A Tooth

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

stomatology [,stOmq’tOlqGi], mucous [‘mjHkqs], fibrous [‘fQibrqs], periodontal membrane [periq’dOntql ‘mqmbrein], dentine [‘dentin], enamel [I’nqemql], cementum [si’mentqm], pressure [‘preSq], object [‘ObGqkt], porous [‘pLrqs[, premolar [pri’moulq]

II. Learn the following words and word combinations:

to deal with [dJl] - иметь дело с …

gum [gAm] - десна

dental arch [RtS] - зубная дуга

crown [krQun] - коронка

neck - шейка

root - корень

brittle [britl] - хрупкий, ломкий

ёto withstand [wiD’stqend] - выдерживать, противостоять

to bite (bit, bitten) - кусать

bite - прикус

core [kL] - ядро, сердцевина

foramen [fO’reimqn] - отверстие

tip - кончик

to reach [rJtS] - достигать

set of teeth - зубной ряд, набор зубов

deciduous teeth [di’sidjqs] - молочные зубы

permanent teeth [‘pWmqnqnt] - постоянные зубы

incisor [in’sQizq] - резец

jaw [GL] - челюсть

canine [‘keinein] - клык

cuspid [‘kAspid] - клык

to erupt [I’rApt] - прорезывать(ся)

III. Read the sentences, find Passive predicates and translate the sentences.

1. The human teeth are made up of four tissues.

2. Dental pulp is found in the soft center of the tooth.

3. The pulp is surrounded by dentine.

4. The pulp of a tooth is composed of a fibrous network containing nerves, blood and lymph vessels that nourish the tooth.

5. In the crown the dentine is covered with enamel and in the root and neck it is covered with cementum.

6. It was decided to examine the oral cavity of the patient.

7. It is known that the cervical portion of the teeth is surrounded by gingival.

8. By the end of the second year a child is supposed to have a complete set of deciduous teeth.

9. By the age of 12 a child is supposed to have all the permanent teeth except the third molar.

10. Sticky carbohydrate is being transformed into the acid responsible for dissolving enamel and dentine.

IV. Read and translate the text.

A Tooth

Dentistry or stomatology is the science which deals with human teeth, gums, dental arches, mucous, fibrous and periodontal membranes of the oral cavity. But still the central “figure” of dentistry is a tooth. Each tooth had a crown, a neck and a root (or roots). Pulp makes up the center of the tooth. It is surrounded by dentine. In the crown dentine is covered with enamel and in the root and neck it is covered with cementum. Enamel is the hardest tissue of a human body. It is relatively inelastic and rather brittle. Enamel must withstand very high pressures when a person bites on hard objects. Cementum is also rather hard. In fact, it is a layer of modified bone which blends with the fibers of the periodontal membrane. Inside enamel and cementum is the main body of the tooth made of dentine. Dentine is softer, more porous and more elastic than enamel. Dentine is sensitive. In the very center of the tooth is a soft core – dental pulp. It contains nerves and blood vessels. The nerves and vessels enter the tooth and are closely connected with the pulp. They are often considered together.

A human has two sets of teeth: deciduous (or milk, baby) teeth and permanent teeth. The first deciduous tooth is one of the incisors. It should appear at the age of about six months. By the end of the second year a child is supposed to have a complete set of deciduous teeth.

The deciduous teeth are 20 in number, 5 on each side of the upper and lower jar: two incisors, one canine (cuspid), two premolars and three molars. The first permanent tooth to erupt is one of the molars. It should appear during the sixth year. By the age of 12 a child is supposed to have all the permanent teeth except the third molar which may appear at different age, usually starting from 17.