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Han G.-S.,Peking University | Han G.-S.,Stomatology Center | Cheng J.-G.,Peking University | Li G.,Peking University | Ma X.-C.,Peking University
Dentomaxillofacial Radiology | Year: 2013

Objectives: To evaluate the shielding effect of thyroid collar for digital panoramic radiography. Methods: 4 machines [Orthopantomograph® OP200 (Instrumentarium Dental, Tuusula, Finland), Orthophos CD (Sirona Dental Systems GmbH, Bensheim, Germany), Orthophos XG Plus (Sirona Dental Systems GmbH) and ProMax® (Planmeca Oy, Helsinki, Finland)] were used in this study. Average tissue-absorbed doses were measured using thermoluminescent dosemeter chips in an anthropomorphic phantom. Effective organ and total effective doses were derived according to the International Commission of Radiological Protection 2007 recommendations. The shielding effect of one collar in front and two collars both in front and at the back of the neck was measured. Results: The effective organ doses of the thyroid gland obtained from the 4 panoramic machines were 1.12 μSv for OP200, 2.71 μSv for Orthophos CD, 2.18 μSv for Orthophos XG plus and 2.20 μSv for ProMax, when no thyroid collar was used. When 1 collar was used in front of the neck, the effective organ doses of the thyroid gland were 1.01 μSv (9.8% reduction), 2.45 μSv (9.6% reduction), 1.76 μSv (19.3% reduction) and 1.70 μSv (22.7% reduction), respectively. Significant differences in dose reduction were found for Orthophos XG Plus and ProMax. When two collars were used, the effective organ doses of the thyroid gland were also significantly reduced for the two machines Orthophos XG Plus and ProMax. The same trend was observed in the total effective doses for the four machines. Conclusions: Wearing a thyroid collar was helpful when the direct digital panoramic imaging systems were in use, whereas for the indirect digital panoramic imaging systems, the thyroid collar did not have an extra protective effect on the thyroid gland and whole body. © 2013 The Authors. Published by the British Institute of Radiology. Source


Deng T.,Chinese Peoples Liberation Army | Wang L.,Institute of Geriatric Cardiology | Lv J.,Chinese Peoples Liberation Army | Pang J.,Chinese Peoples Liberation Army | And 3 more authors.
Journal of Clinical Microbiology | Year: 2011

Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Tannerella forsythia are oral pathogens associated with periodontitis. The association between these three bacteria and periodontal disease has been reported in populations of many countries. However, corresponding data in Chinese populations are still lacking. The aim of this study was to detect these pathogens in subgingival plaque collected from 468 subjects with chronic periodontitis in a group of Chinese adults by using a PCR method and to determine the degree of association between the target bacteria and periodontal status based on logistic regression analysis. A. actinomycetemcomitans, P. gingivalis, and T. forsythia were found in 20.5%, 70.7%, and 77.1% of the subjects, respectively. About one-third (36.1%) of subjects had chronic periodontitis. Upon univariate analysis, age, male gender, current smoking status, diabetes, and the presence of A. actinomycetemcomitans or P. gingivalis were positively associated with chronic periodontitis, whereas education and income exhibited inverse associations with chronic periodontitis. Upon multivariate analysis, education, current smoking status, diabetes, and the presence of A. actinomycetemcomitans and P. gingivalis remained significant. The adjusted odds ratios for having chronic periodontitis were 2.5 and 3.4 in subjects positive for A. actinomycetemcomitans and P. gingivalis, respectively. However, no significant association was observed between the presence of T. forsythia and periodontal status. This study assesses the prevalence of periodontal pathogens and chronic periodontitis and the associations with sociodemographic characteristics among this group of Chinese adults. These findings also suggest that PCR should be considered for field oral epidemiologic studies and may be necessary in investigations presenting major logistic challenges. Copyright © 2011, American Society for Microbiology. All Rights Reserved. Source


Gorugantula L.M.,Texas A&M University | Rees T.,Stomatology Center | Plemons J.,Stomatology Center | Chen H.-S.,The New School | Cheng Y.-S.L.,Texas A&M University
Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology | Year: 2012

Objective: The objective of this study was to gather preliminary data concerning the feasibility of using salivary basic fibroblast growth factor (bFGF) for detecting development of oral squamous cell carcinoma (OSCC) in patients with oral lichen planus (OLP), and in patients with OSCC whose disease was in remission. Study Design: Saliva samples were collected from 5 patient groups: patients with newly diagnosed OSCC, patients with OSCC whose disease was in remission, patients with OLP in disease-active state, patients with OLP in disease-inactive state, and healthy controls. Salivary bFGF levels were determined by enzyme-linked immunosorbent assay, and data were analyzed using the Mann-Whitney U test. Results: Salivary bFGF levels were significantly elevated in patients with newly diagnosed OSCC compared with patients with OSCC in remission, patients with disease-active OLP, and healthy controls. No significant difference was found between patients with newly diagnosed OSCC and patients with disease-inactive OLP. Conclusions: Our results suggested that salivary bFGF might be a potential biomarker for detecting OSCC development in patients with OSCC in remission, but not in patients with OLP. © 2012 Mosby, Inc. All rights reserved. Source


Jin C.,Hospital of Chinese Medicine | Ren L.-F.,Stomatology Center | Ding H.-Z.,Stomatology Center | Shi G.-S.,Stomatology Center | And 2 more authors.
Journal of Biomedical Materials Research - Part B Applied Biomaterials | Year: 2012

Surface modification of dental implants with biomolecules is of particularly interest recently. To mimic the structure and function of native extracellular matrix (ECM), a derivative of hyaluronic acid (HA), HA-GRGDSP, was synthesized, Arg-Gly-Asp (RGD)-containing collagen (Col)/HA multilayer polyelectrolyte films (MPFs) coating was fabricated on titanium (Ti) through alternate deposition of Col and HA-GRGDSP with 4.5 assembly cycles; moreover, bioactive molecule, basic fibroblast growth factor (bFGF), was also incorporated into such coating. This coating was then carefully characterized using scanning electronic microscope (SEM) and scanning force microscopy (SFM); bFGF release from the coating was also evaluated. (Col + bFGF)/HA-RGD coating was successfully deposited on Ti surface, and about 300 pg of bFGF could be slowly released from this coating for a week. This coating significantly promoted the initial cell attachment of human gingival fibroblasts (HGFs) compared with other groups (p < 0.05), and HGFs adhered and spread better on this coating than other groups (p < 0.05). Regarding cell proliferation and differentiation of HGFs, they were greatly stimulated when cultured on this coating (p < 0.05). These results indicated that surface modification of Ti using biomolecules might improve the sealing between the neck section of a dental implant and the soft tissue. © 2012 Wiley Periodicals, Inc. Source


Zhang F.,Stomatology Center | Zhang C.-F.,Stomatology Center | Yin M.,Stomatology Center | Ren L.-F.,Stomatology Center | And 2 more authors.
Medical Science Monitor | Year: 2012

Surface chemistry of dental implant plays an important role in osseointegration. Heat treatment might alter surface chemistry and result in different biological response. The aim of this study was to investigate the roles of heat treatment of H 2O 2/HCl-treated Ti implants in cell attachment, proliferation and osteoblastic differentiation. Sandblasted, dual acid-etched and H 2O 2/HCl heat-treated discs were set as the control group and sandblasted, dual acid-etched H 2O 2/HCl-treated discs were the test group. Both groups' discs were sent for surface characterization. MC3T3-E1 cells were seeded on these 2 groups' discs for 3 hours to 14 days, and then cell attachment, cell proliferation and cell differentiation were evaluated. Scanning electron microscope analysis revealed that the titanium discs in the 2 groups shared the same surface topography, while x-ray diffraction examination showed an anatase layer in the control group and titanium hydride diffractions in the test group. The cell attachment of the test group was equivalent to that of the control group. Cell proliferation was slightly stimulated at all time points in the control group, but the alkaline phosphatase (ALP) activity and osteocalcin (OC) production increased significantly in the test group compared with those in the control group at every time point investigated (p<0.05 or p<0.01). Moreover, the osteoblastic differentiation-related genes AKP-2, osteopontin (OPN) and OC were greatly up-regulated in the test group (p<0.05 or p<0.01). The results implied that surface chemistry played an important role in cell response, and H 2O 2/HCl etched titanium surface without subsequent heat treatment might improve osseointegration response. © Med Sci Monit. Source

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