In vitro infrared thermographic assessment of root surface temperatures generated by the thermafil plus system

The purpose of this in vitro study was to investigate root surface temperatures generated by the Thermafil Plus system using infrared thermography. A total of 60 extracted human maxillary central incisors and maxillary first molars were biomechanically instrumented using ProFile 0.04 Taper Series 29 rotary instruments. The root canals were obturated using the Thermafil Plus system. An infrared thermography camera was used to measure the external root surface temperatures during and after the completion of obturation. The mean temperature rise of the external root surface from the ambient temperature was 4.26 degrees C for the mesial buccal roots, 4.58 degrees C for the distobuccal roots, 4.76 degrees C for the palatal roots, and 4.87 degrees C for the anterior roots. These temperatures were well below the critical level of 10 degrees C needed to cause damage to the attachment apparatus. From this in vitro experiment, no evidence was discovered which would indicate that the Thermafil Plus obturation system would result in damage to the periodontal ligament and the surrounding attachment apparatus as a consequence of temperature rise on the external root surface.