EFFECT OF TOOTH POSITION AND CBCT SETTINGS ON IMAGE ARTIFACT AND CONTRAST-TO-NOISE RATIO GENERATED BY 4 TYPES OF ROOT-END FILLING MATERIALS

Abstract

<h3>Background</h3> After endodontic surgery, radiographic assessment is the method of choice to monitor bone defect healing. Cone beam computed tomography (CBCT) scans are useful to identify the cause of surgical intervention failure or to confirm healing; however, the artifacts generated by some root-end filling material might compromise this objective. <h3>Objective(s)</h3> The aim of this study was to compare the artifact and contrast-to-noise ratios generated by four root-end filling materials at multiple CBCT exposure settings and positions within the field of view (FOV). <h3>Study Design</h3> Twelve central incisors were endodontically treated, obturated, and then retrograde-filled using amalgam, Biodentine, SuperEBA (ethoxy benzoic acid), and mineral trioxide aggregate (MTA). A phantom was created; then, tooth samples were inserted and scanned in the center and periphery of a 4 × 4 mm field of view (FOV) using a Morita MCT-1 F8 (at multiple kV and degree acquisition settings). Image J was used to determine the artifact and contrast-to-noise generated at the same relative slice image of each tooth. <h3>Results</h3> <i>Artifacts FOV position</i>: periphery had less artifact than central (<i>P</i> value < .0001); scan setting (Degrees): 360^o had less artifact than 180^o (<i>P</i> value < .0001); tube voltage (kV): artifact decreased with increased kVp (<i>P</i> value < .0001); Materials: Biodentine was associated with less artifact compared with MTA (<i>P</i> value = .031) <i>CNR FOV position:</i> Periphery had higher contrast-to-noise ratio (CNR) than central (<i>P</i> value < .0001); scan setting (Degrees): 360^o had higher CNR compared with 180^o (<i>P</i> value <.0001); <i>Tube voltage (kV):</i> CNR increased with increased kVP (<i>P</i>-value < .0001); Materials: Amalgam was associated with lower CNR than all others (<i>P</i> value = .002) <h3>Discussion/Conclusions</h3> Biodentine, MTA, and SuperEBA are biomechanically adequate for retrograde obturation because they generated significantly less artifact compared with amalgam. The use of the 360° image slice acquisition mode generated significantly less artifact than the 180^o setting for all materials. Finally, a periphery position led to lower artifact and higher CNR compared with the central position, a finding that was contrary to previous findings in the literature.