Radiographic simulation of a periapieal lesion comparing the paralleling and the bisecting-angle techniques
Article first published online: 25 SEP 2007
International Endodontic Journal
Volume 27, Issue 3, pages 133–138, May 1994
How to Cite
FORSBERG, J. and HALSE, A. (1994), Radiographic simulation of a periapieal lesion comparing the paralleling and the bisecting-angle techniques. International Endodontic Journal, 27: 133–138. doi: 10.1111/j.1365-2591.1994.tb00242.x
- Issue published online: 25 SEP 2007
- Article first published online: 25 SEP 2007
- dental radiology;
Sixty apical areas of single-rooted teeth were examined in this study. A simulated periapical lesion was produced using an acrylic sphere (diameter 2.0 mm), the surface of which was covered with a thin layer of zinc cement. The sphere was placed in close contact with the apical foramen using a thin orthodontic wire inserted into the apical portion of the root canal. The correctly adjusted parallel projection depicted the simulated lesion with a very low degree of error. Overangulation of the central beam with maintenance of parallelism between tooth and film resulted in a moderate degree of magnification.
When correctly adjusted, the bisecting-angle technique produced images with almost the same accuracy as the paralleling technique. Over-angulation resulted in most images showing a reduced size of the simulated lesion. Moderate under-angulation most often recorded the correct dimension of the globe. In some cases a magnified image of the sphere was produced. Generally, this was associated with a palatally curved root. The investigation thus clearly indicated that the paralleling technique provides the most reliable information about the extent of a pathological process.