An interbody fusion implant fits between adjacent vertebrae for fixation during fusion thereof. Upper bores extend into a cephalid surface of the implant and preferably include threads therein. A guide tool is removably attachable to the implant which supports guide bores along centerlines aligned with the upper bores in the implant. A drill can pass along these guide bores to form holes in a vertebra adjacent the cephalid surface of the implant which is precisely aligned with the upper bores. A hybrid screw then passes through these holes in the vertebra adjacent the cephalid surface and threads into the upper bores to secure the implant to the adjacent cephalid vertebra. Bone screws can also be used to secure the implant to caudal vertebra by passing through bores passing through the implant, such that the implant is securely mechanically fastened to both cephalid and caudal vertebrae adjacent the implant.