Artifacts due to dental and maxillofacial restoration materials in cone beam computed tomography images

Abstract

Over the last 20 years, three-dimensional X-ray imaging, cone beam computed tomography (CBCT), has become an important method when making the diagnoses in the dental and maxillofacial area. There has been rapid development in CBCT devices, and the image quality has improved considerably during the last two decades. Despite the many improvements in CBCT image quality, artifacts induced by dental and maxillofacial restoration materials are still a problem, especially when diagnosing the dental area. CBCT manufacturers produce artifact reduction algorithms, which are intended to decrease or remove the artifacts in the image. However, the results of the studies on artifact reduction algorithms vary and there is no final consensus, as yet, on their efficacy. The studies of the present thesis focus on the arti-facts induced by different dental restoration materials in CBCT images. Another aim was to compare how the different materials interfere with the radiologic diagnosis. The materials investigated were titanium, zirconia, composite, and fiber reinforced composite (FRC).

The results showed that composites with ra-dio-opacifying BaAlSiO2 20% (weight%) or more caused artifacts in the CBCT images. Composites with BaAlSiO2 68% (weight%) or more caused artifacts with similar intensity as titanium. Titanium orbital floor implant caused artifacts in the CBCT images, whereas nonmetallic fiber reinforced composite (FRC) orbital floor implant did not cause hampering artifacts in the CBCT images. The diagnosis of apical perio-dontitis can be complicated in 70% of the CBCT images of paranasal sinuses because of the artifacts induced by dental and endodontic restorations. In the CBCT images, zirconia dental implants caused in-tense artifacts despite the artifact reduction algorithm.

To conclude, different dental restoration materials cause image hampering artifacts of different intensities in CBCT images. Zirconia is especially problem-atic in CBCT images. More studies are needed on artifact reduction methods to achieve an image quality without artifacts to make the correct diagnosis. In addition, the consequences of restoration and implant material options should be considered in postoperative CBCT images.