[Digital subtraction radiography technique in oral diagnosis]

The introduction of digital subtraction radiography for the evaluation of standardised dental radiographs offered increased diagnostic accuracy in the detection of subtle density changes over interpretation of conventional radiographs. The digital imaging techniques for the analysis of dental radiographs were reviewed with emphasis on periodontal diagnosis. Recently, these methods, which have been extensively tested in vitro, were applied to clinical trials for the assessment of alveolar bone density changes due to progression of disease or healing following therapy.