Magnetostrictive Ultrasonic/Piezoelectic Scalers and Pacemakers

You are correct that piezoelectric ultrasonic devices do not interfere with cardiac pacemakers and can be used without concern. Magnetostrictive ultrasonic devices interfere with unshielded cardiac pacemakers and are contraindicated for use. Thank you for your diligence in seeking qualification on this issue. http://www.jcda.ca/article/b113 Statement from the ADA: Ultrasonic Devices and Cardiac Pacemakers Dentists who use ultrasonic devices, like ultrasonic scalers or instrument cleaning systems, should be aware that they could interfere with some implantable cardiac devices, such as pacemakers or implantable defibrillators. The implantable cardiac devices use electrical impulses to help the heart maintain the proper rhythm. Ultrasonic devices can potentially create an electromagnetic interference, which could cause the device to malfunction. Although there are no reports in the literature of this occurring with patients, one in vitro study found that use of an ultrasonic scaler or cleaning system within 4 to 6 inches of the cardiac implants interfered with the performance of those devices.1 Some research, however, suggests that not all pacemakers are affected by ultrasonics.2 Consideration should be given to the possible effects such devices could have on patients or staff who have implantable cardiac implants. Some manufacturers offer recommendations on use of their device in the vicinity of such implants. Dentists also may consult with the treating cardiologist to determine if ultrasonics can be safely used. 1. Roedig JJ, Shah J, Elayi CS, Miller CS. Interference of cardiac pacemaker and implantable cardioverter-defibrillator activity during electronic dental device use. JADA 2010;141:521-6. 2. Patel D, Glick M, Lessard E, Zaim S. Absence of in vivo effects of dental instruments on pacemaker function. Oral Surg Oral Med Oral Pathol Radiol Endod 2005;99(4):430. Abstract.