title: Assessment of metal artefact reduction around dental titanium implants in cone beam CT.
abstract: OBJECTIVE
  The aim of this study was to investigate if the metal artefact reduction (MAR) tool used in the software of the ORTHOPANTOMOGRAPH(®) OP300 (Instrumentarium Dental, Tuusula, Finland) can improve the gray value levels in post-operative implant scans.
  
  
  METHODS
  20 potential implant sites were selected from 5 edentulous human dry mandibles. Each mandible was scanned by a CBCT scanner, and images were produced under three different conditions: implant sites drilled but no implants inserted, implants inserted without application of MAR and implants inserted with application of MAR. Using Geomagic(®) Studio 2012 (Geomagic, Morrisville, NC) and 3Diagnosys(®) v. 5.3.1 (3Diemme(®) SRL, Cantù, Italy) software, three scans of each mandible were superimposed. The mean gray value of identical regions of bone around the implants was derived for each condition. The differences between gray value measurements at implant sites derived from different conditions were assessed.
  
  
  RESULTS
  A significant difference was found between mean gray values from the scans with no implants inserted and with implants inserted (with and without MAR) (p = 0.012). No significant difference was revealed for gray values measured from scans with and without MAR (p = 0.975).
  
  
  CONCLUSIONS
  The MAR tool in the software of the ORTHOPANTOMOGRAPH OP300 CBCT scanner does not significantly correct the voxel gray values affected by the metal artefact in the vicinity of an implant in human dry mandibles.
authors.affiliation: 1 Department of General and Specialized Dentistry, Section Oral and Maxillofacial Radiology, Academic Center for Dentistry Amsterdam (ACTA), Amsterdam, Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Parsa
authors.forename: N
authors.initials: N
authors.lastname: Ibrahim
authors.forename: B
authors.initials: B
authors.lastname: Hassan
authors.forename: K
authors.initials: K
authors.lastname: Syriopoulos
authors.forename: P
authors.initials: P
authors.lastname: van der Stelt
keywords: artefacts; cone beam computed tomography; dental implants; titanium