Abstract: An endosseous dental implant system having an implant body and an abutment. The implant body has a tapered cylindrical surface near its top end and an internally threaded or unthreaded passage extending into the implant body through an opening at the top of the implant. The abutment has an internal passage for receiving a fastener or, alternatively has a fastener as part of the abutment. The fastener threads into the implant body so that a tapered cylindrical cavity in the abutment mates with a matching tapered cylindrical surface of the implant to form an anti-rotational and locking junction with the implant when fastened by a screw or fastener. In addition to the anti-rotational and locking junction formed by the mating of external tapered cylindrical surface and internal tapered cylindrical surface, the dental implant system may also include an implant body having a multi-sided projection. In this embodiment, the abutment has a cavity for receiving the projection.