Reliability of different methods of measurement of working length in endodontics

Abstract

They compared measurements using radiographic images and mathematical calculations, computed tomography and electronic foraminal locator in vivo, comparing them with the real measurement determined by digital calipers after tooth extraction in 12 dental elements of patients of both sexes indicated. for tooth extraction due to advanced periodontal disease. The patients underwent Cone Beam Computed Tomography examination to determine the real length of the tooth. Afterwards, periapical radiographs were taken to establish the apparent length of the tooth. Subsequently, isolation of the operative field, the teeth had their canals accessed, emptied and subjected to conventional measurement by subtracting 3 millimeters from the radiographic vertex in this radiograph. Afterwards, a file was introduced inside the root canal, taking a new radiograph, measuring on this radiograph the distance between the tip of the instrument and the radiographic vertex, adding this measurement to the actual size of the instrument minus 0.5 millimeter as safety margin determined for the working length. Simultaneously, the canal was measured with an electronic foraminal locator. Next, the teeth were sealed and extracted, placed in containers with saline solution. The extracted teeth were measured using a digital caliper and these measurements were recorded in tables. It was concluded that odontometry using computed tomography represented the method that came closest to the real values of the dental elements, constituting the electronic locator with little significant difference in relation to the tomographic examination. Conventional dentistry, especially in anterior elements, showed a considerable degree of distortion.