in vitro comparison of microleakage of two materials used as pit and fissure sealants

background and aims. marginal seal of the material is extremely important in fissure sealant therapy. the aim of this study was to investigate microleakage of flowable composite resins and conventional fissure sealants with or without dentin bonding agent. materials and methods. the occlusal surface of 60 intact extracted human premolars, divided into four groups, were cleaned with pumice/slurry, etched with 37% phosphoric acid for 15 seconds, rinsed and dried. groups were treated differ-ently: excite bonding agent followed by helioseal f fissure sealant in group1; helioseal f alone in group 2; excite bonding agent followed by tetric flow in group 3; and tetric flow alone in group 4. light-curing was done after each application. after thermocycling, the whole surface of each specimen was coated with nail varnish except for one millimeter around the fissure sealant. the teeth were immersed in 2% basic fuchsin for 24 hours and then sectioned buccolingually. the sections were analyzed for leakage under a stereomicroscope. data was analyzed by kruskal-wallis and mann-whitney tests at a significance level of p 0.05), except for groups 2 and 4 (p = 0.002) and groups 3 and 4 (p = 0.033). conclusion. use of a flowable composite with bonding agent is a good alternative for sealing pits and fissures; however, further in vitro and in vivo studies are necessary.