A dental prophylaxis angle and handpiece assembly for cleaning and polishing teeth is provided. The dental prophylaxis angle is removably attached to the dental handpiece by an interlocking mechanism that includes extension locking tabs, a locking annular member, and an interlocking drive member in the handpiece. The prophy angle is securely snap-fitted onto the handpiece and locked in place so that it has minimal lateral movement. After the prophy angle has been used to treat a patient, it can be removed easily from the handpiece and disposed thereof.