[Sonic and ultrasonic instruments for endodontics. 2. Operative sequence and clinical advantages].

The authors describe the differential characteristics between sonic and ultrasonic endodontic devices: the former type is pneumatic and uses the air coning from the odontoiatric chair that gives to the endodontic instrument only a lateral way of swinging. The latter type changes the ultrasonic activity coming from piezoeletric phenomena into swinging mechanical energy (operating at 25 KHz). The authors specify the characteristics of endodontic instruments and explain their operating ways, demonstrating that reaming by endosonic instruments increases effects of hypochlorite. They also describe the operating train, pausing on the opportunity that the root canal should be manually probed, measured and reamed up to a diameter that gives sufficient space to the file vibration. They conclude listing the advantages that gives the correct use of sonic and ultrasonic devices; they also augur that with their use endodontics could have a greater diffusion.