Vibration of dental handpieces.

The vibration of new (n=4) and used (n=16) dental handpieces was tested in three directions during idling. In addition, work was simulated by drilling on plastic plate with all new and five used handpieces. The weighted vibration according to standard ISO 5349:1986 and the total acceleration of high-frequency vibration ("ultravibration") in the frequency range of 1.43-11.06 kHz were analyzed. Neither the water and air injection nor the grip force of fingers had any significant effect on the vibration level. The work simulation did increase the vibration of the handpieces, and the vibration became more broadband. The weighted accelerations were plainly below the hazardous acceleration determined in ISO 5349 and the ACGIH-TLV. The vibration spectra of the handpieces contained powerful vibration at high frequencies, but the effects of this ultravibration and exposure during work are not well known.