Gutta-percha is the most common obturation material used in root canal therapy. Heated thermo plasticised obturation techniques have shown to cause a temperature rise on the external root surface which may result in potential damage to the surrounding periodontium. Forty five human permanent incisors, with a single canal, were divided into 3 groups of 15 teeth each. Root canal preparation was done and the teeth were surrounded by alginate simulating the periodontal ligament in the clinical situation. A small window was cut into the test tube and through the alginate to allow access for the thermocouples for measuring the temperature. Canals were obturated using Warm vertical compaction(group I), Injectable thermo plasticized gutta percha techniques Obtura II(group II )and Elements obturating system(group III).Immediately before each experiment, the teeth were equilibrated at 300 C and all experiments were performed at a constant room temperature. Results showed that there was a significantly higher rise in temperature on the outer root surface of mandibular incisors in Elements group when compared to Obtura II and Warm vertical compaction groups. Out of 7 mandibular incisor teeth, 5 teeth exhibited temperature rise above 60c.So, the relatively higher temperature rises on the root surface suggest that caution should be exercised when using higher temperature thermo plasticized gutta percha technique to fill teeth with thin remaining root dentin.
