Evaluation of Threshold Values for Root Canal Filling Voids in Micro-CT and Nano-CT Images

Orhan, Kaan
Jacobs, Reinhilde
Celikten, Berkan
Huang, Yan
de Faria Vasconcelos, Karla
Nicolielo, Laura Ferreira Pinheiro
Buyuksungur, Arda
Van Dessel, Jeroen
While several materials and techniques have been used to assess the quality of root canal fillings in micro-CT images, the lack of standardization in scanning protocols has produced conflicting results. Hence, the aim of this study was to determine a cutoff voxel size value for the assessment of root canal filling voids in micro-CT and nano-CT images. Twenty freshly extracted mandibular central incisors were used. Root canals were prepared with nickel titanium files to an ISO size 40/0.06 taper and then filled with a single cone (40/0.06 taper) and AH Plus sealer. The teeth were scanned with different voxel sizes with either micro-CT (5.2, 8.1, 11.2, and 16.73 <jats:italic>μ</jats:italic>m) or nano-CT (1.5 and 5.0 <jats:italic>μ</jats:italic>m) equipment. Images were reconstructed and analyzed with the NRecon and CTAn software. Void proportion and void volume were calculated for each tooth in the apical, middle, and coronal thirds of the root canal. Kruskal-Wallis and post hoc Mann–Whitney <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mi>U</mml:mi></mml:math> tests were performed with a significance level of 5%. In micro-CT images, significantly different results were detected among the tested voxel sizes for void proportion and void volume, whereas no such differences were found in nano-CT images (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mi>p</mml:mi><mml:mo>&gt;</mml:mo><mml:mn>0.05</mml:mn></mml:math>). Micro-CT images showed higher void numbers over the entire root length, with statistically significant differences between the voxel size of 16.73 <jats:italic>μ</jats:italic>m and the other sizes (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mi>p</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>0.05</mml:mn></mml:math>). The values of the different nano-CT voxel sizes did not significantly differ from those of the micro-CT (5.2, 8.1, and 11.2 <jats:italic>μ</jats:italic>m), except for the voxel size of 16.73 <jats:italic>μ</jats:italic>m (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><mml:mi>p</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>0.05</mml:mn></mml:math>). All tested voxel sizes enabled the detection of root canal filling voids except for the voxel size of 16.73 <jats:italic>μ</jats:italic>m. Bearing in mind the limitations of this study, it seems that a voxel size of 11.2 <jats:italic>μ</jats:italic>m can be used as a reliable cutoff value for the assessment of root canal filling voids in micro-CT imaging.


Terahertz pulsed imaging study of dental caries
Karagöz, Burcu; Altan, Hakan (2015-06-23)
Current diagnostic techniques in dentistry rely predominantly on X-rays to monitor dental caries. Terahertz Pulsed Imaging (TPI) has great potential for medical applications since it is a nondestructive imaging method. It does not cause any ionization hazard on biological samples due to low energy of THz radiation. Even though it is strongly absorbed by water which exhibits very unique chemical and physical properties that contribute to strong interaction with THz radiation, teeth can still be investigated ...
Investigation of tensile strength of hydroxyapatite with various porosities by diametral strength test
Evis, Zafer (2008-04-01)
It is appropriate to administer the diametral test to biomedical materials used in dental applications because stresses formed on dental implants are similar to those that formed in this test. To show this similarity, an experimental study of diametral strength testing of hydroxyapatite was performed. The influence of porosity on hydroxyapatite was investigated experimentally to determine how the diametral strength was affected. Hydroxyapatite was air sintered at 1100 degrees C for 1 h with porosities rangi...
Analysis and modelling of machine tool dynamics and cutting stability during operation
Özşahin, Orkun; Özgüven, Hasan Nevzat; Budak, Erhan; Department of Mechanical Engineering (2014)
Self-excited vibrations of machine tools during cutting result in process instability, poor surface finish and reduced material removal rate. In order to obtain stability lobe diagrams to avoid chatter vibration, tool point frequency response function (FRF) must be determined. In classical machine tool studies, tool point FRF is obtained experimentally or analytically for the idle state of the machine. However, during cutting operations, discrepancies are frequently observed between the stability diagrams o...
Additional studies on the distribution of stresses during vertical compaction of gutta-percha in the root canal
Telli, C; Gulkan, P; Raab, W (1999-07-10)
Objective This study was designed to investigate the effect of certain pathological alterations of the dental structures (diminishing bone support, internal resorption, root perforation, periapical lesion) on stress distribution during root canal filling procedures by the warm vertical compaction technique.
Theoretical investigation and design for x-ray lasers and their lithographic application
Demir, Pınar; Bilikmen, Kadri Sinan; Department of Physics (2008)
Grazing incidence pumping (GRIP) is a scheme to produce x-ray lasers and extreme ultraviolet lithography is a means of lithographic production which requires soft x-rays with a bandwidth of 2% centred at 13,5 nm. In this work firstly a grazing incidence pumping of Ni-like Mo and Ne-like Ti x-ray laser media were simulated by using EHYBRID and a post-processor code coupled to it. The required atomic data were obtained from the Cowan code. Besides, the timing issue needed for amplification purpose in a Ti:Sap...
Citation Formats
K. Orhan et al., “Evaluation of Threshold Values for Root Canal Filling Voids in Micro-CT and Nano-CT Images,” Scanning, pp. 1–6, 2018, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/52012.