Caries. Causes of caries

Dental caries, also known as tooth decay or cavity, is a disease where bacterial processes damage hard tooth structure (enamel, dentin and cementum). These tissues progressively break down, producing dental cavities (holes in the teeth). Two groups of bacteria are responsible for initiating caries, Streptococcus mutans and Lactobacilli. If left untreated, the disease can lead to pain, tooth loss, infection, and, in severe cases, death. Today, caries remains one of the most common diseases all over the world. Cariology is the study of dental caries.

There are four main criteria required for caries formation: a tooth surface (enamel or dentin); caries-causing bacteria; fermentable carbohydrates (such as sucrose); and time.

There are certain diseases and disorders affecting teeth which may leave an individual at a greater risk for caries. Teeth may be left more vulnerable to decay because the enamel is not able to protect the tooth. Caries is more likely to develop when food is trapped between teeth.

The mouth contains a wide variety of oral bacteria, but only a few specific species of bacteria are believed to cause dental caries: Streptococcus mutans and Lactobacilli among them. Bacteria collect around the teeth and gums in a sticky, creamy-coloured mass called plaque, which serves as a biofilm. Plaque may also collect along the gingiva.

Bacteria in a person's mouth convert glucose, fructose, and most commonly sucrose (table sugar) into acids such as lactic acid through a glycolytic process called fermentation. If left in contact with the tooth, these acids may cause demineralization, which is the dissolution of its mineral content. Fluoride toothpaste or dental varnish may aid remineralization.

Medical conditions that reduce the amount of saliva produced by salivary glands, particularly the submandibular gland and parotid gland, are likely to lead to widespread tooth decay.

The use of tobacco may also increase the risk for caries formation.

POST-TEXT ASSIGNMENTS

Exercise 6. Look through the text and answer the questions:

1. What is dental caries?

2. How many groups of bacteria are responsible for initiating caries? Call them.

3. What can untreated caries lead to?

4. How is the study of dental caries called?

5. What are the main criteria required for caries formation?

6. What is trapped between teeth?

7. Where do bacteria collect around?

8. What may aid remineralization?

9. By what did medical conditions that reduce the amount of saliva produce?

10. What may tobacco do?

Exercise 7. Explain the following terms in English:

E. g. Hard tooth structure

Hard tooth structure is enamel, dentin and cementum.

Tooth decay, enamel, dentin, cementum, plaque, fermentation, acid

Exercise 8. Make the following sentences negative:

1. Caries remains one of the most common diseases all over the world.

2. Teeth may be left more vulnerable to decay because the enamel is not able to protect the tooth.

3. The mouth contains a wide variety of oral bacteria.

4. Fluoride toothpaste or dental varnish may aid remineralization.

5. The use of tobacco may also increase the risk for caries formation.

Exercise 9. Give a brief survey of the text.

TEST

1. Dental caries, also known as …

a) tooth formation

b) cavity

c) tooth decay

d) acid formation

e) extraction of teeth

2. If..., the disease can lead to pain, tooth loss, infection, and, in severe cases, death.

a) treat b) fill c) untreat d) rinse e) cut

3. … is the study of dental caries.

a) cardiology

b) surgery

c) cariology

d) dentistry

e) ophthalmology

4. There are … main criteria required for caries formation.

a) two b) three c) four d) five e) six

5. There are certain diseases and disorders affecting teeth which may leave an individual at …

a) a greater risk for caries

b) a worse condition

c) a greater filling of teeth

d) a better criteria for caries

e) a minimal risk for caries

6. Caries … develop when food is trapped between teeth.

a) is known to

b) is believed to

c) appears

d) is likely to

e) is found to

7. The mouth contains a wide variety of …

a) anaerobic bacteria

b) hemophilic bacteria

c) oral bacteria

d) prototrophic bacteria

e) acid-fast bacteria

8. Bacteria collect around the …

a) mouth

b) lips

c) teeth and gums

d) face

e) throat

9. If left in contact with the tooth, these acids may cause …

a) demineralization

b) mineralization

c) fermentation

d) remineralization

e) dissolution

10. The use of tobacco … also increase the risk for caries formation.

a) need b) can c) must d) may e) should

b)

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