Most dental practices offer an X-ray service to their patients and, as you know all too well, this comes with its own set of challenges.
Firstly, let’s get the regulations front and centre so we know what we’re dealing with:
- The Ionising Radiations Regulations 1999 (IRR99) are specifically directed at those who work with ionising radiation, including the undertaking of dental radiography. IRR99 requires the employer to keep radiation doses as low as is reasonably practicable (ALARP) together with establishing and maintaining a quality management system.
- The Ionising Radiation (Medical Exposure) Regulations 2000 [as amended] (IR(ME)R) address the protection of the patient. The radiation dose received by the patient must again be kept ALARP while still achieving a satisfactory clinical diagnosis. You must be able to show that you have written staff entitlements, procedures and an up to date equipment inventory, as well as being able to show how optimisation of dose is achieved.
When working to ensure the relevant requirements are being complied with, a good starting point is to read the Guidance Notes for Dental Practitioners on the Safe Use of X-ray Equipment. In addition you may find it helpful to have access to the book Working with Ionising Radiation - L121, which includes the text of IRR99, the Approved Code of Practice and guidance, and IR(ME)R.
If you are thinking of working with cone beam computed tomography (CBCT), or as you may know it 3D imaging, then the Guidance on the Safe Use of Dental Cone Beam CT (Computed Tomography) Equipment is essential reading.
Policy and protection
To demonstrate compliance with IRR99 and IR(ME)R, every dental practice should have a radiation protection policy covering the use of ionising radiation and defining the person who is legally responsible (‘legal person’) for implementing and managing the policy, which includes:
- Consultation with a ‘suitable’ Radiation Protection Advisor and obtaining medical physics expertise.
- Carrying out a radiological risk assessment and reviewing it regularly.
- Appointing and arranging training for at least one radiation protection supervisor (RPS) whose role is to ensure adherence to local rules.
- Ensuring local rules are produced that are relevant and ’fit for purpose’.
- Training of staff and maintenance training records.
- Issuing and recording personal dosimetry results (when provided).
- Issuing and instructing on proper use of personal protective equipment (when provided).
- Arranging for acceptance testing, routine testing and the servicing of X-ray equipment, as appropriate.
- Reporting potentially adverse radiation incidents and equipment failures.
- Implementing, reviewing and auditing radiation safety, quality assurance procedures and protocols.
- Setting up a referral criteria protocol, establishing radiographic examination and exposure criteria, identification of patients prior to exposure, creating a pregnancy enquiry protocol, clinically evaluating exposures and recording results.
- Recording of persons entitled to act as practitioner, referrer and operator.
- Ensuring that everyone works in accordance with the regulations, local rules and schemes of work at all times.
X-ray equipment
Equipment must be properly installed and maintained if the principles of quality assurance and keeping doses as low as is reasonably practicable are to be achieved. The installation, modification or re-positioning of an X-ray set must be followed by a ‘critical examination’, which will be undertaken by the installer. An acceptance test should also be carried out prior to the equipment being put into clinical use; the acceptance test may be undertaken by the installer of the equipment on behalf of the user. The aim of these tests is to demonstrate that adequate protection from X-rays is provided for persons in adjacent areas, that the equipment is in working order and is capable of keeping radiation doses ALARP, that it meets the manufacturers’ specifications, and to provide useful information for future comparative tests.
Although guidance specifies routine X-ray equipment assessments should be carried out every three years, the legal person should consider this to be the maximum period between test and thought should be given to the age and performance of equipment when setting testing schedule protocols. A test performance record should be kept to record all relevant findings for each X-ray set. This record should include the manufacturers’ specifications and performance parameters, which can then be used in comparative studies to analyse the effectiveness and operation of the equipment concerned.
If at any time the quality of radiographs drops below an acceptable standard and/or a diagnostic reference level (DRL) is regularly exceeded, the legal person must pursue all possible avenues in the radiological process in order to isolate, identify the problem and, if necessary, seek further advice about what remedial action is required.
In addition, a system of daily checks should be performed to confirm that the X-ray equipment and the ancillary equipment are working correctly, such as:
- Operation of warning lights (mains ‘on’, X-rays ‘on’) and audible signals.
- Stability of X-ray fixing (wall, ceiling or chair mount).
- Intra-oral X-ray equipment’s counterbalancing.
- Panoramic/CBCT X-ray equipment’s rotational and positioning devices.
- Timing devices.
- Visual checks of electrical cables, connections, plugs.
A more formal check of all the above should be undertaken at regular intervals – for example every six months – and a record kept of the outcome.
Risk assessment
A ‘suitable and sufficient’ risk assessment must be carried out, preferably in conjunction with an RPA, to determine the magnitude and hazard of the work with X-rays, whether the protection measures are satisfactory, and whether further improvements are required.
The risk assessment should address various issues including the type of equipment being used, the adequacy of shielding, designation of controlled areas, whether the provision of additional warning devices is required, the provision of any personal protective equipment and the likely outcome of accident situations and how to minimise the consequences.
Local rules
Once the risk assessment has been undertaken and documented, the legal person is able to draw up local rules for the work with X-rays. Local rules are key working instructions to which all members of the dental team must adhere. You may decide that members of staff should sign a local rules ‘issue log’ to demonstrate their commitment to adherence.
Local rules should be relevant and be kept up to date. If you update the local rules for any reason, then a new
version should be issued and the changes recorded. Again, members of staff should be made aware of the changes and sign up to them.
Comprehensive care
The topic of radiation protection is vast and one article can only offer a snapshot of what is required from dental practices to ensure the safety of staff and patients alike. While for the majority of dental practitioners, many of the requirements are already in place and being complied with, it is not a situation where anyone can afford to rest on their laurels. It is important to be able demonstrate compliance, so if you have any questions or worries please do not hesitate to get in contact with the experts.