An endosseous dental implant fastening system is provided with a fastening screw
that is configured to prevent complete disengagement of the fastening screw from
a screw extraction tool during removal of the screw from threaded engagement with
the implant and abutment members. A fastening screw is modified from conventional
construction by providing the mouth of the socket in the head of the screw that
is utilized to rotate the screw with left-hand threads, and to provide an installation
and removal tool with a shank having corresponding left-hand threads at it distal
tip. Counterclockwise rotation of the installation and removal tool relative to
the fastening screw causes the distal tip of the installation and removal tool
to advance into engagement with the left-hand threads defined in the socket of
the fastening screw. The fastening screw is thereby temporarily attached to the
installation and removal tool during installation and removal of the fastening screw.
