ORE Part 1 Radiology & Radiation Protection 3

Question 1

What does IR(ME)R 2017 define as the roles of 'referrer', 'practitioner', and 'operator' in dental radiography?

Accepted Answer

Referrer: justifies clinical need for the X-ray; Practitioner: takes clinical responsibility by justifying the specific exposure; Operator: performs the practical procedure and optimises the technique

Answer

IR(ME)R defines: the Referrer requests the X-ray (usually dentist or other clinician), the Practitioner justifies and authorises the specific exposure, and the Operator sets up and performs the exposure. One person may hold multiple roles.

Question 2

What is the typical kVp range used for intraoral dental radiography?

Accepted Answer

60–70 kVp (higher kVp reduces patient dose but increases scatter)

Answer

Intraoral dental radiography typically uses 60–70 kVp. Higher kVp produces more penetrating (harder) X-rays, reducing patient dose through less photoelectric absorption, while increasing scatter. Rectangular collimation at this kVp greatly reduces dose.

Question 3

What is rectangular collimation and why is it preferred in dental radiography?

Accepted Answer

A rectangular lead collimator limiting the X-ray beam to match the size of the intraoral film/sensor — reduces patient dose by approximately 60–70% compared to circular collimation

Answer

Rectangular collimation restricts the primary beam to closely match the film/sensor dimensions, minimising exposure of surrounding tissues. It reduces effective patient dose by approximately 60–70% compared to circular/round collimators.

Question 4

What is a 'periapical index' (PAI) and how is it used?

Accepted Answer

A standardised radiographic scoring system (1–5) for assessing periapical pathology severity on radiographs — used in research and clinical outcome assessment of endodontic treatment

Answer

The Periapical Index (Ørstavik 1986) scores the periapical appearance on a 1–5 scale: 1 = normal bone structure; 5 = severe periodontitis with features of systemic spread. Used to assess endodontic treatment success.

Question 5

What is the 'bitewing' radiograph specifically used for?

Accepted Answer

Detecting interproximal caries and monitoring alveolar bone levels in posterior teeth — the standard caries detection radiograph

Answer

Bitewing radiographs show the crowns and coronal third of roots of both upper and lower posterior teeth simultaneously, making them the most sensitive and standard method for detecting early approximal caries and monitoring posterior alveolar bone.

ORE Part 1 Practice Test

ORE Part 1 Practice Test

ORE Part 1 Radiology & Radiation Protection 3