Influence of voxel size on dentinal microcrack detection by micro-CT after root canal preparation

Abstract This study aimed to evaluate the cause-effect relationship between canal preparation with ProTaper Universal (PTU) system and dentinal defects formation using micro-computed tomography (micro-CT) analysis. Forty mesial canals of mandibular molars with a type II Vertucci's canal configuration were scanned at an isotropic resolution of 14.16 µm. The sample was assigned to an experimental (n = 30) and a control (n = 10) groups, and the mesial canals were prepared with PTU system up to F2 instrument. The specimens from the experimental group were scanned and the cross-section images of the mesial roots, before and after preparation, were screened to identify the presence of dentinal defects. In the control group, the specimens were sectioned perpendicularly to the long axis of the root into 1-mm-thick slices (n = 80) and examined under optical microscope. Once a dentinal defect was detected, the slice was scanned through micro-CT. In the experimental group, dentinal micro-cracks were observed in 4,828 slices (24.04%). In all cross-section images, dentinal defects identified in the postoperative images were already present in the corresponding preoperative image. In the control group, 13 out of 80 slices (16.25%) had at least one dentinal defect visualized under stereomicroscopy, which was identified after a further micro-CT scanning. Micro-CT showed reliability as similar as optical microscopy in detecting dentinal defects, adding the possibility of tracking the dentinal tissue, before and after canal preparation, and providing a clear visualization of micro-cracks. Root canal preparation with PTU system did not induce the formation of new dentinal defects.

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

Scanning ◽

10.1155/2018/9437569 ◽

2018 ◽

Vol 2018 ◽

pp. 1-6 ◽

Cited By ~ 9

Author(s):

Kaan Orhan ◽

Reinhilde Jacobs ◽

Berkan Celikten ◽

Yan Huang ◽

Karla de Faria Vasconcelos ◽

...

Keyword(s):

Root Canal ◽

Ct Images ◽

Void Volume ◽

Micro Ct ◽

Root Canal Filling ◽

Voxel Size ◽

Significance Level ◽

Root Canals ◽

Ah Plus ◽

Post Hoc

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 μm) or nano-CT (1.5 and 5.0 μm) 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 U 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 (p>0.05). Micro-CT images showed higher void numbers over the entire root length, with statistically significant differences between the voxel size of 16.73 μm and the other sizes (p<0.05). 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 μm), except for the voxel size of 16.73 μm (p<0.05). All tested voxel sizes enabled the detection of root canal filling voids except for the voxel size of 16.73 μm. Bearing in mind the limitations of this study, it seems that a voxel size of 11.2 μm can be used as a reliable cutoff value for the assessment of root canal filling voids in micro-CT imaging.

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Microcomputed Tomography Studies of the Effectiveness of XP-endo Shaper in Root Canal Preparation: A Review of the Literature

The Scientific World JOURNAL ◽

10.1155/2019/3570870 ◽

2019 ◽

Vol 2019 ◽

pp. 1-5 ◽

Cited By ~ 5

Author(s):

Christianne Velozo ◽

Diana Albuquerque

Keyword(s):

Literature Review ◽

Root Canal ◽

Microcomputed Tomography ◽

Micro Ct ◽

Review Of The Literature ◽

Root Canal Preparation ◽

Ct Technology

The aim of this study was to undertake a literature review on the use of XP-endo Shaper (FKG Dentaire SA, La Chaux-de-Fonds, Switzerland) for root canal preparation evaluated using microcomputed tomography (micro-CT) technology, with emphasis on the analysis of untouched canal walls. We searched the PubMed, Science Direct, SciELO, and MEDLINE databases for articles published from 2017 to 2019 using the following keywords: micro-CT, untouched walls, XP shaper, and XP endo. Articles without an abstract were excluded. Five papers were selected. Few studies on this topic are available. The studies published so far show that the XP-endo® Shaper system performs well in terms of canal preparation but leaves untouched walls.

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Shaping ability and apical debris extrusion after root canal preparation with rotary or reciprocating instruments: a micro-CT study

Restorative Dentistry & Endodontics ◽

10.5395/rde.2021.46.e16 ◽

2021 ◽

Vol 46 ◽

Author(s):

Emmanuel João Nogueira Leal da Silva ◽

Sara Gomes de Moura ◽

Carolina Oliveira de Lima ◽

Ana Flávia Almeida Barbosa ◽

Waleska Florentino Misael ◽

...

Keyword(s):

Root Canal ◽

Micro Ct ◽

Root Canal Preparation ◽

Reciprocating Instruments ◽

Shaping Ability

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Effect of Reciprocating Systems and Working Lengths on Apical Microcrack Development: a micro-CT Study

Brazilian Dental Journal ◽

10.1590/0103-6440201701527 ◽

2017 ◽

Vol 28 (6) ◽

pp. 710-714 ◽

Cited By ~ 2

Author(s):

Bruna Paloma de Oliveira ◽

Andréa Cruz Câmara ◽

Daniel Amancio Duarte ◽

Richard John Heck ◽

Antonio Celso Dantas Antonino ◽

...

Keyword(s):

Root Canal ◽

Ct Scanning ◽

Micro Ct ◽

Root Canal Preparation ◽

Cross Sectional ◽

Isotropic Resolution ◽

Computed Tomographic ◽

Working Length ◽

Group B ◽

Reciprocating Systems

Abstract The objective of this study was to evaluate the effect of root canal preparation with single-file reciprocating systems at different working lengths on the development of apical microcracks using micro-computed tomographic (micro-CT) imaging. Forty extracted human mandibular incisors were randomly assigned to 4 groups (n=10) according to the systems and working length used to prepare the root canals: Group A - WaveOne Gold at apical foramen (AF), Group B - WaveOne Gold 1 mm short of the AF (AF-1 mm), Group C - Unicone (AF) and Group D - Unicone (AF-1 mm). Micro-CT scanning was performed before and after root canal preparation at an isotropic resolution of 14 µm. Then, three examiners assessed the cross-sectional images generated to detect microcracks in the apical portion of the roots. Apical microcracks were visualized in 3, 1, 1, and 3 specimens in groups A, B, C, and D, respectively. All these microcracks observed after root canal preparation already existed prior to instrumentation, and no new apical microcrack was detected. For all groups, the number of slices presenting microcracks after root canal preparation was the same as before canal preparation. Root canal preparation with WaveOne Gold and Unicone, regardless of the working length, was not associated with apical microcrack formation.

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