Layered resin filling technology is based on resin curing shrinkage characteristics and aesthetic effects. This article, from several aspects such as curing light of cured resin, aesthetic effect needs, reducing shrinkage and shrinkage tension, wear resistance and intensity, gives a detailed description.

Objective To evaluate the biomechanical effects of intracellular changes on the voltage-gated sodium channels（VGSCs） on trigeminal ganglion neuron（TRGN）. Methods TRGN cells were acutely isolated from the neonatal SD rats. The voltage-dependent currents of the VGSCs on these neurons were elicited and analyzed by whole-cell patch-clamp recordings and the intracellular anisotonicity stimuli was established by adjusting the content of pipette solution. The effects of hypo-（260 mOsm） and hypertonic（350 mOsm） osmolarity on the activation and inactivation kinetics of VGSCs on TRGN were evaluated, compared with the normal intracellular environment. Results The results demonstrated that intracellular hypotonic stimuli could influence both the activation and inactivation characteristics of VGSCs currents, including the membrane potential at half inactivation（V0. 5） of the G-V and inactivation curves had obvious statistics significance（P<0.05） between hypotonicity（260 mOsm） and isotonicity（306 mOsm）. However, only inactivation properties changed under intracellular hypertonic effects, including inactivation rate and k value. Conclusion It suggests that the kinetics of VGSCs on TRGN can be modulated both by intracellular hypo- and hypertonic with different characteristics.

Objective To compare the adhesive strength and observe the bonding interface. According to statistic analysis and scanning electron microscope（SEM） observation, the resistance capacity of four adhesive systems is evaluated. Methods Prime & Bond NT（PBNT）, Tetric N-Bond（TNB）, Clearfil SE Bond（CSEB）, G Bond（GB） were bonded to the occlusal surfaces and mesial surfaces of third molars respectively. The mesial resins received shear force experiment and the fracture load were recorded. The tensile bond strength（TBS） of the remaining parts were tested. The interfacial configuration were observed under SEM. Results In the shear bond strength（SBS） experiment, PBNT and TNB showed the best result, but there was no significant difference between them（P>0.05）. The SBS of PBNT was stronger than that of CSEB and GB（P<0.05）. The SBS of TNB was stronger than that of GB（P<0.05）. There was no
significant difference between TNB and CSEB（P>0.05）. In accordance with the shear force result, the TBS of PBNT and TNB was larger than CSEB and GB（P<0.05）. Under SEM, resin tags of PBNT and TNB were longer and slender, the bonding layer was thick. Resin tags of CSEB were shorter, the ones of GB were the fewest and shortest. Conclusion Compared to self-etching system, total-etching system could reach better bonding strength. There is some connection between the interfacial configuration of adhesives and bond strength of them.

Objective To investigate the change of T lymphocyte subsets, interleukin（IL）-2 and tumor necrosis factor（TNF）-α in the tumor- bearing mice and patients with oral cancer receiving thermo-chemotherapy, and investigate the correlation among them. Methods After treatments, the expression of lymphocyte transformation index（LTI）, IL-2 and TNF-α in the tumor-bearing mice were detected with methyl thiazolyl tetrazolium（MTT）, the expression of IL-2 and TNF-α in the patients with oral cancer were detected with MTT, the expression of LTI, CD4+ and CD8+ were detected with 3H-TdR incorporation. Results LTI, IL-2 and TNF-α of thermo-chemotherapy group（HP group） had no significant difference comparing with those of normal mice group（N group）（P>0.05）, but which were significantly
higher than those of chemotherapy group（P group） and no treatment group（NT group）（P<0.01）. In clinical trials, the expression of LTI, CD4+, CD4+/CD8+, IL-2 and TNF-α on oral cancer patients after thermo-chemotherapy were significantly higher than those before thermo-chemotherapy（P<0.01）. Conclusion After thermo-chemotherapy, the expression of LTI, IL-2 and TNF-α of tumor-bearing hosts are significantly improved, there is a significant correlation between IL-2 and T cell.

Objective To detect the biological influence to human tongue squamous cell carcinoma（TSCC） cells of micro ribonucleic acid-21（miR-21）. Methods Referring to mature miR-21 sequence, the sense and antisense oligonucleotide（sense-miR-21 and AS-miR-21） modified by 2’O-Me were designed to transfect into TSCC cells（Tca8113 and high metastasis cells） by liposome transfection technology, in order to establish an in vitro TSCC cell model. The expression changes of miR-21 in the transfected cells were detected with real-time fluorescence quantitative polymerase chain reaction（real-time PCR）. The changes of cell proliferation, cell cycle, cell early apoptosis, cell migration and invasion capabilities were detected respectively by the technologies of methyl thiazolyl tetrazolium（MTT）, flow cytometry,  Annexin Ⅴ cell early apoptosis assay, scratch assay and Transwell assay, to check AS-miR-21’s effect on the biological
characteristics of human TSCC cell lines. Results For the TSCC cells, the antisense oligonucleotide of targeting miR-21 could effectively inhibit cell proliferation, promoted cell apoptosis, and inhibited the capability of cell’s migration and invasion. Conclusion The expressions of miR-21 decrease after AS-miR-21 transfected into TSCC cells, and miR-21 can affect biological behavior of TSCC cells.

Objective To investigate the stress distributions under load in an all-ceramic crown of the upper central incisor in differential thickness. Methods The 3-dimensional finite element model of all-ceramic crown of the upper central incisor in differential thickness was applied with differential loads（100, 150, 200 N）. The stress values and distributions of all-ceramic crown were calculated and expressed. Results The tendency of stress distributions in all-ceramic crown of differential thickness and loads was similar. The maximal stress intensity value was located in the loading site and the cervical region. As the thickness of all-ceramic crown increased, the stress concentration reduced. When the load increased, the stress values increased, especially in the loading site and the cervical region.
Conclusion The increasing of the thickness of all-ceramic crown will decrease stress concentration. Because stress concentration is mainly in cervical region and loading site, these regions should be cared in fabrication of all-ceramic crown.

Objective To investigate the expression of receptor activator of nuclear factor κB ligand（RANKL） and osteoprotegerin（OPG） in periapical cyst and periapical granuloma by comparison with the expression in the normal periodontal tissue as control, and to identify their functional mechanism in the bone destruction of periapical cyst and granuloma. Methods 20 periapical cyst tissues（cyst group）, 20 periapical granuloma tissues（granuloma group）, and 20 normal periodontal tissues（control group）were collected respectively. Immunohistochemical technology was performed to detect the expression of RANKL and OPG in above three groups. Results In cyst group, granuloma group and control group, the expression of RANKL were 75.00±7.54, 68.40±6.74 and 29.40±2.46, respectively. The expression of OPG were 38.10±7.09, 47.65±13.85 and 58.60±5.88, respectively. The differences among the three groups were statistically
significant（P<0.05）. RANKL and OPG in cysts group were negatively correlated（r=-0.56, P=0.01） and were not correlated with granuloma and control group（P>0.05）. Conclusion RANKL and OPG play roles in the bone absorption of periapical disease. In periapical disease, abnormal expression of RANKL and OPG are detected, RANKL significantly increase, OPG decrease, bone absorption accelerate and osteolytic lesion are observed. In periapical cyst, the
bone absorption is more active compared with periapical granuloma.

Objective The purpose of this study was to investigate the regulatory role of tyrosine kinase 2 with immunoglobulin-like and epidermal growth factor homology domains（Tie2）on apoptosis and proliferation in the endothelial cells. Methods RNA interference（RNAi） technique was used to silence Tie2 gene expression by transfecting an expression vector containing short hairpin RNA（shRNA） for Tie2 into human umbilical vein endothelial cells（HUVECs）. Real time quantitation reverse transcriptase polymerase chain reaction（QRT-PCR） and Western blot were used to monitor Tie2 mRNA, as well as protein expression. The proliferation of HUVECs was examined by methyl thiazolyl tetrazolium（MTT）, and the apoptosis was detected under microscope. HUVECs transfected with pGenesil-hk was negative control, and HUVECs transfected with nothing was empty control. Results Tie2 mRNA expression was down-regulated 24 h and 48 h after transfection, and Tie2 protein expression was significantly down-regulated at 24 h and 48 h（P<0.05）, especially 48 h after transfection. The apoptosis rate was conspicuously higher in experimental group than in negative control and empty control group after 48 h（P<0.05）. The growth monitoring showed that proliferation was also markedly inhibited in experimental group（P<0.05） compared with two control groups. Conclusion Down-regulated expression
of Tie2 by RNAi can promotes apoptosis of HUVECs and has an anti-proliferation activity effect on them.

Objective To analyze the imaging manifestations of third molar（M3） in aged 11, and to explore the relationship of development between M3 and second molar（M2）, canine（C）. Methods A total of 399 cases, aged 11, of West China School of Stomatology in June—August 2010 were selected as the imaging database. The M3, M2, C on the panoramic images were observed and the development degree in 399 was divided. And then the correlation analysis was done. Results 45.5% of M3 in aged 11 was in stage C. 30.8% of M2 was in stage F. 36.1% of C was in stage G. The development of M3 appeared earlier in girls than in boys, and earlier in the mandible than in the maxillary． There was no significant difference between the left and right side. The correlation coefficient between M3 and
M2 was 0.437, and the correlation coefficient between M3 and C was 0.132. Conclusion The general trends of the developments of M3 and M2, C were the same. The development of M3 can be used to describe the development of M2 and C, according to the close relationship in radiograph．

Objective To evaluate the effects of different surface treatment on the fracture resistance of teeth restored with fiber posts and core system. Methods 24 fiber posts were divided into three groups according to different surface treatment techniques, including sandblasting, etching with hydrogen peroxide, and no treatment performed（the control group）. All fiber posts were luted with a composite resin luting agent in the canal roots. The teeth were restored with composite resin cores and metal crowns. After cementation, the teeth were subjected to simulated aging conditions consisting of mechanical loading cycles and thermal cycles. All teeth were loaded in a mechanical testing machine, and the fracture load and fracture mode of each teeth were recorded. Results The fracture resistances of sandblasting and hydrogen peroxide groups were higher than the control group（P<0.05）, while the fracture resistances of two test groups had no significant differences（P>0.05）. Fracture modes of all fiber post groups were nearer to the coronal third of the root. Conclusion Sandblasting and etching with hydrogen peroxide can improve the fracture resistance of teeth.

Objective This paper explores the relationships between mental health status of the patients’parents, whose children have cleft lip and palate, and their social impact factors. Methods The 12-item general health questionnaire（GHQ-12） and the social support rating scale were used to conduct a questionnaire survey of 59 patients’ parents. A data statistical analysis was done by using SPSS 13.0 software and Excel 2007 software. Results 1）The mental health status of the patients’parents was in the middle level. 2）The mental health status of the patients’ parents was related with the basic personal situations. It was apparently influenced by the qualifications and subjective state of mind. 3）The structure and relationship of the interpersonal networks of the patients’parents were the major constraint factors on the mental health status. 4）The social support degree and mental health status were positively correlated. Conclusion The social network and social support have important influences on the mental health status of the parents whose children have cleft lip and palate. It should create a more harmonious and tolerant social environment.

Objective To further understand the clinical features of chronic sublinguitis（CS） and to guide the clinical practice by a retrospective study. Methods 18 cases with CS were enrolled in the retrospective study and the age, gender, history of present illness, signs, diagnosis and treatment were analyzed. Results In 18 patients with CS, 15 patients（83.33%） had palpable masses. 8 masses（53.33%） had poor-defined borders, 11 masses（73.33%） were unmovable. There were only 3 patients（16.67%） who were diagnosed correctly in all 18 cases, while 10 patients（55.56%） were diagnosed as tumor. Conclusion CS are often misdiagnosed as sublingual gland tumor and the way to confirm diagnosis is pathological examination. Auxiliary examination should be used properly with clinical manifestation to make the right diagnosis.

Objective To evaluate alveolar bone shape changing after orthodontic teeth moving in the alveolar bone graft area by dental CT. Methods Three unilateral complete alveolar cleft patients were chosen in this study. Patients were examined before and after alveolar bone grafting, after orthodontic treatment by dental CT. The alveolar bone shape changing after orthodontic teeth moving in bone graft area was evaluated. Results The orthodontic teeth could move in the bony graft area, and graft alveolar bone could reshape the morphology followed the teeth move in. Conclusion Alveolar bone grafting and orthodontic treatment are good for reconstruct dental arch integrity.

Objective To evaluate the outcome of endodontic microsurgery in 54 cases with persistent apical periodontitis. Methods All surgical procedures were performed under a dental operating microscope after root canal treatment. Surgical procedures included periapical curettage, root-end resection, retropreparation with ultrasonic microtips, and root -end filling with mineral trioxide aggregate（MTA）. Healing was monitored clinically and radiographically. Results One year later, 31（57.41%） cases were cured, 19（35.19%） cases were improved, 4（7.41%） cases were failure. There were no statistical difference between sex, age, tooth location, size of the lesion and pathological features（P>0.05）. Conclusion The outcome of the present study indicates that endodontic microsurgery may result in a predictable treatment outcome in teeth with persistent periradicular lesions.

Objective To evaluate the clinical effect of semi-attached quad-helix appliance in expanding the narrow maxillary arches in patients with cleft lip and palate. Methods 15 cases with cleft lip and palate were selected and treated by semi-attached quad-helix appliance. Before, during, and after treatment, the dental arch width between cuspid, the first premolar and first molar were measured. Results The upper dental arches of all patients were expanded effectively in about five months. After orthodontic treatment, the upper dental arches were expanded, and the teeth were alined regularly, which provided good conditions for alveolar bone grafting. Conclusion The semi-attached quad-helix appliance with the fixed orthodontic treatment can expand the narrow maxillary arches in patients with cleft lip and palate effectively and conveniently.

Objective To study the nursing methods and its effect in mandibular mesioangular impacted third molar extraction with reversal high-speed air turbine. Methods 60 patients with mandibular mesioangular impacted third molar were selected in this study, who were treated in Department of Senior Dentists, West China School of Stomatology, Sichuan University, between June to December 2010. They were randomly and equally divided into control group and experimental group（n=30）. The former was treated with tradition chisel splint method while the latter was treated with reversal high-speed air turbine extraction and provided appropriate nursing interventions. Postoperative reactions and wound healing status were evaluated through consultation. Results There were significant differences between
control group and experimental group in terms of postoperative bleeding wound, swelling, dry socket and so on（P<0.05）. Conclusion Mandibular mesioangular impacted third molar extraction with reversal high-speed air turbine is effective, and the corresponding nursing measure is worthy further promotion.

Objective To evaluate the value of cone-beam CT（CBCT） in the diagnosis and orientation of supernumerary teeth in the anterior maxilla. Methods 195 supernumerary teeth in the anterior maxilla of 146 patients were included, which were examined by CBCT. The number, shape, size, 3-dimensional position, growth direction of the supernumeraries and their relationship with the neighboring teeth were analyzed. Results The 146 patients aged from 5 to 39, and males were affected more than females in a ratio of 2.95∶1. 102（69.9%） patients had single supernumerary teeth. Of the 195 supernumerary teeth, 126（64.6%） were near the middle line, 131（67.2%） were conical, 51（26.2%） were curved root, 98（50.3%） were inverted and had a length of （11.97±2.40）mm. The supernumerary teeth often caused complications. Conclusion The position of the supernumerary teeth is varied in the maxilla，and often causes permanent dentition complications. CBCT imaging yields accurate 3-dimensional pictures of supernumerary teeth, local dental and bony structures, which is helpful for diagnosis and orientation of supernumerary teeth.

Objective To guide doctors in precisely positioning surgical operation, a new production method of minimally invasive implant guide template was presented. Methods The mandible of patient was scanned by CT scanner, and three-dimensional jaw bone model was constructed based on CT images data. The professional dental implant software Simplant was used to simulate the plant based on the three-dimensional CT model to determine the location and
depth of implants. In the same time, the dental plaster models were scanned by stereo vision system to build the oral mucosa model. Next, curvature registration technology was used to fuse the oral mucosa model and the CT model, then the designed position of implant in the oral mucosa could be determined. The minimally invasive implant guide template was designed in 3-Matic software according to the design position of implant and the oral mucosa model. Finally,
the template was produced by rapid prototyping. Results The three-dimensional registration technology was useful to fuse the CT data and the dental plaster data, and the template was accurate that could provide the doctors a guidance in the actual planting without cut-off mucosa. Conclusion The guide template which fabricated by comprehensive utilization of three-dimensional registration, Simplant simulation and rapid prototyping positioning are accurate and can achieve the minimally invasive and accuracy implant surgery, this technique is worthy of clinical use.

Objective To investigate the acquaintance to orthodontics and possible factors that obstruct orthodontic treatment in middle school students in zones with different economic levels in Jiangjin, Chongqing. Methods The students were randomly divided into four groups: A class from a junior high school in town（group 1）, a class from a senior high school in town（group 2）, a class from a junior high school in the countryside（group 3）, a class from a senior high school in the countryside（group 4）. The information was collected by questionnaire, and the statistical analysis of results was carried out by SPSS 17.0 software. Results Sex made difference in the acquaintance to orthodontics treatment. Girls worried more about teeth extraction and pain that may occur during treatment than the boys.
Students in the city had more access to related consultations compared to those in the countryside. Different economic conditions made much contribution to the proportion to go for orthodontics treatment in cities and rural areas. The evaluation from families and friends may affect patients’subjective estimation to themselves. Conclusion Orthodontists should learn more about student patiens from various aspects, and make different therapies according to their sexes, economic conditions of family, education levels, etc. Only so can orthodontists get better compliance from their patients.

Objective To make a clinical retrospective analysis of reconstruction using autogenous non-vascularized iliac bone graft for patients with mandibular defects, and then to evaluate the treatment effectiveness and operation announcements of this method. Methods 34 patients who were suffered from discontinued mandibule because of tumor or trauma, were treated with autogenous non-vascularized iliac bone graft. The surgery technique, postoperative outcomes and complications were analyzed. Results In 34 patients adopted non-vascularized iliac bone graft, 31 patients adopted rigid internal fixation with titanium mini plate, 3 patients with bridging titanium plate. 27 bone grafts survived completely, the overall success rate was 79.41%. 3（8.82%） of the bone grafts healed after infection, 4（11.76%） bone grafts lost because of infection. Conclusion The autogenous non-vascularized iliac bone graft is one of the most important way for the reconstruction of mandibular defects. The methods of internal fixation includes titanium mini pate and bridging titanium plate.

Objective To evaluate the effects of a bleaching gel and a whitening strip on the microleakage of three different glass-ionomer cements. Methods Forty-five freshly extracted human premolars were used and class Ⅴ cavity was prepared on the buccal and lingual surfaces. The teeth were randomly assigned to A, B and C groups and restored as follows: Conventional strengthen glass-ionomer cement（KetacTM Molar Easymix）, compomer（F2000） and compomer （Dyract AP）. Teeth were kept in distilled water at 37 ℃ for 7 days. Then the specimens were thermocycled for 500 times. Each group was randomly divided into 3 subgroups which were treated for 21 days with one of the following: Whitening strip（14% hydrogen peroxide）, bleaching gel（10% carbamide peroxide）, or distilled water（control）. After bleaching, the teeth were placed in a solution of basic fuchsin dye for 24 hours, then the teeth were sectioned longitudinally to evaluate the dye penetration. The depth of staining along the tooth restoration interface was recorded with a stereomicroscope. Results There were no signicant differences between the two bleaching agents in microleakage of restorations（P>0.05）. The two bleaching agents did not significantly affect the microleakage of compomer（P>0.05）, whereas the microleakage of glass-ionomer cement in the experimental groups was higher than that in the control group （P<0.05）. Conclusion There are no significant differences in microleakage of restorations between bleaching gel（10%carbamide peroxide） and whitening strip（14% hydrogen peroxide）. The two bleaching agents do not significantly affect the microleakage of compomer but adversely affect the microleakage of strengthen glass-ionomer cement.

Objective To evaluate the effects of firing numbers on the total opening pore volume（TPV）, translucency parameter（TP） and color of dental all-ceramic systems. Methods Specimens of three kinds of all-ceramics systems were made, i.e. heat pressed all-ceramic（IPS Empress Ⅱ）, alumina all-ceramic（In-Cream alumina blanks） and zirconia all-ceramic（Cercon CAD/CAM zirconia）. The specimens’TP, lightness（ΔL）, chroma（ΔC） and TPV after 1, 3 and 5
firings were measured and calculated by spectrophotometer and surface area/porosity system. The data were analyzed statistically using SAS 8.0 software. Results There were significant differences in TPV, TP, ΔL and ΔC for all-ceramic specimens at same number of firings（P<0.05）, i.e. IPS>alumina and zirconia for TPV（P<0.05）; IPS>zirconia>alumina for TP and ΔL（P<0.05）; IPS and alumina>zirconia for ΔC（P<0.05）. The significant differences also presented in TPV, TP,
ΔL and ΔC for a same specimen at different number of firings（P<0.05）. With increasing number of firings, TPV decreased, and TP, ΔL and ΔC increased gradually. There were negative linear correlation between number of firings and TPV, TP, ΔL and ΔC（P<0.05）. Conclusion Repeated firings will affect TP and ΔL of all-ceramic restorations via the change of TPV.

Objective We ascertained the effect of bone morphogenetic protein-2（BMP-2） and basic fibroblast growth factor（bFGF） by a series of experiments: Proliferation and differentiation of bone marrow stromal cells（BMSCs） in vitro, ectopic and in situ bone formation and loaded porous calcium phosphate cement（CPC） on the repair of bone defects around dental implants. Methods BMSCs from Beagle dogs were cultured in vitro with basic culture medium containing BMP-2, bFGF, and BMP-2+bFGF. Proliferation and differentiation of BMSCs were quantified using methyl thiazolyl tetrazolium（MTT） and alkaline phosphatase（ALP） test. The CPC seeded with BMSCs and BMP-2, bFGF, combined BMP-2 with bFGF were implanted subcutaneously into nude rats in ectopic bone formation, and were implanted into critical-sized bone defects of Beagle dogs in the in situ bone formation. The bone formation was detected by histology examination and quantified using an image analysis system. Polychrome sequential fluorescent labels and fluorescence histological examinations of undecalcified sections were performed post-operatively. Results It was determined that BMP-2+bFGF promoted BMSCs statistically significant proliferation and differentiation compared to either BMP-2 or bFGF in vitro. The CPC with BMP-2+bFGF group yielded more bone than those with either BMP-2 or bFGF in
ectopic bone formation test. The percentages of newly ectopic formed bone were higher in the BMP-2+bFGF group （48.79%±11.31%） than those in other groups（BMP-2 group, 30.71%±10.85%; bFGF group, 27.33%±9.67%; and the control group, 10.65%±6.05%）. Undecalcified sections showed that new bone was actively formed in the BMP-2+bFGF group after 12 weeks in the in situ bone formation test. The bone mineralization apposition rate（MAR） was better in the BMP-2+bFGF group than in other groups（P<0.01）. Conclusion BMP-2 combined with bFGF are more effective than one alone in promoting the formation of new bone.

Objective To determine if locally administered bone morphogenetic protein-2（BMP-2） and osteoprotegerin（OPG） improved osteogenesis and new bone formation by trans-sutural distraction osteogenesis. Methods Twenty four dogs were divided into three groups randomly and received new internal trans-sutural distraction osteogenesis treatment. Five days after operation, infusion apparatus with double-tube was inserted to submucosa near the distracted zone
to deliver controlled release agent of recombinant human bone morphogenetic protein-2/poly（lactic-co-glycolic acid）/fibrin sealant（rhBMP-2/PLGA/FS） in group A and group C. Recombinant human osteoprotegerin/fibrin sealant（rhOPG/FS） was injected three weeks later in group B and group C. Histology staining and bone histomorphometry were used to measure the changes of maxillary bone sutura after distraction for 1, 2, 4 and 6 weeks. Results New bone formation
observed in distracted zone showed a significant increase in group A and C. Transmission electron microscope showed the osteoblast and osteocyte were active with dilated rough endoplasmic reticulum and a large number of chondriosomes and Golgi complex. After distraction for 6 weeks, indexes of osteoblast of group A, B, and C were 38.5±7.7, 35.7±6.5, and 41.7±11.0, indexes of osteoclast（Ioc） were 5.9±1.0, 1.2±0.3, and 2.8±0.4, bone trabecula thicknesses were （38.36±13.28）,（66.20±9.16）, and（51.85±9.92）μm respectively. Increased bone density and decreased Ioc were found in group B and C. Conclusion The new elastic distractor is effective in inducing new bone formation. BMP-2 and OPG combination acts synergistically, and leads to significant enhancement of bone formation and remodeling.

Objective To investigate the relationship between c-fos gene and filamentous actin（F-actin） in MG-63 osteoblasts under cyclic tensile stress. Methods MG-63 osteoblasts were subjected to cyclic tensile strss（0.5 Hz, 2 000 μstrain） for 3, 6, and 12 h. The changes of c-fos gene were investigated by fluorescent quantitation polymerase chain reaction. Then the best loading time group was screened as the experimental group compared with 0 h group. The changes of F-actin and c-fos were investigated with or without cytochalasin D treatment. Results Cyclic tensile stress induced high expression of c-fos mRNA, and peaked at 3 h. After loading, F-actin had a structure reorganization, but had no change in expression. After cytochalasin D treatment, the formation of stress fibers and the fluorescence intensity of F-actin cytoskeleton significantly reduced, meanwhile the c-fos mRNA expression was inhibited. Conclusion After loading, there is only structure reorganization for F-actin, and the expression has not any change. That means the remodeling F-actin is the existing one. F-actin reorganization is an important part in c-fos gene expression induced by stress.

Objective To investigate the effect of different concentrations of fluoride on the expression of transforming growth factor-β1（TGF-β1）, and explore the mechanism of dental fluorosis. Methods 40 Wistar rats were randomly divided into three groups, and supplied with low dose F-（60 mg·L-1, 13 rats）, high dose F-（120 mg·L-1, 13 rats） and distilled water（control group, 14 rats） respectively. After 10 weeks, hematoxylin-eosin（HE） and immunohistochemistry staining were used to observe the changes of the ameloblasts and the expression of TGF-β1 in rat incisors. Results The fluoride groups showed typical symptoms of dental fluorosis. The surfaces of the rat teeth fed with fluoride appeared chalky color and cross striation on the enamel surface. The HE staining showed that the morphous of
ameloblast were disarranged and cellular derangement, even appeared vacuolar change. TGF-β1 were expressed both in ameloblast of the secretory and maturation stage, and also in stellate reticulum and stratum intermedium. The expression of TGF-β1 in rat’s ameloblasts in experiment group was significantly lower than that in the control group （P<0.01）, yet low dose group and high dose group still had no significant difference（P>0.05）. Conclusion By inhibiting the expression of TGF-β1 in ameloblast, fluoride interferes the normal signal transduction between epithelial and mesenchymal, and affect the differentiation and development of enamel, so leading to the occurrence of dental fluorosis.

Objective To detect the expression of aldehyde dehydrogenase（ALDH） in tongue squamous cell carcinoma Tca8113 cell line and observe the biological characteristics of tumor cells expressing high level of ALDH （ALDHhig）. Methods The expression of ALDH in tongue squamous cell carcinoma Tca8113 cell line was detected by the flow cytometry. The ALDHhig and ALDHlow subpopulation cells were isolated and cultured in vitro respectively. The ability of differentiation, proliferation and tumorsphere formation were detected. Suppression subtractive hybridization（ SSH） was employed to screen the genes overexpressed in ALDHhig subpopulation cells. Results The ALDHhig cells in tongue squamous cell carcinoma Tca8113 cell line was rarely 1.3%. Compared with ALDHlow cells and unsorted cells, ALDHhig cells demonstrated increased proliferation capacity. After culture in vitro, the percentage of ALDHhig cells decreased gradually to the level of that in unsorted tumor cells. The ALDHhig subpopulation cells could survive in serum free medium and generate tumorspheres. SSH analysis revealed these tumor cells also expressed stem cell related genes. Conclusion There is a rare subpopulation cells expressing ALDH highly, which displays characteristics similar to stem cells. ALDH may be one of markers for cancer stem cells of tongue squamous cell carcinoma Tca8113 cell line.

A case diagnosed as adenolymphoma and pleomorphic adenoma in unilateral parotid gland was reported. The clinic pathological features, possible mechanism, diagnosis and treatment were discussed based on previously reports in the literature.