Comparison of three imaging techniques for assessing endodontic working length

Abstract

The accuracy of endodontic working length estimation was investigated using three imaging techniques: radiography (Rd), Xeroradiography (Xr) and Radiovisiography (RVG positive and negative prints). An in-vitro model of extracted single straight roots, mounted in wooden blocks with wax, was employed in the study. Optimum exposures were established for each of the imaging techniques. The magnification of the images was measured and the resolution of the RVG images was also investigated. Comparable Rd (D-speed film), Xr,RVG positive and RVG negative images were made of five roots with size 10 files in situ. Images of 10 standard files were made, ranging from 2.0 mm through the root apex to 2.5 mm short of the apex, resulting in 200 images. Six observers each assessed the working distance on 100 images, measuring the distance from the apical foramen to the file tip. After allowing for the magnification of the images, these results were compared with the 'true' file tip to apical foramen (measured with the aid of a reflex microscope). The inaccuracy of working distance estimations was considered to be of clinical significance (> 0.5 mm) in 6% of measurements made from Rd and Xr, 19.2% of measurements from RVG negative and 32.3% from RVG positive images. In addition, 14% of RVG images were too poorly defined to be assessed. The first-generation RVG system was used in this study. It was therefore concluded that the most accurate estimates of working distance were made from Xr and Rd images, and that RVG images, particularly the RVG positive images, were the least accurate and most difficult to read.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro comparison of root-canal measurements with conventional and digital radiology

“…For all three file sizes used, the conventional film was seen to yield results close to 0. Similar findings were reported in another study involving size 10 files (Griffiths et al . 1992).…”

“…1994). On the other hand, on the screen images obtained with both digital techniques were used, as they offered better quality than the paper‐printed images (Griffiths et al . 1992).…”

Detection of a transitional ion concentration zone during electronic measurement of root canal length: a study in vitro

“…1990 ). The negative aspects of determining canal length by radiography include the use of ionizing radiation, and the potential inaccuracy in root canals with an asymmetric foramen ( Griffiths et al . 1992 ).…”

Digital Radiography for Determination of Primary Tooth Length: In Vivo and Ex Vivo Studies

“…Presence of periapical pathology, degree of pathological or physiological resorption, and presence of permanent successor tooth are also factors complicating the working length determination of primary teeth [ 3 ]. Clinically, the radiographic apex is used as reference point [ 4 ]. However, because apex does not always coincide with the actual apical foramen position, there is a difference between apparent tooth length (APTL) and actual tooth lengths (ACTL) in the majority of the cases [ 4 ].…”

“…Clinically, the radiographic apex is used as reference point [ 4 ]. However, because apex does not always coincide with the actual apical foramen position, there is a difference between apparent tooth length (APTL) and actual tooth lengths (ACTL) in the majority of the cases [ 4 ].…”