Seal out decay - seal in a smile

4 World Health • 47th Year, No. l, January-February 1994 Seal out decay - seal in a smile Alice M. Horowitz The use of fluorides in drinking-water, salt, milk, toothpaste and mouth-rinses has played a major role in reducing the number of cavities in the teeth of children and young adults throughout the world, especially in the industrialized world. But the problem of cavities is not over. In young people, most cavities develop in the pits and grooves of the chewing surfaces of back teeth, which derive the least benefit from fluorides . Fortunately, such damaging tooth decay can be prevented by sealing the teeth with a thin plastic coating which will protect them from the acids formed from bacteria and food that cause decay. Unfortunately, dental sealants have been underused by oral health care providers. Too often, they are also unknown to parents and children. Yet youngsters all over the world could suffer significantly less from tooth decay if sealants were used more frequently by dentists, their helpers and community health workers with special training. The sealing of teeth first started in the mid-1950s, when an American scientist discovered that by etching (putting a very mild acid on the tooth surface to make it rough) a bond could be established between the tooth and the plastic coating. The plastic coating . seals the pits and grooves so that food and bacteria cannot get in. Today, sealants are made of plastics similar to Applying sealant to a schoolchild's teeth in Thailand those used in some other dental procedures, such as repairing the broken edges of teeth. They can be applied by dentists, dental hygienists, dental assistants or properly trained community health workers. In the United States, a demonstration project was carried out which taught mothers how to apply pit and fissure sealants. In Thailand, community health workers have been specially trained to apply this protection to children's teeth. And in China, more than 25 000 children are benefiting from this procedure applied by community health workers in schools. Portable equipment Sealants can be applied in oral health clinics located in buildings or in mobile trailers. Sometimes the process can be carried out in schools or even outdoors in a village, using portable equipment. The procedure for applying sealants is relatively simple. First the tooth to be sealed is isolated by a rubber "dam" or cotton rolls to keep the tooth dry. After being thoroughly cleaned and dried, the surface is etched by putting on a mild acid solution for about one minute, sufficient to create a rough surface. The acid is then washed away, the tooth is again dried, and the sealant is painted on this rough tooth surface. It takes about one further minute for the sealant to harden. Those who can benefit most from this preventive treatment are children whose first and second permanent molars have just erupted, that is, have just become visible in the mouth. First permanent molars appear between the ages of 6 and 8 years; second permanent molars arrive between 11 and 14 years. Sometimes premolars or bicuspids can also be sealed. It must be stressed that sealants are not a substitute for other preventive procedures such as fluorides, cutting down on sweets, and using oral hygiene. The technique should be used to complement these measures so as to ensure maximum protection against tooth decay. • Dr Alice M. Horowitz is with the National Institute of Dental Research, National institutes of Health, Bethesda, MD 20892, USA