Performance Evaluation of Three Versions of Software Designed to Detect Mach Band Effect

In digital panoramic images، amalgam filled teeth may be observed with a radiolucent band called mach band (a visual illusion) which can be confused with secondary caries. The purpose of present study is performance evaluation of three versions of software designed for identification of mach band effect and caries. In this study، 40 digital panoramic images with 233 class I and II amalgam filled posterior teeth were selected. Three observers evaluated these teeth and agreed about the presence or absence of caries and mach band in them. All the cases were evaluated in three versions (A، B، C) of the software On the basis of agreement of 3 observers، 178 teeth had mach band، 23 teeth had caries and 32 teeth was normal. Sensitivity، specificity، positive likelihood ratio and negative likelihood ratio in version A for mach band detection was 94%، 11%، 1. 05، 0. 57 and for version B was 79%، 47%، 1. 50، 0. 44 and for version C was 82%، 47%، 1. 56، 0. 38 respectively and in detection of caries for version A was 13%، 96%، 3. 42، 0. 90 and for version B was 57%، 93%، 7. 91، 0. 47 and for version C was 70%، 91%، 7. 69، 0. 33. So، version C was better than others in both detection of mach band and caries. The results of this study indicate that this software can help users in detection of caries and mach band.