Dental caries

Dental caries is a disease that causes demineralization and dissolution of the dental tissues. This process occurs not only in the crown of the tooth, but also on the root surface, when it is exposed.

Today, caries remains one of the most common diseases throughout 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. Depending on the extent of tooth destruction, various treatments can be used to restore teeth to proper form, function, and aesthetics, but there is no known method to regenerate large amounts of tooth structure. Instead, dental health organizations advocate preventive and prophylactic measures, such as regular oral hygiene and dietary modifications, to avoid dental caries.

A person experiencing caries may not be aware of the disease. The earliest sign of a new carious lesion is the appearance of a chalky white spot on the surface of the tooth, indicating an area of demineralization of enamel. This is referred to as incipient decay. As the lesion continues to demineralize, it can turn brown but will eventually turn into a cavitation ("cavity"). Before the cavity forms, the process is reversible, but once a cavity forms, the lost tooth structure cannot be regenerated. A lesion which appears brown and shiny suggests dental caries was once present but the demineralization process has stopped, leaving a stain. A brown spot which is dull in appearance is probably a sign of active caries.

As the enamel and dentin are destroyed, the cavity becomes more noticeable. The affected areas of the tooth change color and become soft to the touch. Once the decay passes through enamel, the dentinal tubules, which have passages to the nerve of the tooth, become exposed and cause the tooth to hurt. The pain may worsen with exposure to heat, cold, or sweet foods and drinks. Dental caries can also cause bad breath and foul tastes. In highly progressed cases, infection can spread from the tooth to the surrounding soft tissues.

Primary diagnosis involves inspection of all visible tooth surfaces using a good light source, dental mirror and explorer. Dental radiographs (X-rays) may show dental caries before it is otherwise visible, particularly caries between the teeth. Large dental caries is often apparent to the naked eye, but smaller lesions can be difficult to identify. Visual and tactile inspection along with radiographs is employed frequently among dentists, particularly to diagnose pit and fissure caries.

Ex.12. Find in the text English equivalents for these words and word-combinations:

Візуальний огляд, менші пошкодження, часто використовується стоматологами, м’який на дотик, призводити до, залишатися, при наявності, залежно від, відновити зуби, чутливий, особливо, гігієна ротової порожнини, більш помітний, різні методи лікування, профілактичні заходи, видимі поверхні зуба, тьмяний на вигляд.

Ex.13. Answer the following questions:

1. What kind of disease is dental caries? 2. What is tooth decay caused by? 3. Is there any known method to regenerate large amounts of tooth structure? 4. What preventive and prophylactic measures are recommended to avoid dental caries? 5. What is the earliest sign of a new carious lesion? 6. When is it impossible to regenerate the lost tooth structure? 7. What is the sign of active caries? 8. When does the cavity become more noticeable? 9. What causes the tooth to hurt? 10. What does primary diagnosis involve?

Ex.14. Insert the missing prepositions: (at, against, before, of, with, on, from):

Some dental researchers have cautioned________ the use of dental explorers to find caries. In cases where a small area ___ tooth has begun demineralizing but has not yet cavitated, the pressure ____ the dental explorer could cause a cavity. Since the carious process is reversible _______ a cavity is present, it may be possible to arrest the caries _____ fluoride and remineralize the tooth surface. When a cavity is present, a restoration will be needed to replace the lost tooth structure.

____ times, pit and fissure caries may be difficult to detect. Bacteria can penetrate the enamel to reach dentin, but then the outer surface may remineralize, especially if fluoride is present. These caries, sometimes referred to as "hidden caries", will still be visible ___ x-ray radiographs, but visual examination ____ the tooth would show the enamel intact or minimally perforated.

Ex.15. Entitle the text and answer the questions:

1. What kind of caries is called "facial caries”? 2. What kind of caries is called " lingual caries”? 3. What kind of caries is called cervical caries? 4. What is the difference between "mesial" and "distal” caries?

Carious lesions can be described further by their location on a particular surface of a tooth. Caries on a tooth's surface that is nearest the cheeks or lips is called "facial caries", and caries on surfaces facing the tongue is known as "lingual caries". Facial caries can be subdivided into buccal (when found on the surfaces of posterior teeth nearest the cheeks) and labial (when found on the surfaces of anterior teeth nearest the lips). Lingual caries can also be described as palatal when found on the lingual surfaces of maxillary teeth because they are located beside the hard palate.

Caries near a tooth's cervix—the location where the crown of a tooth and its roots meet—is referred to as cervical caries. Occlusal caries is found on the chewing surfaces of posterior teeth. Incisal caries is caries found on the chewing surfaces of anterior teeth. Caries can also be described as "mesial" or "distal." Mesial signifies a location on a tooth closer to the median line of the face, which is located on a vertical axis between the eyes, down the nose, and between the contact of the central incisors. Locations on a tooth further away from the median line are described as distal.

Ex.16. Organize the information of the text in table:

Carious lesions	Location on a particular surface of a tooth
facial caries	surface that is nearest the cheeks or lips

Ex.17. Read following text, divide it into logical parts, and retell them:

Дата добавления: 2015-07-11