LESSON 5. PREVENTIVE DENTISTRY. GRAMMAR: MODAL VERBS. INFINITIVE (REVISION)

Exercise 1. Active vocabulary to the text. Learn the following words:

to trap - ловить, поймать (в ловушку)

to improve - улучшать

to reduce - снижать, уменьшать

to occur - иметь место, происходить

to extract (a tooth) - удалять (зуб)

to eliminate - ликвидировать, устранять

to fill (a tooth) - пломбировать (зуб)

to damage - наносить вред

acrylic resin - акриловая смола

porcelain teeth - фарфоровые зубы

to tint - тонировать

Exercise 2. Read and translate into Russian the following text and answer the questions:

PREVENTIVE DENTISTRY

Preventive dentistry includes cleaning the teeth, removing plaque, and advising patients how to brush teeth properly and how to use dental floss (a thread which removes food particles trapped between the teeth). Studies have shown that tooth decay is decreasing in many countries as a result of preventive dentistry, improved diet, dental care, and the use of fluoride. Fluoride is a substance which can reduce tooth decay, and can be incorporated in the tooth enamel by taking tablets or drops, or by using a fluoride toothpaste. It occurs naturally in some drinking water but is also added artificially in a ratio of one part per million.

The form of treatment known as orthodontics involves first X-raying the teeth, then using braces and other devices to straigthen them, to even out any gaps, and to make the teeth, gums and jaws work correctly.

This treatment should be carried out while the teeth are still growing and developing, but, in a few cases, orthodontic treatment is carried out on adults.

Another branch of dentistry, called periodontics is concerned with the treatment of gum disease, which is a particular problem among older people. Like tooth decay, gum disease is also caused by excess plaque, which irritates

the gums and eventually leads to receding gums and loss of bone. Lacking support the teeth become loose and have eventually to be extracted. Regular removal of plaque is very important in the fight against gum disease.

People who have lost most or all of their teeth go to the dentist to have dentures, or false teeth, fitted. In the past, dentists made sets of false teeth using real human teeth or carved ivory. Today dentures are made from a plastic called acrylic resin or from metals such as chrome, cobalt, stainless steel, or gold. Plastic or porcelain teeth can be tinted to look like natural teeth. Dentures may be either complete (when all teeth are missing) or partial (when the patient still has some teeth left).

Questions to be answered:

1. What measures does prevention in dentistry include?

2. Why is plaque removal so important?

3. What chemical substance, when added to drinking water, can reduce tooth decay?

4. How much fluoride is usually added to drinking water?

5. In what cases is orthodontic treatment necessary?

6. What methods help orthodontists in their treatment?

7. What branch of dentistry is concerned with the treatment of gum disease?

8. What factors can cause gum disease?

9. Why is gum disease so dangerous?

10. How can dentists help patients in case of periodontitis?

11. What do people, who have lost their teeth, have to do?

12. What did dentists use as dentures in the past?

13. What materials are used for prostheses nowadays?

VOCABULARY EXERCISES

Exercise 1. Give the English equivalents to the following words and word combinations:

удалять (зуб), уменьшать(ся), добавлять, выполнять, развиваться, ликвидировать, пломбировать (зуб), наносить вред, обеспечивать, зубной налет, советовать, рентгеновское обследование.

Exercises 2. Give nouns for the following verbs:

to develop, to involve, to fill, to decrease, to reduce, to use, to damage, to extract, to improve, to trap, to advise, to remove, to study.

Exercise 3. Find in the text synonyms for:

grown-ups, to catch, to contain, to reduce, a field (of dentistry), dental caries, to involve, to perform, in some cases, false teeth.

GRAMMAR EXERCISES

Exercise 1. Complete the sentences using one of the modal verbs given in brackets.

1. Any food containing sugar____cause caries (must, can, should).

2. Before caries is treated, it____first be detected (have to, may, must).

3. All unnecessary instruments_____be out of view before a patient enters

the surgery (should, might, can).

4. Used instruments____be cleaned and sterilized (could, have to, must).

5. Healthy adults_____lose up to a pint of blood without any ill effects

(can, must, should).

6. If the pulp is still vital, and not affected by pulpitis, the tooth_____be

filled (must, have to, can).

Exercise 2. Translate the sentences into Russian and determine the function of the Infinitive:

1. To walk is useful.

2. To know English means first of all to be able to speak English.

3. May I come in?

4. I don't know what to do.

5. We stopped to have a rest.

6. Who was the last to come?

7. I am waiting to be told the results.

8. This work must be finished today.

9. They were the last to be asked about it.

10. Do you want me to translate this text?

11. The earth was believed to be flat in ancient times.

12. That monument is supposed to have been erected by this architect.

13. I'd like you to meet my friend.

14. We expect her to come tomorrow.

Exercise 3. Change the sentences and use Complex Subject:

1. It has been found out that dried fruits like dates, figs, raisins have a similar effect to sticky sweets because they are rich in concentrated sugars and get stuck to the teeth.

2. It is known that periodontal disease results from inflammation of the gum that gradually causes destruction of the bone supporting the teeth.

3. There appears to be tooth loss resulting from periodontal disease.

4. It is believed that water fluoridation is the most effective public health strategy for caries prevention.

5. It is likely that starchy foods that stick to the teeth cause decay.

Exercise 4. Translate the sentences from English into Russian:

1. Drinking tea on a regular basis has been reported to reduce the number of carious teeth.

2. Excessive intake of fluoride appears to cause fluorosis in the enamel of the teeth.

3. The structure of the teeth will actually be stronger and less likely susceptible to decay.

4. Bleeding gums appear to be a sign of vitamin С deficiency.

5. Components of tea seem to contribute to the inhibition of caries.

6. Tannin along with other components of tea such as catechin, caffeine and tocopherol has been shown to be effective in increasing the acid resistance of the enamel.

7. A person who is susceptible to dental caries is required to avoid eating between meals and restrict the intake of confections to once a week.

8. Cheese is reported to prevent the formation of acids in the mouth which attack the enamel.

9. He is supposed to discharge the patient from the hospital.

10. He is supposed to have discharged the patient from the hospital.

11. He is supposed to be discharged from the hospital.

12. He is supposed to have been discharged from the hospital.

Exercise 5. Translate the sentences from Russian into English:

1. Говорят, что печень является лучшим источником молибдена.

2. Очевидно, замена сладостей твердой, волокнистой пищей замедлит образование налета.

3. Если вы не соблюдаете сбалансированную диету, очень вероятно, что у вас будет кариес или заболевание десен.

4. Обнаружено, что бактерии в бляшке продуцируют кислоты, которые могут разрушить эмаль зуба.

5. Доказано, что всякий раз, когда кислота образуется, она воздействует на зубную эмаль в течение 20 минут.

6. Неправильное питание матери, весьма вероятно, может являться причиной аномалий развития зубов у ребенка.

7. Как известно, в молоке содержится крахмал.

Exercise 6. Use the words given in brackets in proper forms:

1. Some years ago dental scientists (проводить) research to see the effect of fluoride (добавлять) to drinking water.

2. Prevention in dentistry (включать) a balanced diet.

3. In some countries fluoride (добавлять) to drinking water.

4. In some countries tooth decay (уменьшаться).

5. Excess plaque often (вызывать) gum disease.

6. This treatment (проводиться) at our dental clinics.

7. At that time dentists (не давать) patients anesthetics to kill pain.

8. In the past dentists (использовать) natural human teeth as dentures.

9. A regular removal of plaque (помогать бороться) against gum disease.

10. Today dentures (изготавливать) from a plastic (называть) acrylic resin.

11. This treatment (снижать) irritation of the gums.

SPEECH EXERCISES

Exercise 1. Give your opinion as to:

a. the importance of preventive dentistry

b. the rules to be followed to have healthy teeth

c. the role of fluoride in dental disease prevention

Exercise 2. What piece of advice can you give to your patients concerning:

a. the choice of a tooth paste

b. the use of dental floss

c. the way of brushing of teeth

d. consumption of candy and soft drinks

Exercise 3. Read the text and summarize it. Find phrasal verbs and explain their meaning.

STOP THE GAP

What to do if a tooth is knocked out? Teeth can get knocked out in a fall, a fight or an accident, but with quick action the tooth could be saved. Pick the tooth up and, if it is dirty, rinse it in clean, lightly salted water or clean milk and put it straight back in its place. Do not use disinfectant! Then - and only then - start looking for a dentist or a dental hospital. The tooth has a very good chance of surviving. A delay, even as little as 30 minutes, reduces the tooth's ability to heal back to the gum.

A dental expert writing in the British Dental Journal says that a knocked-out tooth has a 99 per cent chance of survival if reinserted quickly. Putting the tooth back can still be useful even if the tooth itself dies. It helps the damaged flesh to heal and stops neighbouring teeth moving to fill in the gap. This makes it easier for the dentist to repair the damage.