The Effect of Gamma Value Alterations for Detecting Vertical Root Fracture in Indirect Digital Radiograph (an In-vitro Study)

Abstract

Background and Objectives Most digital imaging systems offer a variety of image processing techniques. Due to the importance of the accuracy of these images and their widespread application, this study aims to evaluate the detection of vertical root fracture (VRF) in indirect digital images by changing their gamma values. Subjects and Methods In this study, 23 extracted teeth were prepared as samples from dental clinics in Ahvaz, Iran. The radiographs were obtained from the samples before and after VRF induction. After root canal preparation, a very thin disc was used to divide the teeth into two halves in the buccal-lingual direction to create a VRF. The two halves were re-attached to each other and mounted in in molds filled with a mixture of plaster and sawdust. After processing the images by adjusting their gamma values using low, medium and high settings, the images were viewed by two radiologists for the presence or absence of VRF. Results In all three modes of gamma adjustment, the sensitivity, specificity and overall accuracy of images were high and there was no significant difference between the three modes. Conclusion The high gamma for digital images can used to as a filter to detect VRF. The images with medium and low gamma values are less helpful for detecting VRF