MFDS Part 1 - Membership of Faculty of Dental Surgery Dental and Maxillofacial Radiology Questions and Answers — Questions and Answers
Question 1: According to the Ionising Radiation (Medical Exposure) Regulations 2017 (IRMER), who holds the primary legal responsibility for the justification of a dental radiograph exposure?
- The Radiographer
- The IRMER Practitioner (Correct answer)
- The Practice Owner (Employer)
- The Radiation Protection Adviser (RPA)
Correct answer: The IRMER Practitioner
IRMER 2017 places the legal responsibility for justifying an individual medical exposure on the 'Practitioner'. This individual must be a registered healthcare professional who is entitled to take responsibility for an exposure. In dentistry, this is typically the dentist or another appropriately trained dental care professional who has decided the exposure is necessary.
Question 2: A dental practice is conducting a routine quality assurance audit of its digital intraoral radiographs. According to the 'Guidance Notes for Dental Practitioners on the Safe Use of X-ray Equipment (2nd Edition)', what is the minimum target for 'diagnostically acceptable' radiographs?
- Not less than 85%
- Not less than 90%
- Not less than 95% (Correct answer)
- Exactly 100%
Correct answer: Not less than 95%
The guidance co-published by Public Health England and the FGDP(UK) specifies quality assurance targets. For digital radiography, the target for diagnostically acceptable images (rated 'A') is not less than 95%. For film-based systems, the target is slightly lower at not less than 90%.
Question 3: Under the Ionising Radiations Regulations 2017 (IRR17), which of the following is a primary responsibility of the appointed Radiation Protection Supervisor (RPS) within a dental practice?
- To conduct critical examinations of new X-ray equipment.
- To provide detailed advice on the design of new dental facilities.
- To ensure compliance with the Local Rules on a day-to-day basis. (Correct answer)
- To carry out the justification and authorisation of all medical exposures.
Correct answer: To ensure compliance with the Local Rules on a day-to-day basis.
The RPS is appointed by the employer to supervise the work and ensure that the Local Rules are being followed by all staff. The Radiation Protection Adviser (RPA) provides advice on facility design and regulatory compliance, while the critical examination is performed by the installer/manufacturer. Justification is the role of the IRMER Practitioner.
Question 4: A new 8-year-old patient attends for an initial examination. Clinically, they have a mixed dentition with closed posterior contacts and no evidence of caries. According to the Faculty of General Dental Practice (UK) 'Selection Criteria for Dental Radiography', what is the most appropriate radiographic investigation for caries diagnosis at this visit?
- No radiographs are indicated at this visit.
- Bilateral posterior bitewing radiographs. (Correct answer)
- A panoramic radiograph (OPT/OPG).
- Periapical radiographs of all posterior teeth.
Correct answer: Bilateral posterior bitewing radiographs.
The FGDP(UK) 'Selection Criteria for Dental Radiography' recommends that for a new child patient in the mixed dentition, if posterior contacts are closed (preventing visual and tactile inspection), posterior bitewing radiographs are indicated to assess for proximal caries, irrespective of the apparent clinical absence of disease.
Question 5: A dental practice in the UK must register its use of X-ray equipment under IRR17. Which organisation is responsible for handling this registration?
- General Dental Council (GDC)
- Care Quality Commission (CQC)
- Public Health England (PHE)
- Health and Safety Executive (HSE) (Correct answer)
Correct answer: Health and Safety Executive (HSE)
The Ionising Radiations Regulations 2017 (IRR17) require any employer working with ionising radiation, including dental X-ray equipment, to register their activities. This registration process is managed by the Health and Safety Executive (HSE).
Question 6: The 'Guidance Notes for Dental Practitioners on the Safe Use of X-ray Equipment' recommends a simplified two-tier system for rating the quality of radiographs. What are the two categories in this system?
- Excellent / Poor
- Acceptable / Unacceptable
- Diagnostically Acceptable / Not Diagnostically Acceptable (Correct answer)
- Grade 1 / Grade 2
Correct answer: Diagnostically Acceptable / Not Diagnostically Acceptable
The updated guidance from 2020 moved away from a previous three-tier system to a simpler two-tier system for image quality rating. Radiographs are now rated as either 'Diagnostically Acceptable' (A) or 'Not Diagnostically Acceptable' (N).
MFDS Part 1 - Membership of Faculty of Dental Surgery Dental and Maxillofacial Radiology Questions and Answers
According to the Ionising Radiation (Medical Exposure) Regulations 2017 (IRMER), who holds the primary legal responsibility for the justification of a dental radiograph exposure?