Electronic length determination has become the gold standard over the last few years. The German Association for Dental, Oral and Maxillofacial Surgery DGZMK confirms in a statement that this technique is superior to working length determination with a conventional radiograph. However, 3D radiography (CBCT: cone-beam computed tomography) provides an additional method to determine the endodontic working length.

A study conducted at the University of Granada/Spain focusses on the accuracy of working length determination based on these modern methods. For this purpose, 150 extracted teeth were divided into 5 random groups. The test results obtained by electronic length determination with the apex locator RAYPEX^® 6 were examined in 4 groups, under dry conditions (1) or in the presence of 3 different irrigating solutions (2-4). Measuring points were the major foramen and the apical constriction. The accuracy of the radiological working length calculated by CBCT scan was assessed in control group 5.

The results obtained by electronic measurement were more reliable than by CBCT scan, in particular regarding the determination of the major foramen. The study therefore confirms that RAYPEX^® 6 measures the working length with more accuracy and reliability than cone-beam computed tomography.

Original study: onlinelibrary.wiley.com/doi/10.1111/iej.12140/abstract