1.CBCT-based assessment of root canal treatment using micro-CT reference images
Alessando LAMIRA ; Jardel Francisco MAZZI-CHAVES ; Laura Ferreira Pinheiro NICOLIELO ; Graziela Bianchi LEONI ; Alice Corrêa SILVA-SOUSA ; Yara Terezinha Corrêa SILVA-SOUSA ; Ruben PAUWELS ; Nico BULS ; Reinhilde JACOBS ; Manoel Damião SOUSA-NETO
Imaging Science in Dentistry 2022;52(3):245-258
Purpose:
This study compared the root canal anatomy between cone-beam computed tomography (CBCT) and micro-computed tomography (micro-CT) images before and after biomechanical preparation and root canal filling.
Materials and Methods:
Isthmus-containing mesial roots of mandibular molars (n = 14) were scanned by micro-CT and 3 CBCT devices: 3D Accuitomo 170 (ACC), NewTom 5G (N5G) and NewTom VGi evo (NEVO). Two calibrated observers evaluated the images for 2-dimensional quantitative parameters, the presence of debris or root perforation, and filling quality in the root canal and isthmus. The kappa coefficient, analysis of variance, and the Tukey test were used for statistical analyses (α= 5%).
Results:
Substantial intra-observer agreement (κ= 0.63) was found between micro-CT and ACC, N5G, and NEVO. Debris detection was difficult using ACC (42.9%), N5G (40.0%), and NEVO (40%), with no agreement between micro-CT and ACC, N5G, and NEVO (0.05<κ<0.12). After biomechanical preparation, 2.4%-4.8% of CBCT images showed root perforation that was absent on micro-CT. The 2D parameters showed satisfactory reproducibility between micro-CT and ACC, N5G, and NEVO (intraclass correlation coefficient: 0.60-0.73). Partially filled isthmuses were observed in 2.9% of the ACC images, 8.8% of the N5G and NEVO images, and 26.5% of the micro-CT images, with no agreement between micro-CT and ACC, and poor agreement between micro-CT and N5G and NEVO. Excellent agreement was found for area, perimeter, and the major and minor diameters, while the roundness measures were satisfactory.
Conclusion
CBCT images aided in isthmus detection and classification, but did not allow their classification after biomechanical preparation and root canal filling.
2.In vivo quantification of mandibular bone remodeling and vascular changes in a Wistar rat model: A novel HR-MRI and micro-CT fusion technique
Dandan SONG ; Sohaib SHUJAAT ; Ruiting ZHAO ; Yan HUANG ; Eman SHAHEEN ; Jeroen Van DESSEL ; Kaan ORHAN ; Greetje Vande VELDE ; Ruxandra COROPCIUC ; Ruben PAUWELS ; Constantinus POLITIS ; Reinhilde JACOBS
Imaging Science in Dentistry 2020;50(3):199-208
Purpose:
This study was performed to introduce an in vivo hybrid multimodality technique involving the coregistration of micro-computed tomography (micro-CT) and high-resolution magnetic resonance imaging (HR-MRI) to concomitantly visualize and quantify mineralization and vascularization at follow-up in a rat model.
Materials and Methods:
Three adult female rats were randomly assigned as test subjects, with 1 rat serving as a control subject. For 20 weeks, the test rats received a weekly intravenous injection of 30 μg/kg zoledronic acid, and the control rat was administered a similar dose of normal saline. Bilateral extraction of the lower first and second molarswas performed after 10 weeks. All rats were scanned once every 4 weeks with both micro-CT and HR-MRI. Micro-CT and HR-MRI images were registered and fused in the same 3-dimensional region to quantify blood flow velocity and trabecular bone thickness at T0 (baseline), T4 (4 weeks), T8 (8 weeks), T12 (12 weeks), T16 (16 weeks), and T20 (20 weeks). Histological assessment was the gold standard with which the findings were compared.
Results:
The histomorphometric images at T20 aligned with the HR-MRI findings, with both test and control rats demonstrating reduced trabecular bone vasculature and blood vessel density. The micro-CT findings were also consistent with the histomorphometric changes, which revealed that the test rats had thicker trabecular bone and smaller marrow spaces than the control rat.
Conclusion
The combination of micro-CT and HR-MRI may be considered a powerful non-invasive novel technique for the longitudinal quantification of localized mineralization and vascularization.