An oral care implement, such as a toothbrush, which includes a handle and a replacement head utilizing a specially designed structure for coupling the replacement head to the handle of the oral care implement. The replacement head comprises a head and a tubular sleeve comprising a cavity for receiving a handle. A protuberance protrudes radially inward from an inner surface of the tubular sleeve for engaging a boss of a stem on the handle to impede rotation of the tubular sleeve about the stem in a first angular direction. A locking tab protrudes radially inward from the inner surface of the tubular sleeve for engaging an undercut surface of the boss to prevent axial disengagement of the tubular sleeve from the stem. The locking tab is circumferentially spaced from the protuberance so that an first axial channel exists therebetween for receiving a section of the boss.