Methods : Three-dimensional computer-guided implant placement in oligodontia
Patient and methods
Implant planning and placement
Pre-implant procedure and 3D planning
A CBCT (ICat, Image Sciences International, Hatfield, UK; 576 slices, voxel size 0.3 mm, FOV: 11 × 16 cm) was made of two oligodontia patients (for patient details, see Figs. 1 and 2) for implant planning. Detailed patient information was obtained with regard to the nerve position and bone quality and quantity. In addition, a digital intra-oral scan was made to get a detailed 3D image of the dentition (Chairside Oral Scanner: C.O.S., Lava™).
CBCT and intra-oral scanning data were combined using Simplant Pro (Dentsply, Hasselt, Belgium) in order to obtain a detailed 3D model of both patients (Fig. 3a,b) for virtual implant planning. The intra-oral scans, representing the dentition, were superimposed by a registration process, based on the contour of the corresponding dentition, onto the CBCTs. The intra-oral scan data was imported into the 3D virtual plan software as a stl-file. First, the objects representing the upper and lower dentition were globally positioned on the 3D data of the CBCT using manual translation functions. Next, exact positioning was determined using translation and rotation functions, starting in the mid-sagittal plane based on the contour of the model projected on the two-dimensional (2D) CT data. Refinements to the position were made while scrolling through the 2D CBCT data.
Virtual set-ups of the ultimate treatment goal were made for both patients with the virtual planning software Simplant Pro (Fig. 4a-c). Virtual teeth were aligned in the 3D virtual model. Based on the position of these teeth, the implants were planned in the optimal prosthodontic position; tooth size, optimal implant position, location of the mandibular nerve, bone quality and volume and antagonists were also accounted for. The planning was done by the technical physician (J.K.) for both cases, and the implant positions were checked and optimized by the prosthodontist (M.F. and A.V.), orthodontist (K.J.) and surgeon (G.R.).
Fabricating 3D templates
Tooth-supported implant drilling templates were designed by the dental technician, based on the final virtual set-ups using the Geomagic Freeform software (3D Systems, Rock Hill, USA), and then fabricated out of polymethacrylate (Fig. 5a,b). The positioning of each implant was enabled with a 5-mm outer diameter metal drill sleeve (Nobel Guide, Nobel Biocare Holding AG, Zürich-Flughafen, Switzerland; Fig. 5a) as drill sleeves minimize deviation in drill position. The templates were checked for fit and stability in the intra-oral situation.
Implant placement
After raising a mucoperiostal flap, the dental implants were placed using the virtual developed tooth-supported drilling templates using metal inserts (Fig. 5c). It was checked whether no dehiscences of the implant surface were present.
Serial posts:
- Three-dimensional computer-guided implant placement in oligodontia
- Introduction : Three-dimensional computer-guided implant placement in oligodontia
- Methods : Three-dimensional computer-guided implant placement in oligodontia
- Results : Three-dimensional computer-guided implant placement in oligodontia
- Figure 1. Patient 1—orthopantomogram (OPT) at age of 13
- Figure 2 a Patient 2—pre-implant orthopantomogram
- Figure 3. a Patient 1—detailed 3D model of the combined data
- Figure 4. a Patient 1—virtual set-up of the ultimate treatment goal
- Figure 5. a Drilling templates of patient 1
- Figure 6. Patient 1—post-operative orthopantomogram (OPT) at age of 18
- Figure 7. Patient 2—post-operative orthopantomogram (OPT) at age of 13. Situation 10 months after implant placement. Three months after starting the orthodontic treatment, the 34 is already erected
- Figure 8. Patient 2—intra-oral situation during orthodontic treatment
- Figure 9. Patient 1—prosthodontic end result 5 months after implant placement
- Figure 10. Patient 1—post-operative evaluation of placement accuracy of the implants