SCIENCE IN THE NEWS - Dental Health

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:

 
Graphic¹ Image
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.

1 graphic   

adj.生动的，形象的，绘画的，文字的，图表的

参考例句：

• The book gave a graphic description of the war.这本书生动地描述了战争的情况。
• Distinguish important text items in lists with graphic icons.用图标来区分重要的文本项。

2 doughty   

adj.勇猛的，坚强的

参考例句：

• Most of successful men have the characteristics of contumacy and doughty.绝大多数成功人士都有共同的特质：脾气倔强，性格刚强。
• The doughty old man battled his illness with fierce determination.坚强的老人用巨大毅力与疾病作斗争。

3 swelling   

n.肿胀

参考例句：

• Use ice to reduce the swelling. 用冰敷消肿。
• There is a marked swelling of the lymph nodes. 淋巴结处有明显的肿块。

4 acupuncture   

n.针灸，针刺法，针疗法

参考例句：

• Written records show that acupuncture dates back to the Song Dynasty.文字记载表明，宋朝就已经有了针灸。
• It's known that acupuncture originated in China.众所周知，针灸起源于中国。

5 mercury   

n.汞，水银，水银柱

参考例句：

• The liquid we can see in thermometers is mercury.我们看到的温度计里的液体是水银。
• Mercury has a much greater density than water.水银的密度比水大得多。

6 helping   

n.食物的一份&adj.帮助人的，辅助的

参考例句：

• The poor children regularly pony up for a second helping of my hamburger. 那些可怜的孩子们总是要求我把我的汉堡包再给他们一份。
• By doing this, they may at times be helping to restore competition. 这样一来, 他在某些时候,有助于竞争的加强。

7 cavity   

n.洞，穴，凹处，龋洞

参考例句：

• There's a cavity in the boy's tooth.这个男孩的牙上有一个洞。
• The dentist carefully located the filling in the cavity.牙医小心地把填塞的东西放入牙洞里。

8 decay   

vi.腐烂，衰落；n.腐烂，腐朽，衰败状态

参考例句：

• The vegetables have begun to decay.那些蔬菜已开始腐烂。
• Our powers decay in old age.我们的体力在老年时就衰退。

9 cavities   

腔，洞( cavity的名词复数 )； （龋齿的）洞

参考例句：

• Cavities in teeth are caused by decay. 牙齿上的空洞是由龋蚀造成的。
• The dentist filled several cavities in my teeth. 牙医给我的牙堵了好几个洞 excavation 指“挖掘的洞”，如：

10 plaque   

n.饰板，匾，(医)血小板

参考例句：

• There is a commemorative plaque to the artist in the village hall.村公所里有一块纪念该艺术家的牌匾。
• Some Latin words were engraved on the plaque. 牌匾上刻着些拉丁文。

11 swollen   

adj.肿大的，水涨的；v.使变大，肿胀

参考例句：

• Her legs had got swollen from standing up all day.因为整天站着，她的双腿已经肿了。
• A mosquito had bitten her and her arm had swollen up.蚊子叮了她，她的手臂肿起来了。

12 diabetes   

n.糖尿病

参考例句：

• In case of diabetes, physicians advise against the use of sugar.对于糖尿病患者，医生告诫他们不要吃糖。
• Diabetes is caused by a fault in the insulin production of the body.糖尿病是由体內胰岛素分泌失调引起的。

13 costly   

adj.昂贵的，价值高的，豪华的

参考例句：

• It must be very costly to keep up a house like this.维修这么一幢房子一定很昂贵。
• This dictionary is very useful,only it is a bit costly.这本词典很有用，左不过贵了些。

14 calcium   

n.钙(化学符号Ca)

参考例句：

• We need calcium to make bones.我们需要钙来壮骨。
• Calcium is found most abundantly in milk.奶含钙最丰富。

15 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。

16 fiber   

n.纤维，纤维质

参考例句：

• The basic structural unit of yarn is the fiber.纤维是纱的基本结构单元。
• The material must be free of fiber clumps.这种材料必须无纤维块。

17 cereals   

n.谷类食品，谷类；麦片粥

参考例句：

• By cereals we mean wheat,oats,rye,barley,and all that.谈到谷物，我们指的是小麦、燕麦、黑麦、大麦之类的东西。
• Wheat and rice are cereals.小麦和水稻是谷类植物。