1.Influence of tooth position within the field of view on the intensity of cone-beam computed tomographic imaging artifacts when assessing teeth restored with various intracanal materials
Martina Gerlane de Oliveira PINTO ; Saulo Leonardo Sousa MELO ; Yuri Wanderley CAVALCANTI ; Elisa Diniz de LIMA ; Patrícia Meira BENTO ; Daniela Pita de MELO
Imaging Science in Dentistry 2020;50(2):141-151
Purpose:
This study aimed to quantify the influence of tooth position within the field-of-view (FOV) on cone-beam computed tomography (CBCT) imaging artifacts' intensity when assessing teeth restored with various intracanal materials.
Materials and Methods:
Seventy single-rooted teeth were divided into 7 groups (10 teeth per group): NiCr post (NC), AgPd post (AP), metal core fiberglass post (MCFG), fiberglass post (FG), anatomical fiberglass post (AFG), fiberglass post cemented with core build-up cement (FGCo), and anatomical fiberglass post cemented with core build-up cement (AFGCo). All posts were cemented using a regular dual-curing resin cement (Allcem), except FGCo and AFGCo which were cemented with a core build-up dual-curing resin cement (AllcemCore). Each tooth was scanned on a CS9000 in 5 positions within the FOV: a central position, anterior horizontal peripheral, peripheral superior, peripheral inferior, and posterior horizontal peripheral position. Hyperdense, hypodense, remaining teeth areas and ROI areas were quantitatively analyzed using ImageJ software.
Results:
Posterior horizontal peripheral position increased the intensity of artifacts on FGCo and AFGCo post groups (p<0.05), and specifically the hypodense artifact intensity on FG and AFG post groups (p<0.05). NC and AP groups presented greater intensity of artifacts than any other post groups (p<0.05).
Conclusion
Artifact intensity increases in the presence of high atomic number materials and when the object is not centered within the FOV. The impact of positioning within the FOV on artifact was greater for fiberglass posts cemented with core build-up dual-curing cement than for metal posts and fiberglass posts cemented with regular dual-curing cement.
2.The effects of different metal posts, cements, and exposure parameters on cone-beam computed tomography artifacts
Ana Priscila Lira de Farias FREITAS ; Larissa Rangel PEIXOTO ; Fernanda Clotilde Mariz SUASSUNA ; Patrícia Meira BENTO ; Ana Marly Araújo Maia AMORIM ; Karla Rovaris SILVA ; Renata Quirino de Almeida BARROS ; Andrea dos Anjos Pontual de Andrade LIMA ; Daniela Pita de MELO
Imaging Science in Dentistry 2023;53(2):127-135
Purpose:
This study assessed the intensity of artifacts produced by 2 metal posts, 2 cements, and different exposure parameters using 2 cone-beam computed tomography (CBCT) units.
Materials and Methods:
The sample was composed of 20 single-rooted premolars, divided into 4 groups: Ni-Cr/ zinc phosphate, Ni-Cr/resin cement, Ag-Pd/zinc phosphate, and Ag-Pd/resin cement. Samples were scanned before and after post insertion and cementation using a CS9000 3D scanner with 4 exposure parameters (85/90 kV and 6.3/10 mA) and an i-CAT scanner with 120 kV and 5 mA. The presence of artifacts was assessed subjectively by 2 observers and objectively by a trained observer using ImageJ software. The Mann-Whitney, Wilcoxon, weighted kappa, and chi-square tests were used to assess data at a 95% confidence level (α<0.05).
Results:
In the subjective analyses, AgPd presented more hypodense and hyperdense lines than NiCr (P<0.05), and more hypodense halos were found using i-CAT (P<0.05) than using CS9000 3D. More hypodense halos, hypodense lines, and hyperdense lines were observed at 10 mA than at 6.3 mA (P<0.05). More hypodense halos were observed at 85 kV than at 90 kV (P<0.05). CS9000 3D presented more hypodense and hyperdense lines than i-CAT (P<0.05). In the objective analyses, AgPd presented higher percentages of hyperdense and hypodense artifacts than NiCr (P<0.05). Zinc phosphate cement presented higher hyperdense artifact percentages on CS9000 3D scans (P<0.05). CS9000 3D presented higher artifact percentages than i-CAT (P<0.05).
Conclusion
High-atomic-number alloys, higher tube current, and lower tube voltage may increase the artifacts present in CBCT images. (Imaging Sci Dent 2023; 53: 127-35)