Microbe infection is not only the key pathogenic factor of primary endodontic infectious diseases, but also the arch-crimina of endodontic treatment fail. Therefore, the endodontic treatment success is based on the debridement of infectious root canal, elimination of bacteria, and the prevention of endodontic reinfection. It is beset with difficulties to control the endodontic infection in clinic because of the bacterial variety, anatomic complexity of root canal, and limitation of the root canal therapeutic methods. In order to get the ideal prognosis of the root canal treatment, in the procedure of the therapy, it should be the tight isolation of tooth, reasonable choose of the root canal preparation technique, rational use of root canal preparation instrument, effective irrigation of root canal, proper root canal dressing, and the 3-dimensional obturation of root canal.

Objective To investigate the effect of insulin-like growth factor-Ⅰ（IGF-Ⅰ） on the proliferation and alkaline phosphatase（ALP） activity of human periodontal ligament cells（hPDLCs） under three-dimensional（3D） culture system. Methods The hPDLCs were cultured from periodontium of human teeth by the outgrowth method. Rotary cell culture system（RCCS） was enrolled to set 3D culture system. Samples were set to four groups: Negative control group, positive control group（3D group, IGF-Ⅰ group）, and experimental group（3D with IGF-Ⅰ group）. Proliferation was tested with methylthiazolyl tetrazolium（MTT）, and ALP activity was assayed by spectrophotometer at 1, 3, 5, 7 d respectively. Results Compared with that of negative control group, cell proliferation increased significantly in 3D with IGF-Ⅰ group since 3 d（P<0.05）. Besides, the cell proliferation of 3D with IGF-Ⅰ group was significantly higher than that of 3D group（P<0.05）. ALP activity of 3D with IGF-Ⅰ group was significantly higher than that of negative control group，and 3D group at 3, 5, 7 d（P<0.05）. Conclusion IGF-Ⅰsignificantly promotes the proliferation and ALP activity of hPDLCs under 3D culture system.

Objective To investigate the influence of systemic application of Alendronate sodium, a bone resorption inhibitor, on the osseointegration of implant-bone interface in estrogen-deficient rabbits through mechanical assessment. Methods 27 five-month-old Japanese white female rabbits were randomly divided into three groups（9 rabbits each group）. An ovariectomy group（OVX）, an ovariectomy and Alendronate sodium group（ALN） and a shamed- operated group（S）. 12 weeks after operation, implants were installed into bilateral distal femurs and proximal tibias in each group. Alendronate sodium was administrated by intraperitoneal injection in ALN group; meanwhile equivalent of normal saline was administrated by intraperitoneal injection in OVX group and S group. Bone mineral density was measured right after the implant operation and also in 4, 8, 12 weeks. Torque-out values were measured in 4, 8, 12 weeks after animal sacrifice. Results Bone mineral density of tibias in ALN group was closed to S groupand was significantly different from OVX group（P<0.05） after 8 weeks. While after 12 weeks, the bone mineral density of tibias and femurs in ALN group was both closed to S group and was significantly different from OVX group（P<0.05）. The torque-out values of tibias in ALN group were closed to S group and were significantly different from OVX group （P<0.05） after 8 weeks. After 12 weeks, the torque-out values of tibias and femurs in ALN group were both closed to S group and were significantly different from OVX group（P<0.05）. Conclusion Systemic application of Alendronate sodium in osteoporosis rabbits can improve the bone-implant osseointegration significantly.

Objective The study established an animal model of autologous tooth transplantation in dogs and aimed to explore the effects of orthodontic loading time and duration on the periodontal repair in autologous tooth transplantation. Methods 12 Beagle dogs were selected and grouped randomly in this research. Four first premolar teeth in every dog were carried on autologous transplant operation. These teeth were exerted the orthodontic force after the operation in 2, 4, 8 and 12 weeks respectively. The loading duration was 1, 2 and 4 weeks respectively. We examined the dental and periodontal tissue samples in first premolar teeth by histological study, measured root absorption rate and analyzed reconstruction condition of periodontal tissue with statistical methods. Results Root absorption rates of the experimental group which was exerted the orthodontic force were lower than those of the control group. The difference between two groups had statistical significance（P<0.05）. Root absorption rates in different levels of orthodontic loading time（X） and the duration（Y） had no statistical significance（P>0.05）, but these two factors had interaction effect（PX×Y＜0.05）. Conclusion Orthodontic force contributes to the improvement of root absorption and reconstruction of periodontal tissue in transplant teeth. The orthodontic loading time and the duration have no obvious effect on root absorption rate of transplant teeth. When X is two weeks and Y is four weeks, it is most beneficial for the reconstruction effect of periodontal tissues in transplant teeth.

Objective To establish a quantitative real-time PCR assay for the detection of human cytomegalovirus （HCMV） DNA load in subgingival specimens from the patients with aggressive and chronic periodontitis, and to investigate the relationship between HCMV infection and the periodontal status. Methods A total of 114 subgingival plaque specimens were taken from 18 subjects with aggressive priodontiti（AgP）, 24 subjects with chronic periodontitis （CP） and 15 healthy control subjects. Standard quantification was performed with recombinant plasmid containing a conserved fragment of HCMV. The SYBR Green Ⅰ fluorescent quantitative real-time PCR assay was established based on positive plasmid. HCMV DNA load in the specimens were detected with quantitative real-time PCR based on SYBR Green Ⅰ fluorescence. Results HCMV were detected in 58.3% of AgP sites and 41.7% of CP sites, however, only 6.7% of periodontally-healthy sites were HCMV positive. The detection rate of HCMV in periodontitis lesions was significantly higher than in periodontal health（P＜0.01）. High copy-counts more than 104 of HCMV were detected in 33.3% of AgP sites, which were significantly higher than in CP sites（10.4%）（P＜0.05）. Conclusion Subgingival infection with HCMV is closely associated with periodontitis. Active HCMV infection may be related to the rapid tissue destruction of AgP.

Objective To study the relationship between phosphatidylinositol-3-kinases（PI3K）/protein-serine-threonine kinase（AKt） signaling pathway and orthodontic tooth movement. Methods Twenty-four rabbits were chosen to establish rabbit models for the study. The right maxillary teeth of each animal treated by orthodontics were as the test side, and the untreated left teeth were as the control side. The animals were sacrificed at 3, 5, 7, 14 d, respectively. The prepared tissue specimens were processed for the study. The changes of the expression of PI3K, AKt in periodontal tissues were detected by real-time quantitative-polymerase chain reaction（RQ-PCR）and Western blot techniques. Results RQ-PCR showed that the expression of PI3K, AKt mRNA dramatically changed at 3 d. The expression of PI3K, AKt mRNA in the test side was higher than the control side, especially at 7 d, and then decreased. Compared with the control side, there was statistical significant difference in the test side（P＜0.05）. The study obtained consistent conclusion from Western blot and RQ-PCR. Conclusion Expression of PI3K, AKt in rabbit periodontal tissues increase during orthodontic tooth movement, which prompts that PI3K/AKt signal pathways relate to orthodontic tooth movement and PI3K/AKt signal pathway involve in the periodontal tissue remodeling.

Objective To study the mechanical properties of Co-Cr ceramic alloy after recasts. Methods Co-Cr ceramic alloy cast samples were prepared and recast for 3 times without adding any new Co-Cr ceramic alloy. The tensile strength, 0.2% yield strength, percentage of elongation, flexural strength, flexural modulus and Vickers hardness of each specimen were measured. Results Being cast for different times, the Co-Cr ceramic alloy showed no significant differences on their tensile strength, 0.2% yield strength, percentage of elongation, flexural strength, flexural modulus and Vickers hardness. Conclusion Co-Cr ceramic alloy can be recast for 3 times at least, without decrease of the mechanical properties.

Objective To investigate the drug distribution in tissues of cervical lymph node metastasis mice model after submucosa adjacent cancer injection of pingyangmycin-activated carbon nanoparticles（PYM-CH-NP） and evaluate the lymph targeting effect of PYM-CH-NP. Methods Pingyangmycin（PYM） was radiolabeled with 125I by modified the chloramine T method. Cervical lymph node metastasis mice model was established by buccal submucosa inoculation of a high lymph metastasis cell line U14 cancer cell. 360 mice models burdened with cervical lymph metastasis were randomly divided into 3 groups. PYM group was treated with PYM water solution, PYM-CH-NP group was treated with PYM-CH-NP. Negative control group was injected with activated carbon nanoparticles. PYM-CH-NP and pingyangmycin water solution were injected in pericancer submucosa of the mice respectively. The radioactivity of drug in blood, heart, liver, spleen, lung, kidney and cervical lymph node were measured after 0.5, 1, 4, 8, 12, 24, 48, 72, 96, 120, 144, 168 h administration. The radioactivity of each samples per unit weight were calculated. The selectivity index（SI）and targeting index（TI） of drug were calculated. Results The radioactivity of drug in cervical lymph node of PYMCH- NP group was much higher than PYM group in each time point（P<0.001）, whereas the blood, heart, liver, spleen, lung and kidney uptake of pingyangmycin was greatly decreased in PYM-CH-NP group after 4 h administration（P< 0.001）. The SI value of PYM group at each time point was less than 1. While the minimum SI and TI value of PYMCH- NP was 1.793 and 1.562, the maxlmum value reached to 68.126 and 14.623 after 72 h administration. Conclusion PYM-CH-NP can increase drug dosage in metastasized cervical lymph nodes, and decrease drug dosage of other organs. So better therapeutic outcome and little adverse reaction may be achieved for lymph node metastasis.

Objective To determine the longitudinal growth changes of mandible from mixed dentition to permanent dentition on Angle Class Ⅱ division 2 malocclusion. Methods The sample consisted of 95 students with Angle Class Ⅱ division 2 malocclusion and 75 students with normal occlusion. Cephalometric radiographs and hand-wrist radiographs were obtained for all the samples. And analysis of all the cephalograms was carried out. Results The study of growth changes of mandible from mixed dentition to permanent dentition showed that: 1）angle: The control group showed an increase in SNB and S-Ba-Go and a decrease in Ar-Go-Me, SN-MP and NSGn. In the experimental group, the changes in SNB, Ar-Go-Me, Cd-Go-Me, SN-MP, S-Ar-Go, S-Ba-Go were not of statistical significance, however, Y angle and NSGn were increased. In the control group, there was no statistically significant change in the Y angle. 2）chin: In the experimental group, chin concavity increased. The changes were not statistically significant for the other index. In the control group, chin curvature decreased. The chin height, chin depth, chin concavity, chin depth/chin height, SL and Pog to NB increased. 3）spacing: The growth of Cd-Go, Gn-Cd, Go-Me, Ar-Pog, Ar-Go in the control group was more than that of the experimental group. Conclusion The present finding will help the clinicians to come to a diagnosis and reasonable treatment plan in Angle Class Ⅱ division 2 patients.

Objective To summarize the cooperative measures on circulation restore during the operation of microvascular submandibular gland transfer. Methods Fifty-six cases of microvascular submandibular gland transfer were performed in Peking University School & Hospital of Stomatology from January 2005 to March 2009. The related data was collected retrospectively and the cooperative measures on circulation restore during the operation were summarized. Results The circulation restore of transferred glands were satisfied in all 56 cases when the submandibular gland transfer operation finished. Thrombosis happened in 7 cases within the postoperative 48 hours and the secondary emergency operations were done. At last 6 glands were salvaged and the final successful rate was 98.21%. Conclusion Successful circulation restore was one of the key points on microvascular submandibular gland transfer. The most important mission of the nursing during the operation was the prevention of vascular crisis. The main measures include persistent wet packing using narceine, fomentation using warm saline and special nursing on postoperative complications. Our experience proves that it is beneficial to the success of operation.

Objective The morphological characteristics of posterior tooth in the Beagle dog were investigated in order to provide reference to mini-screw implant（MSI） implantation in the root furcation site. Methods Seventy posterior teeth of five Beagle dogs were collected and measured as follows: First, the greatest mesio-distal diameter AB of 1the crown was measured, which was  endicular to the tooth long axis. Second, mesial cusp of maxillary posterior tooth or central cusp of mandibular was marked as the piont C, and CD which was equal and perpendicular to AB was drawn. The piont D was planned to be the reference point for MSI implantation. Finally, Dm, Dd and Df were measured, which were the distance from the point D to the mesial and distal root surface and root furcation. Results The difference between the left and right sides teeth with the same name had no statistical significant（P>0.05）. The measurement results of all indices assumed a Gaussian distribution. The mean Dd was basically equal to Dm. All the average Df were more than 4 mm. Conclusion The point D could be used as a reference point for MSI implantation in the root furcation site of posterior tooth in the Beagle dog. The data of this study can provide certain reference for MSI implantation in the study of the biomechanics of anchorage stability, and provide certain reference for MSI implantation in the study of root repair after injury.

Objective To compare the clinical efficacy of the infiltration anesthesia with primacaine and the nerve blocking anesthesia with lidocaine for microport extraction of impacted lower third molar. Methods 104 chosen patients had both sides of impacted lower third molars extracted in this study. Patients were given local anesthesia with either primacaine or lidocaine randomly at each side, and then underwent microport extraction. Clinical factors including effective proportion（EP）, effecting time point（ETP）, visual analogue scale of pain（VASp）, alteration of systolic pressures（ ASP） and analgesia duration（AD） were evaluated statistically by means of paired t-test. Results The EP of experimental group was higher than the control group（P=0.024）. The ETP of soft tissue and alveoli-dental pulp was （1.04±0.21）, （2.44±2.60）min in the experimental group, and much earlier than that of the control group（P=0.002, P=0.032）. The VASp and ASP of experimental group were lower than the control group（P=0.041, P=0.018）. AD was （103.6±35.5）min, and higher than the control group（P=0.04）. Conclusion The infiltration anesthesia with primacaine has been proven to be a easier, reliable and quick-acting method. We suggest it an alternative method replacing the 2% lidocaine blocking during microport extraction of impacted lower third molar.

Objective To evaluate accuracy of Propex, Raypex R5, Root ZX electronic apex locator in positions of the perforation with different irrigations in the root canal. Methods Perforation lengths were measured with Propex, RaypexR5, Root ZX electronic apex locators in 19 extracted human teeth embedded in model after simulate perforation preparation by ultrasonic ET40 and compared with the actual canal length measurements taken before embedding the teeth in model. Measurements were taken with the different canal contents. Results Propex, RaypexR5, and Root ZX could locate the positions of the perforation with different irrigations in the root canal. The differences between actual root canal perforation length and measured root canal perforation length of same electronic apex locators in different irrigations were no statistically significant（P>0.05）. Meanwhile, the differences between actual root canal perforation length and measured root canal perforation length of three kinds of electronic apex locators in same irrigations were not statistically significant（P>0.05）. Conclusion Propex, RaypexR5, and Root ZX electronic apex locators can detect perforation accurately.

Objective To study the changes of palate cleft gap of complete unilateral cleft lip and palate（UCLP） infants before and after presurgical orthodontic and cheiloplasty. Methods The sample consisted of 18 complete UCLP infants who were treated using presurgical nasoalveolar molding（PNAM） appliance and cheiloplasty. The maxillary models were obtained at the initial visit, after PNAM treatment 1 month before cheiloplasty, and 2 months after cheiloplasty. The change of palate cleft gap were compared. Results After PNAM treatment and cheiloplasty, the lip profile was obviously improved, cleft gap was reduced, and the height of ala nasi fornix was recovered. Conclusion PNAM treatment can improve the lip shape and nasal deformity degree of UCLP patient. The cleft gap and upper lip tension are reduced.

Objective To explore a new access for internal rigid fixation of mandibular mid-and-low condylar fracture. Methods 16 patients of unilateral mid-and-low condylar fractures were treated with a 2 cm mini-retromandibular approach. The subcutaneous tissues superficial to the superficial muscular aponeurotic system（SMAS） were dissected forward that parallel to the masseter muscle fiber bundles, aiming to the fracture. After exposing the fracture, the fracture segments were reduced and fixed under sufficient exposure. Results Correct anatomic reduction and occlusion were achieved in all cases. Additionally, all patients showed normal articular function and the surgical scars were barely visible. Conclusion The transmasseter approach by retromandibular access is one of the feasible methods for curing mid-and-low condylar fracture, which minimizeing the risk of facial nerve injury and reducing the visible scars.

Objective To evaluate the effect of using cone-beam computed tomography（CBCT） and dental operating microscope（DOM） in treating maxillary molars containing bifurcative canals buccally. Methods 304 endodontically treated maxillary molars（159 maxillary first molars and 145 maxillary second molars） were included. After preparing access to pulp chamber, the number of canal orifices and location in the pulp chamber floor of each tooth were recorded. For those teeth with bifurcative canals buccally confirmed by preoperative radiographs, the root canals were negotiated by naked eyes firstly, then under DOM according CBCT results. Following working length determination, the root canals were prepared by step-down technique and obturated with cold lateral condensation technique. The efficiency was evaluated with radiographs before, during and after operation. Results In 304 maxillary molars, 51 molars were found to have two canal orifices（buccal one and palatal one） in the pulp floor, 30 bifurcative canals buccally（8 upper first molars and 22 upper second molars） were found. CBCT information indicated the level of bifurcation in buccal canals were 3-8 mm under the pulp chamber floors. In 30 maxillary molars, 7 teeth treated by X-rays and eyes could be negotiated, 22 teeth treated by CBCT and DOM could be negotiated and were well instrumented and filled by evaluating with radiographs during and after operation, 8 teeth with deep divergent MB2 canals or calcified canal could not be negotiated. Conclusion Operative field can be located precisely by CBCT and dental operating microscope that could be effective method in treating these sort of canals.

Objective To study the effect of Actinobacillus actinomycetem（A.actinomycetem） on the secretion and apoptosis rate of polymorphonuclear leukocytes（PMN） in type 2 diabetes patients. Methods Peripheral PMN from healths and type 2 diabetes patients were isolated by Percoll gradient centrifugation. The PMN were stimulated with filtrate of ultrasonic pulverization from  .actinomycetem as the experiment group. As the control group, PMN suspension was incubated with PBS. The release of interleukin-6（IL-6） was measured at 20, 40, 60 min by enzymelinked immune sorbent assay（ELISA） technique. The apoptosis rate of PMN was tested at 6 and 12 hours by flow cytometry. Results Incubated with filtrate of ultrasonic pulverization from A.actinomycetem, the PMN of type 2 diabetes patients released  significantly higher levels of IL-6 compared with the healthy subjects（P＜0.001）. The apoptosis rate of PMN from the healthy subjects was higher than that from type 2 diabetes patients（P<0.001）. Regardless of body condition, interaction with filtrate of ultrasonic pulverization from A.actinomycetem could induce the seretion of IL-6 and reduce the apoptosis rate. Conclusion The PMN of type 2 diabetes patients may possess hyper-reactive inflammatory response trait.

Objective To study the effects of Saccharomyces albicans（S.albicans） on the cell cycle distribution and proliferation of human umbilical vein endothelial cell ECV304 cells in vitro. Methods The line of ECV304 cultured in vitro were divided into four groups which were treated by S.albicans supernatant, S.albicans inactivated bacilli, supernatant and inactivated bacilli mixture, normal culture medium. The proliferous effect of ECV304 induced by supernatant, inactivated bacilli, supernatant and inactivated bacilli mixture using the methods of MTT, cell count, microscope and flow cytometry were conducted. Results In the condition of different times and different culture concentrations, ECV304 cells incubated with 4-fold diluted S.albicans supernatant for 48 h increased the proliferation rate. The S and G2/M population of ECV304 cells increased after incubated with S.albicans supernatant for 40 h, which showed significant increasing cell proliferation index（PI）（P<0.05）. The PI of the cells treated by inactivated bacilli showed no significant change （P>0.05）. Conclusion S.albicans could induce ECV304 cell proliferation which depends on the release of metabolic products of S.albicans.

36 Wistar rats were divided into 3 groups on average randomly: Control group, light force group and heavy  force group. The experimental teeth were drawn-off mesially by the force of 0.392 N in light force group and 0.98 N in heavy force group, with both of the maxillary central incisors as the tooth of anchorage. At the 7th day, the gingival crevicular fluid of rats were collected; the histological slices were made, including the experimental tooth and periodontal tissue; the tissues was stained with hematoxylin-eosin（HE） staining and tartrate resistant acid phosphatase（TRAP） staining to observe the histological changes of the root resorption of rats. Then the expression of DSPP and DSP were assayed by using biochemistry techniques of Western blot. Results Histological observation: There was not root resorption in control group. Neither root resorption nor cementoclast was observed in light force group. And in heavy force group visible root resorption came out in pressure zone. Western blot results: There was expression of DSPP and no DSP in control group, and there was the expression of DSPP and DSP in both light force group and heavy force group. The result of statistical analysis showed that there were significant differences in the expression of DSPP and DSP among three groups. The highest one was heavy force group, followed by the light force group and control group with the least amount of proteins. Conclusion There is the expression of DSPP and DSP in gingival crevicular fluid following experimental tooth movement with root resorption.

Objective To investigate the expression and significance of Cyclin D1 in oral squamous cell carcinoma（OSCC）. Methods A immunohistochemistry method, Envosion, was employed to test the manifesting levels of Cyclin D1 in pathological slices of 50 OSCC cases and 10 normal cases, and the results was treated with statistical analysis. Results In 50 OSCC cases, Cyclin D1 mainly manifested in karyon, and a little in cytoplasm. The positive manifesting rates of Cyclin D1 in the samples was 80.0%, which was significantly higher than the manifesting rates of 20.0% in normal oral mucous membrane（P<0.01）. The manifestation of Cyclin D1 was correlated with the different pathological grades, clinical phases and lymph node metastasis（P<0.05）. Conclusion The abnormal manifestation of Cyclin D1 is closely related with the occurrence and development of OSCC. Therefore, it can be used as subsidiary index for OSCC treatment and prognosis.

Objective To investigate the antagonistic effects of three species of oral Streptococcus on the growth of oral Saccharomyces albicans in vitro. Methods Direct inoculation method, reverse inoculation method and mixed culture methods were respectively chosen to observe the changes of Saccharomyces albicans colony formation on the effects of Streptococcus mutans, Streptococcus sanguis and Streptococcus salivarius. Results 1）No clear inhibition zone was observed in each of the groups by direct inoculation method. 2）Compared with the control groups, Saccharomyces albicans colony formation on soft agar of Streptococcus sanguis decreased significantly（P<0.05）. 3）Mixed culture method results showed that Streptococcus mutans could inhibit the growth of Saccharomyces albicans significantly at different time points（P=0.001）. 4）Under the action of  acteria culture supernatant, the count of Saccharomyces albicans in experiment groups showed statistical significance when compared with the control groups at 24, 48, 72 h（P=0.001）; The differences among the experimental groups were of no statistical significance at majority times（P>0.05）. Conclusion  treptococcus mutans, Streptococcus sanguis, and Streptococcus salivarius could obviously inhibit the growth of Saccharomyces albicans in vitro. However, it is still unclear that among which the inhibition effects is stronger. The antagonistic effects is weakened gradually.

Objective To construct the recombinant vectors that express mouse Dishevelled 2（Dvl2）, and to evaluate its expression level in transfected RAW264.7 cells. Methods A pair of specific primers were designed according to the mouse Dvl2 cDNA sequence published in GenBank. Total RNA of RAW264.7 cells was extracted, and open reading frame of Dvl2 was obtained by RT-PCR, which was then cloned into pEZ-M29 plasmid. Electrophoresis after macrorestriction and DNA sequence analysis were used to identify the reconstructed plasmids. After transient transfection via liposome, the transfection of RAW264.7 cells was confirmed under a fluorescence microscope, and the expression level of Dvl2 was evaluated by real-time RT-PCR. Results The recombinant plasmid containing mouse Dvl2, namely pEZ-M29/ Dvl2, was successfully constructed, and confirmed by DNA sequence analysis. After 48 h of tranfection, the expression of enhanced green fluorescene protein was observed under a fluorescence microscope, and real-time RT-PCR analysis revealed that the Dvl2 mRNA level was prominantly elevated in the transient transfected RAW264.7 cells. Conclusion The recombinant plasmids pEZ-M29/Dvl2 are successfully constructed and can elevate the Dvl2 mRNA level in the transient transfected RAW264.7 cells, which can be used in further studies aiming at revealing the functional significance of Dvl2 in the osteoclastogenesis.

Objective To observe the effect of Ciclosporin（CsP） on apoptosis and expression of the associated protein Bcl-2, Caspase-3 in gingival epithelium of rats in order to approach the mechanism of CsP-induced gingival epithelium overgrowth. Methods Eighty SPF grade male 7-week-old Wistar rats were randomly divided into experimental group and control group, and each group was divided into 4 subgroups according to the duration of treatment（10, 20, 30 and 40 days）. The experimental objects were given fresh milk including CsP intragastrically and the control ones were given only fresh milk. After perfusion of 4% paraform for internal fixation, the specimens’bucco-lingual paraffin sections at lower first molar were made. Apoptosis was detected using TdT-mediated dUT nick end labeling（TUNEL） and the expression of Bcl-2 and Caspase-3 using immunohistochemisty of PV. The apoptotic index, positive cell rate of Caspase-3 and average gray scale of Bcl-2 was measured with an image analysis system. Data were analyzed by two-way analysis of variance of factorial design. Results The apoptosis index and positive cell rate of Caspase-3 were downregulated in the experimental group, and were significant difference from the control group（P<0.05）. The average gray scale of Bcl-2 was up-regulated in the experimental group, and was significant difference from the control group（P<0.05）. Conclusion CsP-induced gingival epithelial overgrowth is likely to associated with interference to the path of mitochondrial apoptosis and inhibition apoptosis.

Objective To construct self-assembly fibrocartilage model of goat temporomandibular joint disc and observe the biological characteristics of the self-assembled fibrocartilage constructs, further to provide a basis for tissue engineering of the temporomandibular joint disc and other fibrocartilage. Methods Cells from temporomandibular joint discs of goats were harvested and cultured. 5.5×106 cells were seeded in each agarose well with diameter 5 mm × depth 10 mm, daily replace of medium, cultured for 2 weeks. Results One day after seeding, goat temporomandibular joint disc cells in agarose wells were gathered and began to self-assemble into a disc-shaped base, then gradually turned into a round shape. When cultured for 2 weeks, hematoxylin-eosin staining was conducted and observed that cells were round and wrapped around by the matrix. Positive Safranin-O/fast green staining for glycosaminoglycans was observed throughout the entire constructs, and picro-sirius red staining was examined and distribution of numerous type Ⅰ collagen was found. Immunohistochemistry staining demonstrated brown yellow particles in cytoplasm and around extracellular matrix, which showed self-assembly construct can produce type Ⅰ collagen as native temporomandibular joint disc tissue. Conclusion Production of extracellular matrix in self-assembly construct as native temporomandibular joint disc tissue indicates that the use of agarose wells to construct engineered temporomandibular joint disc will be possible and practicable.

Objective To investigate the effects of different X-ray doses on the expression of nuclear factor-κB （NF-κB） P65 in human oral squamous cell carcinoma cell（OSCC） line and the relationship between NF-κB P65 and radiation-induced OSCC cell line apoptosis. Methods The squamous cell carcinoma of Tca8113 cell was cultivated in the 37 ℃, 5%CO2 incubator after recovery. The experiment samples were divided into six groups（control group, 2, 4, 6, 8, 10 Gy）. After growing to logarithm period, Tca8113 cells were irradiated using above-mentioned X-ray doses. The immunocyteochemistry and Western blot were used to detect the expression of NF-κB P65 after irradiation in various times（1, 3, 6, 10, 24, 48 h）. The apoptosis rates under different radiotherapy dose were detected by flow cytometer and TDT-mediated dUTP-biotin nick end labeling（TUNEL）. Results Compared with the control group, cytoplasm expression of P65 under different X-ray doses had statistically significant differences（P＜0.05）. While the cytoplasm P65 protein expression at different time were compared each other, the 3 h group demonstrated significant difference（P＜ 0.05）. Apoptosis rates in various groups, compared with control group, had statistically significant differences（P＜0.05）. While the groups at different time points were compared each other, the apoptosis rates of 3 h group had significant differences（P＜0.05）. Conclusion X-ray can activate the NF-κB P65 in oral squmaous cell carcinoma cell lines. The correlation between expressional quantity of P65 and radiotherapy induced apoptosis of oral squamous cell carcinoma cell lines possesses positive correlation. The activated and intranuclear P65 may have radiotherapy resistant effect.

Objective Trying to find out the mechanism of microstructure influencing bacterial adhesion, we prepared different microstructures to compare the adsorptive behavior of graphite powder and adhesive behavior of oral microbe. Methods We used polydimethylsiloxane（PDMS） to copy 23 microstructures of hydroxyapatite（HA） chip, and cultured them with different sizes graphite powder and oral microbes respectively, to observe and compare their behavior on microstructures. Results The adsorption of 30-50 μm powder on different microstructures was insignificant, while 10-20 μm powder had maximum adsorption on 10 μm and 20 μm microstructures. Saccharomyces albicans was most likely to adhere to 5 μm microstructures which was equivalent to its own size. However, microstructures had little effect on adhesion of Streptococcus mutans which grew in a chain. Conclusion The size of microstructure was the most effective factor that affects the adsorption of non-living powder, and it also had the same effect on the microbial adhesion; but some special bacteria, such as Streptococcus mutans which grew in a chain, was not affected by the sizes or shapes of microstructures.

To track the initiating and developing process of one case diagnosed as chronic periodontitis accompanied with malformed lingual groove in maxillary lateral incisor and report the long-term prognosis to the periodontal conservative and supportive therapy. The patient was diagnosed with mild chronic periodontitis 6 years ago and accepted routine periodontal scaling and root planning（SRP） plus supportive periodontal therapy（SPT） one time. Two years later the periodontal condition deteriorated by deep pockets in molars and severe bone destruction around the maxillary lateral incisor with malformed lingual groove. After SRP in sites which pocket depth more than 4mm plus root canal therapy and lingual groove plasty of maxillary right lateral incisor, the SPT regularly proceeded at 3rd, 6th and 12th month. At present the whole periodontal tissue was healthy, the bone lesion around maxillary lateral incisor recoveredwell, the tooth had no mobile, the cosmetic  effect and tooth function was in good state, and the patient was verysatisfied.

Cysticercosis is a kind of diseases caused by pork tapeworm parasite on the human tissue. It is more common in brain, subcutaneous tissue, muscle and eyes. One case of lingual cysticercosis was reported here and the pathogenesis, clinical manifestation, diagnosis and treatment of lingual cysticercosis were discussed.

Yolk sac tumor（endodermal sinus tumor） is a malignant germ cell tumor which usually arise in gonads. It is rare occurring in the oral cavity. Here, a yolk sac tumor of mouth floor was reported and relevant literatures were reviewed.

Over the last decade, as tremendous innovations have been achieved in scientific technology, translational medicine has come into the focus of academic medicine, and significant intellectual and financial efforts have been made to initiate a multitude of bench-to-bedside projects. The concept of translational medicine is described as the transfer of new understandings of disease mechanisms gained in the laboratory into the development of new methods for diagnosis, therapy, and prevention and their first testing in humans, meanwhile, translational medicine also is described as a patient- oriented population research and the translation of results from clinical studies into everyday clinical practice and health decision making. Translational medicine is a hot spot in recent academic field, and it is crucial for improving the living standard of population and renewing the research idea and technology. It has, however, significant obstacles during the approach of translational medicine. We here review the background, concept, current situation of translational dental medicine, key components and obstacles of translational medicine.