Specification and use of x-ray equipment

Apply online to the Health and Safety Executive (HSE) to register work with a radiation generator (e.g. x-ray device) before beginning work with ionising radiation. Keep a copy of the registration certificate in the Radiation Protection File.

Keep an inventory of all radiographic equipment, including machines, ancillary equipment and software, with details of their specification (e.g. see X-ray Equipment Inventory template in the Radiation Protection File.

Ensure that all x-ray equipment complies with the following:

• intra-oral machines operate at higher than 50 kV, the optimum being 60–70 kV;
• panoramic machines operate at 60–90 kV;
• rectangular collimation should not exceed 40 by 50 mm, circular collimation should not be used;
• panoramic machines have positioning aids and light beams;
• the exposure control switch can be operated at least 2 m from and behind the tube head;
• the exposure occurs only while continuous pressure is maintained on the control switch and terminates if pressure is released;
• there is a light on the control panel to show that the mains is switched on;
• there are visible and audible indicators during exposure time;
• equipment installed after Feb 2018 has a device or other feature that provides information on the relevant parameters to allow assessment of the patient dose.

Ensure that the following requirements for equipment use are implemented:

• use rectangular collimation and beam aiming devices;
• if using film, use the fastest film speed available;
• use a minimum focus-to-skin distance of 200 mm.

Refer to the ‘Guidance Notes for Dental Practitioners on the Safe Use of X-ray Equipment’ [1] for further details on the specifications and use of x-ray equipment.

If using hand-held x-ray equipment, refer to the ‘Guidance Notes for Dental Practitioners on the Safe Use of X-ray Equipment’ [1] and ‘Guidance on the Safe Use of Hand-held Dental X-ray Equipment’ [2] for information on the recommended specifications and use.

If using cone beam CT equipment, refer to the ‘Guidance Notes for Dental Practitioners on the Safe Use of X-ray Equipment’ [1] for information on the recommended specifications and use.