Personal Health: Dental sealants offer high-risk teeth armor against decay
Jane E. Brody
The New York Times
Wednesday, February 19, 1997
sealants, properly applied and periodically replenished, can eliminate
decay in the chewing surfaces of teeth. Sealants, the plastic coatings
applied to permanent molars, are second only to fluorides in preventing
tooth decay over all and are more effective than fluorides in
protecting the chewing surfaces of molars, where most cavities occur.
Yet fewer than
20 percent of American children and only a tiny fraction of adults who
are prime candidates for tooth decay have had their teeth protected by
sealants. This country is far from the goal established by the United
States Public Health Service of sealing one or more teeth of half the
children 8 to 14 years old by 2000.
Dental Association has been urging dentists for years to apply sealants
to permanent molars as they emerge in children's mouths, and it wants
adults to know that you don't have to be a child to seal out tooth
decay. Anyone with healthy molars - teeth that have not yet been
drilled and filled - can greatly increase the chance of keeping those
teeth healthy for life by having sealants applied.
are coatings of plastic that are applied to the chewing surfaces of
molars, where food tends to get lodged in pits and fissures that are
difficult to clean thoroughly with a brush. Even saliva, which helps to
clean food particles from other areas of the mouth, cannot clean the
pits and fissures of permanent molars. Sealants work by filling in the
cracks, preventing accumulations of food and keeping bacteria that
cause decay from getting to the enamel on the tooth surface.
of sealants starts with a thorough cleaning by the dentist or dental
hygienist. Then the tooth surfaces are etched by acid for about 15
seconds so the nontoxic plastic material that is brushed on immediately
afterward will stick more easily. Depending on the product, the plastic
may then be "cured" with a chemical or light. For the sealants to
adhere properly, saliva must be kept from contaminating the area until
the plastic has hardened.
eight first and second permanent molars in the back of the mouth takes
about half and hour. Sealant may also be applied to wisdom teeth and
the premolars, the molars closest to the front of the mouth. But the
pre-molars are not usually treated because they are much less
susceptible to decay than the larger molars behind them.
Sealants can be
applied by a dentist or by a trained dental hygienist or dental
auxiliary person. At each dental visit, teeth should be checked to be
sure the treated areas are still adequately covered. When sealants wear
down, they should be reapplied for continued protection.
According to a
1995 survey by the dental association, the cost of sealing each tooth
averages $24, slightly less than half the typical cost of filling a
cavity. Charges, of course, vary with location. Many private dental
plans cover the cost. In 33 states, Medicaid provides some coverage,
ranging from 100 percent coverage to coverage for only the first
American Indians are more likely than the members of any other group in
this country to get sealants because the public health service that
cares for them offers them this benefit, said Dr Richard Simonsen, a
researcher in the dental products division of the Minnesota Mining and
Manufacturing Company in St. Paul, Minn. He added that a number of
small countries, including Finland, had much higher rates of sealant
application than this country's.
In the early
days of sealants, many dentists feared that coating each tooth would
lead to rampant dental disease if those teeth already had the
beginnings of decay. But quite the opposite is true. Several studies
have shown that an incipient cavity can be nipped in the bud and the
health of the tooth restored by applying a sealant, because the plastic
coating deprives the bacteria of oxygen and food.
are best applied soon after the permanent molars erupt, it is never too
late. Adolescents and college students, whose eating and dental hygiene
habits may be less than ideal, are prime candidates for sealant
protection. Having sealants applied would be a valuable parting gift
for college-bound students. Many adults could also benefit.
especially helpful for adults with deep fissures in their molars,
especially those who grew up without access to fluoridated water and
toothpaste without fluoride. Some adults are at high risk for decay
because illness or injury makes it hard for them to clean their teeth
properly. And some adults suffer from chronic xerostomia, or dry mouth.
They may be on medications that reduce saliva formation, or they may
have disorders that impair salivation, like Sjogren's syndrome, an
autoimmune disease. When saliva is inadequate to cleanse the mouth, the
risk of decay increases greatly.
sealants, fluoride and proper oral hygiene remain critically important
to lasting dental health, and there are many other teeth and tooth
surfaces in need of protection. Teeth should be brushed with
fluoridated toothpaste at least twice a day, including just before
bedtime. They should also be flossed each night. Regular dental
checkups and semiannual cleanings remain vital to dental health, and so
are dietary habits that do not leave the teeth chronically exposed to
sweets and other carbohydrates that provide banquets for decay-causing