Imaging: new versus traditional technological aids.

Until recently film has been the only medium on which to register radiographic images. Despite tremendous increase in sensitivity, the most sensitive films available at present still have a higher resolution than the eye, although at the cost of a more grainy image. Film speed for intraoral films seems to have reached its maximum unless a lower quality is accepted. Other methods, well established in medicine, like digital radiology, teleradiography and picture archiving and communication systems have started to make inroads into dentistry. In 1987 the first intraoral sensor and display processing unit, with the x-ray image on a television monitor, became available as an alternative to conventional radiography. Since then the sensors have improved enabling digital post-processing to enhance details of interest for different diagnostic problems. A dose reduction of approximately 80 per cent compared to D-speed films can be obtained. The sensitive area of the sensor is still relatively small compared to conventional films, resulting in difficulties in positioning it. However new systems approach the image quality of conventional E-speed film. Instant availability of the images is a major attractive benefit of these new technologies. With the arrival of direct digital acquisition of maxillofacial radiographs an 'electronic office' is needed to derive the full benefit from this technology, including local and distant image transfer. Digital imaging in dentistry is presently still in a relatively primitive state although it is anticipated that by the middle of this decade considerable improvement will have been achieved making digital image equipment feasible for the general practitioner.