2. Duty holders: employer, referrer, practitioner, operator

The four IR(ME)R duty holders

Every exposure needs a lawful chain. People can hold more than one role if they are entitled for each role — but the functions are different.

• Employer — usually the practice owner / body corporate. Must have written procedures, entitle staff, appoint a medical physics expert where required, and keep training records.
• Referrer — a registered healthcare professional entitled to request an exposure. In general dental practice this is often the dentist. A referral must include enough clinical information for the practitioner to justify the exposure.
• Practitioner — the person who justifies the exposure (decides it should go ahead). For intra-oral and panoramic work this is typically a dentist. Justification cannot be delegated to someone who is not entitled as a practitioner.
• Operator — anyone who carries out a practical aspect: positioning, exposing, processing, or clinically evaluating the image if that is how your procedures define it. Hygienists, therapists and radiography-qualified nurses may be operators if entitled.

Dentists as practitioner and operator

Most dentists are entitled as referrer, practitioner and operator for the examinations listed in the practice procedures (for example bitewings, periapicals, panoramic). Being a dentist does not automatically entitle you for CBCT or for equipment you have never been trained on.

What you must not do

• Ask a nurse without a radiography qualification to press the exposure button
• Take a radiograph “because the patient asked” without practitioner justification
• Expose a patient when no one has been entitled for that examination