What are Dental Sealants?

The term "dental sealant" or "tooth sealant" refers to a plastic resin that 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 bacteria found in dental plaque (the white film that forms on a person's teeth). In general, the longer dental plaque remains on a tooth's surface the more likely it will be able to form a cavity. The idea behind brushing teeth is that dental plaque that has accumulated on a tooth's surface is scrubbed off. Some teeth however, related to aspects associated with their anatomy, are harder to clean than others. 

Some back teeth, especially molars, can be difficult for a person to clean because the grooves found on their chewing surface (the tooth's "pits and fissures") are deep and narrow. Even though the person brushes their teeth not all of the dental plaque that is present is cleansed off because the individual bristles of their toothbrush are simply too large to gain access into the depths of the tooth's grooves. Because some plaque has not been cleaned away, the tooth is at risk for the formation of decay.

By bonding plastic resin (the dental sealant) into the grooves of a tooth a dentist can create a tooth surface that is smoother. There are no longer any locations on the chewing surface of the tooth that the bristles of a toothbrush can't access and clean. Since dental plaque can be removed more easily and effectively, there is much less of a chance that tooth decay will form.

Another difficulty associated with a tooth having deep grooves is that in some instances the thickness of the enamel that lies at the base of the grooves is thinner than the enamel that encases other aspects of the tooth. This means that not only can deep narrow grooves make it more likely that tooth decay will form (because the tooth can't be cleansed effectively) but also that any decay that does form will have an easier time of penetrating through enamel layer (because it is less thick) and progressing on into the inner aspects of the tooth.

Are Dental Sealants worth they money and are they safe?

The idea of putting a plastic sealant on kids teeth is not appealing to many parents who are worried that the plastiic will inevitably wear off with chewing and be absorbed.

Sealants are composed of various resin systems which may include cyanoacrylates, polyurethanes and BIS-GMA products. The most commonly used products are generally comprised of BIS-GMA and are similar to composite resins used as tooth colored filling materials. Many studies have been done over the last 20 years to determine the safety and efficacy of these products. A recent study did raise questions regarding the estrogenic potential of one ingredient found in some sealant products. However, the only current documented adverse effect of dental sealants and their placement is allergic reaction.

However, studies have shown that sealants are very effective in preventing dental caries particularly in children who may not take the greatest care of their teeth. For example, one study of first permanent molars (a.k.a. six year molars) showed that 15 years after sealant placement, 69 percent had sound occlusal (chewing) surfaces. Only 17 percent of first permanent molars without sealants had sound occlusal surfaces.

Once a cavity is formed and the enamel no longer protects the teeth, it's only a question of time until more teeth decay occurs. In terms of the economics its not simply a question of looking at the average cost of a sealant - $50 and the average cost of an simple one surface amalgam filling $120, or resin based filing $160. However, factor in the cost of a deeper cavity some time later, a three surface filling will cost upwards of $200, and further decay, necessitating a crown or root canal, then the protection offered is clearly worth it.  If your children eat poorly and drink sugared drinks, the investment will pay off in spades.While the thought of small layer of plastic on the back molars may be somewhat disturbing thing of the amount of plastic needed for a full set of dentures later on in life.