Endodontics L10: Disinfection of the root canal system

Question 1

Q1: what can be said about the variation of microbes that dominate the root canals, during different stages of infection?

Answer 1

Early infection you would expect to see facultative anaerobe, as the infection progresses down you would expect to see anaerobic pathogen.

Question 2

Q2: what does it mean when we say primary case in endodontics?

Answer 2

A tooth that has not previously been treated for root canal.

Question 3

Q3: primary cases and root filled teeth have microbes present, which particular microbe is more abundant in root filled teeth compared to primary cases?

Answer 3

Enterococci faecalis is present in both primary and root filled teeth. However, only 5% is present in primary and 29-77% is present in root filled teeth.

Question 4

Q4: what are the two black pigmented bacteria present in primary cases?

Answer 4

Prevotella and Porphyromonas

Question 5

Q5: other than eliminate microorganism, be nontoxic, remove smear layer and bio film and be non caustic to periodontal tissues, what other feature would make it an ideal root canal irrigant?

Answer 5

Lubricate the root canal instruments.

Question 6

Q6: commonly used root canal irrigants can be divided inn to two groups, what are they?

Answer 6

Antimicrobial and removal of smear layer.

Question 7

Q7: what two root canal irrigants fall under the antimicrobial category?

Answer 7

Sodium hypochlorite and 2% chlorhexidine.

Question 8

Q8 what two root canal irrigants fall under the removal of smear layer category?

Answer 8

Citric acid and 17% ethylenediaminetetraacetic acid (EDTA)

Question 9

Q9: which antimicrobial irrigant has no effect on removing necrotic tissue?

Answer 9

2% chlorhexidine

Question 10

Q10: sodium hypochlorite is capable of dissolving necrotic (organic) tissue. It is important to maintain concentration levels to therapeutic range. Concentrations less than…… is said to be not sufficiently antimicrobial?

Answer 10

1 percent. Concentration ranges from 1 to 5.25%

Question 11

Q11: what are the three disadvantages of sodium hypochlorite?

Answer 11

Unpleasant taste, high toxicity, and inability to remove smear layer when used alone.

Question 12

Q12: what is the benefit of bending your irrigant needle 3mm short of the working length?

Answer 12

It prevents the irrigation of sodium hypochlorite beyond the root apex.

Question 13

Q13: if you how somehow managed to get sodium hypochlorite beyond the root apex and into the apical tissues, what symptoms would the patient feel?

Answer 13

Extreme pain, burning sensation, instant swelling.

Question 14

Q14: the patient should be fully informed when a NaOCl accident occurs, and found out the possible aetiology. What would be the treatment plan for the patient?

Answer 14

Treatment should focus on minimising swelling, controlling pain, and preventing secondary infection. Patient must be reviewed until the symptoms have resolved.

Question 15

Q15: the removal of the smear layer would ensure there is a good seal between root canal wall with the ……………………?

Answer 15

Gutta percha.