Analysis of the width of vertical root fracture in endodontically treated teeth by 2 micro-computed tomography systems.
BACKGROUND
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.
Department of Dentistry, Cardinal Tien Hospital, New Taipei City, Taiwan.
Chih-Chia
CC
Huang
Department of Dentistry, Cardinal Tien Hospital, New Taipei City, Taiwan.
Ya-Chi
YC
Chang
Department of Dentistry, Cardinal Tien Hospital, New Taipei City, Taiwan.
Meng-Che
MC
Chuang
Department of Dentistry, Show Chwan Memorial Hospital, Changhua, Taiwan.
Hsueh-Jen
HJ
Lin
Graduate Institute of Clinical Dentistry and Department of Dentistry, National Taiwan University Hospital and National Taiwan University Medical College, Taipei, Taiwan.
Yi-Ling
YL
Tsai
Graduate Institute of Clinical Dentistry and Department of Dentistry, National Taiwan University Hospital and National Taiwan University Medical College, Taipei, Taiwan.
Shu-Hui
SH
Chang
Department of Biomedical Imaging and Radiological Sciences, National Yang Ming University, Taipei, Taiwan. Electronic address: benson86778231@yahoo.com.tw.
Jyh-Cheng
JC
Chen
Graduate Institute of Clinical Dentistry and Department of Dentistry, National Taiwan University Hospital and National Taiwan University Medical College, Taipei, Taiwan. Electronic address: jhjeng@ntu.edu.tw.
Jiiang-Huei
JH
Jeng
D001641:Bicuspid / Q000000981:diagnostic imaging / Q000293:injuries; D042241:Early Diagnosis; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008963:Molar / Q000000981:diagnostic imaging / Q000293:injuries; D019227:Tooth Apex / Q000000981:diagnostic imaging / Q000293:injuries; D014082:Tooth Fractures / Q000000981:diagnostic imaging*; D014092:Tooth Root / Q000000981:diagnostic imaging / Q000293:injuries*; D019553:Tooth, Nonvital / Q000000981:diagnostic imaging*; D055114:X-Ray Microtomography / Q000379:methods*
Cone-beam computed tomography (CBCT); endodontically treated teeth; micro-computed tomography (μ-CT); vertical root fracture (VRF)