Micro-computed tomography and bond strength analysis of different root canal filling techniques.

INTRODUCTION: The aim of this study was to evaluate the quality and bond strength of three root filling techniques (lateral compaction, continuous wave of condensation and Tagger's Hybrid technique [THT]) using micro-computed tomography (CT) images and push-out tests, respectively. MATERIALS AND METHODS: Thirty mandibular incisors were prepared using the same protocol and randomly divided into three groups (n=10): Lateral condensation technique (LCT), continuous wave of condensation technique (CWCT), and THT. All specimens were filled with Gutta-percha (GP) cones and AH Plus sealer. Five specimens of each group were randomly chosen for micro-CT analysis and all of them were sectioned into 1 mm slices and subjected to push-out tests. RESULTS: Micro-CT analysis revealed less empty spaces when GP was heated within the root canals in CWCT and THT when compared to LCT. Push-out tests showed that LCT and THT had a significantly higher displacement resistance (P<0.05) when compared to the CWCT. Bond strength was lower in apical and middle thirds than in the coronal thirds. CONCLUSIONS: It can be concluded that LCT and THT were associated with higher bond strengths to intraradicular dentine than CWCT. However, LCT was associated with more empty voids than the other techniques.

Apical leakage using various sealers and root canal filling techniques / Infiltração apical de varios selantes e técnicas no preenchimento (tratamento) de canais radiculares

The aim for this study was to compare the apical leakage associated with several sealers and root canal filling techniques. Eighty maxillary central incisors were included in the study. Following cleaning and shaping, the root canals were filled by an active or a passive lateral condensation technique with the following endodontic sealers: Fillcanal (Grossman sealer), N-Rickert, Sealapex and AH-26. The teeth were immersed in a 0.5 per cent methylene blue solution, pH 7.2, for 72 hours at 37ºC and then cut longitudinally to reveal the canal walls. Apical leakage along the canal was measured using 20X magnification. The results are as follows: 1) All four sealers allowed apical leakage; 2) No statiscally significant difference was observed between the sealers with techniques studied; 3) When comparing active and passive lateral condensation techniques, Fillcanal, Sealapex and AH-26 showed statiscally significant differences among themselves, with a lower extent to the active lateral condensation technique. N-Rickert sealer showed no significant differences between the techniques