超声工作尖切削根管壁时根面温度变化的研究

目的 评价超声工作尖不同方式作用于根管内壁对根面温度变化的影响。方法 使用ET40超声工作尖分别在两种功率下和有水或无水冲洗两种状态下作用于8颗离体牙的根管内壁，热电偶测温仪测量其根面温度变化。结果 超声作用于根管内壁时会导致根面明显升温。功率大小对根面温度上升的影响显著，水能起到明显的降温作用。结论 临床应避免使用高功率长时间切削牙本质。

Temperature changes of tooth surfaces under ultrasonic tip working against the wall of root canals- an in vitro study

Objective To investigate the temperature changes of tooth surfaces under ultrasonic tip working against the wall of root canals,and the effect of power setting with or without water spray cooling on it.Methods Eight human premolars were used in an in vitro tooth model to use Satelec P5 ultrasonic system and ET40 tips working against the walls of root canal.Combinations of power settings(6 and 10) and with or without water spray were used to test their effect on temperature changes at the tooth surfaces using a thermocouple meter.Results The cutting of ultrasonic tip against the wall of root canal would cause significantly temperature rising on the tooth surfaces.An increase in temperature was observed with increasing power setting and a decrease in water spray.Conclusion Heat generation could be minimized by using low power settings and water spray.Care must be taken while using ultrasonic tips with high power setting and without water spray continued for a long time.