![]() The ability to detect VRFs in the Zr group was further enhanced by clinical experience.īeam hardening artifact cone-beam computed tomography gutta-percha vertical root fracture zirconium.Ĭopyright © 2018 American Association of Endodontists. The reduced BH of the Zr group improved the sensitivity of the detection of artificially induced VRFs. Beam-hardening artifacts are caused by the polyenergetic nature of the x-ray beam and can be reduced by using x-ray filtration, applying higher-energy x-rays, altering patient position, modifying contrast material protocols, and applying certain reconstruction algorithms. The OMRs outperformed the residents in the detection of VRFs in the Zr group with respect to specificity (P =. Receiver operating characteristic area under the curve values were greater for the Zr group than the GP group, but these differences were not statistically significant. However, the specificity was greater for the GP group than the Zr group (P =. The sensitivity was greater for detecting VRFs in the Zr group than the GP group (P =. The area close to the surface of a bulky sample tends to have a higher value (lighter gray) than the center area, as we saw in the example at the beginning. The images were evaluated by 6 oral maxillofacial radiologists (OMRs) and residents. The most common beam hardening artifact is varying gray level within a uniform density object. Each root was then placed in a dry human mandible and imaged with the Carestream 9000 3D CBCT system (Carestream Dental, Atlanta, GA). VRFs were induced in 44 decoronated teeth in each group using an Instron (Norwood, MA) Universal Testing Machine. Beam hardening is the polychromatic nature of the xray beam used in CT scan and its effect on the creation of beam hardening artifacts. The water bag technique was previously used in head scanners to reduce beam-hardening artifact. One hundred seventy-six single-rooted mandibular premolar teeth were obtained, and half of these teeth were filled with GP or Zr (CPoint EndoTechnologies, LLC, Shrewsbury, MA). The correction of beam hardening is a research topic of interest since the inception of Computerized Tomography. Case Discussion CT artifacts are common and can occur for various reasons. The purpose of this study was to evaluate the influence of a zirconium (Zr)-based root filling material with radiologic properties that reduce beam hardening (BH) artifacts using CBCT imaging in the in vitro diagnosis of VRFs. Beam hardening and scatter are different mechanisms that both produce dark streaks between two high attenuation objects, such as metal, bone, iodinated contrast. An 8mm hyper dense foreign body with beam hardening (metal) artifact is noted at right upper anterior chest wall, within the lateral aspect of right pectoralis major muscle. Limited field of view cone-beam computed tomographic (CBCT) imaging has been used to augment clinical testing of vertical root fractures (VRFs) however, the presence of gutta-percha (GP) in the canal space generates substantial imaging artifacts that make fracture detection difficult. ![]()
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