Abstract: Objective: To explore the clinical value of dental radiograph process in digital dental radiography system (DDRS)in diagnosing and treating the proximal caries. Methods: The patients, who were diagnosed as proximal caries with clinical exploration, were taken dental radiographs. The radiographs′ noises were processed and the radiographs were arranged in random order according to their computer number. One kind of image processing setup, following by another one assessed at least one week later, which could eliminate mutual obstruction, was examined jointly by three observers. Relative clinically diagnostic yields and four kinds of image processing setup were compared statistically. Results: Relative diagnostic accordance rate of the clinical exploration and four kinds of image processing setup was higher（P＞0.01）in the first premolars. Relative diagnostic accordance rate of the clinical exploration and the pseudocolor image setup and negative image setup was higher（P＞0.01）, and that of the clinical exploration and the pseudo3D image setup and positive image setup was lower（P＜ 0.01）, showing statistical differences in the second premolars. Conclusion: The computed image processing technique in DDRS can be applied to clinical examination of the proximal caries in premolars as an adjunct method.

Key words: Proximal caries, Computer-assisted image processing, Premolar, Diagnosis