Laser treatment unit especially for medical or dental purposes

A dental laser treatment unit comprising:

• a control unit;
• a supply device;
• a first releasable connection connecting the supply device with the control unit;
• a laser treatment instrument having a front end and an outlet at the front end for a laser beam;
• a second releasable connection connecting the laser treatment instrument with the supply device;
• at least first and second medium supply lines which issue from the control unit, extend through the first releasable connection, along the supply device, and through the second releasable connection to the laser treatment instrument, with the first medium line supplying a laser beam, and the second medium line supplying a fluid;
• wherein at least one of the first and second releasable connections comprises a cylindrical plug-in coupling, which engages and disengages elastically, having a cylindrical coupling peg and a cylindrical coupling bushing which receives the cylindrical coupling peg, with a cylindrical gap being defined between the cylindrical coupling peg and the cylindrical coupling bushing, and wherein the cylindrical coupling bushing is sealed by sealing means relative to the cylindrical coupling peg, with the first medium line for the laser beam extending coaxially through the at least one plug-in coupling, and the second medium line extending to an annular groove provided between the inner wall of the cylindrical coupling bushing and the outer wall of the cylindrical coupling peg, such that the cylindrical coupling peg can rotate by 360.degree. and more relative to the cylindrical coupling bushing without interrupting the second medium line, and wherein the second medium line continues from said annular groove to the front end of the treatment instrument.