Sealing of pits and fissures depends on patient- and tooth factors. Prevention of occlusal carious is indicated for children with a high caries risk and especially when the morphology makes teeth more susceptible for developing caries (deep pits and fissures). Good occlusal caries diagnosis is difficult and a golden standard does not exist. When sealing of pits and fissures is indicated a preventive or a therapeutic approach can be chosen. A generally accepted guideline for sealing is still missing. Every approach has its advantages and disadvantages and depends on the individual operator.