A dental implant having a central longitudinal axis at a bone-entry portion thereof is provided. The dental implant includes a threaded elongate fixture, at the bone-entry portion of the dental implant, shaped and sized for insertion into a bone of a subject, and a non-threaded emergence collar coronal to the fixture and smoother than the fixture. The emergence collar has a non-circular cross-section at least in a plane that is at least 1 millimeter coronal to the fixture and that is perpendicular to the longitudinal axis, the emergence collar and the fixture being formed of, and adjacently disposed along, a single piece of metal. Other applications are also described.