Conventional diagnosis and treatment for facial prostheses have setbacks and limitations, including complicated procedure, inefficiency, low accuracy and poor esthetics, which could not meet the demand for high quality of the prostheses of the patients. With the technology of the computer aided design and computer aided manufacture （CAD/CAM）, the new era for diagnosis and treatment for facial prostheses has been started since 1990s’. The digital diagnosis and treatment system for facial prostheses has been formed during these ten years, which including the digital data acquisition of the facial defect, CAD for facial prostheses, rapid fabrication of the prostheses. This new system will be the development direction and mainstream technology in the future.

Objective Using chitosan（CS）/β-tricalcium phosphate（TCP）/recombinant human bone morphogenetic protein（rhBMP）-2 for the reconstruction of rabbits’mandible defect, to prove the feasibility of CS/β-TCP as an injectable bone tissue engineering scaffold material. Methods Twenty-four New Zealand white rabbits were randomized into 4 groups on average: Experimental group 1 embedding CS/β-TCP/rhBMP-2, experimental group 2 embedding CS/ β-TCP, control group 1 embedding autograft bone group, control group 2 embedding nothing. At 2, 4 and 8 weeks after surgery, all rabbits were executed group by group. The new bone growth situations were observed with hemat oxylin-eosin staining and immunofluorescence microscopy, the bone mineral density was detected by bone sonometers. Results After 2, 4, 8 weeks, there was significant difference among the areas of bone regeneration of all groups. The effect of experimental group 1 was better than experimental group 2. There was significant difference at different times, the areas of bone regeneration was gradually increased with time. The area of stained yellow in experimental group 1 was larger, the area of stained red was smaller. The quantities of bone density in experimental group 1 at every time after surgery were significantly higher than experimental group 1 and control group 2, but had no statistical significance with control group 1. Conclusion CS/β-TCP/rhBMP-2 has good biocompatibility, degradability and the capacity of guided and inducing osteogenesis. CS/β-TCP as a good injection of carrier could become a promising  carrier for rhBMP-2 and potential new degradable biological material for repairing bone defect in clinical application.

Objective To investigate the expression patterns of CD133+ endothelial progenitor cell（EPC） on Wister rats during experimental tooth movement. Methods 40 Wistar rats’teeth movement models were established and divided into experiment group and control group. After loading 1, 3, 5, 7, 14 days killed them respectively. The histological sections were stained with hematoxylin-eosin and rabbit anti-rat CD133 polyclonal antibody to express CD133 immunoreactivity. Results Expression of CD133 in the new vessels did not appear in control group. In the early experiment, the expression of CD133 was discovered in the new vascular endothelial cells of periodontium in experiment group. Expression of CD133 got the maximum after loading 1 day in experiment group, then decreased gradually, but it was not significantly higher than control group（P >0.05）. Conclusion CD133 + EPC participated vascularized reaction in periodontal tissue of rat during the experimental tooth movement, direct participation was few and indirect effects possibly existed.

Objective To compare torsional fracture of three different types of nickel-titanium rotary instruments ProTaper, Hero642 and Mtwo by making a stimulate models in vitro. Methods Through the establishment of model in vitro, compared the different time with 3 kinds of nickel titanium file in cutting-edge bound occurs, and to observe the section of fractured instruments by scanning electron microscope. Results The resistence to torque was different from three types of nickel titanium instruments. The time to fracture of Mtwo was significantly longer than ProTaper’s and Hero642’s, but ProTaper’s and Hero642’s had no significant difference. Three kinds cross-sectional design were different, a lot of toughness nests were seen in broken surface. Most of them were ductile fracture. Time to fracture was influenced by the quality disfigurement. Conclusion The resistance to torque of Mtwo was better than ProTaper and Hero642. The lifespan was influenced by the design of cross-section. The quality disfigurement of the files reduced the resistance to flexual fatigue.

Objective To explore the invasiveness of xenografts on chicken embryo chorioallantoic membrane（CAM） after tissue inhibitor of metalloproteinase-2（T IMP-2）gene transfection. Methods Fresh ameloblastoma tissues were minced into 1-2 mm3 and transplanted on the CAM. There were three groups named as control group（Empt）, plasma transfection group（Lipo）, and TIMP -2 gene transfection group（P）. The specimens were respectively investigated by microscope in different spots after implanting. The volume of the xenografts and the weight of xenografts in the termination time of the experiment were recorded. The invasiveness of xenografts was divided into four grades by pathological examination. Western blot analysis was performed to investigate matrix metalloproteinase-2 （MMP-2） and TIMP-2 protein in xenografts. Results Ameloblastoma tissues can survive on CAM and the tumor cells may invade it on 5-7 days after implanting. At 9 d after implanting, the invasiveness grades in P group were 7 in grade 0, 1 in grade 2, 0 in grade 3. The expression of TIMP-2 protein in P group was significantly higher than that in Empt group（P<0.05）. The expression of MMP-2 protein in P group was lower than that in Empt group（P<0.05）. Conclusion The xenotransplanted tumor model of human ameloblastoma on CAM was successfully established. The invasiveness of ameloblastoma xenografts was suppressed might be due to TIMP-2 gene transfection.

Objective To explore the activation of phospho-p38 mitogen activated protein kinases（p-p38MAPK） and to evaluate the possible role of nerve growth factor（NGF） on neuronal protection and regeneration of injured nerve in a model of hypoglossal nerve injury in rats. Methods Sixty healthy adult SD rats were divided randomly into three groups: NC control group, NS control group and NGF treatment group. The rats were allowed to survive for 1, 3, 5, 7 and 14 days after operation respectively. Frozen sections were processed for immunohistochemistry（IHC） to decide the p-p38MAPK expression level in the motoneurons of hypoglossal nucleus. Nissl’s staining was used to evaluate cellular morphological and architectural changes in the hypoglossal nucleus. Transmission electron microscope （TEM） study was employed to investigate the subcellular structural alternations of the hypoglossal nerve distal to the injury site. Results The expression level of p-p38MAPK was low in NC group and elevated in all operated animals. However, p-p38MAPK immunoreactivity in the hypoglossal motoneurons in NGF group was lower than NS control group after injury. The survival rate of motoneurons in hypoglossal nucleus of injured side in NGF group was higher than that in NS group. Ultrastructural study revealed more regenerating myelinated axons which distributed homogenously in the distal site of the lesioned hypoglossal nerve from the NGF group than NS group. Conclusion p-p38MAPK was slightly expression in normal hypoglossal nucleus but intensively expression after injury. NGF candown-regulate p-p38MAPK expression in the motoneurons of hypoglossal nucleus after hypoglossal nerve was crushed. Exogenous NGF can protect damaged neurons and promote nerve regeneration after hypoglossal nerve crush injury in rats.

Objective The aim of this study is to evaluate whether the firing times affect the chroma of zirconia by adding rare-earth oxides. Methods Six kinds（S1, S2, S3, S4, S5, S6） of tooth-like yttria stabilized tetragonal  zirconia polycrystal（Y-TZP） were available by introducing internal colorating technology, the color were gauged with ShadeEye NCC chromatometry instrument, and one -way ANOVA was used to analysis the color of each kind  of tooth-like zirconia after 1, 2, 3, 4, 5 times firing individually. Results After 1, 2, 3, 4, 5 times firing respectively, the chromatic aberration ranged between 0.10-1.47 merely. The luminosity of three kinds（S1, S2, S6） of tooth-like zirconia were decreased（P＜0.05）, the luminosity of the other three kinds（S3, S4, S5） of tooth-like zirconia were not obviously changed（P＞0.05）, as for the hue and chroma, no significant differences were found（P＞0.05）. Conclusion There are no significant influence on the color of tooth-like Y-TZP after 1, 2, 3, 4, 5 times firing respectively, the chroma of yttria stabilized tetragonal zirconia polycrystal by adding rare-earth oxides are with high stability.

Objective To study the effect of basic fibroblast growth factor on the mRNA expression of β1 integrin subunit by periodontal ligament fibroblasts in culture; to discuss the effect of basic fibroblast growth factor in periodontal regeneration. Methods Human periodontal ligament fibroblasts were cultured and stimulated by basic fibroblast growth factor（0.1, 1.0, 10.0 ng·mL-1） for 24, 48, 72 h respectively, and then mRNA expression of β1 integrin subunit was assessed by fluorescent quantitative real-time reverse transcription polymerase chain reaction. Results Basic fibroblast growth factor enhanced the mRNA expression of β1 integrin subunit, and there was optimal effect when the concentration of basic fibroblast growth factor was 1.0 ng·mL-1 at 24, 48, 72 h respectively; the mRNA expression of β1 integrin subunit at 72 h was higher than that at 24, 48 h. Conclusion Basic fibroblast growth factor can strengthen human periodontal ligament fibroblasts′ adhesion and may be one of important factors which participate in the periodontal regeneration.

Objective To investigate characteristics of incisors inclination and dental compensation in normal occlusion and Angle’s Class Ⅱ division 1 malocclusion with different growth patterns. Methods 158 cephalometric films of normal occlusion and 246 cephalometric films of Angle’s Class Ⅱ division 1 malocclusion were selected and the data of relevant variables were compiled to analyze the inclination of incisors. Results The upper and lower incisors were lingually inclined in normal occlusion with vertical growth pattern while labially inclined in horizontal growth pattern. Compared with the average value of normal occlusion with different growth patterns, the upper incisors of Class Ⅱ division 1 malocclusion were relatively labially inclined in different growth patterns and the lower incisors were labially inclined in vertical and average growth patterns, while there were no obvious changes in horizontal growth pattern. Conclusion When treating patients with Angle’s Class Ⅱ division 1 malocclusion, we should choose a specific method according to patients’growth patterns and characteristics of dental compensation.

Objective To study the lip contour of Class Ⅱ division 1 malocclusion in the early permanent dentition with different growth patterns and gender. Methods 145 patients with Class Ⅱ division 1 malocclusion in the early permanent dentition were included in this study. Their pre-treatment cephalometric X-rays were measured to analyze the influence of gender and growth pattern on the lateral lip contour. One-way analysis of variance was used to analyze the influence of growth pattern on the lip contour of patients in the early permanent dentition, and t-test was used to analyze the influence of gender on the lip contour of patients. Results The lip vertical extension values of male patients were larger than that of female（P<0.05）; the lip sagittal extension value of male seems to be larger too, but no significant difference was found（P>0.05）. The upper lip extension patterns of patients with different growth patterns were the same, but patients of horizontal growth pattern had more everted and protrusive lower lips than patients of vertical growth pattern. Conclusion Gender and growth pattern both have influences on the lip contour of Class Ⅱ division 1 malocclusion in the early permanent dentition.

Objective To determine the incidence of post-operative delirium after oral and maxillofacial surgery under general anesthesia in elderly patients, and to examine its association with plasma concentrations of beta amyloid protein 1-40（Aβ1-40）. Methods Fifty patients underwent elective oral and maxillofacial surgery were divided into two groups: Group C（n=20） aged from 20 to 60 years old, and Group T（n=30） aged from 62 to 78 years old. The two group received the same general anesthesia. Delirium rating scale-revised-98（DRS-R-98） was used as an instrument to diagnose and access the postoperative delirium of the two groups. The scores of DRS-R-98 were recorded before operation（T0） and at 24 h（T1）, 48 h（T2）, 72 h（T3） and 96 h（T4） after the operation. Serial measurements of serum concentrations of Aβ1-40 were also performed at the same time. Results The incidence of post -operative delirium after oral and maxillofacial surgery in Group T was 20.0%. The concentrations of plasma Aβ1-40 in group T were much higher than group C at T0, T1, T2 and T3 significantly（P＜0.01）. The concentrations of plasma Aβ1-40 at T1 and T2 were higher than those at T0 in the same group（P＜0.05）. The scores of DRS-R-98 in Group T at T3 and T4 were much higher than those at T1 and Group C significantly（P＜0.01）. Conclusion The constant increase of plasma Aβ1-40 may be one of the important factors related to post-operative delirium in elderly patients underwent oral and maxillofacial surgery.

Objective To estimate the clinical effect of the maltitol chewing gums in plaque control. Methods Thirty 13-15 years old susceptible adolescent were divided into three groups randomly, group A（maltitol chewing gums）, group B（xylitol chewing gums） and group C（gum base chewing gums）. Subjects chewed gums 5 times each day, 10 min each time. At baseline and at 4-week, subjects were evaluated for supragingival plaque. SPSS 17.0 software package was used for statistical analysis. Results Four weeks later, plaque index of the three groups continulously step down. Significant difference was observed between baseline and 4-week（P=0.000, 0.000, 0.006）. Four weeks later, there was statistically significant difference in clearance rate of plaque among the three groups（P =0.015）. There was still no statistically significant difference between group A and group B（P=0.687）, but they were both different from C group（P=0.019, 0.007）. Conclusion Maltitol chewing gum can lead to similar effect on reduction of plaque as xylitol chewing gum.

Objective To explore the influence of conventional metal materials in oral cavity on brain magnetic resonance imaging（MRI）. Methods Four kinds of metal materials（metal ligature wire, forging hard and slotless denture, casting nichrome denture, casting copper alloy denture） in oral cavity were scanned through MRI. FSE sequence T1 weighted imaging（FSE T1）, EPI diffusion-weighted imaging（DWI） sequence of ordinary, Propeller DWI imaging were used. Results In FSE T1 sequence, metal ligature wire and forging hard and slotless denture produced serious false image, casting nichrome denture produced moderate false image, casting copper alloy denture produced only little false image. In EPI DWI sequence, obvious magnetic-sensitive false image were produced in the dissection tissue of the brain by metal ligature wire. While in Propeller DWI sequence, magnetic -sensitive false image were greatly reduced and satisfactory images were formed. Conclusion Different metal materials in oral cavity have different influence on the MRI. The false images produced by different metal materials are closely related to the type of the material. Magnetic-sensitive false images can be eliminated by Propeller DWI technique.

Objective To investigate the effect of the laser surface hardening technology on the corrosion resistance of dental casting alloy. Methods Twenty -three cobalt -chromium alloy specimens were made in this study. Twenty-two specimens were equally divided into two groups randomly. One was experimental group for laser surface hardening processing and the other was control group without any treatment. In each group, ten specimens were used for corrosion analysis by electrochemical method, and one for surface metallographical structure and morphology observation by scanning electron microscope. Remaining one specimen was partially processed on limited area for surface metallographical structure and morphology comparison. Results Metal grains distributed uniformly and achieved a good refinement with mainly the same size in experimental group. Metal grains in specimen which processed in its partial surface area also achieved a good refinement in the laser processing area. There was statistical difference in electric potential of corrosion and logarithmic value of current of corrosion between experimental group and control group（P<0.01）. Conclusion Laser surface hardening technology has a positive effect in improving the corrosion resistance of dental casting alloy in artificial saliva.

Objective This prospective study was to observe the correlation between the mesial papilla’s height of single implant-supported maxillary central incisor and the distance from the base of the contact point to the alve lar bone crest. Methods 56 patients involved in single implant-supported maxillary central incisor were included in t is study. The distances from the base of the contact point to the alveolar bone crest in the digital periapical film of maxillary central incisor were measured using the software Planmeca Dimaxis Version 3.3.2. The time of measurements were as follows: The pre-surgical and post-surgical periods, before and after the crown installation, the followup examination of more than 0.5 year. To analyze the factor of influencing distance, and the correlation between the distance and the height of gingival papilla during the whole restored period. Correlation analysis between the distance and the height of gingival papilla during the whole restoration was done by the statistical software SPSS 12.0. Results The results demonstrated that the ratio of esthetic papilla can achieve 54.5% at the crown installation and 95.5% at the follow -up examination when the distance was between 3 mm and 5 mm. When the distance was between 5 mm and 6 mm, they dropped to 30.0% and 75.0%, respectively. However, when the distance increased to above 7 mm, the papilla could hardly be in an esthetic outcome. There was a significant change of the distance was found during the periods from the post-surgery to pre-restoration, and the scope of the changes was between -0.13 mm and 0.46 mm. A negative correlation was found between the distance and the index of papilla. The correlation coefficient r was -0.715（P <0.01）. Conclusion It is proposed that the pre -surgery distance of maxillary central incisor from the base of the contact point to the alveolar bone crest can be used as one of the important reference indexes to assess and predict the height conditions of gingival papilla.

Objective The computer aided design and computer aided manufacture（CAD/CAM） template was fabricated basing on CT data of completely edentulous jaws, and the accuracy of template was evaluated by assessment of the deviation between the actual and planning position of the implant after the registration of pre- and postoperative CT images. Methods The CAD/CAM templates for 4 completely edentulous jaws were designed and fabricated basing on the pre-operative CT data and the stone models of the jaws sample. And 14 implants were placed in the posterior region of the jaws aided by the CAD/CAM template. The pre- and post-operative CT was registered by the point to point method, and the deviation between actual and virtual implants was measured to assess the accuracy of the template. Results With the aid of CAD/CAM template, the deviations of the position at the tail of the implant, at the tip of the implant and the projected deviation of angle were （0.19±0.07）mm, （0.47±0.12）mm, and 1.79°±0.68° respectively, and the deviations of the position at the bucco-palatal, disto-mesial, vertical direction were （0.22±0.08）mm, （0.25±0.06）mm, （0.30±0.11）mm at the tip respectively. Conclusion Within the limits of this study, the results verify the accuracy of CAD/CAM template and support its use for safety implant placement.

Objective To evaluate the potential repairing effects of low-intensity pulsed ultrasound（LIPUS） irradiation on acute horizontal alveolar bone defects at the mandibular pre -molar areas in Beagle dogs. Methods Horizontal alveolar bone defect models were established under enamelo-cemental junction 6 mm at the mandibular third and forth pre -molar buccal regions on both sides in 4 beagle dogs, and bilateral sides of each dog were randomly divided into two groups: Experimental groups with LIPUS irradiation（ISATA 30 mW·cm-2，20 min·d-1） and control groups without opening power source of LIPUS radiation. Dual energy X-ray bone densitometer was used to detect the bony density after an 8 weeks′ irradiation. Meanwhile, decalcified bone tissue sections were used to assess the histological effects of new alveolar bone. Results The results of new bony density detection in experimental group and control group were （0.605 3±0.056 6） g·cm-2, （0.604 7±0.055 2）g·cm-2, respectively, and there was no statistical significance between the differences of the two groups（P=0.983 9）. Hematoxylin-eosin staining of decalcified bone tissue sections demonstrated that there were more osteoblasts lining at the edge of new alveolar bone in the experimental groups than that scattered in the control groups, and Masson staining revealed that collagens in new alveolar bone stained bright red indicating higher maturity in the experimental groups, while in the control groups mainly stained blue with some virescent areas indicating lower maturity. Conclusion LIPUS irradiation on acute horizontal alveolar bone defects has potential repairing effects.

Objective To compare the difference of the surface of root resection by Er:YAG laser, ultrasonic or high-speed handpiece with scanning electron microscope（SEM）, and to evaluate the possibility of using Er:YAG laser on the root resection in clinical application. Methods Thirty maxillary central incisors were divided into three groups（Er:YAG laser group, ultrasonic group, high-speed handpiece group）, and the root resection were made at root tip 3 mm with Er:YAG laser, ultrasonic instrument or long needle diamond bur according to grouping. The surface of the root resection by SEM in the aspects of debris, smear layer, opened dentinal tubules, cracks and ablation characteristics were compared. Results The examination revealed that Er:YAG laser group and ultrasonic group had no or little debris and smear layer and with opened dentinal tubules. High-speed handpiece group had great amount of debris and smear layer and without opened dentinal tubules. Cracks were observed in ultrasonic group and highspeed handpiece group, no in Er:YAG laser group. There were ablation characteristics in ultrasonic group and highspeed handpiece group, but no in Er:YAG laser group. Conclusion From the morphological aspect, Er:YAG laser has much more advantage than ultrasonic instrument and diamond bur for the root resection.

Objective To study the color reappearance effect of metal -ceram restoration and foundry -ceram restoration using Crystaleye spectrophotometer. Methods 58 metal-ceram restorations and 58 foundry-ceram restorations according to the result of the Crystaleye spectrophotometer were made respectively. The △E between restorations and natural teeth as referenced were analyzed. And satisfaction of dentists and patients were evaluated. Results The △E between metal-ceram restorations and natural teeth was 7.13±0.74. The △E between foundry-ceram restorations and teeth was 1.47±0.84. There were statistical differences between the △E（P<0.01）. The satisnatural faction of dentists and patients to the foundry-ceram restorations were higher than to the metal-ceram restorations（P<0.05）. Conclusion Crystaleye spectrophotometer can provide accurate reference for foundry-ceram restoration, but for metal-ceram restoration it is not accurate.

Objective To investigate the effect of PTEN tumor suppressor gene combined with doxycycline on telomerase activity in human mucoepidermoid carcinoma cell line. Methods The wild-type PTEN tumor suppressor gene or empty vector was introduced into mucoepidermoid carcinoma cell line in vitro, then the cancer cells were treated with doxycycline. Cancer cell survival was determined by MTT assay. Telomerase activity was determined using telomerase repeat amplification protocol-enzyme-linked immunosorbent assay（TRAP-ELISA）. Results Compared to the control cells, cancer cells transfected with the wild-type PTEN gene showed growth inhibition and increased sensitivity to doxycycyline, and the ratio of augment of drug sensitivity was 1.65-4.75. The telomerase activity in cancer cells treared with PTEN gene transfection or doxycycline alone decreased, however, telomerase activity in combined group decreased more remarkably. Conlusion PTEN gene in combination with doxycycline has significant inhibitory effect on telomerase activity in cancer cells.

Objective To detect the Enterococcus faecalis（E. faecalis） in post-treatment endodontic disease, and to analyze the relationship between the occurrence of E. faecalis and clinical symptom. Methods 108 teeth which need root canal retreatment were collected, and the clinical symptoms and physical signs were recorded. Bacterium samples from root canal were taken, and genome DNA from bacterial samples were extracted. The occurrence of E. faecalis by means of the polymerase chain reaction was investigated. Results The detection rate of E. faecalis in cases of root canal retreatment was 47.2%, while in cases with symptoms or signs, or cases with both symptoms and signs, the root canal E. faecalis detection rates were 52.6% , 57.9% , 62.5%. The detection rates of E. faecalis between cases with clinical symptom and without clinical symptom demonstrated statistical significance（P＜0.05）. The detection rates between cases with both clinical symptom and manifestly aneretic root and cases without clinical symptom and manifestly aneretic root had statistical significance（P＜0.05）. In the group of clinical symptom, the detection rate of E. faecalis in cases with biting pain was 66.7%, clearly higher than those without biting pain（P＜0.05）. Conclusion The occurrence of E. faecalis in cases of root canal retreatment correlates with clinical symptoms.

Objective To study the role of protein kinase C-δ（PKC-δ） in hyperthermia-induced apoptosis in human tongue squamous cell carcinoma Tca8113 cells. Methods Tca8113 cells were treated at 43 ℃ in a heating water bath for 0, 40, 80, 120 min after pretreatment with Rottlerin, a specific inhibitor of PKC-δ, and equal volume dimethyl sulfoxide（DMSO） for 30 min, respectively. The cells were stained by propidium iodide（PI） and Rhodamine 123 to analysis apoptotic rate and the changes of mitochondrial transmembrane potential by flow cytometry（FCM）. The total proteins were extracted for Western blotting analysis of activation and proteolysis of PKC-δ, and for colorimetric assay of relative activity of Caspase-3. Results Hyperthermia could induce proteolysis and activation of PKC- δ, and this was attenuated by Rottlerin. Apoptotic rate, decreasing of mitochondrial transmembrane potential and activity of Caspase-3 which being induced by hyperthermia in Tca8113 cells were inhibited by PKC-δ specific inhibitor Rottlerin. There were significantly statistical differences in apoptosis rates, mitochondrial transmembrane potential and activity of Caspase-3 between Rottlerin- and non-Rottlerin-pretreated cells after hyperthermia for 40, 80, 120 min（P＜ 0.01）. Conclusion Activated PKC-δ may facilitate hyperthermia-induced apoptosis in Tca8113 cells, and may be one of the mechanisms of apoptosis induced by hyperthermia.

Objective The aim of this study was to observed the influence of deposition time on chromatics during nitrogen-doped diamond like carbon coating（N-DLC） on pure titanium by multi impulse arc plasma plating machine. Methods Applying multi impulse arc plasma plating machine to produce TiN coatings on pure titanium in nitrogen atmosphere, then filming with nitrogen-doped DLC on TiN in methane（10-80 min in every 5 min）. The colors of N -DLC were evaluated in the CIE1976 L*a*b* uniform color scale and Mussell notation. The surface morphology of every specimen was analyzed using scanning electron microscope（SEM） and X-ray photoelectron spectroscopy（ XPS）. Results When changing the time of N-DLC coating deposition, N-DLC surface showed different color. Golden yellow was presented when deposition time was 30 min. SEM showed that crystallization was found in N-DLC coatings, the structure changed from stable to clutter by varying the deposition time. Conclusion The chromatics of N-DLC coatings on pure titanium could get golden yellow when deposition time was 30 min, then the crystallized structure was stable.

Objective The aim of the study was to detect the expression of Ki67 and P53 proteins in the gingival issue before and after wearing three kinds of dental casting alloy crowns. Methods The three kinds of dental asting alloys（58% golden alloy, NiCr alloy, NiCr alloy excluding Be） were used to make full crowns for 3 dogs in ach group. Another 3 dogs were taken as control. The immunohistochemistry Envision method was used to measure he expression of Ki67 and P53 proteins in the gingival tissue before wearing the crowns, 2 weeks, 1 month, 2 onths, 3 months after wearing the crowns. Results The expression of Ki67 and P53 proteins in gingival tissue increased  month after wearing NiCr alloy and NiCr alloy excluding Be, then decreased gradually. And the expression f Ki67 and P53 proteins in 58% golden alloy group was similar to that in control. No pathological change was observed n all samples. Conclusion Two kinds of NiCr alloy crowns both can increase the expression of Ki67 and 53 proteins in gingival tissue, but 58% golden alloy crowns can not. So compared with NiCr alloy crowns, 58% olden alloy crowns have better biological properties. And none of three kinds of dental alloy crowns may induce ong-term abnormal proliferation in gingival tissue.

Objective To observe the alteration of fibroblast growth factor 10（Fgf10） and fibroblast growth factor receptor 2（Fgfr2b） signal in mouse embryonic palate after dexamethasone and vitamin B12 exposure. Methods Dams were divided teratogenetic group, antagomistic group and control group and were respectively injected dexamethasone, dexamethasone and vitamin B12, and normal sodium. Dams were killed and fetus was collected at embryo 12.5 and 13.5 day. The expression of Fgf10 and Fgfr2b and mesenchymal cells proliferation of mouse embryonic by western blotting and BrdU assay were checked. Results Fgf10 and Fgfr2b expression was down-regulated and mesenchymal cells proliferation was inhibited significantly after dexamethasone exposure. After vitamin B12 treatment, Fgf10 and Fgfr2b expression did not restore, but cells proliferation was recovered. Conclusion Dexamethasone and vitamin B12 affected the expression of Fgf10 and Fgfr2b of mouse embryonic palate and mesenchyme cells proliferation, but the change was disaccord.

Objective To investigate the effect of Astragalus membranaceus（APS） on the proliferation, osteogenic capacity and structure of periodontal ligament cells（PDLCs） in vitro. Methods PDLCs were cultured in vitro with APS of 0.08、0.1、0.2、0.4 mg·mL -1. Methyl thiazolyl tetrazolium（MTT）, alkaline phosphatase（ALP） and cell structure were detected to determine the proliferation and differentiation of PDLCs proliferation and differentiation. Results When the APS was 0.2mg·mL-1, the absorbance of MTT and ALP exhibit significantly increased as compared to the control（P<0.05）. The cells cultured in vitro with APS of 0.2 mg·mL-1 had the normal structure. Conclusion APS with proper concentration in short-term culture may promote the proliferation and differentiation of PDLCs.

Objective To detect the expression of CD133 in human tongue squamous cell carcinoma Tca8113 cell line and observe proliferation ability of CD133 groups in vitro. Methods Limiting dilution assay was employed to observe the proliferating character of Tca8113 single cell in vitro. The ability of growing as cancer spheroids was observed with ultra-low attachment plates. The flow cytometry was used to detect the expression of putative tumorinitiating cell marker CD133 in human tongue squamous cell carcinoma Tca8113 cell line. The selective technique of immunomagnetic beads was applied to purify CD133 tumor cells, CD133 tumor cells were cultured and their ability of proliferation were observed in vitro. Results After 12 days, the result of single cell culture in vitro revealed that about 5.23% of cultured Tca8113 cells possessed the capacity of continue proliferation. The cells line fromed floating clusters with one week of passaging cells into non-adherent plates. Approximately 0.95％ of cells in Tca8113 cell line expressed CD133. Compared with CD133- cells and control Tca8113 cells, CD133+ cells demonstrated increased proliferation capacity. The proportion of CD133 cells decreased in culture as days passed. The percentage of CD133 + cells decreased from 92.45％ to 1.62％ in twelve days’culture. Conclusion Tumor stem cells have the character of heterogenity and lower proportion of CD133 but higher ability of proliferation, and the diferentiation in human tongue squamous cell carcinoma Tca8113 cell line in vitro, CD133 may be one of makers for tumor-initiating cell of human tongue squamous cell carcinoma Tca8113 cell line.

Objective To purify mutacin produced from isolated Streptococcus mutans （S.mutans） strains in order to, contribute to molecular biological research of mutacin. Methods The antibacterial activity of 80 isolated strains was tested by the stab culture technique against Streptococcus oralis ATCC 10557. The mutacin produced by strain 1G, was initially purified by solid-phase extraction（SPE） after crude extraction by chloroform. And then the active substances were purified by twice reversed-phase high performance liquid chromatography（RP-HPLC）. The purified target peptide（mutacin） was collected and freeze-dried for further study. Results The greatest active strain of these S.mutans isolates, the strain 1G was obtained. Roughly 15 μg crude mutacin was extracted from 200 mL liquid medium of this strain 1G. The purified mutacin through SPE and twice RP-HPLC was obtained. Conclusion It was much complex to separate and purify mutacin due to its small moleculer mass, and extracting and purifying of mutacin may make an important contribution to the further research of mutacin.

Lipoma is one of the most common benign tumors derived from mesenchymal tissues. However, it is seldom to be found in deep neck. A case of lipoma in deep neck involving the epidural space was reported. The incidence, histopathology, diagnosis and treatment of this kind of disease were discussed.

Objective To collect evidence in diagnosis and treatment of oral mucosal diseases. Methods The Cochrane library（Issue 3, 2009） was searched to get the full texts of published related Cochrane systematic reviews. The results were summarized for recommendation to dentists. The current status of evidence based medicine in this field was analyzed. Results Reliable evidence for management of oral submucous fibrosis is still limited; amifostine, hydrolytic enzymes, ice chips and Chinese medicine may be effective in preventing oral mucositis for patients with cancer receiving radiotherapy or chemotherapy; the evidence in treating oral mucositis with allopurinol mouthwash, granulocyte macrophage-colony stimulating factor, immunoglobulin or human placentral extract for patients with cancer receiving treatment is weak and unreliable yet; there is evidence that acyclovir is efficacious in prevention and treatment of herpes simplex virus infections in patients being treated for cancer; there is strong evidence that drugs absorbed or partially absorbed from the gastrointestinal tract prevent oral candidiasis in patients receiving treatment for cancer; relapses and adverse effects are common in using beta carotene, lycopene, vitamin A or retinoids to treat oral leukoplakia; only some weak evidence is provided in using cyclosporines, retinoids, steroids or phototherapy for treating oral lichen planus; the evidence about acyclovir for treating primary herpetic gingivostomatitis is insufficient; there is little research evidence for treatment of burning mouth syndrome. Conclusion It is essential to raise the quality of design and conduction of clinical trials in the field of oral mucosal disease to provide solid bases for systematic review, so that to improve evidence based treatment of these diseases.