The aim of this study was to evaluate retention and efficacy of polyacid-modified composite resin used as fissure sealant (Variglass V.L.C.) after six years. Three-hundred and seventy permanent first molars were sealed. After six years, 42.0% of the original group was re-examined and the sealant was found to be totally present in 3.4%, partially present in 16.2% and absent in 70.4% of the previously sealed occlusal surfaces. During the 6 years period, 9.5% of the sealed surfaces became carious, 25.0% were filled and 65.5% remained sound. Although the retention rate of the material has been very low, it appears to have prevented dental caries in 2/3 of the teeth evaluated after six years of placement.