Sealing means sealing grooves and pits in teeth. The dental hygienist then applies a layer of plastic varnish. This can be transparent or yellowish-white. Because the grooves are sealed, bacteria do not have a chance to cause cavities here. This treatment is often performed preventively in children. Teeth that have just come through are more susceptible to cavities because the enamel has not yet fully hardened. In adults, the grooves in the molars may be too deep, making it difficult to remove bacteria. In this situation, sealing can also be performed. Sealing is performed on indication.