Evaluation of radiographic and eletronic methods for determination of working length in endodontics – an in vivo study

Abstract

The present study was carried out in vivo and aimed at comparing canal lengths as determined by radiographic and electronic methods in clinical situations of pulpar necrosis with and without radiographically visible periapical lesion. Forty (40) monoradicular teeth were selected and divided into two groups of twenty (20) teeth each. Group I comprised teeth with pulpar necrosis and radiographically visible periapical lesion. Group II comprised teeth with pulpar necrosis as well, but periapical lesions were not detected radiographically. All samples had their canal lengths determined by Ingle’s technique and by Root ZXTM. Measurements were registered for comparison. They showed canals located 1 mm from the apex of the root when measured according to Ingle’s technique, and 1 mm from the apical foramen when measured by Root ZXTM. Given that we work to a tolerance of 0.5 mm, there was an 80% coincidence in the measurements for both methods, and the mean difference observed was 0.33 mm. Thus, the differences observed were not statistically significant between the values found for the actual canal lengths as determined by Ingle’s technique and by Root ZXTM (p = 0.35). Moreover, no statistically significant differences were observed between Groups I and II (p = 0.20). They showed coincidences in the measurements, for both methods, in 85% and in 75% of the cases, respectively, with means of difference 0.42 mm (Group I) and 0.25 mm (Group II). Key words: endodontics, odontometry, diagnostic, tooth apex.