超声洁牙.ppt

* * 超声洁牙 Oscillating scaler systems sonic scalers magnetostrictive ----ultrasonic scalers piezoelectric Sonic scaler Magnetosrictive ultrasonic scalers (Dentsply Cavitron--一种无痛穿孔锥 ) Time: in 1950s Are either driven by a metal stack consisting of nickel-iron alloy strips or a Ferrite Insert inserted into a hand-piece. Inside the hand-piece a live coil generates an alternating electromagnetic field that leads to expansion or contraction of the ferromagnetic materials. The resulting vibrations are conducted to the scaler tip, causing oscillations with amplitudes of 13-72um and an elliptical motion pattern at frequencies of 20,000 Hz-45,000Hz. Depending on the angulation of the scaler tip in relation to the root surface, a more or less pronounced hammering or scraping motion pattern will result. Piezoelectric scalers (EMS) frequencies of 20,000 Hz-45,000Hz. The vibration is generated by changes in the dimension of a quartz crystal caused by the application of an alternating current. The resulting oscillation mode of the tip in strictly linear with amplitudes up to 72um. The mode of action of the tip is either of a tapping or a scraping nature, depending on the direction of the tip toward the root surface. Instrument power setting of magnetostrictive and piezoelecric ultrasonic scalers can be adjusted by the operator. A higher power setting increases the amplitude of tip oscillation, however, with a constant and stable tip oscillation frequency and motion pattern. Safety and efficacy of oscillating scalers According to the appropriate phase of periodontal therapy, adjust the amount of substance removal and ,consequently, the use of sonic and ultrasonic scaler tips. Initial periodontal therapy, an instrument needs to efficiently and rapidly remove tenacious calculus; Maintenance therapy, the instruments should efficiently remove bacterial bi