title: Magnetic resonance imaging in zirconia-based dental implantology.
abstract: OBJECTIVE
  X-ray-based planning and post-implantation assessment of titanium implants is the commonly accepted standard to date. However, new implant materials such as zirconia (ZrO2 ) have become available, and magnetic resonance imaging may be a valuable alternative with these implants. The present in vitro study investigated artifacts produced by titanium and zirconia implants in magnetic resonance imaging (MRI) and assessed the accuracy of pre-implant planning and post-implantation assessment comparing MRI to standard X-ray-based imaging modalities: Orthopantomogram (OPT), cone beam (CBCT), and computed tomography (CT).
  
  
  METHODS
  Twelve porcine mandibles were prepared and scanned (MRI, OPT, CBCT, μCT), and bone height above the nerve canal was measured. Specimens were implanted with either two titanium or zirconia implants and rescanned to investigate the influence of implant materials on post-implantation assessment. MRI and μCT artifacts were quantified with implants embedded in gelatin phantoms and porcine specimens.
  
  
  RESULTS
  Compared with CBCT set as standard, μCT, OPT, and MRI showed similar accuracy in pre-op bone height measurements. Post-implantation, while titanium implants induced a strong B0 -field distortion resulting in extensive signal voids, zirconia implants were clearly depictable with only minor distortions.
  
  
  CONCLUSIONS
  Excellent contrast, limited artifacts, radiation-free and accurate implant assessment may indicate that MRI is a valuable imaging alternative for zirconia-based implant dentistry.
authors.affiliation: Department of Oral and Craniomaxillofacial Surgery, University Hospital Freiburg, Freiburg, Germany.
authors.forename: Fabian
authors.initials: F
authors.lastname: Duttenhoefer
authors.affiliation: Department of Experimental Molecular Imaging, Helmholtz-Institute for Biomedical Engineering, RWTH-Aachen University, Aachen, Germany.
authors.forename: Marianne E
authors.initials: ME
authors.lastname: Mertens
authors.affiliation: Department of Oral and Craniomaxillofacial Surgery, University Hospital Freiburg, Freiburg, Germany.
authors.forename: Josef
authors.initials: J
authors.lastname: Vizkelety
authors.affiliation: Department of Experimental Molecular Imaging, Helmholtz-Institute for Biomedical Engineering, RWTH-Aachen University, Aachen, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Gremse
authors.affiliation: AO Research Institute Davos, Davos, Switzerland.
authors.forename: Vincent A
authors.initials: VA
authors.lastname: Stadelmann
authors.affiliation: Department of Oral and Craniomaxillofacial Surgery, University Hospital Freiburg, Freiburg, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Sauerbier
mesh_terms: D000818:Animals; D016477:Artifacts; D054893:Cone-Beam Computed Tomography; D015921:Dental Implants; D003764:Dental Materials; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008334:Mandible / Q000000981:diagnostic imaging; D011861:Radiography, Dental / Q000379:methods*; D011862:Radiography, Panoramic; D013552:Swine; D014025:Titanium; D015040:Zirconium
chemical_list: D015921:Dental Implants; D003764:Dental Materials; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide
keywords: X-ray imaging; computerized tomography; cone beam ct; dental implants; implantology; magnetic resonance imaging; titanium; zirconia