Clinically related properties of ZrO2-containing premixed tricalcium silicate endodontic sealer

Objectives: This study investigated the clinically related properties of a ready-to-use tricalcium silicate endodontic sealer containing zirconium oxide (EndosealTCS) including cytocompatibility, antibacterial effect, tooth discoloration effect and root canal filling quality. We also highlighted the effect of ultrasonic activation which is mediated through the GP cone on filling quality.
Methods: The cytocompatibility was evaluated by measuring the viability of MC3T3-E1 cells and cell morphological observation using SEM in comparison with a mixing type calcium silicate cement (EndocemMTA), grey premixed calcium silicate sealer (EndosealMTA) and epoxy resin sealer (AH plus). The antibacterial effect was assessed by measuring colony forming unit (CFU) of E. faecalis. Tooth discoloration effect was evaluated by measuring ΔE values of standardized bovine tooth specimen containing each material (n=10). Human maxillary premolars with ribbon-shaped canals were filled with EndosealTCS by using three different methods (n=10); single GP cone, single GP cone combined with ultrasonic activation or warm vertical compaction. Then, the filling quality was examined by measuring the presence of voids in root canal filling. The assessment was performed using micro-computed tomography (μ-CT) and tooth specimen sectioning method. The data were analyzed by one-way ANOVA followed by Tukey’s test (p=0.05).
Results: Cell viability of EndosealTCS was higher than other tested materials on 3-day (p<0.05). AHplus showed the lowest viability among all materials through the entire experimental period (p<0.05). CFUs of EndosealMTA was lower compared to the other groups (p<0.05). The ΔE value of EndosealMTA was lowest among all groups (p<0.05). Regarding the filling quality, the ultrasonic-mediated single cone technique showed similar void number and score compared to warm vertical compaction technique (p>0.05). However, the simple single cone technique showed inferior results compared to other groups (p<0.05).
Conclusions: EndosealTCS showed favorable clinically related properties as an endodontic sealer. Moreover, the GP cone-mediated ultrasonic activation is recommended for root canal filling when single cone technique is used.