ObturaⅡアプリケーターニードルの温度

抄録

Abstract : The temperature of the applicator needle of the ObturaⅡ was measured using a thermocouple. For precise measurement, a very thin thermocouple (0.15 mm in diameter) that had low latency and heat capacity was used. The temperature setting of the ObturaⅡ was 200°C. The output of the thermocouple was connected to a digital recorder and later analyzed.

 The temperature at the needle connection was 140°C when its trigger was not activated, and 170°C when the trigger was activated. The temperature at the 25-gauge needle tip was 100°C when its trigger was not activated, and 120°C when the trigger was activated. When air was blown at the needle, the temperature of the needle tip considerably decreased.

 It is suggested that the following be performed to facilitate root canal filling using the ObturaⅡ :

 1. Just before the gutta-percha injection, the gutta-percha remaining in the needle should be discarded.

 2. Before filling, the canal should be dried and only a small quantity of sealer should be left in the canal.

 3. Air blow or air suction near the applicator needle should be avoided when injecting the canal.

 4. A thicker needle should be used if possible.