The purpose of this study was to evaluate with the scanning electron microscope (SEM) the effects of mechanically enlarging the occlusal fissures with a bur in regards to: (1) fissure micromorphology; (2) sealant penetration into fissures; and (3) micromorphology of the fitting surface of sealants. The technique is described as EST, for Enameloplasty Sealant Technique. The conventional sealant technique is referred to as CST. A total of 30 extracted permanent molars were used and divided into four groups: (1) pumice prophylaxis, no sealant; (2) same as Group 1 but with FluoroShield sealant; (3) EST, no sealant; (4) EST followed by FluoroShield. Subgroups were instituted to evaluate the sealant-enamel interface and the sealant fitting surface. The bur used in this, study was specifically designed for this purpose. Some samples were replicated in epoxy resin and all samples were evaluated with the SEM. The results demonstrated that the EST allowed a deeper sealant penetration and a superior sealant adaptation than the CST. An increased surface area for sealant retention was readily evident in all samples treated with the EST.