Huang C.-C.Chang Y.-C.Chuang M.-C.Lin H.-J.YI-LING TSAISHU-HUI CHANGChen J.-C.JIIANG-HUEI JENG2021-07-062021-07-0620140099-2399https://www.scopus.com/inward/record.uri?eid=2-s2.0-84899659088&doi=10.1016%2fj.joen.2013.12.015&partnerID=40&md5=9370e8a96af241634b660ef5b10b7072https://scholars.lib.ntu.edu.tw/handle/123456789/569871Introduction Early detection of vertical root fracture (VRF) is important for clinical endodontic practice. The purpose of this study was to measure the fracture width (distance between 2 sides of the fracture) of VRF teeth in vitro by using 2 micro-computed tomography (μ-CT) systems with different spatial resolution and voxel size. Methods Thirty-seven endodontically treated teeth with VRF were scanned by 80-μm pixel size μ-CT. Fifteen teeth with no obvious fracture line, blurred image, or fracture space less than 100 μm were scanned by 9-μm pixel size μ-CT. Results Presence of 2 VRF lines was more common in premolars (82%) than in molars (53%). In 7 premolars (32%) and 9 molars (60%), the VRF lines extended to within the apical 3 mm of the root. All fracture lines were detected by 9-μm pixel size μ-CT, but only 22 of 37 VRF teeth had vertical fracture identified by 80-μm μ-CT. From μ-CT examination, none of the fracture lines showed consistent and uniform fracture space. If 2 fracture lines were present, they were typically in opposite (not linear) directions. There was a significant correlation between 2 fracture lines or fracture lines extending within the 3 mm of the apex and fracture width greater than 100 μm. Conclusions Application of 9-μm μ-CT can be accurately used for early detection of VRF. Fracture characteristics (eg, number of fracture lines, extension of fracture line) may affect the fracture width. Appropriate use of μ-CT technology can be helpful for early diagnosis of VRF.? 2014 American Association of Endodontists.[SDGs]SDG3early diagnosis; human; image processing; injuries; micro-computed tomography; molar tooth; premolar tooth; procedures; radiography; tooth apex; tooth fracture; tooth pulp disease; tooth root; Bicuspid; Early Diagnosis; Humans; Image Processing, Computer-Assisted; Molar; Tooth Apex; Tooth Fractures; Tooth Root; Tooth, Nonvital; X-Ray Microtomographyjournal article10.1016/j.joen.2013.12.015247675672-s2.0-84899659088