Comparison of reliability of an endodontic three dimensional and CBCT softwaresto measure working length of root canals
Abdualhafid, Ahmed Muhamed
Purpose: The purpose of this study was to evaluate reliability of the 3D Endodontic Software (3-D endo) and conventional CBCT software in accurately determining the preoperative working lengths of root canals, when compared to conventional linear measurement. Materials and Methods: A periapical radiograph of each of 30 preselected teeth was acquired, the teeth were mounted in an artificial bone block and a CBCT scan was acquired. Working length measurements for each tooth were obtained using conventional CBCT and 3D endo softwares, as well as linear measurements using endo files and digital calliper. For each method the measurements were repeated. Test-retest reliability was assessed for each method. The Bland Altman analyses were used to compare both CBCTand 3D endo with linear measurements to determine their limits of agreement and whether these were clinically relevant. Results: Both readings for each method were found to be reliable (>0.9). The Bland-Altman analyses determined the limits of agreement to range between 0.13 mm and 0.25 for linear and CBCT measurements, and between -0.14mm and 0.12 mm for linear and 3D-Endo measurements, with 95% of the values residing within this range for both analyses. Conclusion: The margin of error for both methods compared to linear measurement translated to between -140 μm and 250μm of canal length. Clinically, this is far less than the critical margin of error for termination of canal obturation (≤ 2mm short of radiographic apex). This study suggests that CBCT and 3D-Endo softwares are reliable methods for determining working length in endodontic treatment. The limits of agreement for linear vs. CBCT measurements were higher than those for linear vs. 3D endo measurements. The mean difference of the latter wascloser to zero. This suggests that the 3D endo method could be more accurate than CBCT.
A research report submitted to the Department of Prosthodontics, School of Oral Health Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa in partial fulfilment of the requirements for the degree of MDent in Prosthodontics