Technical quality of root canal treatment and detection of iatrogenic errors in an undergraduate dental clinic.

AIM: To evaluate the technical quality of root canal treatment (RCT) and detect iatrogenic errors in an undergraduate dental clinic. METHODOLOGY: Three-hundred and eighty-eight root-filled teeth from the records of the Department of Endodontology at the Aristotle University of Thessaloniki, Greece were evaluated. Evaluation of root-filled teeth was based on two variables: length and presence of voids within the root filling. The technical standard of root fillings was categorized as: < or = 2 mm from the apex with no voids (acceptable); >2 mm from the apex with no voids; overfilling with no voids; < or = 2 mm from the apex with voids; >2 mm from the apex with voids and overfilling with voids. Iatrogenic errors that were detected included ledges, root perforations, furcation perforations, strip perforations and presence of fractured instruments. Chi-squared analysis was used to determine statistically significant differences between frequencies of root fillings between each tooth type. Significant differences were also determined between frequencies of ledges and root perforations according to tooth type and separately in molars according to tooth number, canal location and root canal curvature. Results Three-hundred and forty-three out of 620 root canals (55.3%) had a root filling that was classified as 'acceptable'. The frequency of root canals with an 'acceptable' filling was significantly greater in the anterior teeth (72.1%) than in pre-molars (55.2%) (P < 005) or in molars (46.7%) (P < 0.001). One-hundred and fifty-four (24.8%) root canals had ledges and 17 (2.7%) had a root perforation. The frequency of ledged root canals was significantly greater (P < 0.001) in molars than in anterior teeth. In molars, 105 out of 270 root canals (38.9%) had been ledged. Mesiobuccal, mesiolingual and distobuccal root canals were the most frequently ledged. Canal curvature was found to be the most important factor associated with ledges and root perforations. Conclusions Technical quality was found to be acceptable more often in anterior teeth. Ledges were identified more often in curved canals in molar teeth.

In vitro evaluation of apical leakage of root canal fillings after in situ obturation with thermoplasticized and laterally condensed gutta percha.

The purpose of this investigation was to compare in vitro the sealing ability of root canal treatments performed in situ with injected thermoplasticized gutta-percha compared with the lateral condensation technique. Thirty single-rooted teeth with straight canals, due for extraction for orthodontic or periodontal reasons were prepared using a step-back technique. Teeth were then divided randomly into groups A and B and obturated, respectively, with the sectional injection thermoplasticized gutta-percha and the lateral condensation techniques. Teeth were extracted after 15 days, immersed in India ink for 3 days and the leakage was determined using area-metric analysis. The roots were ground transversally and the root portion was incrementaly removed with successive steps of 250 microns each, up to the coronal level of the dye penetration. Every section was photographed with a stereoscopic microscope under the same magnification (x20); 310 photographs were taken. Measurements of the area covered by ink as well as the whole cross-sectional area of the canal were made from each photograph with the aid of a digitizing computer. The measurements were subjected to non-parametric statistical analysis. No significant difference was found (P > 0.05). The technique of lateral condensation proved to be better in the first five sections (1.2 mm from the foramen) while thermoplasticized gutta-percha technique was superior in the rest of the root canal.