Comparison of the Effects of Different Preprocessing Methods on Homogeneity Assessment of Digital Intraoral Radiographs of Root Canal Fillings.

Root canal treatment is a very common method in the treatment of pulpitis, however, filled root canals do not last forever, which means a tooth on which this has been performed will eventually have to be extracted. Therefore, the homogeneity of a filling is very important because the better it is, the longer the tooth will survive; however, there is no universal method of assessing the homogeneity of a filling. In this paper, the use of textural parameters for qualitative assessment of root canal fillings is proposed; these include the homogeneity of the gray levels in an image or long-run emphasis. The use of different preprocessing methods can be helpful to obtain even better results. Three different methods of preprocessing are tested: histogram equalisation, CLAHE and CLAHE + histogram equalisation.