Sealants are placed in the natural grooves and pits of posterior permanent teeth to prevent decay.  They are usually placed soon after these teeth erupt into the mouth and so near age 6 and again at age 12, as soon as the second molar erupts, into the mouth.  The material used to seal these grooves and pits has evolved over time and is now very effective at its work.

With the newer sealant materials, we are now able to gain a chemical bond between tooth and sealant, so as not to allow bacteria to find their way into this minute space and go to work destroying tooth structure.  Chemical bonds are not prone to detachment and do not leak at the juncture (or we use the term margin) of tooth and sealant.  Glass ionomer sealants are state of the art.  They also have a fluoride release characteristic.  And there is a difference between a product that has fluoride in it and one that releases fluoride from it into the tooth.

Glass ionomer sealants wear more quickly than the old school sealant material.  But even if they are worn on the surface, the material remains intact down in the depths of the pits and grooves of the teeth.  So the tooth is still very well protected and the sealant does not need to be replaced.  They can be placed in a wet environment and are self- curing ( as opposed to needing to be cured with an ultraviolet light).

The "old school" resin sealant will not adhere well to aprismatic enamel, which is the primary type of enamel in  the pits and fissures.  Glass ionomer sealants do adhere to aprismatic enamel.  The "new school" glass ionomer sealants actually recharge each time it comes into contact with an external fluoride source.  So with each brushing where fluoride toothpaste is used and with each sip of fluoridated water as well as when fluoride mouthrinse is used, the fluoride level of the sealant is back to the level at initial placement.

My vote for my teeth and for the teeth of my children and friends is for glass ionomer sealants!!!!!