The position of intra-osseous implants and abutments to analogs is enabled and enhanced by using the longitudinal axial locked position of a post (12a) of an implant (12) having a locking taper in a bore (10a) of an implant (10) having a generally matching locking taper as a reference to determine the position of a stop surface (14c) on impression posts, abutment analog posts and the like received in the bore of an implant and implant analog. In another embodiment the bore (16) of an implant analog (16) is provided with a shelf (16c) located at a position determined by the axial distance of the locked position of the abutment post to prevent over-seating. Controlled retentive resistance and stability of a post is provided by using flats formed in the bore of an implant analog and by forming rings on a post receivable in the bore of an implant or implant analog. One such ring (18c) is formed with an outer periphery sized and configured to allow bending of the outer peripheral portion in a direction opposite to the direction of insertion in a bore to provide greater retentive resistance than insertion resistance.