title: Artifacts in magnetic resonance imaging and computed tomography caused by dental materials.
abstract: BACKGROUND
  Artifacts caused by dental restorations, such as dental crowns, dental fillings and orthodontic appliances, are a common problem in MRI and CT scans of the head and neck. The aim of this in-vitro study was to identify and evaluate the artifacts produced by different dental restoration materials in CT and MRI images.
  
  
  METHODS
  Test samples of 44 materials (Metal and Non-Metal) commonly used in dental restorations were fabricated and embedded with reference specimens in gelatin moulds. MRI imaging of 1.5T and CT scan were performed on the samples and evaluated in two dimensions. Artifact size and distortions were measured using a digital image analysis software.
  
  
  RESULTS
  In MRI, 13 out of 44 materials produced artifacts, while in CT 41 out of 44 materials showed artifacts. Artifacts produced in both MRI and CT images were categorized according to the size of the artifact.
  
  
  CONCLUSIONS
  Metal based restoration materials had strong influence on CT and less artifacts in MRI images. Rare earth elements such as Ytterbium trifluoride found in composites caused artifacts in both MRI and CT. Recognizing these findings would help dental materials manufacturers and developers to produce materials which can cause less artifacts in MRI and CT images.
authors.affiliation: Polyclinic of Prosthodontics and Biomaterials, Greifswald University, Greifswald, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Klinke
authors.forename: Amro
authors.initials: A
authors.lastname: Daboul
authors.forename: Juliane
authors.initials: J
authors.lastname: Maron
authors.forename: Tomasz
authors.initials: T
authors.lastname: Gredes
authors.forename: Ralf
authors.initials: R
authors.lastname: Puls
authors.forename: Ahmad
authors.initials: A
authors.lastname: Jaghsi
authors.forename: Reiner
authors.initials: R
authors.lastname: Biffar
mesh_terms: D016477:Artifacts; D003188:Composite Resins / Q000737:chemistry; D003442:Crowns; D003722:Dental Alloys / Q000737:chemistry; D003723:Dental Amalgam / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry*; D005459:Fluorides / Q000494:pharmacology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*; D015018:Ytterbium / Q000494:pharmacology; D015040:Zirconium / Q000737:chemistry
chemical_list: D003188:Composite Resins; D003722:Dental Alloys; D003764:Dental Materials; C501891:Tetric EvoCeram; C102799:ytterbium fluoride; C041332:amalcap; D003723:Dental Amalgam; D015040:Zirconium; D015018:Ytterbium; D005459:Fluorides; C028541:zirconium oxide