Endodontics L11: Obturation

Question 1

Q1: the literature ‘outcome of primary root canal treatment’ summarised that the success of root canal treatment is dependant on 4 key factors. What are they?

Answer 1

1. Absence of periapical lesion,
2. Root canal filling with no voids,
3. Obturation to within 2mm of apex,
4. Adequate coronal restoration.

Question 2

Q2: the Washington study, which was a radiographic study observed that 58.66% of endodontic failures were caused by?

Answer 2

Incomplete obturation

Question 3

Q3: the objective of obturation is to achieve a complete seal, where must these seals be completed?

Answer 3

Apical, lateral and coronal.

Question 4

Q4: root canal systems cannot be completely cleaned and disinfected, as a result remaining bacteria can initiate/perpetuate a lesion. It is imperative that obturation is done correctly, what would a good obturation prevent?

Answer 4

Obturation is necessary to eliminate leakage. Reduces coronal leakage and bacterial contamination, seals the apex from periapical tissue fluids and entombs remaining irritants in the canals.

Question 5

Q5: what is a hermetic seal?

Answer 5

A seal which prevents the escape or entry of air

Question 6

Q6: what type of seal are we trying to accomplish?

Answer 6

Fluid tight or bacteria tight seal.

Question 7

Q7: when is one visit preferred when having a root canal treatment?

Answer 7

When there is vital pulp tissue present, with or without asymptomatic periapical pathology.

Question 8

Q8: when would multiple visits be acceptable when doing root canal treatment?

Answer 8

1. Presence of acute signs, symptoms, swelling,
2. Persistent exudate in root canal,
3. Anatomical difficulties,
4. Technical difficulties,
5. Patient or dentist is tired or has lost patience.

Question 9

Q9: what is the advantage of having multiple visit in references to bacteria?

Answer 9

The application of antibacterial dressing will reduce the number of bacteria remaining following cleaning and shaping.

Question 10

Q10: how long is the calcium hydroxide dressing (non-setting) be kept in before the next visit?

Answer 10

Minimum 1 week.

Question 11

Q11: which obturation technique involves the use of a finger spreader, which allows small accessory gutta percha to be placed in to the root canal?

Answer 11

Cold lateral compaction.

Question 12

Q12: which obturation technique involves the use of a heated plugger, where the apical portion of the gutta percha is heated to form a apical seal, then injected gutta percha is backfilled in the remaining canal?

Answer 12

Warm vertical compaction.

Question 13

Q13: once the gutta percha has been placed, the entrance to the root canal must be sealed to prevent coronal leakage. What two resin materials can be used to seal the root canal?

Answer 13

Resin modified glass ionomer (vitrebond) and smart dentine replacement (SDR)