Introduction: The image quality as well as film speed is influenced by the film processing conditions. Different combinations of films and processing methods affect the diagnostic accu-racy. Temperature and developer exhaustion result in different image quality. The purpose of this study was to evaluate the influence of film type and processing conditions on caries detec-tion.
 Material and Methods: Eighty proximal surfaces in forty extracted unrestored premolars were radiographed under standardized conditions using D and F speed Flow Dental intraoral films. The exposure time was reduced by 50% for F-speed films. Half of the samples in each group were processed manually while the others automatically. No replenishment was used and the temperature was kept constant during the procedure. True caries diagnosis was based on histological assessment of the surfaces after sectioning the teeth. Two observers read the radiographs using a four-point scale to record their diagnosis. Observers' responses were evaluated using repeated measures analysis of estimation error.
Results: No significant differences were found in the diagnostic efficiency between two films and two processing methods in fresh and exhausted processing solution. F-speed(FV-58), however, showed earlier loss of diagnostic efficiency than D-speed(DV-58). Differences between observers were also not statistically significant.
Conclusion: The performance of the new F-Speed film(FV-58) was not statistically different from D-Speed for caries detection under differ-ent processing condition, and could be recom-mended for using in dental practice contributing to dose reduction.