X. Read the sentences, find the predicates and define their tenses. Translate the sentences.

1. Enamel and dentin have different expansion coefficient.

2. Cracks are most frequently found in the molars of older patients.

3. It was found that in addition to pain on mastication sensitivity to thermal changes, sweet and sour foods were frequent.

4. The teeth were sensitive to cold and almost one sixth of patients had heat sensitivity.

5. A newer method of diagnosing cracks in enamel has been proposed by a group of scientists.

6. The excess of oil is then removed with a water jet.

7. If the crack has not involved the pulp such treatment is effective.

XI. Read and translate the text.

Text A. Dental Cracks

        Cracks in the enamel and dentin may develop from thermal stresses. The cycling of temperatures which occurs, for example, in eating and drinking may crack the enamel because enamel and dentine have different expansion coefficient. The continuing stress of mastication coupled with clenching and grinding habits and restorative work may deepen the cracks. Thermal testing with frozen carbon dioxide (dry ice) may also deepen cracks or form new ones. The cracks may involve the pulp, and in extreme cases, the roots may be split. Cracks are most frequently found in the molars of older patients.

    In reviewing 100 cases of incomplete crown-root fractures it was found that in addition to pain on mastication sensitivities to thermal changes, sweet and sour foods and alcoholic beverages were frequent; according to another researcher out of 150 patients studied almost half complained of pain on chewing and sensitivity to pressure, in 0ne-third the teeth were sensitive to cold, and almost one-sixth had heat sensitivity.

    A newer method of diagnosing cracks in enamel has been proposed by a group of scientists. They recommend applying a fluorescent oil for 8 minutes after cleaning and polishing the tooth surface. The excess oil is then removed with a water jet and the tooth is examined under a surgical microscope with ultraviolet light. The cracks are visible as yellowish green lines.

    Treatment consists in covering the crown of the tooth with an onlay or preferably a full crown. Such treatments are effective if the crack has not involved the pulp. When it has, endodontic therapy should be performed.

XII. Answer the questions.

1. Why do cracks in the enamel and dentin develop?

2. What process helps to crack the enamel?

3. What deepens the cracks?

4. What happens when the cracks involve the pulp?

5. In the molars of what patients are the cracks most frequently formed?

6. What did the researchers find in reviewing 100 cases?

7. What did they find in reviewing 150 patients?

8. What new method was proposed by a group of scientists?

9. Are the cracks visible under a surgical microscope?

10. What does the treatment of cracks consist of?

11. When is the treatment effective?

12. When should endodontic therapy be performed?

XIII. Translate the following word combinations:

трещины эмали и дентина, смена температур, разный коэффициент расширения, привычка стискивать зубы и скрежетать зубами, сухой лед, в крайнем случае, частичный (неполный) перелом, боль при жевании, сладкая и кислая пища, реакция (чувствительность) на холодное и горячее, алкогольные напитки, чистка и полировка зубной поверхности, видимые трещины, накладывать мазь, удалять излишек мази

XIV. Translate the following sentences.

1. Во время еды и питья могут появиться трещины на эмали и дентине.

2. Эмаль и дентин имеют разный коэффициент расширения.

3. Продолжительная нагрузка при жевании вместе с привычкой стискивать зубы и скрежетать зубами могут углублять трещины.

4. Кроме боли при жевании, пациенты могут реагировать на изменения температуры, сладкую и кислую пищу, алкогольные напитки.

5. Был предложен новый метод диагностики трещин.

6. После чистки и полировки зубной поверхности рекомендуется прикладывать мазь.

7. Излишек мази удаляют струей воды.

8. Такое лечение эффективно, если не задета пульпа.

XV. Read and translate the text using a dictionary.

Text B. Composite Resins

    There are several groups of composite resin materials; although most are tooth-coloured, some have been designed for use in anterior teeth where appearance is most important while others have been designed for posterior teeth where strength and abrasion resistance are of prime importance. In both cases the material is capable of being attached physically to the enamel by means of the acid-etch technique. Composite is strong in thin section when attached to enamel and so the enamel margins can be beveled.

    Composite resins can be attached to dentine by chemical bonding materials or via an intermediate layer of glass ionomer cement. Unfortunately, the bond to dentine is not as strong as the bond to enamel. Since the material shrinks as it sets there is a danger that it will move away from the dentine towards the enamel in cavities bounded by enamel on one side and dentine on the other as commonly occurs with cervical cavities.

Lesson 15

Грамматика: цепочки существительных, функции to have (повторение),оборот there is

Pulp Involvement

I. Read the words of the Latin and Greek origin and give their Russian equivalents:

odontoblastic process [ou,dOntq’blqestik]

degenerative [di’Genqrqtiv]

chronic hyperemia [‘krOnik hQipq’rJmiq]

clinician [kli’niSn]

bacterial toxins [bqk’tiqriql ‘tOksinz]

chronic pulpitis [‘krOnik pql’pQitis]

necrosis [nik’rousis]

gangrene [‘gqengrJn]

subpyogenic [sAb,pQiq’Genik]

microorganism [,mQikrq’Lgqnizm]

extirpation [,ekstW’peiSqn]

virulent [‘virulqnt]

edema [I’dJmq]

pulpotomy [pAl’pOtqmi]

procedure [prq’sJGq]

termination [,tWmi’neiSn]

drainage [‘dreiniG]

sterilization [,sterilQi’zeisqn]

II. Learn the following words:

to evoke [I’vouk] - вызывать

mild [mQild] - слабый, легкий

moderate [‘mOdqrit] - средний, умеренный

to reach [rJC] - достигать, добиваться

to disturb [dis’tWb] - беспокоить, нарушать

disturbance - беспокойство, нарушение

to respond [ris’pOnd] - реагировать, отвечать

response - реакция, ответ

to injure [‘inGq] - повреждать

injury [‘inGqri] - повреждение

purulent [‘pjuqrulqnt] - гнойный

attempt [q’tempt] - попытка

to heal [hJl] - излечивать, заживлять

to require [ri’kwQiq] - требовать

extirpation [,ekstW’peiSqn] - удаление

exacerbation [eks,qesW’beiSqn] - обострение, усиление

value [‘vqelju] - значение

relief [ri’lJf] - облегчение, помощь

III. Read and translate the following word combinations:

wide apical pulp canal, partial chronic pulpitis pulpotomy, remaining pulp tissue, a root canal filling, prosthetic dentistry department, the involved tooth surface, decreased saliva flow, difficult plaque removal, root surface caries

IV. Read and translate the sentences paying attention to the functions of the verb to have.