Comparative Evaluation of the Artefacts Index of Dental Materials on Two-Dimensional Cone-beam Computed Tomography.

Fusong Yuan,Xiaofei Wang,Litong Chen,Yong Wang,Yuchun Sun,Peijun Lyu

doi:10.1038/srep26107

Abstract

The aim of the study was to propose the artefact index on cone-beam computed tomography (CBCT) images of clinical prosthodontics materials, and to compare the effect of the artefacts on CBCT image clarity of normal oral tissues. Seven spheres of different materials were secured on the centre of a resin baseboard, respectively, and four human molars in vitro were placed at 10 mm front, back, left and right of the sphere. The board was scanned using CBCT with the same setting. 10 tomographic images from each of the seven data sets with clear artefacts was selected. The grayscale measuring tool of Photoshop software was used to measure the grayscale (G0) within the boundary of tomographic image and the grayscales of the streaky artefacts that were 1 mm and 20 mm outside the circular boundary (G1 and G2). The arc length, L1, of the circular boundary with artefacts was measured; the circumference, L2, was calculated. The artefact index, A, was determined as (G1/G0) × 0.5 + (G2/G1) × 0.4 + (L2/L1) × 0.1. The artefact index A can comprehensively represent the effect of artefacts on CBCT image clarity for oral tissue.

Highlights

Cone beam computed tomography (CBCT) has entered oral and maxillofacial region as an alternative for conventional CT and a valuable addition to two-dimensional radiographic modalities for diagnosis, treatment planning and follow-up
Marker point Grayscale reported by many authors that the diagnostic image quality of head and neck CT or cone-beam computed tomography (CBCT) is hampered by the presence of metallic objects in the dental area[13,14,15,16,17,18]
Dental materials are classified into metallic materials and non-metallic-materials

Summary

Introduction

Cone beam computed tomography (CBCT) has entered oral and maxillofacial region as an alternative for conventional CT and a valuable addition to two-dimensional radiographic modalities for diagnosis, treatment planning and follow-up. X-ray radiation is drastically attenuated because of the effect of these objects, resulting in data distortion of the corresponding projection and artefacts in reconstructed images. These artefacts induced by metal implants are all referred to as metal artefacts[7]. Complete absorption (i.e., starvation) of all photons along certain beam paths may occur These effects result in different types of image deterioration, ranging from bright streaks radiating from the metallic object to darkening of areas in its vicinity and even the complete loss of gray values between adjacent metallic objects[12]. The aim of the study was to propose the artefacts index on CBCT images of dental restoration materials, and to compare the effect on CBCT image clarity of normal oral tissues

Objectives

Methods

Results

Conclusion