Examples of the images obtained are shown in Figs 1 and 2.
Figure 1. (a) Periapical radiograph immediately postoperatively and recall radiograph at 3 months. (b) Corresponding subtraction image.Inter-examiner agreement.
The colour-converted region of interest demonstrates the increase in density over 3 months projected on top of the radiograph obtained immediately postoperatively.
Figure 2. (a) Periapical radiograph at 3 months and recall radiograph at 12 months. (b) Corresponding subtraction image.
The colour converted region of interest demonstrates the increase in density over 12 months projected on top of the radiograph obtained at the 3 months recall.
Figure 3. The inter- and intra-examiner agreement rates expressed as kappa values.
Figure 3s hows the results of the inter-examiner agreement. The agreement between the examiners when digital radiographic images where evaluated was statistically significantly higher compared with conventional radiographs (kappa value for digital radiographic images 0.89 x 0.05; for conventional radiographs 0.25 x0.03; P = 0.001 by Mann-Whitney U-test). Intra-examiner agreement.
Figure 3 right shows the intra-examiner agreement. Digital interpretation showed statistically significantly better results than conventional radiographs (kappa value for digital radiographic images 0.83 x0.13; for conventional radiographs 0.32x0.11; P = 0.02 by Mann-Whittney U-test).