Epidemiology of dental caries

public health dentistry

1. EPIDEMIOLOGY OF DENTAL CARIES PRESENTED BY :- Dr SAKSHI KAUR CHHABRA 2 ND YEAR POST GRADUATE DEPARTMENT OF PUBLIC HEALTH DENTISTRY

2. DENTAL CARIES

3. EPIDEMIOLOGY Epidemiology has been defined by John M. last in 1988 as:- ‘The study of the distribution and determinants of health-related states or events in specified populations and the application of this study to the control of health problems.’

4. THEORIES OF CARIES ETIOLOGY There is no universally accepted opinion of the etiology of dental caries.

5. [A] EARLY THEORIES OF CARIES THE LEGEND OF THE WORM

6. [B] ENDOGENOUS THEORIES HUMORAL THEORY The four humors of the body were blood, phlegm, black bile and yellow bile. According to the Galen , the ancient Greek physician and philosopher, ‘dental caries is produced by internal action of acrid and corroding humors. According to the Hippocrates , the father of medicine, also referred to the accumulated debris around teeth and their corroding action. He also stated that stagnation of juices in the teeth was the cause of toothache.

7. 2. VITAL THEORY

8. [C] EXOGENOUS THEORIES [A] CHEMICAL (ACID)THEORY In the 17 th and 18 th century , there emerged the concept that teeth were destroyed by acids formed in the oral cavity by fermentation of food particles around teeth. On the basis of findings of Robertson, this theory proposed that tooth decay was caused by the fermentation of food particles around the teeth.

9. [B] PARASITIC (SEPTIC) THEORY Earlier Antoni Van Leeuwenhock (1632-1723) stated that the micro-organisms were associated with the carious process. In 1954, Dubos postulated that micro-organisms can have toxic effects on tissue.

10. [C] Miller’s Chemicoparasitic (ACIDOGENIC) THEORY This theory was proposed by W.D. Miller in 1890. The micro-organisms found in the oral cavity produced enzymes demineralization (enamel) that act upon the fermentable carbohydrates to produce acids like Enamel of the tooth lactic acid, butyric acid, formic and succinic acid. These acids acts upon the DENTAL CARIES

11. [D] PROTEOLYTIC THEORY This theory was proposed by Gottileb in 1934. According to this theory, the organic matrix would be attacked before the mineral phase of the enamel. Oral bacteria liberate Proteolytic enzymes destroy organic matrix of enamel whole structure collapse Loosening apatite crystals

12. [E] PROTEOLYSIS - CHELATION THEORY This theory was originated by Schatz and Martin in 1955 . This theory suggested that demineralization of the enamel could arise without acid formation.

13. PROTEOLYTIC BREAKDOWN OF THE ORGANIC PORTION OF THE ENAMEL MATRIX TAKES PLACE CHELATING AGENT IS FORMED BY THE COMBINATION OF PROTEOLYTIC BREAKDOWN PRODUCTS, ACQUIRED PELLICLE AND FOOD DEBRIS. TOOTH DECAY

14. [D] OTHER THEORIES AUTO – IMMUNE THEORY This theory was given by Burch and Jackson (1966). This theory analyzed caries epidemiological data and suggested that genes, partly inherited and partly mutational, determine whether a site on a tooth is at risk.

15. ETIOLOGIC FACTORS IN DENTAL CARIES EPIDEMIOLOGICAL TRIAD

16. [A] HOST FACTORS TOOTH SALIVA SEX RACE AGE FAMILY HEREDITY DEVELOPMENTAL DISTURBANCES ECONOMIC STATUS CONCOMITANT DISEASE ORAL HYGIENE HABITS

17. TOOTH Morphological characterstics of tooth have been suggested as influencing the initiation of caries. Presence of deep and narrow occlusal fissures or deep buccal and lingual pits which tend to trap food, bacteria and debris. Caries may develop in these areas.

18. b. SALIVA A no. of different enzymes have been isolated from saliva. They are derived from extrinsic and intrinsic sources. Urease is an enzyme derived from oral micro – organisms.

19. pH of the saliva is determined by the bicarbonate concentration. The saliva pH increases with flow rate. Saliva may be slightly acidic as it is secreted as unstimulated flow rates but it may reach a pH of 7.8 at high flow rates. As it is exposed to the atmosphere, carbon dioxide will diffuse out & pH will rise, often to 9 or more in saliva present as thin film. Other salivary components contributing to the ability of saliva to neutralize acid are salivary phosphate, salivary proteins, ammonia, urea and statherin .

20. Sialin is an arginine peptide which is pH rise factor present in saliva which rapidly clears glucose from plaque, increases base formation and elevates pH in the plaque. The quantity of saliva secreted normally is 700-800 ml/day. The quantity of saliva may influence caries incidence as is especially evident in cases of salivary gland aplasia and xerostomia in which salivary flow may be entirely lacking, with rampant dental caries the typical result.

21. c. SEX d. RACE Dental caries is more common in whites compared to the blacks.

22. e. AGE Pit and fissure caries is more commonly seen in young age . Root caries is seen in old age (gingival recession). f. DEVELOPMENTAL DISTURBANCES The presence of deep pits and fissures, enamel hypoplasia and enamel defects make the tooth more prone to caries.

23. g. Socio-Economic status In young primary school children dental caries decreases with increase in Income. In adults, when income decreases there is decrease in dental caries.

24. h. CONCOMITANT DISEASE

25. i . ORAL HYGIENE STATUS

26. [B] AGENT FACTORS

27. [C] ENVIRONMENTAL FACTOR

28. [1] DIET AND NUTRITION

29. Some dietary studies are :-

30. [2] GEOGRAPHIC VARIATIONS

31. [3] SOIL

32. [4] URBANIZATION

33. [5] CLIMATE