Dental sealants are done with the intention of preventing cavities before they start in the pits and fissures of back teeth. Traditionally in dental schools and the majority of offices I would say, the sealant material of choice is a resin based composite material. The resin based composite material works great, but only under very controlled extremely dry conditions. I explain it to my patients like this. Imagine that you have a granite counter top, its very hard and slick. You put some plain elmers glue on there. You scrape it and it will come right off, right?
Now if you had a special drill and you drilled 50 tiny holes on that same spot and then let your elmers glue run into those holes and set up, you will not be able to remove that glue. This is how resin based composite sticks, it runs into pores in the tooths enamel that we create with an acid.
Now back to the granite counter top with pre-drilled little holes. If you now fill those holes with water, wipe your counter and then try to get your glue to stick it will now pop off again because the glue cannot run down into the little holes because they are full of moisture.
When any moisture gets onto the tooth surface while trying to bond a resin sealant, this is exactly what happens. (If you would like to see what pictures of a failed resin sealant look like click here on my air abrasion page here.) The little pores are totally or partially filled with moisture and the bond to the tooth is very weak. Let me tell you that on the young kids that typically have sealants, they are little saliva factories and if a hygienist is attempting to do them by herself, it is challenging if not almost impossible in my opinion to keep all of the teeth dry enough to achieve the proper bond that we talked about earlier. So, now after reading this you are probably skeptical and maybe a little alarmed about sealants, right? Well don’t be, because there is a material that addresses the moisture-bond issue and some others.
In my dental office here in Victoria, I do all of my patients sealants myself and the material we use is a Glass Ionomer. This material is actually moisture tolerant and it bonds in a totally different manner. It actually forms an ionic bond to the minerals in the tooth structure. This bond is also acid resistant, which is another problem that materials in the mouth face. It has a very high fluoride content and actually recharges and soaks up any fluoride it contacts. Now before those who have concerns about fluoride get worried about it, we are talking about an extremely localized, tiny dose at the sealant-tooth interface. This sealant can even be placed in many cases on the tooth while it is still erupting and at most risk for fissure decay because it cant be effectively cleaned.
So, I don’t have any hesitation in placing sealants, as long as they are the moisture tolerant ionic bonding glass ionomer variety. I am making a big deal out of sealants because I don’t believe that they are typically given much thought. But as you can see if you click on the link to my air abrasion page Below is some information from the manufacturer of our sealant material.