The invention relates to a device for the axial retention of a dental instrument extremity (1) and for transmitting the rotational drive of said instrument, said device being provided in a counter-angle head or a hand piece, said extremity (1) including an annular groove (1a) at the end thereof in which at least one lug (3a) is capable of radial engagement as well as a flat (12) for rotationally driving said extremity (1), the rotational movement being transmitted to the instrument by an output sprocket (7) of a transmission mechanical assembly coupled to a driving motor and provided in the handle connected to the counter-angle head or the hand piece, wherein said device is characterised in that it comprises a combination including an axis (2) that can be axially crossed by the extremity (1) of the instrument, at least one elastic lever (3) axially provided in an outer housing of said axis (2) and each bearing a lug (3a) and at least one pin each provided in a transverse hole (9, 10) at the upper portion of the axis (2) and laterally offset relative to the axial direction (11) of the axis (2) so as to allow the interaction of the pin(s) with the flat formed on the extremity (1) of the instrument.