Is there any difference in length measurement methods for pulpectomies in primary teeth?-A double-blind, controlled clinical trial

Background: Working length is an important step in primary teeth pulpectomy. Aim: To evaluate whether there is a significant difference in the accuracy of electronic apex locators compared to the conventional radiography in working length measurements. Design: Sixty-four children (192 canals) between 5 and 9 years of age with indication for pulpectomy of a primary molar were included after eligibility criteria. A radiographic measurement was obtained from pre-operative radiography from the cusp tip to the apex or resorption of the root. The electronic measurement was obtained from a complete measurement of the canal with an electronic device up to the apex. Data were analysed with Bland-Altman plots and Wilcoxon test. Statistical significance was set at P <= .05. Results: Statistically, there is not any significant difference between radiographic and electronic measurements for the palatal canal or distal canal, as well as mesiobuccal canals (P >.05). Statistically, there, however, is a significant difference between the measurements for the distobuccal canal and mesiolingual canal measurements (P <.05). High internal consistency for both radiographic and electronic methods was achieved (alpha congruent to 1). Conclusions: Electronic and radiographic methods are similar in determining the length measurement of the root canals in primary teeth pulpectomies, except in distobuccal or mesiolingual canals.