2021 Volume 64 Issue 1 Pages 66-73
Purpose: Resin-based sealers are difficult to remove at the time of root canal retreatment due to their adhesion to the root canal dentin. This study investigated the working time taken to remove the filling material and the remaining percentage in the root canal for MetaSEAL Soft (MSS), MetaSEAL Soft Paste (MSSP) with increased bismuth content for improved X-ray contrast, and two other usual standard sealers.
Materials and Methods: For the root canal filling, 48 transparent simulated resin models with a 30-degree curved root canal were used. The working length was set to 12.5 mm. The root canals were enlarged up to 30/06 NiTi rotary file with TriAutoZX2. After root canal preparation, four root canal filling sealers, CANALS (CA), MSS, MSSP and AH Plus jet (AP), were used. The blocks were divided into the single-point root canal filling group and the sealer filling group (n=24). After the sealer had set, the filling material was removed until the file reached the working length and the time of sealer removal was measured as the removal time. In addition, Micro-CT was taken, and the volume of the remaining root canal filling material at the 3-mm apical area was measured and calculated with 3-dimensional analysis software. The obtained data were analyzed statistically with PC software.
Results: The removal time of the single-point filling group was shorter in the order of MSS<MSSP<CA<AP. The removal time of MSS was significantly shorter statistically between MSS and MSSP, and between MSS and CA (p<0.05). In the sealer filling group, the removal time was shorter significantly in the order of MSS<CA<MSSP, and all three groups finished in less time than the single-point filling group. On the other hand, the file did not reach the working length after more than 10 minutes in the AP. The amount of remaining filling material was lower in MSS than in MSSP, in the order of MSS<MSSP<CA. There were significant differences between CA and MSSP, and between MSS and MSSP.
Conclusion: MSS and MSSP were not affected by bismuth carbonate oxide and showed equal or superior removal to CA.
