Abstract
Radiography is still the best diagnostic technique which is widely available to dentists. Digital radiography offers improved imaging through lower dose and lack of chemical processing. However, monitoring of incipient caries progression requires imaging systems which are as good as film with testing at the D1 level (WHO). Care is required in constructing valid caries models. Work is required to define the necessary digital image quality as measurement accuracy for monitoring caries progression may be as high as 0.15 mm. A case has been made for using the highest sensitivity possible, since caries is a disease where a 'wait and see' policy should produce no unnecessary treatment from increased false positives. Individual site monitoring should be performed on both low and high caries risk patients. High-risk subjects still need to be monitored since DMFS is not a valid site level predictor.