Expression of Metallic Artifacts Caused by Intracanal Medications with Different Chemical Compositions in Cone Beam...

Background/Objectives: Evaluation of artifact expression in CBCT images caused by different intracanal medications (IMs) considering variations in scanning and reconstruction protocols. Reconstruction protocols refer to the specific parameters and image processing techniques applied during CBCT acquisition, including voxel size, slice thickness, and artifact reduction settings. MicroCT was used as the reference standard. Methods: Root canal preparation (45./05) of upper canines was performed, and the teeth were divided into four groups (n = 10) according to the IM used: G1: Ultracal XS (UC); G2: Bio-C Temp (BCT); G3: Metapex (MT); and G4: Metapaste (MP). The specimens were sealed with temporary provisional material and stored at 37 °C and 100% humidity for 7 days. Then, they were scanned using microCT (SkyScan 1174) and two CBCTs in high and low resolutions: EagleX3D and OP300. Image registration was performed using FIJI ImageJ software (v. 1.54k). Axial, sagittal, and coronal reconstructions were quali-quantitatively evaluated by two calibrated examiners following the scores for the artifacts (dark streaks, hypodense areas, and distortion): definitely absent; probably absent; not sure; probably present and definitely present; and the possibility of using the images for endodontic diagnosis: No/Yes. Statistical analysis was performed using Fleiss' kappa test and two-way ANOVA (α = 95%). Results: CBCT images showed greater volume distortion of intracanal medication (p < 0.05) compared to microCT images. X3D CBCT showed the highest values of distortion, regardless of resolution, compared to OP300 (p < 0.05). The highest and lowest volume distortion for intracanal medications was observed in the UC and BCT groups, respectively (p < 0.05). Conclusions: Intracanal medication generates metallic artifact expression in CBCT images, hampering endodontic diagnosis.