Real-time Intracanal Temperature Measurement During Different Obturation Techniques

The purpose of this study was to assess temperature development in endodontic sealers during different obturation techniques in a closed system simulating the surrounding biological structures at body temperature. Methods: The root canals of 48 human single-rooted maxillary canines were instrumented with ProTaper Gold (Dentsply Sirona, York, PA) to size F3. On the buccal aspect of each root, artificial side canals with a diameter of 0.5 mm were drilled at a distance of 3, 6, and 9 mm from the apical foramen, and type K thermocouples were inserted via plastic pipes. The roots were positioned in plastic vials filled with alginate. The root canals were obturated by the continuous wave and warm backfill technique, Thermafil obturators (Dentsply Sirona), or single-cone obturation (n = 12) at body temperature using AH Plus sealer (Dentsply Sirona). Temperature measurement during the obturation procedure was assessed by thermocouples. Statistical analysis of the maximum temperature change was performed using the Kruskal-Wallis test (P = .05). Results: The continuous wave and warm backfill technique caused significantly higher temperatures than Thermafil and singlecone obturation (P < .05). The continuous wave technique revealed significantly higher temperatures than the warm backfill technique at 3 mm and 6 mm from the apex (P < .05). Conclusions: In a closed system with simulated surrounding tissues at 37 degrees C, the continuous wave technique produced higher increases in temperature than the warm backfill technique with a maximum of 19.1 degrees C. The temperature increase during Thermafil obturation was negligible. The temperature increase in the endodontic sealer was markedly lower than expected from root surface temperature measurement studies.