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3D-CT scan image based planning
to allow precise transfer to the surgical field and immediate loading
of a final fixed prosthesis.
The aim of this IT methodology is to allow an optimal
placement of implants both from a biomechanical and esthetic viewpoint.
This system offers the major advantage to allow pre-fabrication
of a fixed full bridge.
Thus the over-all clinical treatment time can be shortened, since
much is done prior to surgery and prior to the prosthetic phase
at the industrial/laboratory level.
A double CT-scan procedure is used, one of the patient wearing the
prosthesis and one of the prosthesis only, visualized through adjusting
the scanning window. The specially designed computer software which
was developed in Leuven allows fusing both images on the basis of
a few radio-opaque reference points added to the prosthesis. The
same program allows to plan in a fully 3-D environment implants
and abutments from a bone and prosthetic point of view. Thus the
mutual cooperation between periodontologist/oral surgeon and dentists
can be improved.
The CT-scan data sets are transformed through stereolithography
in jaw bone and overlying gum models. Thus the technician can fabricate
a drill guide and even the final bridge. A cadaver study proved
that the deviations from the installed implants towards the planned
implants are less than 1 mm.
Surgery time for a full jaw is regularly about half an hour.
The fixed final bridge will fit upon the implants and can be fixed
by expanding abutments. This can be done by the dentist immediately
after or at least the same day as surgery took place.
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