OBJECTIVETo investigate the expression of chemokine receptor CXCR4 and its ligand CXCL12 in oral squamous cell carcinoma (OSCC) cells, and their effects on proliferation and migration of tumor cells.

METHODSThe expression of CXCR4 mRNA and protein in 20 cases of OSCC tissue, cervical lymph nodes, tongue cancer cell line Tca8113, buccal cancer cell line Bca885, and 10 specimens of normal oral mucosa tissue were examined by reverse transcriptase-polymerase chain reaction(RT-PCR) and Western blot. The expression of CXCL12 mRNA was examined by RT-PCR. MTT assay was used to evaluate the CXCR4/CXCL12 influence on proliferation of tumor cells. Chemotaxis and migration response to CXCR4 particular ligand-CXCL12 were detected by chemotaxis assay.

RESULTS1) Expression levels of CXCR4 mRNA and protein in OSCC tissues, Tca8113 and Bca885 cells were 2.31 +/- 1.13, 1.89 +/- 1.20, 1.67 +/- 1.10 and 1.36 +/- 0.15, 1.85 +/- 0.34, 1.97 +/- 0.23, respectively. CXCR4 mRNA and protein couldn't be detected in normal tissues. CXCL12 mRNA level in cervical lymph nodes was 1.14 +/- 0.87, CXCL12 mRNA couldn't be detected in OSCC and normal tissues. 2) In MTT assay, recombinant CXCL12 stimulated proliferation of tumor cells and CXCR4 neutralization by monoclonal antibodies decreased proliferation. 3) The chemotactic migration of OSCC cells could be induced by CXCL12. CXCL12 at a concentration between 30 ng x mL(-1) and 100 ng x mL(-1) induced the chemotactic migration of OSCC cells in a dose-dependent manner.

CONCLUSIONCXCR4/CXCL12 system may promote proliferation and migration of tumor cells, and may play an important role in lymph node metastasis of OSCC.

Carcinoma, Squamous Cell ; Cell Line, Tumor ; Cell Movement ; Chemokine CXCL12 ; Chemotaxis ; Humans ; Lymph Nodes ; Lymphatic Metastasis ; Mouth Neoplasms ; RNA, Messenger ; Receptors, CXCR4

OBJECTIVETo provide reliable seed cells with unlimited passage proliferation and stable biological characteristics for periodontal tissue engineering research through infecting a retrovirus carrying SV40Tag into SD rat dental follicle cells.

METHODSRetroviral virus vector containing SV40Tag by 293 cells was packaged and infected into SD rat dental follicle cells. Normal dental capsule cells were used as control group. The cell morphology and vitality were observed by inverted microscope, telomerase activity, osteogenic differentiation and proliferation of dental follicle cells were analyzed.

RESULTSThe SD rat dental follicle cells infected with SV40Tag could be passaged for 60 generations in vitro culture with strong growth activity. The telomerase activity was significantly enhanced compared with the control group (P = 0.033). The expression of alkaline phosphatase, osteocalcin, bone morphogenesis protein-2, Runx2, basic fibroblast growth factor, insulin-like growth factors had no statistical difference compared with control cells (P > 0.05).

CONCLUSIONThe SD rat dental follicle cells infected with SV40Tag not only have a strong growth activity and infinite passaged capacity, but also have a stable biological property as normal dental follicle cells, so it can be regarded as the excellent seed cells in periodontal tissue engineering.

Alkaline Phosphatase ; Animals ; Cell Differentiation ; Cells, Cultured ; Dental Sac ; Fibroblast Growth Factor 2 ; Osteoblasts ; Osteocalcin ; Osteogenesis ; Rats ; Rats, Sprague-Dawley ; Tissue Engineering

Dental bonding technique has become an essential technique for dental clinical practice over the past several decades. Dental adhesion is widely used in direct and indirect restorations. However, problems such as technique sensitivity, postoperative sensitivity, secondary caries and marginal discoloration always appear in the dental bonding procedures. Fiber post and all-ceramic restoration bonding are essential step in esthetic dentistry. If these problems are not well handled, it will result in failure of the restorations. Therefore, the aim of this article is to provide adequate consultations and advice for the clinical practitioners based on the author's experience and relevant literatures.
Ceramics ; Dental Bonding ; Dental Caries ; Dental Restoration Failure ; Humans

OBJECTIVETo analyze the relationship between inorganic ingredients (Ca, P and F) concentration of plaque residues in the primary teeth and caries status, sugar exposure frequency.

METHODSSubjects were 93 of 3-5 years old children living in Beijing area. According to their caries status, they were classified into two groups: Severe early childhood caries(S-ECC) group and caries free(CF) group. Plaque samples were collected from subjects respectively. Ca, P and F concentration of plaque residues was measured by atomic absorption spectroscopy, spectrophotometer and fluoride electrode respectively. The information of daily sugar exposure frequency of children was obtained from a standardized questionnaire filled by their parents. The relationship between inorganic ingredients (Ca, P and F) concentration of plaque residues and daily sugar exposure frequency was analyzed and the relationship between inorganic ingredients (Ca, P and F) concentration of plaque residues and caries status in the S-ECC group was also analyzed.

RESULTSThe mean values for Ca, P and F concentration of plaque residues were lower in the S-ECC group, but the difference was not statistically significant (P > 0.05). The daily sugar exposure frequency in the S-ECC group was higher than that in the CF group. There were no relationships between Ca, P and F concentration of plaque residues and caries status (dmft, dmfs), sugar exposure frequency in the primary dentition.

CONCLUSIONPlaque residues from CF subjects did not contain a greater pool of calcium, inorganic phosphorus, and fluoride ions than that from S-ECC subjects.

Calcium ; Carbohydrates ; Child ; Child, Preschool ; Dental Caries ; Dental Caries Susceptibility ; Dental Plaque ; Fluorides ; Humans ; Phosphates ; Tooth, Deciduous

OBJECTIVEThe aim of this study was to investigate the in vitro effect of cell behavior on a new titanium alloy and coarsening surface with sandblasting and duplicate treated by sandblasting and acid etching (SLA), including cell proliferation, morphology as well as alkaline phosphatase expression.

METHODSThe cell derived from calvarial bone of neonate and co-cultured with the surface treated titanium alloys in vitro. The samples were treated by mechanical polishing, the sandblasting and the SLA. Cell proliferation on samples for 3 d was examined by MTT assay and cell morphology was observed by scan electron microscope. Alkaline phosphatase activity was measured at 5 d by ALP-special assay.

RESULTSThe sandblasting and the SLA surface showed a significant different to smooth surface in the proliferation osteoblasts. The cells were elongated and spread well and having plentiful filopods on the coarse surface. The basal ALP activity indicated that optical density value of osteoblasts was not significant difference between coarse surface and smooth surface.

CONCLUSIONThe observed effects are attributed to coarsening surface and support the concept that roughness can enhance the differentiation, good morphology and alkaline phosphatase expression of the cells. These results suggest that the good biological performance evaluation of sandblasting and etching surface is merited.

Alkaline Phosphatase ; Alloys ; Cell Differentiation ; Cell Proliferation ; Osteoblasts ; Prostheses and Implants ; Surface Properties ; Titanium

OBJECTIVEAs a new kind of reinforcing filler, ultrafine diamond (UFD) is added into photocurable composite core materials. The properties of the materials are then measured to see if there is any improvement.

METHODSDifferent content of barium glass and UFD were added into resin matrix to fabricate six groups of photocurable composite core materials. For each group of the materials, the flexural strength, Vicker's micro-hardness and depth of cure were measured. Data of the flexural strength and Vicker's micro-hardness was then collected and analyzed by One-Way ANOVA.

RESULTSFor the two kinds of composites with barium glass of 60% and 70%, only a small quantity of modified UFD with 0.2% weight percentage could improve the flexural strength of the composites by 34% and 21% respectively, the microhardness was improved by 23% and 30% respectively. The depth of cure of the composite core materials were more than 2 mm, which had reached the demand of the corresponding ISO criteria. The addition of UFD could make the composite core materials darker and grayer.

CONCLUSIONMicro-quantity of UFD can improve the mechanical properties of composite resins notably, and it will not affect the curability of the materials, but the defect in the color need to be reformed.

Barium Compounds ; Composite Resins ; Diamond ; Hardness ; Materials Testing ; Methacrylates ; Pliability ; Silicon Dioxide

The bracketless invisible aligner technique has been considered as a new developed orthodontic technique since its appearance during the period of late 1990s. It is characterized with the advantages of more aesthetic, comfortable, simple, high-efficient and predictable compared with current traditional orthodontic techniques depending on brackets and wires for orthodontic tooth movements. There have been many opportunities for further development and clinical application for the technique with the developments of material sciences, computer software and hardware technology, rapid prototyping techniques, et al. Nevertheless, kinds of difficulties and challenges have been and should be met either at present or in the future for this relatively new technique which just occurred around 10 years ago. The histories, developments with opportunities and challenges and prospects of the technique will be reviewed and discussed in this paper.
Humans ; Orthodontic Appliances ; Tooth Movement Techniques

The patient visited for swell and ache of sublingual region. The patient's two sides of sublingual glands were swelled. The mandibular central incisors were repaired by the ill fitting prosthesis, and there was an irregular oral ulcer under it. The area of the ulcer was about 2 mm x 2 mm. The sublingual glands recovered in two days after the ill fitting prosthesis of mandibular central incisors was removed away, iodoglycerin was applied on the oral ulcer, vitamin B1, vitamin B2, prednisone and amoxicillin was taken.
Humans ; Incisor ; Prostheses and Implants ; Sublingual Gland

Letterer-Siwe disease (LSD) is a kind of a histiocytosis, rarely seen in clinic. However, its prognosis is poor. A case of LSD which complaints of the oral ulcer is reported in this article. The patient of the case was a boy, came to hospital on July 5, 2003 because of oral ulcers, teeth loosing and falling off for a month, and pus running over from both antra auris for two weeks. No familial history of genetic diseases and special infections were found. The case consisted of the following features after exam: Erythematous papules and petechia dotted in the skin, primarily on scalp and trunk, two ears suffering otitis media, oral proliferative ulcers appearing in palate and lower gingival accompanying with the lower teeth loosing in the lesion area, in the meantime, the destruction of madibula on the left side also found out by X-ray, hepatic dysfunction and poor cellular immunity coming along with pertinacious candidosis. The pathologic exam showed histioid cell infiltration, and the immunohistochemical exam showed CDla(+), S-100(+). Diagnosis defined it LSD. According to the case's character and literature review, the clinical features, diagnosis and therapy of LSD were discussed.
Child ; Histiocytosis, Langerhans-Cell ; Humans ; Male ; Skin

OBJECTIVETo investigate the effect of a new engineering technique of vacuum deposition-plasma magnetron reactive sputter deposition technique on the metal-porcelain bond strength of a new type of Co-Cr ceramic and framework dental alloy.

METHODSBefore porcelain painted on the specimens, the standardized metal strips made from DA9-4 dental alloy were coated with a thin Al2O3 ceramic film by plasma magnetron reactive sputter deposition technique. The conformation, structure and thickness of the ceramic film were analyzed. The specimens for three-point bending test made from DA9-4 alloy and VMK95 porcelain were used for metal-porcelain bond strength measurement, in the same time the interface of metal-porcelain and element distribution were also observed.

RESULTSThe flexural bonding strength of metal-porcelain of sputtering group and control group were (180.55+/-16.45) MPa and (143.80+/-24.49) MPa. The flexural bonding strength of metal-porcelain of sputtering group was higher than control group significantly through statistical analysis (P<0.01).

CONCLUSIONThe plasma magnetron reactive sputter deposition technique has a positive effect in improving the bonding strength of DA9-4 dental alloy and ceramic.

Ceramics ; Chromium Alloys ; Dental Alloys ; Dental Bonding ; Dental Porcelain ; Humans ; Materials Testing ; Metal Ceramic Alloys ; Surface Properties ; Vacuum