he study included 360 children aged 7 to 8 years with caries-free permanent teeth. Children were divided into 4 groups, and fissure sealing was performed as follows: group 1 -- 1 maxillary first molar and 1 mandibular first molar sealed; group 2 -- all first molars sealed; group 3 -- all molars and premolars sealed on eruption; group 4 -- controls, no teeth sealed. Materials used for sealing were Nuva-Seal (Caulk), Concise Brand White Sealant System (3M ESPE), and Concise Enamel Bond System (3M ESPE). Control examinations were performed over 15 years, every 6 months for 2 years and then every 12 months.