Comparasion of 4 obturation−techniques in C−shaped canal: analysis by micro−CT

Objectives: The purpose of this study was to compare the sealing ability of 4 different obturation techniques in irregular C−shaped root canal system in vitro using micro−computed tomography(μCT). Methods: Forty extracted teeth with C−shaped root canal system were randomly divided into 4 groups. After root canal cleaning and shaping, Group I teeth were obturated by cold lateral condensation technique(CLC), Group II teeth were obturated by warm lateral condensation technique(WLC); Group III teeth were obturated by warm vertical condensation technique(WVC); Group IV teeth were obturated by carrier−based thermoplasticized gutta−percha (CBT). All samples were scanned by μCT and 2−D reconstruction after obturation. The cross−sectional images of each tooth was submitted to computer analysis, and the obturation ratio of each tooth was calculated by Photoshop 7.0 software. The results were analyzed by ANOVA and Student′s t test to compare the obturation ratio of different techniques and different levels (coronal, middle, and apical) at each group. Result: The obturated ratio was significantly less in the CBT group(93.94%,p<0.001), but with no significant difference among WLC(99.65%),WVC(98.57%)and CLC(98.33%).The apical level had more un-obturated ratio than middle and coronal levels in each group (p<0.05). Conclusion: The WLC technique can provide better quality in obturation of C−shaped root canal system, while there is no significant difference among WLC, WVC and CLC.