Magnitude of beam-hardening artifacts produced by gutta-percha and metal posts on cone-beam computed tomography with varying tube current

Abstract

Purpose: This study was performed to evaluate the magnitude of artifacts produced by gutta-percha and metal posts on cone-beam computed tomography (CBCT) scans obtained with different tube currents and with or without metal artifact reduction (MAR). Materials and Methods: A tooth was inserted in a dry human mandible socket, and CBCT scans were acquired after root canal instrumentation, root canal filling, and metal post placement with various tube currents with and without MAR activation. The artifact magnitude was assessed by the standard deviation (SD) of gray values and the contrastto-noise ratio (CNR) at the various distances from the tooth. Data were compared using multi-way analysis of variance. Results: At all distances, a current of 4 mA was associated with a higher SD and a lower CNR than 8 mA or 10 mA (P<0.05). For the metal posts without MAR, the artifact magnitude as assessed by SD was greatest at 1.5 cm or less (P<0.05). When MAR was applied, SD values for distances 1.5 cm or closer to the tooth were reduced (P<0.05). MAR usage did not influence the magnitude of artifacts in the control and gutta-percha groups (P>0.05). Conclusion: Increasing the tube current from 4 mA to 8 mA may reduce the magnitude of artifacts from metal posts. The magnitude of artifacts arising from metal posts was significantly higher at distances of 1.5 cm or less than at greater distances. MAR usage improved image quality near the metal post, but had no significant influence farther than 1.5 cm from the tooth.

Head motion during cone-beam computed tomography: Analysis of frequency and influence on image quality

“…Technical causes of artifacts, such as electrical and phantom noise, scatter, beam hardening, and the exponential edge-gradient effect, as well as artifacts caused by the materials used for dental restorations, are known problems that must be taken into account. 11,[32][33][34] This study presents an analysis of the direct correlation of different patterns of patient motion on image quality in CBCT scans of the oral and maxillofacial region in a large cohort of patients, and the results of similar studies could be validated. Although significant technical advances have been made in recent years in implementing motion artifact correction tools, other studies are warranted to further reduce the need for re-exposure and to improve interpretability, thereby possibly enhancing operational areas for CBCT imaging.…”

“…Technical causes of artifacts, such as electrical and phantom noise, scatter, beam hardening, and the exponential edge-gradient effect, as well as artifacts caused by the materials used for dental restorations, are known problems that must be taken into account. 11 32 33 34 …”

Influence of adjacent teeth restored with metal posts in the detection of simulated internal root resorption using CBCT

“…2018, Gaêta‐Araujo et al . 2020). Furthermore, although beam‐hardening dark streaks might mimic some pathological conditions (e.g.…”

“…2018, Gaêta‐Araujo et al . 2020). Thus, different metal alloys or different dental materials, such as dental implants, could create different results.…”

“…2018, Gaêta‐Araujo et al . 2020). Previous studies assessed the influence of artefacts originated from dental implants in the diagnosis of teeth close to them and found a deterioration of diagnostic values for vertical root fractures (Freitas et al .…”