ORE Part 2 Endodontics 2

Question 1

What is considered the most common biological cause of post-treatment endodontic failure?

Accepted Answer

Residual bacteria persisting within the root canal system

Answer

Inadequate coronal seal allowing recontamination

Answer

Overfilling of the root canal system

Answer

Procedural errors during canal instrumentation

Question 2

Which obturation material remains the gold standard for filling root canals in conventional endodontic treatment?

Accepted Answer

Gutta-percha with a root canal sealer

Answer

Zinc oxide eugenol paste alone

Answer

Mineral trioxide aggregate (MTA)

Answer

Calcium hydroxide paste

Question 3

What is a 'ledge' as a complication in endodontic treatment?

Accepted Answer

An artificial step created in the canal wall preventing further instrument progress

Answer

A perforation through the root canal wall into the periodontium

Answer

A fractured instrument segment lodged within the canal

Answer

An area of external cervical root resorption

Question 4

If a sodium hypochlorite injection accident occurs with extrusion beyond the apex, what is the most appropriate immediate management?

Accepted Answer

Stop irrigation immediately and manage pain and swelling conservatively

Answer

Increase irrigation pressure to dilute the extruded material

Answer

Prescribe antibiotics and discharge without further intervention

Answer

Immediately refer to hospital for surgical debridement

Question 5

What is the principle behind the step-back technique in root canal preparation?

Accepted Answer

Preparing the apex first then using progressively larger files coronally to create a taper

Answer

Preparing the coronal flaring before beginning apical instrumentation

Answer

Using ultrasonic instruments to clean the apical third

Answer

Removing the smear layer in a coronal-to-apical direction

Question 6

Which microorganism is most strongly associated with persistent and treatment-resistant endodontic infections?

Accepted Answer

Enterococcus faecalis

Answer

Streptococcus mutans

Answer

Porphyromonas gingivalis

Answer

Fusobacterium nucleatum

Question 7

Which radiographic appearance is most characteristic of a chronic apical periodontitis lesion?

Accepted Answer

Well-defined radiolucency at the root apex

Answer

Widening of the periodontal ligament space alone

Answer

Diffuse periapical radiopacity with loss of lamina dura

Answer

Round radiolucent defect within the root canal space