Comparison between CMOS Digital Detector and Film in Detection of Simulated External Root Resorption: An In Vitro Study

Root resorption is one of the most difficult diagnostic problems in endodontic treatments. Since successful treatment depends on early diagnosis of this pathology, using several diagnostic methods such as radiographic Images based on films, digital images and finally advanced diagnostic techniques are important. Therefore, in this study, we compared digital detector (CMOS) and conventional films by changing the different variables in diagnosis of simulated external root resorption (RR). In this in vitro study, in the first group, twelve intact premolar teeth extracted for orthodontic treatments, were selected. On the root surface of each tooth, we created a 2×2 mm window on buccal, lingual or proximal surface in cervical or middle levels and covered the remaining parts of the teeth with nail varnish. The root resorption was stimulated using acid in two different steps. The radiographic images were taken by two detectors, conventional film and CMOS sensor in three angulations (ortho, 15 degree mesial shift and 15 degree distal shift) before and after resorption induction. In the second group, on another 12 premolar teeth, mechanical root resorption was created by bur in two different sizes. The above mentioned steps were repeated the same as the first step. The images were observed by an expert endodontist and radiologist to find out whether there was root resorption or not. The data were analysed by Chi square test. Overall, the rate of correct diagnosis of acidic resorption in digital method (CMOS) was significantly higher than that of conventional method; however, in mechanical resorption the difference was not significant. According to our study, digital radiographs are more effective and helpful than conventional images in diagnosis of external resorption.Variables such as size, shape of cavity, location and level of root resorption are effective in observers’ ability in detection of root resorption.