HPA Publishes Guidance On Using Dental Scanners

RADIATION protection guidance for dentists using certain new types of scanners, is published by the Health Protection Agency.


In the past few years specialist dental surgeries all over the UK have been introducing Cone Beam Computed Tomography (CBCT) technology to aid treatment. The scanners are similar to those used in hospitals for medical examinations but only scan the jaw and skull.


They are used for specialist examinations and can deliver higher doses of radiation than other X-ray equipment that dentists use.


Because of the rapid uptake of this new technology, and a lack of specific safety guidance on its use, the Health Protection Agency's dental radiation specialists assembled a group of experts to formulate guidance for dentists.


Dr John Cooper, Director of the Health Protection Agency's Centre for Radiation, Chemicals and Environmental Hazards, said: "Cone Beam Computed Tomography is a new and useful tool for dentists. However, like any X-ray equipment this technology utilises radiation and therefore there are risks.


"I am sure that the detailed and thorough work undertaken, and published today, will play an important role in ensuring that doses to patients are effectively controlled and that all others involved in the use of this technology, dentists and their staff, are well protected."


The new guidance sets out;


- What dentists should do before acquiring a CBCT scanner, including choosing suitable equipment, ensuring staff are adequately protected and making sure rooms where the equipment will go are specifically designed for the technology.


- How existing regulations apply to the use of CBCT.


- Standards that dental CBCT scanners should be tested against to make sure they work correctly and are capable of keeping patient doses as low as practicable.


- The training that dentists, and other users, will need to enable them to use the new technology properly.


The expert group included HPA dental and medical radiation protection staff, dentists, regulators, medical physicists and academics.


Dr Cooper added: "This guidance will play an important role in protecting all involved in the use of CBCT and I want to thank the group which developed it for its hard work. The fact that those on the group come from such diverse backgrounds illustrates how this advice has been developed by all those with a professional interest in this field.


"I hope that dental professionals will find this guidance useful."


Notes


- The first advice to come from the working party was published on the HPA website in summer 2009. A further advisory document was published in March this year.


- The Health Protection Agency is the official adviser to all arms of the UK Government on the health effects of radiation.


- The HPA's specialist dental radiation team created a working party two years ago to develop guidance on using the technology. There had been no specific guidance on the use of dental CBCT equipment, so it was unclear how existing radiation protection legislation applied to its use.


- CBCT technology works by an X-ray tube rotating around the patient's head and sending out a cone shaped X-ray beam, which is then picked up by a detector. The data from the scan is translated into a 3D image of the teeth and jaws and other bones of the skull. The technology is useful to dentists as it has been designed to image bone and dental tissue, and delivers dimensionally accurate 3D images that are useful for planning some types of dental surgery.


- A scan from a dental CBCT unit can deliver a dose of between 0.048 and 1.1 millisieverts (mSv) to the patient, depending on the nature of the examination. A conventional dental X-ray will deliver a dose of between 0.01 - 0.02 mSv. Those undergoing a medical chest X-ray will receive a radiation dose of about 0.02 mSv and those undergoing a medical CT scan of the head will receive about 2mSv.


- The working party included representatives from the Health Protection Agency, the Institute of Physics and Engineering in Medicine, the Care Quality Commission, the Faculty of General Dental Practice (UK), the British Dental Association, the British Society of Dental and Maxillofacial Radiology (BSDMFR), the University of Manchester School of Dentistry, the Health and Safety Executive, the University Dental Hospital, Cardiff and the Royal Surrey County Hospital, as well as private dental practitioners