Purpose: To assess (i) heat generated by pluggers during warm vertical compaction of gutta-percha and investigation
of temperature changes on the external root surface during canal filling, and (ii) the chemical changes of root canal sealers induced by heat.
•N= 4 types of sealers (AH plus, MTA plus and 2 experimental sealers), continuous wave pluggers with 4 tapers (0.06, 0.08, 0.10 and 0.12)
•The sealers were characterized by scanning electron microscope, X-ray energy dispersive analysis (SEM-EDX) X-ray diffraction analysis (XRD). •Temperature changes on the system B pulggers tips during heating (preset at 200 °C) and external temperatures generated on the root surface during warm vertical compaction of gutta-percha with different sealers inside the root canal were monitored using an infrared thermography camera. •Chemical changes induced by heating the sealers were assessed by Fourier transform infrared (FT-IR) spectroscopy.
Most highlighted Results:
•MTA Plus and the experimental sealers were composed of a cement and radiopacifier, with epoxy resin or a water-soluble polymer as dispersant, whilst AH Plus was epoxy resin-based.
•The heat generated at the tips of the system B pluggers was found to be lower than the temperature set and indicated on the device LCD display (maximum was 78.5 °C by 0.08 taper).
•The sealers reduced the heat generated on the external root surfaces during the heating phase by 10 °C.
•AH Plus exhibited changes to its chemical structure after exposure to heat, whilst the other sealers were unaffected.
The use of sealer reduced the temperature generated at the external root surface to between 37–41 °C for all sealers, which is tolerated by the bone and periodontium. A temperature of 47 °C (10 °C above body temperature) for 1 min is sufficient to cause necrosis of the alveolar bone,