DEVELOPMENTS IN RADIOGRAPHIC CARIES DIAGNOSIS

The developments that have been taking place in radiographic caries di agnosis, within the context of the changes occurring in both the disea se process and the available technology, are reviewed. The decline in caries prevalence seen in many western countries has been accompanied by changes in the pattern and behaviour of lesions. More lesions are n ow seen on occlusal surfaces, more are concealed (and thus imperceptib le to conventional diagnostic techniques), while the average progressi on rates for approximal lesions have also slowed. Systems employed for caries diagnosis must take account of these changes and the varying n eeds of users employing different diagnostic thresholds. This paper re views and discusses developments in: conventional film radiography), x eroradiography; indirect digital imaging (with computer image analysis and subtraction radiography), and direct digital imaging. It is concl uded that: for the detection in high caries prevalence groups of both approximal caries (especially small lesions in enamel) and dentinal oc clusal lesions in teeth with little or no surface breakdown, radiograp hy is still a significant and reasonably accurate diagnostic method, a nd that, in spite of the more limited resolution, digital imaging meth ods seem to perform as well or better than conventional film radiograp hy. Digital systems possess a number of advantages, primarily the poss ibility for image enhancement and significant dose reduction. It may b e predicted that digital imaging techniques will enter the clinical ro utine in the near future.