Introduction: Different techniques and materials have been introduced over time to improve the quality of root canal treatment. This study aimed to compare the quality of root canal obturation using three root canal obturation techniques based on the existing void using cone beam computed tomography imaging techniques. Methods: Thirty-three single canal teeth were selected and the root canals were prepared. The roots were obturated with single-cone, lateral compaction with cold gutta-percha, and vertical compaction techniques. Afterward, the roots were scanned, and the presence of voids in the 1-, 3-, 5-, and 7-mm sections of the root apex was investigated, and then the area and volume of voids were calculated by Mimics 10. 01 software. Results: The highest percentage of voids presence in all groups was detected in the 7-mm section of the apex (60. 6%), while the lowest percentage was found in the 1-mm section of the apex (12. 1%). Conclusion: There was no significant difference between the three techniques evaluated in this study in terms of void size, void volume, and obturation quality. Voids were present in all samples. Considering the technique used to obturate the root canals, voids were different in terms of shape and volume.

Statement of Problem: Due to the anatomic complextieis of C-shaped canals, using an obturation technique capable of filling the irregular isthmus in the root canal system seems to be necessary.Purpose: The aim of this study was to compare the efficacy of three different root canal obturation techniques used for filling the irregular root canal system in C-shaped teeth.Materials and method: The study was perfomed on 30 human extracted molar teeth which were radiographically and anatomically recognized as having C-shaped canals. All root canals were prepared in the same way and the samples were divided into 3 groups, each of 10 teeth. The root canals in group I were filled by cold lateral condensation technique (CL). Teeth in group II were filled by means of warm lateral condensation technique (WL) and those in group III were filled by means of warm vertical condensation technique (WV). All teeth were demineralized and then cleared with methylsalicilate. Images were taken from both longitudinal and cross-sectional feature of the cleared teeth by a digital camera connected to a stereomicroscope. The filling quality of the main canals and the isthmus between them was evaluated by three independent endodontists. The data were statistically analyzed by chisquare, one way and two way ANOVA and t-test.Results: In longitudinal photographs, the highest percentage of good filling quality (80%) was observed in the WV group and was significantly more acceptable than WL group (p<0.05). The lowest percentage of good filling quality was observed in the isthmus area of the canals (46.7%) which was significantly less than other areas (p<0.05). Cross- sectional photographs demonstrated no significant difference between the percentage of isthmuses filled with the filling material and the two areas of the canals in the three obturation techniques (p>0.05).Conclusion :The results indicated that none of the suggested techniques could successfully fill the root canal space, but the warm vertical and cold lateral condensation techniques were more acceptable than warm lateral condensation technique.

Introduction: There is a direct relationship between the quality of root canal obturation and success of endodontic therapy. The aim of the present study was to assess the quality of canal obturation performed by undergraduate dental students at the Faculty of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran.Materials and Methods: Records of 200 endodontically treated teeth from patients who were visited by undergraduate students between 2009 and 2010, at the Endodontic department, Faculty of Dentistry, Mashhad University of Medical Sciences, were randomly selected for evaluation. Periapical radiographs of all treated teeth were assessed in terms of canal obturation quality (i.e. adequate density and length). Statistical analysis of data was carried out using SPSS software and chi-square test.The Statistical significance level was set at P=0.05.Results: Forty-five percent of teeth fulfilled the criteria of an acceptable root canal obturation. Adequate length and density of root filling was found in 89% and 34% of teeth, respectively. There was a significant difference between maxillary and mandibular teeth regarding the length of root canal obturation (P=0.004). A significant difference was observed between molars and other tooth types. The frequency of root canals with an acceptable filling was significantly greater in the anterior teeth compared to premolars or molars.Conclusion: The technical quality of root canal treatment performed by undergraduate dental students was found to be less than ideal.

Introduction: One of the key factors in successful endodontic therapy is to adequately fill the root canals. The aim of this in vitro study was to compare the quality of four different root canal obturation techniques: cold lateral condensation (CLC), warm vertical condensation (WVC), Obtura II (OII) and Gutta Flow (GF) by using micro-computed tomography (micro CT).Materials and Methods: A total of 20 extracted maxillary first molars prepared with ProTaper files, were randomly divided into four groups. Micro CT was used to measure the internal volume of root canals. Following application of AH26 sealer to canal obturation, new micro-CT images were taken and the volume percentage (VP) of voids, gutta-percha and sealer at different levels were calculated with CT software. Data was statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests.Results: The highest percentage of filling material was observed in GF group followed by OII with no statistically significant difference (P>0.05).These two groups had a significantly more acceptable filling than WVC and CLC groups (P<0.05). Voids were detected in all samples. There was a significant difference between the highest and the lowest percentage of voids in CLC (19.6%) and GF groups (6.7%), respectively. In the apical third, CLC and OII showed the highest and the lowest percentage of voids (5.5% and 2.6%) and the lowest and highest percentage of gutta-percha (76.52% and 94.26%), respectively. These differences were statistically significant (P<0.05).Conclusion: None of the root canal filled teeth were gap-free. GF and CLC techniques showed the highest and lowest VP of obturation materials, respectively.