Xieqi Shi

Prof. Dr. Xieqi Shi

orcid

Research Focus & Metrics

Academic Career Length

30Years (1997-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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31 March 2000 in Caries Research
Verified
Journal Article
Closed access
XSXieqi Shi
Xieqi Shi
UWU. Welander
U. Welander
BAB. Angmar-Månsson
B. Angmar-Månsson
A new laser fluorescence method, KaVo DIAGNOdent, was tested with respect to reproducibility and validity and compared with radiography regarding accuracy in the detection of occlusal caries. Seventy–six extracted premolar and molar teeth were measured twice with DIAGNOdent under both wet and dry conditions, at an interval of 2 weeks. Conventional film radiographs were exposed. Microradiographic analysis of sections of the teeth served as the gold standard. Intra–class correlation coefficient and Pearson’s correlation coefficient were used to assess the reproducibility and the validity of the method, respectively. The influence of time and varying humidities on DIAGNOdent readings were analysed by two–way repeated measure ANOVA. ROC curves were plotted for DIAGNOdent readings and radiographic registration of caries by 6 observers, and the areas under the curves were compared using Student’s t test. Under both wet and dry conditions, the reproducibility of the DIAGNOdent method was excellent: R = 0.97 and 0.96, respectively. The diagnostic accuracy of DIAGNOdent was significantly better than that of radiography (p≤0.001). In this in vitro study of detection of occlusal caries, the diagnostic performance of the DIAGNOdent method was superior to that of radiography.

9 August 2018 in Stem Cell Research & Therapy
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Journal Article
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CGCecilie Gjerde
Cecilie Gjerde
KMKamal Mustafa
Kamal Mustafa
SHSølve Hellem
Sølve Hellem
MRMarkus Rojewski
Markus Rojewski
HGHarald Gjengedal
Harald Gjengedal
Pierre LayrollePierre Layrolle
Pierre Layrolle
Autologous grafting, despite some disadvantages, is still considered the gold standard for reconstruction of maxillofacial bone defects. The aim of this study was to evaluate bone regeneration using bone marrow-derived mesenchymal stromal cells (MSCs) in a clinical trial, a less invasive approach than autologous bone grafting. This comprehensive clinical trial included subjects with severe mandibular ridge resorption. The study included 11 subjects aged 52–79 years with severe mandibular ridge resorption. Bone marrow cells were aspirated from the posterior iliac crest and plastic adherent cells were expanded in culture medium containing human platelet lysate. The MSCs and biphasic calcium phosphate granules as scaffolds were inserted subperiosteally onto the resorbed alveolar ridge. After 4–6 months of healing, new bone formation was assessed clinically and radiographically, as were safety and feasibility. Bone at the implant site was biopsied for micro-computed topography and histological analyses and dental implants were placed in the newly regenerated bone. Functional outcomes and patient satisfaction were assessed after 12 months. The bone marrow cells, expanded in vitro and inserted into the defect together with biphasic calcium phosphate granules, induced significant new bone formation. The regenerated bone volume was adequate for dental implant installation. Healing was uneventful, without adverse events. The patients were satisfied with the esthetic and functional outcomes. No side effects were observed. The results of this comprehensive clinical trial in human subjects confirm that MSCs can successfully induce significant formation of new bone, with no untoward sequelae. Hence, this novel augmentation procedure warrants further investigation and may form the basis of a valid treatment protocol, challenging the current gold standard. EudraCT, 2012-003139-50. Registered on 21 August 2013. ClinicalTrials.gov, NCT 02751125 . Registered on 26 April 2016.

22 December 2000 in Caries Research
Verified
Journal Article
Closed access
XSXieqi Shi
Xieqi Shi
STS Tranaeus
S Tranaeus
BAB Angmar-Månsson
B Angmar-Månsson
The aim was to compare the detection and quantification of smooth surface caries by KaVo DIAGNOdent and quantitative laser/light–induced fluorescence (QLF) using a laser and a lamp as two different light sources. On 40 premolar teeth extracted from adolescents, 71 non–cavitated approximal surfaces were assessed. For QLF, both mean and maximum fluorescence losses were registered. To provide a gold standard for verification, the teeth were then sectioned and lesion depth, stratified on a five–point scale, was determined by histopathology and microradiography. The correlation between the gold standard and the two methods was assessed by Spearman’s rank correlation coefficient. The sensitivity and specificity of the methods for detection of smooth surface caries at D3 level were also assessed. For lesion depth, correlation with the gold standard was similar for QLF and DIAGNOdent: about 0.85. With respect to dentinal caries detection, sensitivity for DIAGNOdent was 0.75 and specificity 0.96, with a cut–off point of 9. The corresponding values for QLF were 0.94 and 1, with a cut–off value of 20% of fluorescence loss. Spearman’s rank correlation coefficients for enamel mineral loss and QLF and DIAGNOdent, respectively, were 0.76 and 0.67. It was concluded that for quantification of smooth surface caries, the methods are of equal merit, but for scientific purposes, QLF offers the advantage of closer correlation with changes in mineral content.

1 January 2001 in Acta Odontologica Scandinavica
Verified
Journal Article
Closed access
XSXieqi Shi
Xieqi Shi
STSofia Tranaeus
Sofia Tranaeus
BABirgit Angmar-Månsson
Birgit Angmar-Månsson
The aims were 1) to validate a laser-based device, KaVo DIAGNOdent, for quantification of caries lesions on smooth surfaces, using histopathologic and microradiographic analyses as the gold standard, and 2) to test inter- and intra-observer agreements. We also investigated the influence on DIAGNOdent readings of the storage medium used for extracted teeth. Two observers measured independently the tooth surfaces of 40 extracted premolars that had been stored in thymol-saturated saline. After subsequent storage in neutral-buffered formalin for 14 days they were re-measured. The teeth were then sectioned for histopathologic and microradiographic analysis. The Spearman rank correlation coefficients between lesion depth and DIAGNOdent readings were 0.78–0.83 and 0.85 for teeth stored in thymol-saturated saline and formalin, respectively. Inter- and intra-observer agreements were 0.94 and 0.95 when the teeth were stored in thymol-saturated saline. The DIAGNOdent reading was almost 1.5 times higher for teeth stored in formalin than for those stored in thymol saline. The Spearman rank correlation coefficient between mineral loss in enamel (ΔZ) and DIAGNOdent readings ranged from 0.64 to 0.68. It was concluded that DIAGNOdent may be helpful for assessing smooth-surface caries, but the cut-off points need to be assessed under clinical conditions. The increase in fluorescence associated with storage of teeth in formalin warrants further investigation.

1 February 2015 in American Journal of Orthodontics and Dentofacial Orthopedics
Verified
Journal Article
Closed access
XFXin Feng
Xin Feng
GLGang Li
Gang Li
ZQZhenyu Qu
Zhenyu Qu
LLLin Liu
Lin Liu
KNKarin Näsström
Karin Näsström
XSXieqi Shi
Xieqi Shi

1 January 2015 in Journal of Foot and Ankle Research
Verified
Journal Article
Open access
PDF file
JKJuha Koivisto
Juha Koivisto
TKTimo Kiljunen
Timo Kiljunen
NKNils Kadesjö
Nils Kadesjö
XSXieqi Shi
Xieqi Shi
JWJan Wolff
Jan Wolff
Background: The aim of this study was to assess and compare the effective doses (ICRP 103) in the ankle region of X‐ray imaging resulting from a multi slice computed tomography (MSCT) device, two cone beam CT (CBCT) devices and one conventional x‐ray device.Methods: Organ dose measurements were performed using 20 metal oxide field effect transistor (MOSFET) dosimeters that were placed in a custom made anthropomorphic RANDO ankle phantom. The following scanners were assessed in this study: Siemens Sensation Open 24‐slice MSCT‐scanner (120 kVp, 54 mAs), NewTom 5G CBCT scanner (110 kVp, 2.3 ‐ 59 mAs), Planmed Verity CBCT‐scanner (90 kVp, 48 mAs), Shimadzu FH‐21 HR direct radiography equipment (AP + LAT), (57 kVp, 16 mAs).Results: Measurements of the MSCT device resulted in 21.4 μSv effective dose. The effective doses of CBCTs were between 1.9 μSv and 14.3 μSv for NewTom 5G and 6.0 μSv for Planmed Verity. Effective doses for the Shimadzu FH‐21 HR conventional radiography were 1.0 μSv (LAT) and 0.5 μSv (AP), respectively.Conclusions: Compared with a conventional 2D radiographic device, this study showed a 14‐fold effective dose for standard MSCT and 1.3 ‐10 fold effective dose for standard CBCT protocols. CBCT devices offers a 3D view of ankle imaging and exhibited lower effective doses compared with MSCT.