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Virtual implant planning and fully guided implant surgery using Magnetic Resonance Imaging - Proof of principle.

OBJECTIVES
To present a workflow of virtual implant planning and guided implant surgery with Magnetic Resonance Imaging (MRI) and virtual dental models without the use of ionizing radiation.


METHODS
Five patients scheduled for implant placement underwent an MR examination at 3 Tesla using individualized 2D- and 3D Turbo Spinecho (TSE) sequences and dedicated head coils. The MR imaging data and virtual dental models derived from either optical model scans or intraoral scans were imported to a virtual implant planning software (coDiagnostiX, Dentalwings, Montreal, Canada). Virtual prosthetic planning and implant planning were performed regarding the hard- and soft tissue anatomy. A drill guide was designed on the virtual dental model using Computer Aided Design (CAD) and manufactured in-house, using a 3D printer (Eden 260V, Stratasys, Eden Prairie, MN, USA).


RESULTS
The MR images displayed all relevant anatomical structures for dental implant planning such as cortical and cancellous bone, floor of the nasal and maxillary sinus, inferior alveolar nerve and neighboring teeth. The manual alignment of virtual dental models with the MR images was possible using anatomical landmarks. Dental implant planning, CAD/CAM of a drill guide and fully guided implant placement were successfully performed.


CONCLUSIONS
Guided implant surgery is feasible with MR images without ionizing radiation. Further studies will have to be conducted to study the accuracy of the presented protocol and compare it to the current workflow of guided surgery using CBCT.