In recent years, clinical diagnostic and treatment techniques of orthodontics have been developed rapidly. The orthopedic mechanism of malocclusion has been the hot spot of basic research of orthodontics.

Objective To observe the microscopic characteristic of the dentinal surface and cross section after using dental desensitizer, and evaluate the effect of the dental desensitizer on the shear strength of resin cements. Methods To use the dental desensitizer（Gluma, Single Bond 2, BisBlockTM） individually on the prepared human bicuspid teeth which were extracted for orthopaedics. The microscopic characteristic of the dentinal surface and cross section were observed with scanning electron microscope（SEM）. The adhered posts to the teeth pretreated with desensitizer were bonded with resin cements. The shear strength was measured and data was analyzed by SPSS 13.0 statistics software. Results The orifices of dentinal tubule were mostly occluded in Gluma samples and partly occluded in BisBlockTM samples. Resin layer was observed in Single Bond 2 samples. BisBlockTM group gathered the best shear strength, the shear strength value was （13.04 ±2.76）MPa. Marked statistic difference were found when compared with control group. Conclusion Gluma, Single Bond 2 and BisBlockTM can block the orifices of dentinal tubule. BisBlockTM enhanced the bonding strength of the resin cements.

Objective To investigate biological transport of minocycline by human periodontal ligament fibroblasts（HPDLF）. To verify the hypothesis of delivering medicine to periodontium and the whole body through the root canal. Methods HPDLF and MC3T3- E1 cells were incubated in minocycline solutions. The intracellular antibiotics contents were measured by high performance liquid chromatography（HPLC） and the cell total protein was measured by Bradford protein assay. Results HPLC was an accurate, sensitive method for measurement of the intracellular minocycline. The incubation time and cell property had significant effect on the intracellular minocycline contens（P< 0.01）. The intracellular contents increased with extracellular concentration. Conclusion Minocycline can be transported by HPDLF. The transport is concentration- dependent, time- dependent and cell specific.

目的通过溶胶凝胶法制备含锌的碳磷灰石（Zn- CHA）涂层材料，并探讨锌离子取代反应对羟磷灰石物理化学性质的影响。方法实验制备了锌离子取代量和钙磷比不相同的两组样本，其中钙足量组样本的钙磷比为1.67，锌离子取代4%的钙离子；钙不足量组的钙磷比小于1.67，锌离子取代8%的钙离子。采用X射线衍射仪（XRD）、傅立叶变换红外光谱仪（FTIR）对样本的物相结构和化学组成进行分析研究，并采用扫描电镜观察样本的表面形貌。此外，还采用原子吸收分光光度计（AAS）对样本的溶解特性与锌离子的关系进行研究。结果X射线衍射分析表明样本中含有羟磷灰石相，傅立叶变换红外光谱分析结果表明样本为碳磷灰石，溶解实验表明钙不足量组和钙足量组样本中分别存在锌离子整合到羟磷灰石晶格内和吸附在羟磷灰石晶体表面两种情况。结论研究表明含锌的碳磷灰石能够通过简单的溶胶凝胶法制备获得。

Objective To investigate the effects of overdose fluoride, boron and two factors on the expression of enamelin in rat incisor. Methods 32 Wistar rats were randomly divided into 4 groups. GroupⅠ：The distilled water was given. Group Ⅱ：220 mg/L NaF were given. GroupⅢ：382 mg/L Na2B4O2·10H2O were given. Group Ⅳ：220 mg/L NaF and 382 mg/L Na2B4O2·10H2O were given. The rats were sacrificed in the eighth week. HE staining was used to observe the morphology of ameloblasts. Immunohistochemical staining was used for study the expression of enamelin in rat incisors. Results The results showed that the expression of enamelin was reduced in the group Ⅱ（P<0.01）. Compared with group Ⅰ , the expression of enamelin in group Ⅳ had no significant difference. The expression of enamelin in group Ⅳ and group Ⅱ had significant difference（P<0.01）. Conclusion The overdose fluoride can inhibit the expression of enamelin. The effection was weaken when boron added. Boron reduced the toxicity of fluoride on teeth.

Objective To study the clinical significance of osteopontin（OPN） and its receptor CD44v6 expression in oral squamous cell carcinoma（OSCC）. Methods OPN and CD44v6 expression were examined in OSCC（n=59）and normal oral mucosa（n=12）by EnVisionTM method, the staining- grade were quantitatively studied by multiple functional image analyzer. Their expression grade of different clinical and pathological index were statistically studied. Results OPN expression grade was significantly higher in OSCC than that in normal oral mucosa（P<0.05）. Significant deviation of OPN expression grade was found between different clinical stages, as well as between the groups with or without cervical lymph node metastasis. The group with cervical lymphnode metastasis had higher expression than that of the group without lymph node metastasis（P<0.05）. However, there was no significant deviation between the expression grade in well- differentiated group and moderate or poorly differentiated group. The expression of CD44v6 showed no correlation with that of OPN, nor any difference between OSCC and normal oral mucosa. Conclusion OPN over expression was found in OSCC, and the expression level has correlation with the clinical staging and with cervical lymph node metastasis status. CD44v6 expression showed no difference between OSCC and normal oral mucosa nor any correlation with that of OPN.

Objective To investigate the suppression effect of exogenous fragile histidine triad（FHIT） gene on biological property of MEC- 1 cells. Methods In order to study the FHIT function in MEC- 1 cells, wild- type FHITgene was transferred into mucoepidermoid carcinoma MEC- 1 cells. The proliferation and kinetics, cell cycle, clonal forming rate, and apoptosis of MEC- 1 cells, before and after FHIT gene transfection in vitro, and tumor loci formed on mice after injection of transferred MEC- 1 cells in vivo were observed by immunochemical staining, flow cytometry analysis, and so on. Results It can be seen that exogenous FHIT gene transfer could significantly inhibit the proliferation and reduce the kinetics of MEC- 1 cells in vitro, prolong DT from（21.03±0.41）h to（26.86±0.71）h, and also keep less cells in cell cycle phase S, whilst more cells in phase G1, Additionally, the exogenous FHIT was found to be able to remarkably suppress MEC- 1 cells of forming tumor loci in nude mice by lessen tumor weight, and promote higher differentiation of MEC- 1 cells to be mucous cells. Conclusion Exogenous FHIT gene could suppress the proliferation, tumorigenicity and improve the differentiation of MEC- 1 cells, in vitro and in vivo.

Objective Muscle segment homeobox gene（MSX）1 has been proposed as a gene in which mutations may contribute to nonsyndromic cleft lip with or without cleft palate（NSCL/P）. To study MSX1 polymorphisms in NSCL/ P by means of polymerase chain reaction- single- strand conformation polymorphism（PCR- SSCP）, and investigate the association of MSX1 exons 1 polymorphisms with NSCL/P. Methods DNA were extracted from blood samples from NSCL/P and unrelated normal subjects. Genome DNA from peripheral leukocyte with these blood samples were extracted, which was used as template to amplify desired gene fragment of MSX1 exons 1 by means of polymerase chain reaction（PCR）. The PCR products were examined by single- strand conformation polymorphism（SSCP）. The  MSX1 exons 1 polymorphisms were examined by sequencing if mutations were found. Results MSX1 genes of exon 1 mutation was not been found in the NSCL/P and unrelated normal subjects by SSCP. Conclusion No correlation between MSX1 exon 1 and NSCL/P was found. MSX1 exon 1 may not be a key gene（susceptibility gene）in NSCL/P.

Objective To observe the bonding interface of sclerotic dentin after treated with total- etching system and self- etching system by confocal laser scanning microscope（CLSM）. Methods A total of 12 maxillary bicuspids with non- caries, natural cervical sclerotic lesions were divided into three groups. The sclerotic dentin was bonded with Single Bond（SB, total- etching adhesive）, Clearfil SE Bond（CB, two- step self- etching）and Xeno Ⅲ（XB, onestep self - etching）according to the manufacturer′s instruction. Artificially prepared wedge - shaped lesions made in sound maxillary bicuspids and bonded with same adhesive were used as control. The primer component was labeled with Rhodamine B Isothiocyanate. Hybrid layer and resin tag of dentin bonding interface were observed by CLSM. Results Two- way ANVOA revealed significant influence of both the type of dentin and the bonding adhesive systems tested on resin tag and hybrid layer（P<0.05）. Resin tag and hybrid layer in total - etching adhesive（SB） were longer and thicker than in self- etching adhesive（CB, XB）whatever in normal dentin or sclerotic dentin, while the resin tag and hybrid layer thickness were similar in two kind self- etching adhesive（P<0.05）. Conclusion The resin rags were fewer and shorter and the hybrid layers were thinner in sclerotic dentin than in normal dentin. When bonding the same type dentin substrate, the resin rags were shorter and the hybrid layer thinner in used selfetching adhesive than total- etching.

Objective To investigate the correlation between moderately and severely chronic periodontitis and coronary heart disease, as well as the role of fibrinogen in the mechanisms responsible for the correlation between periodontitis and coronary heart disease. Methods 95 subjects who were systemic health or patients of coronary heart disease with or without periodontitis were enrolled. All the subjects were placed into 4 groups based on their periodontal status and cardiovascular health. The 4 groups were healthy control group（HC）, moderately and severely chronic periodontitis group（MSP）, coronary heart disease group（CHD）, and MSP coexisted with CHD group（MSP+CHD）. Clinical periodontal index were examined, at the same time, plasma fibrinogen levels and serological changes used in diagnosing of cardiovascular disease routinely were determined. ANOVA and ANCOVA were used in the statistical analysis. Results Fibrinogen levels of HC, MSP, CHD, and MSP+CHD group were（2.36±0.37）, （3.63±0.73）, （4.08± 0.84）, and （4.14±0.96）g/L, respectively. Fibrinogen levels of MSP and MSP+CHD group were significantly higher than that of healthy controls（P<0.01）. The patients with moderately to severely chronic periodontitis were more likely to have coronary heart disease as compared to periodontally healthy controls（OR=2.527, P=0.047）after adjusted for blood pressure and body mass index. Conclusion Moderately and severely chronic periodontitis maybe a risk factor of coronary heart disease and fibrinogen could be one of the biological basis which links periodontitis with coronary heart disease.

Objective To translate the original English version of the child perception questionnaire（CPQ11- 14）into Chinese version and to test the psychometric properties of the Chinese version in order to use among the Chinese children. Methods The original English version of CPQ11- 14 was translated into Chinese, and pre- tested and crosscultural adapted. Subsequently, the Chinese version with a general questionnaire was administered to 218 children aged from 11 to 14, clinical data on caries status and malocclusion were collected through oral health examination. Results Test- retest reliability was substantial（r=0.82, P<0.001）. Cronbach′s alpha of the translated scale was 0.79. The 16 items were divided into five domains by factor analysis. There was certain logical relation between the items in the same domains. There was highly significant association between perceived oral health status, perceived impact to quality of life by oral health and CPQ11-14 score（P<0.000 5）. Significant relationships were identified between caries status and CPQ11- 14 scores（P<0.001）, and between malocclusion and CPQ11- 14 scores in middle- school- group（P<0.05）. Conclusion The translated Chinese version of CPQ11-14 demonstrated good reliability and validity. Its good psychometric properties provide the theoretical evidence for further use in Chinese population. It is available for use by researchers in oral health related quality of life studies in Chinese children.

Objective To measure the vertical height of mesio- distal marginal ridge to cusp in posterior teeth, which may be helpful to brackets positioning. Methods The study groups comprised of 60 patients（30 men, 30 women, mostly aged 12 - 14 years） who underwent orthodontic treatment without tooth extraction and matched the Andrews normal occlusion standard after treatment. Study model of each patient was made. Three- dimensional laser measurer was used to evaluate the vertical height of mesio- distal marginal ridge to mesial cusp in posterior teeth. The data were stored in a personal computer and submitted to statistical analysis of paired t test. Results No statistical significant difference was found in the same teeth between men and women. Not only in maxilla but also in mandible, there was no significant difference between the left and the right（P>0.05）. The average vertical height of maxillary first premolars was （1.70±0.50）mm, the maxillary second premolars was （1.24±0.45）mm, and for maxillary first molars, the result was （0.83±0.40）mm. The difference between each result was statistically significant（P< 0.01）. The average vertical height of mandibular first premolars was（2.25±0.45）mm, the mandibular second premolars was （1.55±0.45）mm, and for mandibular first molars, the result was （1.18±0.40）mm. The difference between each result was statistically significant（P<0.01）. Conclusion The vertical height of brackets position in posterior teeth should be considered to guarantee that mesio- distal marginal ridges of deferent posterior teeth located in the same plane, so that satisfying goal could be achieved. If the vertical height in the first molar was X mm, the vertical height in the second premolar should be（X+0.5）mm, and（X+1.0）mm might be suit for the first premolar.

patients with Class Ⅱ division 1 treated with extraction of four first premolars by Begg appliance and Edgewise appliance. Methods The study was conducted using lateral cephalometric radiographs taken pretreatment, posttreatment and following- up. Thirty patients who had an Angle′s Class Ⅱ division 1 malocclusion were treated with first premolar extractions（19 by Begg appliance and 11 by Edgewise appliance）. Cephalometric radiographs were scanned and the data were analyzed according to the paired and unpaired t- test. Results The differences between the pretreatment and posttreatment periods were statistically significant for all the incisor and molar cephalometric variables（P<0.05） except UMA- PPV and UMC- PPV by Edgewise appliance. During treatment the incisors moved lingual - inclined and extrusively, the molar moved mesially and extrusively except that the upper molar of the Edgewise group stayed relatively stable anteroposteriorly. During the follow- up period the anterior teeth moved forward and extrusively, the upper molar moved mesially and extrusively. There was no significant differences of tooth movement and stability between Begg appliance and Edgewise appliance（P>0.05）. Conclusion There is no significant differences of hard tissue changes and stability between Begg appliance and Edgewise appliance.

Objective To measure the translucency parameter（TP）, masking effect（ME）, and contrast ratio（CR） of opal porcelain of Ceramco, Shofu, Noritake, and Vita, and to compare the correlations among the three transmission parameters, in order to provide reference for selecting opal porcelain correctly. Methods The color of specimens was measured according to CIE L*a*b* under different background and reflectance mode with a Color- Eye 7000A spectrophotometer. The color difference, TP, and ME value were calculated. Within 400- 750 nm spectra, the ratio of light reflectance was measured, and CR was also calculated. The data was compared by ANOVA and SNK- q test （α=0.05）. The correlation and multiple linear regression between TP, CR, and ME were analyzed（α=0.05）. Results There were statistical difference with different shade of the same brands （P<0.05）. The correlations between ME and TP, TP and CR, ME and CR were existed（P<0.05）. TP was correlated not only with ME but also with CR based on multiple regression analysis（P<0.05）. The partial correlation coefficients were statistically significant（P<0.05）. CR was the main devotion to translucency parameter on multiple regressions. Conclusion It is recommended to select opal porcelains based on transmission parameters. CR value has an inner significance of opaque property of opal porcelain and can express opacity property of opal porcelain more appropriately than ME.

Objective The aim of this study was to evaluate the changing of alveolar cleft bone volume before and after bone graft. Methods 11 complete unilateral alveolar cleft patients were scanned with dental CT before bone graft surgery and 3 months after surgery. Matlab7.0 software was used to calculate the bone volume of alveolar cleft before bone graft and bone bridge volume after bone graft. The method was clockwise identify the irregular area of alveolar cleft by several points at different vertical level, then calculated the irregular area of alveolar cleft and the volume of alveolar cleft using Matlab7.0 software. The volume of implant bone was evaluated with same method after 3 months surgery. The ratio of graft bone bridge volume and alveolar cleft volume was calculated. Results The maximum ratio of bone bridge volume and alveolar cleft volume was 114.99%, the minimum ratio was 13.36%. The average ratio was 71.80%, coefficient variation was 47.987. Conclusion Bone bridge volume after bone graft is varying.

In recent years our research team introduced many foreign patterns to our clinics, kept innovating and exploiting more reasonable modes and methods to cure the cleft patients in the situation of a developing country. Now we concluded the treatment principles, patterns and techniques of the sequential therapy according to the different temporal stages of cleft, from its arising to the evolution, evaluated our therapy results and induced a preliminary guide line of our treating clefts. We sincerely hope this rule could promote the general progress in both clinical treatment and researching.

Objective The aim of this investigation was to examine the changes of the color stability, surface microstructure and chemical constitution of light- curing composite resin after accelerated aging, and the relations between them. Methods Four light - curing composite resin were aged in an accelerated aging instrument. The color was measured by CIE L*a*b* with a spectrophotometer after treatment for 24 h and 96 h. And the color differences were calculated. Environmental scanning electron microscopy（ESEM） and Fourier transform infrared spectroscopy （FTIR） spectrometer were used to examine the microstructure and chemical composition of the specimens before and after accelerated aging. The color differences were analyzed statistically by repeated- measures two- way analysis of variance and t- test after aging for 24 h and 96 h. The level of significance was defined as α=0.05. Results The materials demonstrated statistically significant differences in color after aging between the 24 h and 96 h（P<0.05）. There were significant influences on the microstructure and the chemical composition after aging. The matrix appeared some concaves and pores, the filler particles exposed after aging. The energy of chemical bonds were weaken or broken under the aging, and the unsaturated polymer reacted again. Conclusion The color differences of the composite resin increase with the aging time and irradiation dose. The hybrid filled composites have the best color stability.

Objective To introduce and evaluate the procedure and the effect of maxillary sinus lift with closed  technique by Summers osteotome, bone grafting and simultaneous implant placement. Methods 66 cases with severely resorbed alveolar bone in maxillary posterior region received sinus lift with Summers osteotome, simultaneously bone grafting and implants placement. The final restoration was finished at 6 months postoperatively. Results The operation procedure were eventless in the 66 cases, the sinus floor were elevated by 2- 5 mm, three- dimensional reconstruction of the CT scan pictures showed the smooth dome profile of the lifting sites and no signs of laceration on the membrane, and there were no maxillary antritis after operation. After 6 months, no significantly bone graft resorption and good osseointegration were noticed in X- ray imaging. The final restoration was finished at this time. 12- 24 months after the restoration, all implants inserted were remain, the hard and soft tissue were healthy, prosthesis were stable and functioned. X- ray showed good osseointegration in the lifting sites, the vertical resorption around the implants were less than 1 mm. Conclusion With properly use of Summers osteotome, scraps of the bone in the implant sockets can be pushed into the sinus, these autogenous bone scraps were in favor of the osseogenesis and the sinus floor can be easily elevated by the method with very infrequent complications. It enlarged indication of dental implants and avoided operation of harvesting autogenous bone in other site. The method is simple and valuable to clinical application.

Objective The aim of this study was to observe the change of the prevalence of five- year- old children′ s dental caries for 10 years in Shanghai and to establish a related policy to provide a basis for the government. Methods The sampling method was multi- stage, stratified, adqulis capacity and whole flock in this study. The method of third national survey for oral health was used. The data of prevalence of dental caries, dmft and relative component were collected and were compared with the data of the second survey in 1995. Results The prevalence of dental caries, dmft, caries filling constitutent ratio of 5- year- old children in 2005 was 71.74%, 4.17, 7.70%, respectively, and denscend 6.54%, 0.59, 1.12% compare with the data in 1995. There was significant difference between them（P<0.01）. Conclusion The results showed the descend trend of prevalence of dental caries in 5- year- old children in Shanghai and the oral health condition had an obvious improvement. However, caries filling constitutent ratio was decreases. Therefore, it is very important to strengthen the public oral health care service for children.

Objective To evaluate the efficacy of Tooth Mousse in reducing enamel demineralization lesions adjacent to bonded orthodontic brackets and promoting remineralization in vitro. Methods 60 bovine teeth with bonded orthodontic brackets were randomly divided into three groups, negative control group, positive control group and experimental group, applied separately with distilled water, Duraphat fluoride varnish, Tooth Mousse. 3 groups were dipped into an artificial caries solution and an artificial saliva solution, cycling between them. All samples were detected by polarized light microscope, scanning electron microscope and electron probe micro- analysis. Results Polarized light microscope showed that the enamel surface of the experimental group were completed, the areas of positive birefringence were decreased obviously. Scanning electron microscope showed that a large number of deposits were found on the dental enamel surface of the experimental group, filled in the small local concave of enamel surface. Compared with the control group, electron probe micro- analysis showed that calcium and phosphate concentration of enamel surface was higher in experimental group than in negative control group（P<0.05）, there was no significant differences between experimental group and positive control group（P>0.05）. Conclusion Tooth Mousse can reduce enamel demineralization and promoting remineralization in vitro.

Objective Retention elements were added in the removable reverse headgear appliances in order to achieve better treatment effects of skeletal Class Ⅲ malocclusion. Methods Eighteen patients who needed treatments with reverse headgear appliances were randomly and equally divided into two groups with traditional type of retention elements（T group） and modified type of retention elements（M group） respectively. For the modified type appliances, an adams clasp was added in the position of central incisors on the basis of the traditional type. The minimum dislocating force for both types was measured with the same forcemeter in the first and second visit, respectively. The occurrence of dislocation caused by traction was recorded during the visits of the first three months. Results The M group showed significantly greater retention than the T group. The minimum dislocating force for M group was larger in the first and second visit （P<0.01, P<0.001）. Furthermore, during the first three months, two times of dislocation occurred in M group while it was nine times for T group, indicating great difference in retention （P<0.05）. Conclusion Adding an adams clasp in the position of upper central incisors could effectively prevent the downward dislocation of the appliance when traction force was applied. Accordingly, the therapeutic efficacy was greatly improved.

Objective To investigate the effects of the improved FUS- invest investment for zirconium- oxide titanium crown and bridge on the reaction layer. Methods 10 mm×10 mm×1 mm titanium castings were invested. Spectrum analysis was done to its reaction layer, the metallographic examination was observed and Vickers hardness was measured. Results The reaction layer was not obvious by the metallographic examination. The layer with plenty of Si was hardly detectable. The needle crystal layer diffused distribution on the surface of the titanium matrix. The depth was about 55 μm. Spectrum analysis showed that the contents of Si and Zr decreased as the depth increased. The microhardness, which obviously decreased from the surface to the matrix, tended to be equal with the hardness of the matrix after the depth reached 75 μm from the surface. Conclusion The thickness of the reaction layer of the improved FUS- invest investment for zirconium- oxide titanium crown and bridge was decreased to 55 μm from 85 μm, which was the thickness before improvement.

Objective To study the effect and mechanism of salidroside on salivary adenoid cystic carcinoma （SACC- 2）cells in vitro. Methods To detect the effect of salidroside on SACC- 2 cells growth with CCK- 8 kit, the growth curve of cells were drawn. To detect the expression of cysteine proteinase（Caspase 3 and Caspase 8） and proliferating cell nuclear antigen（PCNA） in SACC - 2 cells, immunohistochemistry staining was used. Results According the results of CCK- 8 kit detected, salidroside could inhibit the proliferation of SACC- 2 cells, IC50 value was （4.99 ±0.23）μg/mL. Growing curve showed that SACC- 2 cells of salidroside groups decreased with extending cell culture time. Immunohistochemistry staining showed that Caspase 3 and Caspase 8 were both strong positive expression in SACC- 2 cells of salidroside groups, and poor positive expression in SACC- 2 cells of control group, the difference was significant（P<0.01）. The expression of PCNA was reverse（P<0.01）. Conclusion Salidroside could inhibit the proliferation of SACC- 2 cells and induce SACC- 2 cell apoptosis in vitro, which could be a kind of antitumor medicine in the future.

Objective Developing mouse molar was used as a model for the study of Syndecan- 1, a transmembrane heparan sulfate proteoglycans, in order to approach the possible mechanism and function of this macromolecule during tooth development. Methods Mouse embryos were removed at different days of gestation. The frozen sections of the first lower molar were made from the embryonic mouse heads and then indirect immunofluorescence was performed on  these sections. The altered distribution pattern of Syndecan- 1 in embryonic mouse first lower molars at different stages of development from the bud to the late bell stage was observed under a conventional fluorescence microscope. Results There was a ubiquitous staining in the dental tissues at bud stage: Both the epithelium and mesenchyme were weakly positive for Syndecan- 1. From the bud to the cap stage, there was a strong decrease of the staining for Syndecan- 1 in the epithelial compartment, while an intense staining in dental mesenchyme was observed at cap stage. At bell stage, Syndecan- 1 was again detected in dental epithelium including the stratum intermedium and the outer enamel epithelium, and it was found having some intense signal in the stratum intermedium. However, the staining for Syndecan- 1 in dental mesenchyme of this stage became weaker and finally disappeared. Furthermore, a positive expression for Syndecan- 1 was also found at the top of pre- ameloblasts as well as odontoblasts. Conclusion These changes in the patterning of Syndecan- 1 during tooth development might be related with cell proliferation during morphogenesis and later be involved in the differentiation of ameloblast and odontoblast.

Objective To study the influence of emotion stress on mechanical hyperalgesia of masseter muscles in rats through the equipment of communication box. Methods 50 Sprague- Dawley rats were randomly divided into 5 groups: Control group, emtion stress（ES） group, drug control group, saline treated control group and footshock （FS） group, 10 rats each group. Footshock group only induced emotion stress and was not concerned with the result ofthe experiment. The last four groups of the rats were placed in communication box and bred under the same conditions during the experiment time. According to Rens′method, von Frey filaments were used to assess the muscle mechanical threshold, head withdrawal, leg raising and crying were observed as pain action. Results 1） During the adaptive period of 7 days before the emotion stress experiment, mechanical pain values of bilateral masseter muscles were descent and were stabilized in the 5 th to 7 th day. In emotion stress period, hyperalgesia of emotion stress group was induced in bilateral masseter muscles, and the peak time was the 7 th day, then it alleviated in the following days and was stabilized in the 12 th to 14 th day, but its pain threshold was lower than blank control group. 2）During the emotion stress period, the change of drug control group was similiar to stress group but its pain threshold was higher. Conclusion It is suggested that emotion stress can lead to the hyperalgesia of masseter muscles and antidepressant drug can lower the hyperalgsia resulted of emotion stress.

Objective Titanium, by far one of the oldest materials in medical implants used for hard tissue replacement and rehabilitation, was used widely as implant material. The objective of the present study was to fabricate the TiN modified layer on the surface of medical pure titanium and improve its surface properties. Thus the wear resistance, biocompatibility and antisepsis were improved. Methods A continuous- wave 2 kW Nd：YAG laser was used to irradiate the sample in the environment of N2 with concentration of 99.995%. Titanium nitride surface coatings had been extensively used as corrosion resistant and biocompatible layers on titanium and its alloys. The microstructure and composition of the laser nitrided coating were studied by scanning electron microscopy and X- ray diffraction. Microhardness of the modified sample was also analyzed by micro- hardmeter. Results TiN modified layer with the thickness of about 400 μm was obtained. TiN distributed gradually from surface to the substrate. There was a good metallurgical bonding between the nitrided layer and the substrate. The hardness of the modified layer was reduced from the surface to the inside. Conclusion With optimum process parameters, a compact laser modified gradient coating reinforced with fine TiN was achieved on the surface of medical titanium.

Objective The purpose of this article was to investigate the changes of the estrogen and insulinlike growth factors（IGF） level induced by orthodontic tooth movements in order to elucidate the bio- mechanism of or - thodontic treatments during the estrous cycle. Methods A Wistar rat experimental model was established to apply orthodontic activation during different stages of estrous. The serum and periodontal tissue estradiol level were determined by radioimmunoassay and immunohistochemistry. In situ hybridization was also used to detect the variation of the IGF mRNA expression in the periodontal tissues. The data of each group was analyzed with SPSS 11.0 software package. Results Both serum and periodontal estradiol level were increased by orthodontic activation during various stages of the estrous. IGF mRNA expression were also enhanced with the same trend. The estradiol and IGF- Ⅰ level showed in a similar pattern during the estrous cycle and the rhythm was not changed by the orthodontic activation. There was no rhythm of IGF- Ⅱ expression found in the estrous cycle. Conclusion It was concluded that estrogen and IGF were involved in the remodeling activities induced by the orthodontic activation. The speed of the orthodontic tooth movements was closely related to the estrous cycle.

Objective The ability of oral bacteria to adhere to tooth surface is associated with their pathogenicity. The objective of this study was to compare the ability of 4 strains of periodontal pathogens attaching to collagentreated hydroxyapatite（C- HA） beads in order to evaluate the ability of the main periodontal pathogens to form the biofilm on root surface. Methods The binding amount and binding percentage of 4 strains to C- HA were measured and compared by 3H- labeled binding assay. 4 strains of periodontal pathogens were Fusobacterium nucleatum（F. nucleatum）ATCC 10953, Porphyrin gingivalis（P.gingivalis） ATCC 33277, Prevotella intermedia（P.intermedia） ATCC 25611 and Hemophilic.actinomycetemcomitans（H.actinomycetemcomitans） ATCC 29523. Results The differences of the percentage of relative adherence between F.nucleatum ATCC 10953 and P.gingivalis ATCC 33277, as well as between H.actinomycetemcomitans ATCC 29523 and P.intermedia ATCC 25611 could not be observed. However, the percentage of relative adherence of F.nucleatum ATCC 10953 and P.gingivalis ATCC 33277 was higher than that of P.intermedia ATCC 25611 and H.actinomycetemcomitans ATCC 29523（P<0.001）, no matter cultured 24 h or 48 h. No significant difference of the percentage of the relative adherence of each stain between 24 h and 48 h cultured time could be found. Conclusion F.nucleatum and P.gingivalis exhibited strong binding ability to C- HA. Their adherence to root surface may play an important role in their local aggregation, biofilm formation during the development and recurrence of the periodontitis.

Objective To analyze the possible damage to the remaining tooth and composite restorations when various mixing ratios of bases were used. Methods Testing elastic modulus and poission′s ratio of glass- ionomer Vitrebond and self- cured calcium hydroxide Dycal with mixing ratios of 1∶1, 3∶4, 4∶3. Micro- CT was used to scan the first mandibular molar, and the three- dimensional finite element model of the first permanent mandibular molar with class Ⅰ cavity was established. Analyzing the stress of tooth structure, composite and base cement under physical load when different mixing ratios of base cement were used. Results The elastic modulus of base cement in various mixing ratios was different, which had the statistic significance. The magnitude and location of stress in restored tooth made no differences when the mixing ratios of Vitrebond and Dycal were changed. The peak stress and spreading area in the model with Dycal was more than that with Vitrebond. Conclusion Changing the best mixing ratio of base cement can partially influence the mechanistic character, but make no differences on the magnitude and location of stress in restored tooth. During the treatment of deep caries, the base cement of the elastic modulus which is proximal to the dentin and restoration should be chosen to avoid the fracture of tooth or restoration.

There were many masses on a patient′s cervical region which caused significant respiratory compression. After aspiration and incisional biopsy, the results confirmed the diagnosis of local lymph nodes amyloidosis.

Objective To investigate the correlation between moderately and severely chronic periodontitis and coronary heart disease, as well as the role of fibrinogen in the mechanisms responsible for the correlation between periodontitis and coronary heart disease. Methods 95 subjects who were systemic health or patients of coronary heart disease with or without periodontitis were enrolled. All the subjects were placed into 4 groups based on their periodontal status and cardiovascular health. The 4 groups were healthy control group（HC）, moderately and severely chronic periodontitis group（MSP）, coronary heart disease group（CHD）, and MSP coexisted with CHD group（MSP+CHD）. Clinical periodontal index were examined, at the same time, plasma fibrinogen levels and serological changes used in diagnosing of cardiovascular disease routinely were determined. ANOVA and ANCOVA were used in the statistical analysis. Results Fibrinogen levels of HC, MSP, CHD, and MSP+CHD group were（2.36±0.37）, （3.63±0.73）, （4.08± 0.84）, and （4.14±0.96）g/L, respectively. Fibrinogen levels of MSP and MSP+CHD group were significantly higher than that of healthy controls（P<0.01）. The patients with moderately to severely chronic periodontitis were more likely to have coronary heart disease as compared to periodontally healthy controls（OR=2.527, P=0.047）after adjusted for blood pressure and body mass index. Conclusion Moderately and severely chronic periodontitis maybe a risk factor of coronary heart disease and fibrinogen could be one of the biological basis which links periodontitis with coronary heart disease.