A coupling mechanism for an electric toothbrush includes a handle coupling portion and a refill coupling portion structured and configured to engage one another, thereby providing a secure connection between the handle and the refill. The handle coupling portion has a coupling stem disposed at one end of the handle and a coupling pin protruding from the stem. The coupling stem has outer walls terminating at a free end thereof. The refill coupling portion has a tubular structure having refill walls and an interior space for receiving therein the coupling stem, and a pair of mutually opposite and resiliently deformable cantilevered arms disposed in the interior space, each of the arms terminating with a coupling surface for engaging the coupling pin of the handle coupling portion.
