The present invention relates to a dental handpiece (1) comprising: a head (4); a clamping means (13) which is rotatably arranged within a bearing (19) inside the head (4), and adapted for releasably clamping a dental drill (2), wherein the bearing (19) has an inner race (21) fixed to the clamping means (13) and an outer race (21) fixed to a housing (5) of the head (4); a driving means for rotating the clamping means (13) about an axial direction of the dental drill (2); a push button (7) which is arranged movably in the head (4) along the axial direction and configured to actuate the clamping means (13) to release the dental drill (2); and a biasing means to move the push button (7) away from the clamping means (13); characterized in that a radial inner surface (7a) of the push button (7) is arranged to contact and slide on a radial outer surface (20a) of the outer race (20) which configures a guide (12) for the moving push button (7), wherein the radial direction is perpendicular to axial direction of the dental drill (2); and wherein a radial clearance (A) is arranged between a radial inner surface (5a) of the housing (5) and a radial outer surface (7b) of the push button (7).

A dental handpiece configured to rotatably drive a dental treatment tool mounted in a chuck mechanism includes the chuck mechanism in which the dental treatment tool is mounted so as to be attachable and detachable. The chuck mechanism includes a hollow cylindrical sleeve, a cylindrical slide member, a plurality of divided movable pieces disposed in the sleeve, an elastic biasing member configured to bias the cylindrical slide member forward in an insertion direction of the dental treatment tool, and a stopper unit which restricts forward axial movement of the plurality of divided movable pieces in the insertion direction. The divided movable pieces are moved in a radial direction by relative movement between the divided movable pieces and the cylindrical slide member in the axial direction, so that fixation of the dental treatment tool and release of the fixation are performed.

The present invention relates to a dental handpiece (1) comprising: a dental handpiece (1) comprising: a head (4): a rotatable hollow shaft (15) which is rotatably arranged inside the head (4): a driving means for rotating the hollow shaft (15): a chuck (26) having resilient arms (27) for releasably clamping a dental drill (2), wherein the chuck (26) is fixed into the hollow shaft (15) so as to rotate with same: a ball (14) which is axially movably arranged inside the rotatable hollow shaft (15) and in direct contact with the resilient arms (27) of the chuck (26), wherein the ball (14) partly protrudes through an opening (17) on the upper end of the hollow shaft (15), and wherein the opening (17) is smaller than the size of the ball (14): a push button (7) which is arranged in the head (4) and configured to contact. when pressed by a user. the partly protruding ball (14) and move the ball (14) downwardly in between the resilient arms (27) so as flex the resilient arms (27) radially outwards and release the dental drill (2), wherein the resilient arms (27) bias the ball (14) inside the rotatable hollow shaft (15) towards the opening (17); and a biasing means to move the push button (7) away from the ball (14), wherein the push button (7) is not in contact with the ball (15) when it is released.