[The spread of the backspray under different working conditions].

The use of high- and highest-speed preparation instruments and the therefore required intensive spray cooling results not only in more efficient working possibilities but also in an increased infection hazard, especially for the dentist and his assistance caused by the spray rebound. Simulated preparations were carried out on different tooth surfaces at different positions of the patient with or without exhaust under clinical conditions to objectify the space spreading of the spray rebound. The arrangement of the equipment has been objectified by photogrammetry so that the measurement data could be clearly classified. The use of the spraying mist exhaust reduces the spray rebound between 50 and 65%.