What is a sulcus sealant? It is an effective caries prevention method to protect tooth enamel from bacterial and metabolic products erosion by applying a layer of bonded resin to the fissure of the tooth without removing the tooth tissue. Zhang Ping, Department of Stomatology, MCCCI Comprehensive Outpatient Center What is the appropriate age for sealing? It is appropriate to seal the milk molars at the age of 3-4 years old; the first permanent molars, i.e. the sixth-aged teeth, should be closed at the age of 6-7 years old as early as possible; the bicuspid teeth and the second permanent molars should not exceed 12-13 years old in general.