Hard-tissue implants are provided that include a bulk implant, a face, pillars, and slots. The pillars are for implantation into a hard tissue. The slots are to be occupied by the hard tissue. The hard-tissue implant has a Young's modulus of elasticity of at least 10 GPa, has a ratio of the sum of (i) the volumes of the slots to (ii) the sum of the volumes of the pillars and the volumes of the slots of 0.40:1 to 0.90:1, does not comprise any part that is hollow, and does not comprise any non-pillar part extending to or beyond the distal ends of any of the pillars. Methods of making and using hard-tissue implants are also provided.