SCIENCE IN THE NEWS - Dental Health

（单词翻译）

SCIENCE IN THE NEWS - Dental Health
By Nancy Steinbach

Broadcast: Tuesday, April 13, 2004

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VOICE ONE:

This is Steve Ember.

VOICE TWO:

 
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And this is Bob Doughty² with Science in the News, a VOA Special English program about recent developments in science. Today, we tell about diseases of the teeth and gums, and ways to prevent and treat them.

VOICE ONE:

People have been troubled by tooth and gum problems for thousands of years. The earliest record of dental treatment comes from ancient Egypt. Books say the Egyptians treated gum swelling³ by using a substance made of spices and onions. The earliest known person to treat tooth problems was also from Egypt. He lived about five-thousand years ago. He was known as a "doctor of the tooth."

Experts say Chinese people living almost five-thousand years ago treated tooth pain by acupuncture⁴ -- placing small sharp needles in different parts of the body. About one-thousand-three-hundred years ago, the Chinese filled holes in the teeth with a mixture of the metals mercury⁵, silver and tin. That was almost one-thousand years before a similar substance was first used in western countries. Some ancient people like the Maya did not treat dental disease. But they made their teeth pretty by placing pieces of stone and metal on them.

VOICE TWO:

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 that had been lost.

From the fifth to the fifteenth centuries, Europeans with tooth problems went to people called barber-surgeons. These people performed many services, including cutting hair, pulling teeth and treating medical conditions. Dental treatment improved during the fourteenth and fifteenth centuries as doctors increased their knowledge about teeth.

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VOICE ONE:

Modern dentistry began in the Seventeen-Hundreds in France. That was when Pierre Fauchard published his book called "The Surgeon Dentist." It was the first book about dental science. The book provided information about dental problems for other dentists to use. And it described ways to keep teeth healthy. Pierre Fauchard is considered the father of modern dentistry. His work was important in helping⁶ establish dentistry as a separate profession.

Organized dentistry began in Eighteen-Forty. That is when the world's first dental school opened in the American city of Baltimore, Maryland. Four years later, a dentist first used drugs to ease the pain during dental work. Two years after that, another dentist publicly demonstrated the use of the gas, ether, as a way to reduce pain.

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

VOICE TWO:

In Eighteen-Ninety, an American scientist showed that bacteria in the mouth act on sugars that remain on the teeth after eating. This action creates acid that damages the tooth. The damage appears as a hole in the tooth. It is called a cavity⁷. The part of the tooth that has been destroyed by the acid is inside the cavity. It is known as tooth decay⁸.

Tooth decay is common in the United States and around the world. Dental professionals say the acid remaining in the mouth must be removed before it destroys the outer covering of the teeth. Dentists say the best thing people can do for their teeth is to keep them clean. After eating, people should use a toothbrush or other device to clean the teeth. Then they should use a thin string or dental floss to remove particles of food between the teeth. Visiting a dentist every six months can help keep the teeth healthy and prevent cavities⁹.

VOICE ONE:

Experts say the greatest improvement in dental health during the twentieth century began in the United States in the early Nineteen-Hundreds. Dentists in the small western town of Colorado Springs, Colorado found that children there had low rates of tooth decay. They discovered that the town's water supply contained fluoride, an element found in rocks and minerals. Public health researchers thought that adding fluoride to water in other American cities could reduce the rates of tooth decay.

In Nineteen-Forty-Five, a test program began in the middle western state of Michigan. Ten years later, results showed a fifty to seventy percent reduction in cavities in the children who drank water containing fluoride. Since then, many studies have confirmed the value of fluoride. Today, most of the American water supply contains fluoride. And international health organizations, including the World Health Organization, support water fluoridation programs.

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VOICE TWO:

Decay is not the only disease that can cause tooth loss. Another serious disease affects the gums, the tissue that surrounds the teeth. It is also caused by bacteria. If the bacteria are not removed every day, they form a substance that stays on the teeth. This substance is known as plaque¹⁰.

At first, the gums appear to be swollen¹¹, and may bleed when the teeth are brushed. This can lead to serious infection of the tissue around the teeth. The infection may damage the bone that supports the teeth and cause tooth loss and other health problems. Studies have found that people with severe gum disease have an increased risk of developing heart disease, diabetes¹² and stroke.

Gum disease can be treated by a special dentist called a periodontist. Periodontists are trained to repair the gum areas that have been damaged. This can be painful and costly¹³.

Dental health experts say the best thing to do is to stop gum disease before it starts. The way to do this is to clean the teeth every day. People also should use dental floss to remove plaque from between the teeth. Most experts also agree that another way to prevent tooth and gum problems is to eat foods high in calcium¹⁴ and vitamins and low in sugar.

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VOICE ONE:

Scientists continue to develop better dental treatments and equipment. Improved technology may change the way people receive dental treatment in the future. For example, dentists are now using laser light to treat diseased gums and teeth. Dentists use computer technology to help them repair damaged teeth. Researchers have developed improved methods to repair bone that supports the teeth. And genetic¹⁵ research is expected to develop tests that will show the presence of disease-causing bacteria in the mouth.

Such increased knowledge about dental diseases and ways to prevent them has improved the health of many people. Yet problems remain in some areas. In industrial countries, minorities and other groups have a high level of untreated dental disease. In developing countries, many areas do not have even emergency care services. The World Health Organization says people in countries in Africa have the most tooth and gum problems.

VOICE TWO:

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

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

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VOICE ONE:

Many governments and other organizations provide help so people can get needed dental health services. But dental health professionals say people should take good care of their teeth and gums. They say people should keep their teeth as clean as possible. They should eat foods high in calcium and fiber¹⁶. These include milk products, whole grain breads and cereals¹⁷, vegetables, fruits, beans and nuts. Recent studies have shown that eating nuts can help slow the production of plaque on the teeth. Experts say these activities will help everyone improve their dental health throughout their lives.

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VOICE TWO:

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 news about science in Special English on the Voice of America.