissure sealants based on the identified and included clinical trials. CONCLUSIONS Due to the limited number of clinical data for 15 and 20 s, conclusions regarding very short acid etching times were not possible. On the basis of regression analysis, a minimum of 30-s acid etching might be sufficient prior to fissure sealing.