Micro-CT assessment of the sealing ability of bio-ceramic root canal sealers

Objectives: The purpose of this study was to analyse the sealing ability of bio-ceramic sealers by measuring root canal void percentage using micro-computed tomography (micro-CT). Material and Methods: Forty single-root human premolars were selected and randomly allocated into four groups. Teeth were instrumented using #10 K and then Wave One Gold Primary files. Samples were obturated using matched taper Gutta-Percha cones with single cone technique and one of the four tested sealers (n=10) (MTA Fillapex, Bioroot, Endosequence and Wellroot). Following obturation, teeth were stored in Hank’s balanced salt solution for 7 days. All samples were scanned pre-operatively and postoperatively using Micro-CT at a resolution of 13.65 µm. Voids percentages were calculated in the entire tooth length in addition to coronal, middle and apical thirds. Results: There was a significant difference (P<0.05) between Endosequence sealer and MTA Fillapex sealer as well as between Wellroot sealer and MTA Fillapex sealer in total voids percentage and coronal thirds voids percentage. Other comparisons showed no significant difference (P>0.05) in total voids percentage neither comparing middle and apical thirds of each sealer to another. Moreover, there was no significant difference comparing the three thirds of each sealer. Volumetrically, voids percentage was highest in MTA Fillapex sealer followed by Bioroot sealer then Wellroot sealer and finally Endosequence sealer. Conclusions: None of the tested sealers showed void free results. Endosequence and Wellroot sealers showed higher sealing ability compared to MTA Fillapex sealer. Micro-CT is an excellent method to study the sealing ability of endodontic sealers by showing accurate quantitative results. The single cone technique is clinically acceptable when using bioceramic sealers.