What are dental sealants?

       The term "dental sealant" or "tooth sealant" refers to a plastic which a dentist bonds into the grooves of the chewing surface of a tooth as a means of helping to prevent the formation of tooth decay ("cavities").

           Why are dental sealants placed on teeth?    Tooth decay is caused by the white film that forms on a person's teeth, dentist's refer to this film as "plaque". The longer plaque remains on a tooth's surface the more likely it will be able to create a cavity. The idea behind brushing teeth is that the plaque that has accumulated on a tooth's surface is scrubbed off. Some teeth however, because of their anatomy, are harder to effectively clean than others.Some back teeth, especially molars, are difficult for a person to clean because the grooves in the chewing part of the tooth (the tooth's "pits and fissures") are deep and narrow. Even though the person brushes they can not clean the plaque off adequately because the bristles of their toothbrush are literally too large to gain access into the bottom of the tooth's grooves. Because some plaque is not cleaned off a cavity can develop.
       A dentist can combat this situation by bonding plastic (the dental sealant) into the grooves of a tooth. The net result is that the surface of the tooth is somewhat flatter and smoother. There are no longer any places on the chewing part of the tooth that the bristles of a toothbrush can't reach and clean. Since plaque can be removed more easily and effectively, there is much less chance that decay will start. [Another difficulty related to deep grooves in teeth is that sometimes the thickness of the enamel at the base of the groove is less thick than the enamel that encases other portions of the tooth. This means that not only can deep narrow grooves make it more likely a person's tooth will develop decay (because the tooth can't be cleaned effectively) but also that the cavity which does form has an easier time of penetrating the enamel layer because it is less thick.]  At what age should dental sealants be placed on teeth?Most dental sealants are placed on the teeth of children. To properly place a sealant a dentist must be able to keep the tooth bone dry. So, at a minimum, this means that the chewing surface of the tooth being sealed must be erupted (fully through the gums), and also that the patient is at an age where they can provide a degree of cooperation. The specific age at which this combination of events occurs will vary from child to child.
 An adult's teeth can be sealed, although the need this procedure is usually less. Sealants for either a child's or an adult's teeth should be considered on a case by case basis. After their examination, a dentist can tell you what they feel is indicated for your situation.
      On which teeth are dental sealants usually placed?        Any tooth that has characteristics that a sealant can correct, and thus place the tooth at less risk for developing decay, should be sealed. By far the most common teeth for a dentist to seal are a person's "back" teeth, and of these teeth the molars are the most common teeth on which dental sealants are placed. It is probably more common for a dentist to seal "permanent" teeth rather than "baby" teeth, but every person has their own needs. The recommendation for sealants should be considered on a case by case basis.

  Should dental sealants always be placed on teeth?

    Not necessarily. After an examination, your dentist can report to you what they feel is indicated for you or for your child. The shape of the grooves (pits and fissures) in some people's teeth place them more at risk for developing decay than others. Person's whose grooves are deep and narrow will have a greater need for sealants than people whose grooves are naturally shallow and rounded.
   Beyond pit and fissure anatomy your dentist will consider other variables that might indicate that a tooth is at risk for developing decay and thus a candidate for a sealant. They will evaluate the amount of dental plaque they find present, the historic decay rate of the patient, and the patient's history in terms of exposure to fluoride.
 

    How long do dental sealants last?

 The longevity of sealants can vary. Any sealants that have remained in place for three to five years would be considered successful, however, sealants can last much longer. It is not uncommon to see sealants placed during childhood still intact on the teeth of adults. Any sealants that do come off sooner than three to five years should not necessarily be considered failures. Any length of time a sealant remains in place is a time period where it can offer a tooth protection.
A dental sealant can only provide its best protection when it is fully intact. You may notice that a portion or even all of your sealant has come off, and if so you should let your dentist know. As a part of your regular check up your dentist will evaluate the status of your sealants.
A very common reason sealants do come off is related to the fact that the dentist could not maintain adequate dryness during the sealant placement procedure. In the case of children this is very often related to the degree of cooperation that the child can offer. As a child becomes older and more mature, it seems likely that the re-sealing of the tooth will be more successful.

    What is the procedure for placing dental sealants?

  Placing dental sealants can be a very easy process. The plastic used to seal a tooth is somewhat related to the plastic a dentist uses to make "white" fillings. So, even if you have never had a tooth sealed you might have an idea of what the procedure is like.   Here are the individual steps required for placing dental sealants:
1) In order for the sealant plastic to bond to the tooth the tooth's surface must be clean. A common way for dentists to clean a tooth is to polish it with a small brush.

2) Next the dentist will squirt out an "etching gel" on the tooth. This gel prepares the tooth's surface so the sealant plastic will bond to it.

3) Once etched, the dentist will dry the tooth. The part of the tooth that has just been etched will look "frosty" to the dentist, similar to the way etched glass looks.

4) While the tooth is dry the dentist will paint, or dab, the liquid sealant plastic into the grooves of the tooth.

5) Once the sealant plastic is in place the dentist will shine a special light on the tooth, often this light is blue. The light causes the plastic to set immediately. 

6) The sealant is now in place. The dentist will check the bite on the tooth so to make sure the plastic is not too thick. If it is they will simply use a drill and buff it down.
7) Since the sealant plastic is now set, there are no limitations on the patient's activities. Eating and drinking, even immediately, are no problem. As you can tell from the description of each step, the technical aspects of sealing a tooth are pain free and relatively easy. The difficulty connected to placing sealants is related to the dentist's ability to both visualize and keep dry the tooth on which they are working.
Often children, having never had a "filling" done, have no concept of what type of problems are being prevented by the placement of the dental sealant. As a result they are somewhat less than motivated to provide ideal cooperation. The net result can be a less effective or durable tooth sealant.
As a parent you should take efforts, before the dental appointment, to communicate to your child the importance of giving the dentist their best cooperation, so the dentist can accomplish the sealant process both as expertly and quickly as possible.