title: Beam Hardening Artifacts: Comparison between Two Cone Beam Computed Tomography Scanners.
abstract: OBJECTIVE
  At present, cone beam computed tomography (CBCT) has become a substitute for computed tomography (CT) in dental procedures. The metallic materials used in dentistry can produce artifacts due to the beam hard-ening phenomenon. These artifacts decrease the quality of images. In the present study, the number of artifacts as a result of beam hardening in the images of dental implants was compared between two NewTom VG and Planmeca Promax 3D Max CBCT machines.
  
  
  METHODS
  An implant drilling model was used in the present study. The implants (Dentis) were placed in the canine, premolar and molar areas. Scanning procedures were carried out by two CBCT machines. The corresponding sections (coronal and axial) of the implants were evaluated by two radiologists. The number of artifacts in each image was determined using the scale provided. Mann-Whitney U test was used for two-by-two comparisons at a significance level of P<0.05.
  
  
  RESULTS
  There were statistically significant differences in beam hardening artifacts in axial and coronal sections between the two x-ray machines (P<0.001), with a higher quality in the images produced by the NewTom VG.
  
  
  CONCLUSIONS
  Given the higher quality of the images produced by the NewTom VG x-ray machine, it is recommended for imaging of patients with extensive restorations, multiple prostheses or previous implant treatments.
authors.affiliation: Assistant Professor, Department of Oral & Maxillofacial Radiology, Faculty of Dentistry, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Farzad
authors.initials: F
authors.lastname: Esmaeili
authors.forename: Masume
authors.initials: M
authors.lastname: Johari
authors.forename: Pezhman
authors.initials: P
authors.lastname: Haddadi
authors.forename: Mehdi
authors.initials: M
authors.lastname: Vatankhah