Relevance of Microbiology in Managing Periodontal Diseases

Question 1

Why is it important to understand microbial aetiology of periodontal conditions? (6)

Answer 1

1. Prevention
2. Risk assessment
3. Diagnosis
4. Communication
5. Tx planning
6. Monitoring tx outcomes

Question 2

What does asaccharolytic mean?

Answer 2

It means they cannot metabolise sugar

Question 3

What is the pH of perio pockets?

Answer 3

6.9-7.8

Question 4

What type of bacteria is often involved in gingivitis?

Answer 4

Gram negative obligate anaerobes

Question 5

Name 2 species involved in gingivitis

Answer 5

Actinomyces spp.

Capnocytophaga spp.

Question 6

Which species of bacteria is involved in aggressive perio and wasn’t classified in Socransky’s complex?

Answer 6

Aggregatibacterium (actinobacillus) actinomycetemcomitans b.

Question 7

Which species of bacterium is an important bridging species?

Answer 7

Fusobacterium Nucleatum

Question 8

What is the most important protease that p. gingivalis produces?

Answer 8

Gingipain

Question 9

Why is aggregatbacterium actinomycetemcomitans b. very virulent in perio disease?

Answer 9

Leukotoxin (toxic to monocytes- inhibits host protecting itself)

Lipopolysaccharide (endotoxin, can directly cause bone resorption)

Collagenases - destroys collagen fibres (in PDL, dentine etc)

Question 10

What does aggregatbacterium actinomycetemcomitans b. particularly require from it’s environment in order for it to thrive?

Answer 10

Carbon dioxide

Question 11

What are the signs/symptoms of necrotising perio disease?

Answer 11

• pain
• bleeding
• halitosis
• necrotising inflammation of dental papillae
• grey pseudomembranes
• lymph nodes, increased body temp

Question 12

What are the risk factors of developing necrotising perio disease?

Answer 12

• smoking
• poor oral hygiene
• immunosuppression
• emotional stress
• poor diet

Question 13

What type of bacterium complex invades gingiva in necrotising perio disease?

Answer 13

Fuso-spirochaetal complex

Question 14

What ABs may be used in perio therapy, what does each AB inhibit? (3 types)

Answer 14

Penicillins- inhibitions of cell wall synthesis

Tetracycline- inhibition of protein synthesis

Metronidazole- inhibition of nucleic acid synthesis

Question 15

What 4 bacteria species are involved in necrotising perio disease?

Answer 15

Treponema spp.

Fusobacterium spp.

Prevotella intermedia

Borrelia Vincentii