Comparison of the Diagnostic Value of Digital Radiography and Temporal Digital Subtraction Radiography in Detection of Dentinal Caries Progression

The development and progress of computerized technologies has revolutionized radiology with digital imaging. The aim of this study is to compare Digital Radiography(DR) and Temporal Digital Subtraction (TDS)in detection of dentinal caries progression. 27carious teeth were placed in separate vials of sterile buffer solution after extraction. Three radiopaque restorations were placed in each tooth to aid in the alignment of successive radiographs. Each tooth was then mounted in poly methylmethacrylate and then incubated at 37°c in saliva buffer containing 5% glucose for 7hours per day, 5 days a week for 8 weeks. Each day after the7hour incubation period, each tooth was washed with 25ml of salivary buffer and placed in 50ml of salivary buffer at 37°c until the next cycling day and the PH in the medium was maintained above5.Digital radiographs were taken for each tooth on day 1 and then at week 2‚4‚6 and 8. The images were subtracted and results were recorded and analyzed using SPSS software. Statistical calculation showed a meaningful difference between the two methods. In other words, the progression of caries was more readily detected by the TDS technique such that during the first two weeks, diagnostic value of TDS was more than DR, but in the later stages, progression of caries was detected similarly by the two methods. It has been demonstrated that TDS is a more sensitive method for detecting change in tooth mineral content.