Methods: 36 single rooted teeth were collected, decoronated and root canal prepared using ProTaper NiTi rotary files. The teeth were randomly allocated into four groups and each group was obturated using a different material. Group 1 filled with EndoRez resin-coated gutta percha and EndoRez Sealer, Group 2 filled with Resilon points and RealSeal sealer, Group 3 filled with GuttaFlow and Group 4 with gutta-percha points and TubliSeal sealer. Teeth were scanned using micro-CT (SkyScan 1072, Belgium) then root fillings were removed using proTaper retreatment files and time required for removal was measured. Teeth were re-scanned and volumetric measurements were carried out using specialized CT software.
Results: Means and standard deviations of percentage of filling materials remaining for all groups were: Group1 1.62% (0.5 %), Group2 5.69% (2.76%), Group3 0.77% (0.5%) and Group4 8.45% (2.38%). Means and standard deviations of time required for root filling removal (s) were: Group1 97.6s (4.5), Group2 92.5s (7.6), Group3 91.2s (3.2), and Group4 154.7s (7.8). Oneway ANOVA analysis showed statistically significant differences in the percentage of filling material remaining between Groups 3 and 4, and in time required for root filling removal between Group 4 and all remaining groups.
Conclusions: Teeth filled with GuttaFlow showed the least filling material remaining after removal of the different filling materials. The root fillings were removed in less time in EndoRez, RealSeal and GuttaFlow groups.