The invention relates to a handpiece head (1) comprising a housing (2) and a closing cap (3), wherein the housing (2) is releasably connected to the closing cap (3) by means of a screw connection (4). The closing cap (3) comprises at least one recess (8) or at least one elevation (7), wherein the housing (2) correspondingly comprises at least one elevation (7) or at least one recess (8). When the closing cap (3) is screwed in, the elevation (7) on the housing (2) engages in the corresponding recess (8) on the closing cap (3) or the elevation (7) on the closing cap (3) engages in the corresponding recess (8) on the housing (2), so that an inadvertent release of the closing cap from the housing (2) as a result of vibrations of the handpiece head (1) is prevented by the engagement.