The document defines dental caries as a disease caused by bacteria in the mouth that ferment dietary carbohydrates, producing acid that demineralizes tooth enamel and destroys tooth structure. The major factors contributing to dental caries are certain bacteria like Streptococcus mutans; dental plaque that allows bacteria to adhere to teeth; saliva, which can increase the cariogenic effect while also helping to clean teeth; and consumption of fermentable carbohydrates like sugars, which feed the bacteria. The microbiology section notes that the main bacteria involved are streptococci and lactobacilli, while other bacteria like actinomyces may also play a role.

1. DENTAL CARIES DEFINATION ETIOLOGY MICROBIOLOGY BY: DR. KHURRAM ZAFAR www.thedentalclinicpk.com

2. NORMAL TOOTH

3. TYPES OF TOOTH LOSS Loss of tooth substance in different ways: Microbial tooth loss (dental caries) Non microbial tooth loss (attrition, abrasion and erosion)

4. DENTAL CARIES DEFINITION It is a disease of microbial origin in which the dietary carbohydrates are fermented by the bacteria forming an acid which causes the demineralization of the inorganic part and disintegration of the organic part of the tooth

5. Dental caries

6. Dental caries

7. ETIOLOGY

8. Dental caries Etiology of Dental Caries: MAJOR FACTORS 1. Role of bacteria Normal flora of the oral cavity contains abundance of bacteria which derive there energy by the chemical process of fermentation Mainly the bacteria are Streptococcus Mutans,and streptococcus sobrinus collectively known mutans streptococci(MS)

9. Dental caries 2. Role of plaque: Plaque is an adhesive layer which deposits on the surface of the tooth and has colonies of bacteria Plaque tends to stick to the surface of the teeth and in this way the bacteria can have there cariogenic effect on the tooth Increase bulk of the plaque

10. Dental caries Plaque on the surface of the tooth (enamel)

11. Dental caries 3. Role of saliva: It plays role in increasing the cariogenic effect on the teeth and as well it has the buffering action. Saliva has a cleansing effect also

12. Dental caries 4. Role of carbohydrates: Fermentable carbohydrates are on of the most important cause of causing dental caries. Increase in the intake of refined carbohydrates are directly proportional in causing the dental caries Different studies and indicies have been done in order to know the role of carbohydrates in causing the dental caries.

13. Dental caries Dietary sugars are mainly sucrose which is cheap and easily produced from sugar cane and has very high calories sucrose is present in wheat and potatoes. Sucrose substitutes are palatinose, Trehalulose and sugar alcohols

14. Dental caries MINOR FACTORS: Enamel composition Morphology of the tooth Position of the tooth Diet Immunity

15. MICROBIOLOGY

16. Dental caries MICROBIOLOGY 1. Bacteria involved : Streptococci e.g mutans, sobrinus Lactobacilli e.g acidophilus 2. Possibly associated bacteria : Steptococci e.g mitis Actinomyces e.g viscosus

17. Bacteria

18. Bacteria