A dental implant system comprising an implant member, an abutment member and a transfer key with cooperatively engaging structures for ensuring proper alignment and orientation of an abutment assembled on the implant member and for preparing an accurate dental impression and mold which represents the implantation site and its relationship to adjacent teeth structures. The abutment has the advantage of being easily removed for maintenance, repair or replacement with minimal or no discomfort to the patient. The invention also includes a dental implant with an improved bone-engaging structure for enhancing implant stability and fixation, an O-ring type abutment assembly with a reduced footprint in its assembled state when compared with similar conventional systems, a surgical screw and bone screw insertion tool, a healing abutment that need not be removed during an impression taking procedure, and an implant coding system that facilitates selection and identification of dental implants and implant analogs whose dimensional attributes will produce an accurate fit between the dental prosthesis and the dental implant. Further, dental reconstruction and abutment installation methods utilizing the dental implant system and instruments of the invention are disclosed.