Dental Tribune United Kingdom Edition

March 14-20, 201126 Special Feature United Kingdom Edition I n recent government guide- lines on digital imaging, the focus has been on patient safety as much as accuracy and image clarity, so any system that can reduce radiation ex- posure is a must-have for the conscientious practitioner. In the last 10 years imaging tech- nology, in dentistry as well as other fields, has come on in leaps and bounds and the em- phasis in most new machines is on lowering potential radiation exposure. One piece of equipment that has met with much p r a i s e in both general and spe- c i a l - i s t d e n - t i s t r y is the 3D Cone Beam Computerised Tomography (CBCT) scanner, not just for its increased safety but also for its impressive versatility and convenience. Willi Kalender Volumetric CT scanning was developed in the 1980s by Willi Kalender, who nicknamed it ‘spiral’ CT because of the heli- cal trajectory of the rays, and fast became a favourite in the medical profession. Renamed ‘cone beam’ the main advan- tage of the CBCT scanner was that, unlike traditional flat x-ray plates, the cone gener- ates a full 3D image of the area being x-rayed to give the clini- cian access to the image from all directions. This is an invaluable tool in dentistry as it affords a comprehensive view of the patient’s dento-maxillofacial anatomy. It can facilitate di- agnoses and allow for better planning of treatment by giv- ing the clinician a better idea of any problems the patient may be facing. As the imaging picks up both bone structure and soft tissue, it can also be an excellent visual tool when it comes to explaining procedures to patients. Limiting radiation Government regulations (namely IRR99 and IRMER) state that, with regards to ra- diography, dentists have a statutory duty to take into ac- count the best ways to limit radiation doses when buying equipment.1 With the Health Protection Agency (HPA) rec- ommending that the start- ing point for the optimisation of patient dose be set at 250 mGy cm2, low radiation dose should be a serious factor in one’s choice of equipment. The HPA does recognise, however, that local diagnostic reference levels should be set after consultation with the user’s local Medical Phys- ics Expert (MPE) because of differences in equipment mod- els.2 When considered in light of this, a 2004 study found 3D Cone Beam Diagnostic Imaging – Quality and Safety Combined Neil Sanderson discusses imagery and patient safety