The application of adhesive root canal filling materials is the tendency in root canal obturation. The orientation is to develop the adhesive core material and sealer making a whole structure. In this review, we summarized the researches on the resin-dentin adhesion in the root canal obturation.

Objective To explore the driving force of the oral astringency produced by the interaction of theaflavin（TF） and epigallocatechin-3-gallate（EGCG） to human salivary α-amylase（HSA）. Methods The constants of the rate, equilibrium of reaction（ka, kd , KA, and KD） and Langmuir, Freundlich adsorption isotherm（KL, Kf, and Mm） were determined by surface plasmon resonance（SPR） technique and adsorption kinetics. Results Both of Langmuir and Freundlich models could be used for describing the binding processes of TF and EGCG onto HSA surfaces, and there were no significant differences of the correlation coefficient of determination between these two models（P>0.05）. The constants of adsorption isotherm, the rate and equilibrium constants of the association for TF were higher than those of EGCG（P<0.05）. The rate and equilibrium constants of the dissociation for TF were lower than those of EGCG（P<0.05）. The affinity of TF to HSA was higher than that of EGCG. Conclusion The sorely oral astringency is much easily produced by TF from the black tea rather than EGCG from the green tea. The driving force of the oral astringency is attributed to the hydrogen bonds of hydroxyl groups and hydrophobic interaction of galloyl groups in polyphenolic structures.

Objective To explore the protective effect of allicin on nicotine-induced oxidative damage to human periodontal ligament cells（HPDLCs）. Methods 1）Establish nicotine-induced oxidative damage model on HPDLCs. Use water-soluble tetrazolium（WST） colorimetric method to find out the nicotine concentration（X） that could inhibit HPDLCs’growth for the following experiments. 2）HPDLCs of the fifth passage were divided into 5 groups: The control group, the nicotine group and the nicotine+allicin groups（the concentration of allicin was 15, 30, and 60 μg·mL-1 respectively）. Different kinds of culture media were added. Similarly, use WST colorimetric method to choose the allicin concentration（Y） that could significantly improve the survival rate of HPDLCs. 3）HPDLCs were divided into 3 groups: The control group, the nicotine group, the nicotine +allicin group and different media were added. The glutathion（GSH） concentrations in HPDLCs were determined in 1, 4, 8, 12 and 24 h respectively. Results 0.8 mg·mL-1 nicotine could inhibit the HPDLCs survival rate significantly（77% of the control, P<0.05）. But 60 μg·mL-1 allicin could prevent the inhibition effects evidently, improving the survival rate to 112% of that of the nicotine group（P< 0.05） and reaching the survival rate level of control group（P >0.05）. The GSH concentrations of nicotine +allicin group were higher than that of the nicotine group always（P<0.05） and by 82% at 8 h after culture, but had no difference with that of the control group（P>0.05）. Conclusion 60 μg·mL-1 allicin can protect the HPDLCs against oxidative damage induced by nicotine.

Objective To study the effects of surface roughness and titanium dioxide（TiO2） layers on commercially pure titanium（cp-Ti） substrates on attachment of osteoblasts in vitro. Methods 250 pure titanium slices were divided into five groups. Osteoblasts were cultured on five cp-Ti substrates of ground, which blasted with 108-130 μm（S1）, 216-301 μm（S2）, 356-411 μm（S3） TiO2 particles and titanium-sprayed plasma（TPS） surfaces, surfaces prepared by hand grinding with SiC paper to 600 grits served as control（S0）. Surface average roughness and the TiO2 film structure was evaluated. For morphology and attachment measurement, osteoblasts were cultured for 1, 4, 12 and 24 h, evaluated by scanning electronic microscope（SEM） observation and MTT assay. Results Osteoblasts spread well on the titanium surfaces. Further more, osteoblasts spread more well on S3 surfaces. After 1 and 4 h culture, the number of cells on S3 surfaces was the highest（P<0.05）. The number of cells on S3 surfaces was the same（P>0.05） as TPS surfaces and higher than other groups（P<0.05） after 12 and 24 h. The number of cells of all experimental groups were higher than S0 surfaces after 4, 12 and 24 h（P<0.05）. Conclusion It was concluded that the coarse TiO2 particles blasted surface would optimize initial osteoblast responses.

Objective To study the histological change of microscrew-bone interface, detect the relative cytokine of gingival crevicular fluid, and explore the impossible mechanism of peri-implantitis. Methods Four male Beagles were collected. Randomly select one side of animals jaw as the experimental group to induce the peri-implantitis, and another side as the controll group. Four microscrews were implanted on each side. In the 1st, 2nd, 3rd, 4th weeks after implantation, collect peri-implant sulcular fluid（PISF） and detect tumor necrosis factor-α（TNF-α） levels before sacrificed, and the harvest tissue were observed in histological ways. Results According to the extension of time after implantation, the experimental group showed visible progress of interface destruction: 1st week after implantation showed large numbers inflammatory cells collected at the neck but did not undermine the cortical bone; 2nd week after implantation, cortical bone were observed angular absorption; Bone resorption continued to develop and at the 4th week, bone resorption were enlarged to the second thread of microscrew and the interface was filled with a large number of collagen fibers. Conclusion The destruction of interface began at the neck of microscrew, and the further development was along the interface in depth. Both microscrews with peri-implantitis and the healthy controls showed the presence of TNF -α. Inflammation accumulation might trigger the up-regulation of TNF-α level, and the onset of inflammation would enhance the up-trend.

Objective To investigate the efficacy of a new collagen-hydroxyapatite（COL-HA） composite membrane on bone regeneration of SD rat cranial defects. Methods Four defects were produced in the calvaria of 24 SD rats. The animals were divided into four groups: Empty defects without membrane（group 1）; defects covered by COL-HA single-layer dense membranes（group 2）; defects covered by COL-HA double-layer membranes（group 3）; defects covered by Bio-Gide membranes（group 4）. At 2, 4, 8 and 12 weeks after surgery, 6 rats were sacrificed and the following parameters were analyzed: Macroscopic observation, X-ray examination, descriptive histology, regenerate bone quantitative histology. Statistical analysis consisted of generalized linear models/factorial design analysis of variance and LSD-t test was performed. Results Since two weeks after surgery, there were a small amount of bone regenerated in three groups except group 1. At 12 weeks after surgery, the opaque sclerous tissues filled with the defects in three groups, and residual membrane fragments still could be found. X-ray pictures showed the density of regenerate bone in group 3 and group 4 was closed to the original bone and greater than that of group 2. Quantitative analysis of regenerate bone showed that in initial stage, group 4 had more bone regeneration than the other groups（P<0.05）, and at 12 weeks after surgery the differences between group 4 and group 2/group 3 had no statistically significant. Conclusion The COL-HA composite membranes can guide bone regeneration of rat cranial defects. The efficacy of bone regeneration of COL-HA double-layer membrane is superior to COL-HA single-layer dense membrane, because its property is more propitious to the adherence and proliferation of osteoblasts.

Objective To observe the effect of mini-implant lengths on stress distribution in peri-implant surface. Methods The 3D finite element analysis mandible and mini-implant models with diameter of 1.6 mm, lengths of 6, 8, 10 and 12 mm were established. The mini-implants were inserted into designed site of mandibular vertically, respectivly. A force of 1.96 N were applied mesioly and 45° tilted mesio-vertically in models. The stress distribution under every condition was recorded and analyzed. Results When load was applied mesially, the maximum stress varied from 3.500 to 3.765 MPa, the maximum displacement varied from 1.266 to 1.288 μm. When load was applied 45° tilted mesio-vertically, the maximum stress varied from 4.075 to 4.510 MPa, the maximum displacement varied from 1.668 to 1.694 μm. All of the maximum stress and displacement of loading mesially were lower than loading mesiovertically. Conclusion The change of the mini-implant length within 6-12 mm don’t show much influence on the stress distribution. The loading type is an important factor influencing stress and displacement of peri-implant bone.

Objective To evaluate the symmetry rate of nasal floor width and the influencing factor for the unilateral complete cleft lip（UCCL） after repair with Huaxi technique. Methods 27 UCCL patients repaired with Huaxi technique were photographed before repair, 1 week and 1 year after surgery. The distance from columella point to facial midline, the nasal floor width and the fissure width were measured. The approach rate of the columella point, the symmetry rate and the change of the nasal floor width were calculated. The statistical analysis was completed by SPSS 13.0. Results There was statistical difference of the approach rate for the columella point between 1 week and 1 year after surgery（54.06%, 63.96%; P<0.05）, no statistical difference was found of the symmetry rate for the nasal floor between 1 week and 1 year after surgery（69.12%, 75.93%; P>0.05）. There was statistical difference of the change for nasal floor width between the cleft side and the non-cleft side in a week（P=0.000）, but no statistical difference was found in a year（P =0.262）. The linear correlation was obtained between the distance from columella point to facial midline 1 week after surgery and the distance from columella point to facial midline（r=0.465, P=0.014） and the fissure width（r=0.486, P=0.010） before surgery. No linear correlation was obtained between other index after surgery and before surgery（P>0.05）. Conclusion The symmetry rate of nasal floor width is stable after surgery with Huaxi technique, and the growth changes have not significant impact on the effect of the surgery in a short-term.

Objective To evaluate the psychological conditions of parents of children with cleft lip and palate, and to discuss the clinical psychological treatment methods of these parents. Methods 100 parents of children with cleft lip and palate were selected as the parents of children with cleft lip and palate group, and 34 normal adults were selected as the control group. Two groups were tested by the life event scale（LES） and self-rating anxiety scale（SAS） to analyze their psychological states. After the study group was treated by psychological counseling, two groups were tested by the LES and SAS again. Results The LES total scores of the patients of children with cleft lip and palate had significant differences compared with the normal adults（P<0.05） before and after psychological counseling, and the LES scores of negative life event of these patients also significantly decreased before and after psychological counseling（P<0.05）. While the SAS total scores of the patients of children with cleft lip and palate had no significant differences compared with the normal adults before and after psychological counseling（P>0.05）. Conclusion Analyzing the psychological conditions of parents of children with cleft lip and palate by using psychological scales and then treating them by counseling, is an effective psychological treatment method.

Objective To perform a Meta analysis of prognostic cohort studies for evaluating the use of vascular endothelial growth factor（VEGF） as a predictor of survival in patients with oral carcinoma. Methods A search of OVIDMEDLINE, EMBASE database and two Chinese database（CNKI and VIP） was conducted using common text words combined with medical subject headings to capture the related cohort studies. Data were collected comparing disease-free and overall survival in patients with high VEGF levels as compared to those with low levels. Studies were pooled and summary hazard ratios（HR） were calculated. Results 14 texts were included in this study. High tissue VEGF levels predicted poor overall survival（HR: 2.95, 95%CI: 2.14-4.08） and disease-free survival（HR: 2.28, 95%CI: 1.61-3.21）. Similarly, high VEGF levels predicted poor overall survival（HR: 2.60, 95%CI: 1.82-3.73） and disease-free survival（HR: 2.58, 95%CI: 1.73-3.84） in patients with oral squamous cell carcinoma. Conclusion VEGF may be useful for defining prognosis in oral carcinoma.

Objective Clinical cases of immediate loaded implants were retrospectively analyzed, in the aim of evaluating the clinical value of immediate loading. Methods From July 2005 to October 2009, 99 immediate loaded implants were implanted in 29 patients. The overall data including radiography, clinical examination were collected during the follow-up periods ranged from 4 to 46 months. The implants were evaluated with the survival rate, bone resorption, soft tissue esthetics（including gingiva papilla index and pink esthetic score）. Results Survival rate for immediate loaded implant was 97.0%. The average bone resorption were 0.22 mm at 4-6 months after surgery, bone increase of 0.15 mm were found at 6-12 month, and bone increase up to 0.16 mm at 12-46 months. The gingival papilla index was 2.68, while pink esthetic score was 12.58. Conclusion Immediate loaded implant is an effective repairing method for patients missing teeth and the esthetics effect is ideal.

Objective This study investigates the differences in condylar position between centric relation（CR） and maximum intercuspation（MI） in Angle’s Class Ⅱ orthodontic patients before treatment. Methods 80 cases, who were Angle’s Class Ⅱ pretreatment patients, and 50 cases, who were normal（ideal） occlusion were accepted. Dental casts were mounted on Panadent articulator with CR bite record, taken by bilateral manipulation and load testing. The differences in condylar position between CR and MI in all three spatial planes were measured using the Panadent condylar position indication（CPI）. Results 1）The positive rate of CR-MI discrepancy was 92.50%（74 cases） in the group of Angle’s Class Ⅱ malocclusion and 10.00%（5 cases） in the group of normal occlusion（P< 0.001）. 2）74.32%（55 cases） CR-MI discrepancy in 74 cases in the group of Angle’s Class Ⅱ pretreatment patients were coincidence discrepancy. 3）91.25% patients in the group of Angle’s Class Ⅱ malocclusion and 66.00% in the group of normal occlusion present occlusion interferences which located at the posterior teeth. Conclusion The results suggested that orthodontists should be aware of a high incidence of condylar displacement in Angle’s Class Ⅱ pretreatment patients, and measure condylar displacement before the start of comprehensive orthodontic treatment to unmask real jaw relationships and avoid possible misdiagnoses.

Objective To evaluate the retractive effects of different gingival retraction agents. Methods Thirty subjects with healthy gingival conditions were recruited to the trial, and the buccal gingival sulcus of the hibateral first max-illary premolars of each subject（n=60） were treated randomly with one of the six agents—Group A was tetrahydrozoline hydrochloride, Group B was oxymetazoline hydrochloride, Group C was epinephrine hydrochlorid, Group D was AlCl3, Group E was Fe2（SO4） 3, and Group F was normal saline as control. Both pre-treated and post-treated accurate impressions of buccal gingival sulcus of the experimental teeth were made, so were the anhydrite casts. The casts of experimental teeth were sectioned into 2 mm slices bucco-lingually at the buccal eminence. Then the width of the sulcus was measured as the distance from the tooth to the crest of the gingival under a low-power microscope to compare the effect of these gingival retraction agents. Results The width of gingival sulcus became larger after the treatment in all groups（P<0.05）. Either Group A or Group B had greater gingival retraction effects than Group C and Group F（P<0.05）. Except Group F, both Group D and Group E had no significant differences from the other groups（P>0.05）. There was no statistically signification between Group D and Group E（P>0.05）, neither was there any statistically significance between Group A and Group B（P>0.05）. Conclusion Tetrahydrozoline manifested excellent effect of gingival retraction.

Objective To study the prevalence of Tannerella forsythensis（T.forsythensis） in the subgingival plaque of type 2 diabetes, analyze the relationship between T.forsythensis and related factors, discuss the role of T.forsythensis in the chronic periodontitis and type 2 diabetes. Methods 160 subgingival plaque samples were collected from type 2 diabetic patients and pathogens genomic DNA were extracted by phenol and chloroform from plaque. T. forsythensis was detected by polymerase chain reaction, and Pearson correlation and Logistic regression analysis were used to analyze the relationship between T.forsythensis and systemic factors and periodontal status. Results The prevalence of T. forsythensis in mild, moderate, severe periodontitis group was 47.82%, 48.71%, 67.39% respec - tively, and the prevalence was higher in the severe periodontitis group than in mild, moderate group（P<0.05）. There was no T.forsythensis in 6 diabetic patients with healthy periodontium. Logistic regression analysis illustrated that the prevalence of T.forsythensis was associated with simplified oral hygiene index（OHI-S） and diabetic duration（OR= 1.947, OR=0.873）. Conclusion The prevalence of T.forsythensis in type 2 diabetes with chronic periodontitis was related with oral hygiene, periodontal status and diabetic duration.

Objective To screen the wnt and fibroblast growth factor（FGF） ligands involved in palatogenesis and  cleft palate, and to study the dynamic expression of them in the different stages of palatal development and cleft  palate formation. Methods Mouse model of retinoic acid（RA）-induced cleft palate was set up. At embryo day（ED） 14.5, the palatal tissues of RA-treated group and wild type were collected and prepared for gene -chip analysis. According to the gene-chip results, wnt3, wnt8a, fgf9 and fgf10 were selected and their expression level was detected at ED13.5 -15.5 by using semi -quantitative reverse transcription -PCR（RT -PCR）. Results 1）Gene -chip analysis showed that in RA-induced cleft palate group wnt8a and fgf9 were down-regulated, wnt3 and fgf10 were up-regulated in conversely. 2）During the different stage of the control group palatogenesis, intense expression of wnt3, wnt8a, fgf9 and fgf10 were detected with a continuous dynamic pattern. 3）Compared with the control group, the expression level of wnt3, wnt8a, fgf9 and fgf10 in RA -induced cleft palate showed significant difference, respectively（P <0.05）. Conclusion wnt and FGF signaling molecules participate in the palatogenesis, and RA pathway may interact with wnt and FGF signaling pathway.

Objective To investigate the role of inhibitor of DNA binding-1（Id-1） gene in adenoid cystic carcinoma cell growth and invasion behavior. Methods With salivary adenoid cystic carcinoma cell lines ACC-M and ACC-2, dedected Id-1 gene expression was screened with immunofluorescence assay. After Id-1 mRNA knockingdown using small interfering RNA, RT-PCR and Western blot were used to detect the different expressions before and after interference, and the growth of cells before and after interference was deceted using the MTT assay, and the cell invasion ability was checked with the use of Transwell chamber assay. Results Id-1 were both expressed in the ACC-M and ACC-2, and the expression in ACC-M was higher than that in ACC-2. After Id-1 RNA interference, the growth and invasiveness of ACC-M and ACC-2 were inhibited with the restrained degree in ACC-M much stronger than that in the ACC-2. Conclusion In view of the important role of Id -1 in the behavior of growth and invasion in ACC cell, interfering the expression of Id-1 gene is expected to be a novel and effective means for the treatment of adenoid cystic carcinoma.

Objective To isolate and identify human periodontal ligament stem cells（PDLSC） by improved methods and assess the characteristics of PDLSC ex vivo. Methods The periodontal ligament cells were obtained from the healthy impacted third molars and teeth extracted for orthodontic purposes and used to isolate PDLSC by limiting dilution assay. PDLSC were cultured and expanded in α-MEM supplemented with 10% FBS. Colony-forming assay, immunohistochemistry, flow cytometry, osteogenic and adipogenic induction were used to identify PDLSC. Results The obtained cells had high colony-forming efficiency and were positive staining for vimentin and negative for pancytokeratin. Flow cytometry revealed that the isolated cells were positive for STRO-1 and CD146 antibodies and most were in the G0/G1 phase of cell cycle. Under specific conditions, they could differentiate to the osteoblast and adipocyte lineages in vitro. Conclusion Limiting dilution assay is an effective method to isolate PDLSC and the single- cell-derived colonies demonstrate the properties of stem cells in vitro.

Objective To build the physical model of four suturae which are related to the growth of maxilla in the three-dimensional finite-element model of maxillofacial bones. Methods A 16 years old volunteer with individual normal occlusion, good periodontium health condition and without diseases of temporomandibular joint was chosen to be the material of modeling. The three-dimensional finite-element model of the volunteer’s maxillofacial bones was built using the CT scan and the finite-element modeling method. Finally we built the physical model of four suturae which were related to the growth of maxilla in the model of maxillofacial bones. Results The model of maxillofacial bones with 86 575 nodes and 485 915 elements was generated. This model contained four suturae including sutura frontomaxillaris, sutura zygomaticomaxillaris, sutura temporozygomatica and sutura pterygopalatine. Conclusion A three-dimensional finite-element model of maxillofacial bones with good biological similarity was developed.

Objective To study the expression and its relationship of murine double minute 2（MDM2）, P53 protein in oral leukoplakia and squamous cell carcinoma. Methods Immunohistochemical assay was used to detect the expression of MDM2 and P53 proteins in 15 normal oral epithelium tissues, 24 cases of oral leukoplakias and 41 cases of oral squamous cell carcinomas. Results There were no positive expression of MDM2 and P53 in normal mucosa. With significantly difference compared with the normal group（P<0.05）, the positive rates of MDM2 and P53 were 58.3%, 75.6% and 37.5%, 68.3% in oral leukoplakia and squamous cell carcinoma. MDM2-positive rate had no significant difference（P>0.05）, while P53-positive rate was significant difference（P<0.05） compared with oral leukoplakia and oral squamous cell carcinoma. Two kinds of indicators for further correlation analysis showed that MDM2 and P53 protein showed a positive correlation relationship both in oral leukoplakia（P =0.018） and oral squamous cell carcinoma（P=0.000）. Conclusion The expression of MDM2 in oral leukoplakia and oral squamous cell carcinoma suggests that this gene may play a significant role in the process of carcinogenesis of oral squamous cell carcinoma. The correlation of MDM2 and P53 expression indicates that both of them may play a synergistic role in the process of carcinogenesis of oral squamous cell carcinoma.

Objective The purpose of this article is to examine the effect of curcumin on the proliferation and metastasis of human tongue squamous cell carcinoma and analyze its mechanism. Methods SCC-4 were treated with curcumin of 0, 5, 10, 20, 30, 60, 100 μmol·L-1 in 24 h. MTT assay, Matrigel invasion assay, flow cytometry and fluorescence microscopy were used to examine the effect of curcumin on the growth and metastasis of SCC-4. cDNA microarray and RT-PCR were employed to analyze the  expression of genes treated by curcumin. Results The results showed that curcumin could concentration-dependently inhibit SCC-4 cell proliferation at the concentration range from 20 to 100 μmol·L-1. Furthermore, Matrigel invasion assay indicated that curcumin can reduce SCC-4 cell invasion under the dosage of 20, 30, 60 μmol·L-1. Flow cytometry also showed that curcumin can influence the distribution of cell cycle of SCC-4 cell with the dosage of 20, 30, 60 μmol·L-1. And the dosage of 30 μmol·L-1 curcumin could lead to the recruitment of alpha-tubulin. cDNA microarray showed that 87 genes were activated and 198 genes were inhibited with the effect of curcumin. These results were validated by the real time quantitative RT-PCR. Conclusion According to the results, it suggests that curcumin has the potential as the leading compound for anti-cancer proliferation and invasion in oral cancer treatment, and cdc27, EGFR substrate 15, PPAR-alpha and H2A histone may play an important role among this multiple anticancer-targeting ability.

Objective To study the effects of glial cell derived neurotrophic factor（GDNF） on regeneration of facial nerve defects by autogenous facial vein conduit. Methods Thirty -six rabbits were used in this study and 10 mm-length facial nerve defects were made on both sides of all animals. The nerve gaps were bridged using autoge-nous posterior facial vein graft of the same side. The animals received injection of either saline（group A, n= 16） or GDNF（group B, n=16） into the veins. Nerve function was evaluated by evoking nerve action potential immediately after operation and 4, 8 and 16 weeks after operation. Regenerated nerve samples were harvested at 4, 8, and 16 weeks after operation and processed for histology and transmitting electron microscopic examination（TEM）. Results Action potential did not exist immediately after operation but it was evoked at 4, 8, and 16 weeks in both groups. At 4 and 8 weeks after operation, the amplitude and width of action potential were significantly higher in group B than group A（P<0.01）, except wave width at 4 weeks, which showed no significant differences, while the latency period was significantly shorter in group B than that in group A（P<0.01）. At 16 weeks, action potential was similar between two groups, except wave amptitude, which was higher in group B than group A（P<0.01）. Morphologic and TEM examinations showed more matured myelinated nerve fibers and active Schwann’s cells in group B when compared group A during the whole regeneration process. Conclusion GDNF can promote nerve regeneration at early stage during reconstruction of facial nerve defects by autogenous faical vein conduit and combination of GDNF and autogenous vein graft provides a valuable method for clinical reconstruction of facial nerve defects.

Objective To study the effect of peptide -conjugated near -infrared quantum dots（QDs） on growth,
invasion and metastasis of human buccal squamous cell carcinoma cell line（BcaCD885 cell）. Methods 1）BcaCD885
cells were labeled by cell -penetrating peptide -conjugated QDs with a maximum emission wavelength of 800 nm （QD800）, then labeling efficiency was detected by flow cytometry, and laser-scanning confocal microscope was used to observe the distribution of QD800 within the cells. 2）Different concentrations of QD800 was applied to BcaCD885 cells, and the cell growth of control and three test groups were compared respectively. 3）BcaCD885 cells were labeled by QD800（BcaCD885/QD800）, then transwell chambers and wash way were used to dectect the difference of invasion and metastasis ability between BcaCD885/QD800 and BcaCD885 cells. Results 1）The labeling rate of BcaCD885 cells after 6 h was 94.07%, and QD800 distributes in the BcaCD885 cytoplasm. 2）Different concentrations of QD800 showed no negative effects on growth of BcaCD885 cells. 3）The ability of invasion, attachment and motion of BcaCD885 cells were not significantly different between test and control group（P＞0.05）. Conclusion QDs showed no effects on growth, invasion and metastasis ability of BcaCD885 cells. Our results provide science foundation for QDs as a new fluorescence probes to real-time monitor cells and cells imaging in a living.

Objective To study the mechanism in masticatory muscle dysfunctional induced by hemimastication. Methods Ca2 + contents were measured with atomic absorption spectrometry; calcinuerin were measured with colorimetric method; muscle fiber types were measured with adenosine-triphosphate（ATPase） staining. Results 1） Compared with the controls, Ca2+ contents in experimental group had the higher level except 8 weeks（P＜0.05）. 2） The ratio of slow fiber in experimental group increased, higher than the match groups（P＜0.05）. 3）With Ca2+ contents rise， the activities of calcinuerin present a bell -like shape. 4）The ratio of slow -type fiber was positively correlated to the activities of calcinuerin（r=0.876，P＜0.05）. Conclusion The signal way of muscle fiber growth and fiber transformation were activated by high concentration of calcium，then，muscle fiber transfered from fast to slow type. It may play an important role in the mechanism that hemimastication result in masticatory muscles dysfunction.

The fused tooth is the union of two dental enamel or dentin formed together. In the maxillary, the fusion usually occurred within the lateral incisor and canine and very rarely occurred in the upper third molar and supernumerary tooth. This paper reported a fused tooth occurred in the left maxillary impacted third molar with supernumerary tooth.

Three root canals in the mesiobuccal root of maxillary first molar is unusual. The aim of this case report was to describe a maxillary first molar that presented three root canals in the mesiobuccal root. The distance among the three canal orifices was 1.5 mm. The working lengths of the three canals were within the normal range.

Incidence rate of single root canal in maxillary second molar is very low. The emergence of curved single root canal in maxillary second molar with single root is especially rare. A case of curved single root canal in maxillary second molar with single root was successfully treated and reported in this article. This report also highlighted  the role of cone beam computed tomography as an objective method to confirm the three-dimensional anatomy of teeth.

This article explained the character of dental disease and effective facts for dental health utilization, and current situation of basic medical insurance for oral diseases through checking up relative articles. Dental insurance had a positive effect on utilization of dental medical service and public oral health. The PEST tool was used to analyze the environment of dental insurance developing direction and feasibility in this article, and then raise some suggestions and core strategies for developing dental insurance. We believe that the dental insurance can increase the oral health service utilizations and enhance the oral health for Chinese people. Only oral insurance will be developed, Chinese oral health could be geared to international practice.