Because of frequent setup and disassembly,cleaning and autoclaving steam sterilization,the steam is infiltrated into the ultrasonic handpiece,resulting in failure of electric insulation.

• 在医院这种特殊的使用场合，频繁的装拆、清洗，特别是反复的高温、高压水蒸气消毒是造成电气绝缘下降的主要原因。