Purpose: The aim of this study was to evaluate the quality of different root canal obturation techniques by micro-CT.
Methods: Forty single-canal upper incisors were collected and decoronated to obtain 12 mm root segments. The root canals were prepared by using ProTaper rotary files and allocated into 4 groups randomly（n=10）, then obturated with gutta-percha and(or) iRoot SP by cold lateral compaction (CLC), continuous wave condensation (CWC), single core (SC), sealer-only buckfill (SoB) techniques, respectively. Each tooth was then scanned with micro-CT, and the percentage of 3D volume and 2D slices of voids and gaps were calculated 1 week later. The data were analyzed using SPSS 22.0 software package.
Results: Percentage of cross-sections with voids and gaps in CWC group was significantly less than others (P<0.05) , and it had a significantly greater filling area in 3D volume in whole root canal, middle third and coronal third levels (P<0.05), while SOB group had the largest filling quality in apical third levels (P<0.05).
Conclusions: No filling technology can avoid voids. CWC technology provides the best filling performance.