COMPARING THE ACCURACY OF CBCT IMAGES AND DIGITAL INTRA-ORAL RADIOGRAPHY IN ESTIMATING THE PERIAPICAL INDEX

Aim: The importance of evaluating the periapical index and its effect on the treatment plan, prognosis and the inconsistencies and shortcomings done, the aim of this study was to measure the accuracy of digital intra-oral radiography and CBCT in evaluating the periapical index in Islamic Azad University in 2017 and providing a better method for this assessment. Materials & Method: In this in vitro study, 12 extracted single-rooted premolar teeth were subjected to root treatment. In the apex of the teeth, one of the six sizes of the periapical index was placed based on 0-5 scoring with waxy globes. In 12 generators from sawdust and gypsum were mounted for rebuilding the trabecular bone of teeth. Each generator was photographed by the CMOS detector of Villa machine (HD Videograph) at 2 angles of orthogonal and mesial with 25 degrees of difference in horizontal angle. CBCT images were photographed by the Villa machine. The images provided were observed and evaluated in 2 sessions at intervals of 1 week by 1 observer (experienced radiologist) on a DELL laptop LCD monitor with a resolution of 1024 * 1280 at a distance of about 40 cm in a semi-dark room and were recorded in information form number 2. The information was entered into the SPSS software and was statistically analyzed by KRUSKALWALLIS test. Results: The largest difference with the actual size was related to CMOS imaging with mesial angle and with an average difference of 0.0472 +/- 0.081 mm, and then CMOS imaging with orthogonal angle with an average difference of 0.0414 +/- 0.061 mm, and the most accurate CBCT imaging is with a difference of 0.0179 +/- 0.021 from the actual size. The KRUSKAL WALLIS test showed that this difference is significant (p <= 0.01). The pairwise comparison of three groups by MANN-U-WITHNEY test showed that the difference is significant (p <= 0.05). Conclusion: Despite the high accuracy of CBCT radiography, there was no significant difference in the accuracy of CBCT and CMOS imaging with orthogonal angle, and the greatest difference from the actual size is in CMOS with mesial angle.