Abstract
This study was conducted to evaluate the temperature rise on the root surface while the root canal is being obturated using continuous wave of condensation technique. Maxillary central incisor was prepared for repeated canal obturation. Ten thermocouples (Omega Engineering Inc., Stanford, USA) were placed at 1 mm increment from the anatomical root apex. The real temperature of Buchanan plugger was recorded before insertion into the root canal. The root canal was obturated with continuous wave of condensation technique as described by Buchanan and the root surface temperature was recorded during obturation at $150^{\circ}C,{\;}200^{\circ}C,{\;}250^{\circ}C{\;}and{\;}300^{\circ}C$ temperature settings of System B HeatSource (Model 1005, Analytic technologies, Redmond, WA, USA). After completion of the temperature recording, the dentinal-cementum thickness at each sites was measured. The data were analyzed using one-way ANOVA followed by Scheffe's test and linear regression test. The results were as follows. 1. When the temperature was set at $150^{\circ}C,{\;}200^{\circ}C,{\;}250^{\circ}C{\;}and{\;}300^{\circ}C$ on the digital display of System B HeatSource, the real temperature of the plugger at the 1mm point from the tip revealed $130.82{\pm}2.96^{\circ}C,{\;}158.00{\pm}5.26^{\circ}C,{\;}215.92{\pm}6.91^{\circ}C{\;}and{\;}249.88{\pm}3.65^{\circ}C$ respectively. 2. The position of 8 mm from the anatomical apex showed the highest temperature increase at each temperature settings and it was significantly higher than those of other positions (p<0.0l). The temperature rise was constantly increased toward coronal portion from apex of the root. 3. The maximum temperature increase on the root surface was $2.37{\pm}0.09^{\circ}C{\;}at{\;}150^{\circ}C{\;}setting,{\;}3.11{\pm}0.12^{\circ}C{\;}at{\;}200^{\circ}{\;}setting,{\;}3.93{\pm}0.09^{\circ}C{\;}at{\;}250^{\circ}C{\;}setting{\;}and{\;}5.69{\pm}0.15^{\circ}C{\;}at{\;}300^{\circ}C$ setting respectively. These results suggest that it be relatively kind to the supporting tissues of the root that the root canal is obturated using continuous wave of condensation technique at $150^{\circ}C,{\;}200^{\circ}C,{\;}250^{\circ}C{\;}and{\;}300^{\circ}C$ temperature settings on digital temperature display of System B HeatSource.
