In Vitro Comparison of, Accuracy of Raypex 5 and Root ZXII Apex Locators, for Working Length Determination in Primary Teeth

Working length determination is a fundamental step in the endodontic treatment of primary and permanent teeth. Radiography is most commonly used for this purpose. However, it requires patient cooperation and is associated with adverse effects of radiation. Apex locators can serve as an efficient alternative for this purpose. We wanted to compare the accuracy of Root ZXII and Raypex 5 electronic apex locators for working length determination in primary teeth.METHODSThis in vitro study was performed on 154 canals of 58 extracted primary teeth. Access cavity was prepared, and a K-file was introduced into the canal until its tip was visible at the apex under a microscope. 0.5 mm was subtracted from this length to determine the actual working length. The canal length was then measured again using Root ZXII and Raypex 5 apex locators. The obtained values were compared with the actual value. Data was analysed using SPSS version 21 via paired t-test with intraclass correlation coefficient (ICC) at P<0.05 level of significance.RESULTSThe mean difference in values measured by Root ZXII and Raypex 5 and the actual working length was 0.77 ± 0.65 mm and 0.62 ± 0.58 mm, respectively. No significant difference existed in the accuracy of the two apex locators for determination of actual working length (P=0.54). The actual working length had a strong correlation with the values measured by Root ZXII (ICC=0.97) and Raypex 5 (ICC=0.95).CONCLUSIONSBoth apex locators have acceptable accuracy as an alternative to radiography for working length determination in primary teeth.

Effect of Head Position on Maxillofacial Transverse Measurements Made on the Skull and Cone Beam Computed Tomography Scans

Article Incorrect patient positioning and the resultant image distortion occur in many radiographic examinations. This study aimed to assess the effect of tilting, rotation and tipping of the head on the accuracy of maxillofacial transverse measurements made on cone beam computed tomography (CBCT) scans. The CBCT scans were obtained in central position of 10 dry human skulls. Using three-dimensional (3D) Dolphin software, six positions namely 10° and 20° tilts, rotations and tips were reconstructed of central position. Transverse distances between landmarks were measured on 3D scans and the skulls. The intraclass correlation coefficient (ICC) and the Bland-Altman plot were used to compare the mean values measured by the two observers. For most landmarks, no significant differences were noted between the mean transverse distances measured in the six positions and those measured in central position on 3D scans (p>0.005). In conclusion, all measurements of transverse distances made on 3D scans in different positions were underestimated compared to the actual values measured on the skull.