Abstract: A dental handpiece having a turbine rotatable in reverse contains a main handpiece body, a turbine head mounted at a distal end of the main handpiece body, a plurality of turbine vanes for rotatably driving a dental tool romovably mounted within the turbine head, a first air supply passage for ejecting compressed air to one surface of each of the turbine vanes for rotating the turbine vanes in one direction, a second air supply passage for ejecting compressed air to the other surface of each of the turbine vanes for rotating the turbine vanes in the other direction, and an air discharge passage for discharging the compressed air.