This study concerns the prevention of dental caries by sealing pits and fissures of permanent molars with a photopolymerizable resin. It must compare these three techniques Microdentisty (air abrasion, abrasion and sound using small cutters) usually used to prepare micro cavities in the enamel and / or the outer third of the dentin. These three commonly used techniques have never been compared by retaining as endpoint retention of sealant. These techniques are painless and do not require local anesthesia.