Benefits of cbct in implant planning

1. Benefits of CBCT in
implant planning
Gregori M. Kurtzman
Douglas F. Dompkowski
International journal of oral implantology and clinical research january-april 2011;2(1);
31-35

2. Implant planning in many cases can be very straight
forward; yet in some cases ; the remaining anatomy can
be deceptive in standard radiograph and clinically.
The growing use of the cone beam computerized
tomography ( CBCT ) has given new view to the
practitioner on what lies below the soft tissue and within
bone.

3. Age : 46
Sex : Female
Latin American
Chief complaint : Edentulous maxilla prior to age of 20
Wearing denture over 28 years
Dis-satisfied with removable denture and
wants implant supported dentures.
Medical history : No significant

4. Examination : very steep premaxilla with dominant
resorption as comparison to cuspid region where bone
volume was more.

5.  A CBCT ( Sirona Galileos ) was taken to evaluate the
bone for treatment planning.
 Using a DICOM file (Galileos software) image analysis
and implant planning was done.
 Severe resorption was concluded on the premaxilla with
sufficient bone on the cuspid region bilaterally and also
distal to it.
 Virtual implant was place in the software at potential
position and the treatment plan was developed.

6.  A new scan with a barium infused CT – stent was
decided to be taken to determine the thickness of the
soft tissue on the area where implant was to be placed.
 Patients current maxillary denture was used as the
template for CT – stent.
 Using a Lang denture duplicator the denture was
duplicated using 40% barium infused acrylic and a
addition of 20% barium infused acrylic over the tooth
region.

9.  A second CBCT was taken with the patient wearing the
barium infused CT – stent.

11.  Using the implant software axial slices were made at the
planned implant sites.

12.  The benefit of CBCT is the ability to look at these axial
slices which were taken in buccal-lingual direction
allowing the practitioner a true determination of the
volume of the bone available.
 Traditional radiograph do not allow this view and the
bone volume can be deceptive in using them to plan
implant placement.

13.  Axial slide presented with adequate bone at the implant
site and confirmed the need for augmentation to the
height at the molar sites via bilateral sinus lift procedure
which was carried out in a single appointment.

15.  Analysis of the premaxilla with barium CT stent showed
need for extensive cortical block grafting.
 Soft tissue gave deception that more volume of bone
was present.
 If done with traditional radiograph and flapless approach
there would have been no bone to drill

16.  Using a co-axis implant ( southern implant , CA USA )
which is available in several diameter and length and
provides a prosthetic angle correction in the implant of
either 12 to 24 degree
 Thus allowing the surgeon to angle the implant to place
the fixture in the triangle of the bone but not
compromise the prosthesis by having the screw access
emerge at the facial or require correction in the
abutment to align the fixture.

18.  Greater volume of bone buccal to cuspid and premolar
made it the site for implant placement.
 Barium CT stent was modified with holes at selected site
to accommodate the pilot drill.
 For grafting a crestal incision was made from the
tuberosity on the right to left and vertical releasing
incision was made on the buccal region.
 Full thickness flap were elevated with extension to the
nasal fossa in the anterior and zygoma in the posterior.
 A large window was created in the buccal osseous plate
at the molar site and eleveted.

19.  Osteotomies were created in the molar site to
accommodate the selected implant diameter and the
elevated sinus area was filled with a mixture of
autogenous bone and ALLoOss ; a mineralized allograft.
 The molar fixture was placed to the proper depth.
 The placement head were left on the fixture to help align
the co-axis implant that would be placed anterior to the
molar site.
 The osteotomies were created for the remaining fixtures
paralleling the platforms to simplify the prosthetic
restorations.

20.  The placement head were removed and cover screw
placed.
 To remove the undercut and easier anterior prosthetic
restoration , second surgery was carried out using a
mouldable allograft material ( Regegeform ) was placed
from premolar to premolar.
 A collagen membrane ( RCM 6 ) was placed over graft
and closure was done.

21.  A final CBCT was taken to document the implant position

22.  Enlargement of the posterior segment allows us to see
the implants lie within bone in each dimension

23.  To confirm that each fixture is surrounded by osseous
tissue at the cervical;

24.  Illustrates how accurate the virtual planning positions
can be replicated 3D with actual position after placement

25.  The dentures was modified and relined with soft liner
(Premasoft )
 A healthy period of 6 months will be allowed for
integration of the fixtures and incorporation of the graft.

26.  Good preplanning on implant requires information about
bone in all three axis ( X , Y , and Z ) as well as how this
bone relates to anatomical features that could hamper
placement , such as nerve and sinus.
 Traditional radiograph provides 2D image i.e. Only X and
Y axis .
 CBCT provides 3D image so that the implant can be
placed avoiding the important structure and within
available bone.