Objective: Quantitative assessment of apically extruded debris and retreatability of two sealers using two rotary retreatment systems
Methodology: Two NiTi rotary file systems; ProTaper Universal (PT) retreatment files (Dentsply-Maillefer, Ballaigues, Switzerland) and Mtwo R retreatment (MT) rotary files (Sweden and Martina, Padova, Italy) and two sealers; AH Plus (Dentsply International Inc., York, PA, USA) and SmartPaste Bio (DRFP Ltd., Stamford, UK) were used in this study. The root canals of 40 single-rooted human premolar teeth having nearly similar length were prepared. The prepared root canals were obturated with gutta-percha and either AH Plus or Smart Paste Bio sealers (n=20/group). Each group was then sub-divided into two subgroups (n = 10 lsubgroup) according to whether the root filling material was removed using either Protaper Universal retreatment or MTwo Retreatment Kit.
After retreatment, the apically extruded debris was collected in Eppendorf tubes which were weighed before and after retreatment with an electronic balance. The retreatability of the both sealers was assessed using CBCT imaging by calculating the volume of the residual filling material post-treatment in the middle and apical thirds of the root canals. Results were statistically analyzed using one-way-analysis-of-variance; (P<0.05).
Results: Statistically, there was no significant difference in the weight of collected apically extruded debris nor in in the remaining volume of the obturating materials between all groups (P=0.849 and P=0.8831), respectively.
Conclusions: All investigated retreatment techniques caused debris extrusion and left filling remnants inside the root canals. SmartPaste Bio sealer is as retreatable as AH Plus sealers.