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VOICE ONE:

This is Steve Ember.

VOICE TWO:

And this is Bob Doughty withScience in the News, a VOA Special English program about recentdevelopments in science. Today, we tell about diseases of the teethand gums, and ways to prevent and treat them.

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People have been troubled by tooth and gum problems for thousandsof years. The earliest record of dental treatment comes from ancientEgypt. Books say the Egyptians treated gum swelling by using asubstance made of spices and onions. The earliest known person totreat tooth problems was also from Egypt. He lived aboutfive-thousand years ago. He was known as a "doctor of the tooth."

Experts say Chinese people living almost five-thousand years agotreated tooth pain by acupuncture -- placing small sharp needles indifferent parts of the body. About one-thousand-three-hundred yearsago, the Chinese filled holes in the teeth with a mixture of themetals mercury, silver and tin. That was almost one-thousand yearsbefore a similar substance was first used in western countries. Someancient people like the Maya did not treat dental disease. But theymade their teeth pretty by placing pieces of stone and metal onthem.

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The ancient Romans were careful about keeping their teeth clean.More than two-thousand years ago, the Romans treated toothaches,filled holes in teeth, and made false teeth to replace those thathad been lost.

From the fifth to the fifteenth centuries, Europeans with toothproblems went to people called barber-surgeons. These peopleperformed many services, including cutting hair, pulling teeth andtreating medical conditions. Dental treatment improved during thefourteenth and fifteenth centuries as doctors increased theirknowledge about teeth.

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Modern dentistry began in the Seventeen-Hundreds in France. Thatwas when Pierre Fauchard published his book called "The SurgeonDentist." It was the first book about dental science. The bookprovided information about dental problems for other dentists touse. And it described ways to keep teeth healthy. Pierre Fauchard isconsidered the father of modern dentistry. His work was important inhelping establish dentistry as a separate profession.

Organized dentistry began in Eighteen-Forty. That is when theworld's first dental school opened in the American city ofBaltimore, Maryland. Four years later, a dentist first used drugs toease the pain during dental work. Two years after that, anotherdentist publicly demonstrated the use of the gas, ether, as a way toreduce pain.

And in Eighteen-Fifty-Eight, another American dentist invented adental drill that was powered by stepping on a device. This machinemade it possible for dentists to use both hands when working in apatient's mouth.

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In Eighteen-Ninety, an American scientist showed that bacteria inthe mouth act on sugars that remain on the teeth after eating. Thisaction creates acid that damages the tooth. The damage appears as ahole in the tooth. It is called a cavity. The part of the tooth thathas been destroyed by the acid is inside the cavity. It is known astooth decay.

Tooth decay is common in the United States and around the world.Dental professionals say the acid remaining in the mouth must beremoved before it destroys the outer covering of the teeth. Dentistssay the best thing people can do for their teeth is to keep themclean. After eating, people should use a toothbrush or other deviceto clean the teeth. Then they should use a thin string or dentalfloss to remove particles of food between the teeth. Visiting adentist every six months can help keep the teeth healthy and preventcavities.

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Experts say the greatest improvement in dental health during thetwentieth century began in the United States in the earlyNineteen-Hundreds. Dentists in the small western town of ColoradoSprings, Colorado found that children there had low rates of toothdecay. They discovered that the town's water supply containedfluoride, an element found in rocks and minerals. Public healthresearchers thought that adding fluoride to water in other Americancities could reduce the rates of tooth decay.

In Nineteen-Forty-Five, a test program began in the middlewestern state of Michigan. Ten years later, results showed a fiftyto seventy percent reduction in cavities in the children who drankwater containing fluoride. Since then, many studies have confirmedthe value of fluoride. Today, most of the American water supplycontains fluoride. And international health organizations, includingthe World Health Organization, support water fluoridation programs.

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Decay is not the only disease that can cause tooth loss. Anotherserious disease affects the gums, the tissue that surrounds theteeth. It is also caused by bacteria. If the bacteria are notremoved every day, they form a substance that stays on the teeth.This substance is known as plaque.

At first, the gums appear to be swollen, and may bleed when theteeth are brushed. This can lead to serious infection of the tissuearound the teeth. The infection may damage the bone that supportsthe teeth and cause tooth loss and other health problems. Studieshave found that people with severe gum disease have an increasedrisk of developing heart disease, diabetes and stroke.

Gum disease can be treated by a special dentist called aperiodontist. Periodontists are trained to repair the gum areas thathave been damaged. This can be painful and costly.

Dental health experts say the best thing to do is to stop gumdisease before it starts. The way to do this is to clean the teethevery day. People also should use dental floss to remove plaque frombetween the teeth. Most experts also agree that another way toprevent tooth and gum problems is to eat foods high in calcium andvitamins and low in sugar.

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Scientists continue to develop better dental treatments andequipment. Improved technology may change the way people receivedental treatment in the future. For example, dentists are now usinglaser light to treat diseased gums and teeth. Dentists use computertechnology to help them repair damaged teeth. Researchers havedeveloped improved methods to repair bone that supports the teeth.And genetic research is expected to develop tests that will show thepresence of disease-causing bacteria in the mouth.

Such increased knowledge about dental diseases and ways toprevent them has improved the health of many people. Yet problemsremain in some areas. In industrial countries, minorities and othergroups have a high level of untreated dental disease. In developingcountries, many areas do not have even emergency care services. TheWorld Health Organization says people in countries in Africa havethe most tooth and gum problems.

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World Health organization experts say the dental health situationis different for almost every country in the world. As a result, ithas developed oral health programs separately for each area.

The W-H-O oral health program is mainly for people living in poorareas. It provides them with information about mouth diseases andhealth care. It also studies preventive programs using fluoride inwater, salt, milk and toothpaste. And it explores ways to includedental health in national health care systems.

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VOICE ONE:

Many governments and other organizations provide help so peoplecan get needed dental health services. But dental healthprofessionals say people should take good care of their teeth andgums. They say people should keep their teeth as clean as possible.They should eat foods high in calcium and fiber. These include milkproducts, whole grain breads and cereals, vegetables, fruits, beansand nuts. Recent studies have shown that eating nuts can help slowthe production of plaque on the teeth. Experts say these activitieswill help everyone improve their dental health throughout theirlives.

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This SCIENCE IN THE NEWS program was written by Nancy Steinbach.It was produced by George Grow. This is Bob Doughty.

VOICE ONE:

And this is Steve Ember. Join us again next week for more newsabout science in Special English on the Voice of America.