RESUMO
In the past, research has regularly been carried out concerning the sound levels of various drilling devices and the impact these have on those who regularly use these devices. The present research is concerned with the possible permanent damage to hearing which can occur during the use of a newly developed instrument, the Piezosurgery. Measurements have been performed in a standardized set-up in which use is made of the lower jaws of pigs and a weight scale for measuring various degrees of pressure. The boundary values of the permissible exposure to noise were determined. The values of the Piezosurgery were compared with conventional drilling machines. It was concluded that using the Piezosurgery for less than 1.5 hours per day implies no risk of permanent damage to hearing. This means that the risk in the case of Piezosurgery is somewhat lower than that of conventional drilling devices.