Objective　To investigate the functions of DLK1 in the proliferation and differentiation of human dental pulp stem cells (hDPSCs). Methods Immunohistochemical analysis was used to determine the expression of DLK1 in the mouse first maxillary molar. Recombinant lentivirus was constructed to overexpress DLK1 stably in hDPSCs.The cell viability and proliferation of hDPSCs were examined by CCK8 and EdU incorporation assay, respectively. The odontoblastic differentiation of hDPSCs was determined by detection of ALPase activity assay, ALP and alizarin red staining and the expression of mineralization-related genes including ALP, DSPP and DMP1. Result DLK1 was highly expressed in the odontoblasts and dental pulp cells on the first maxillary molar. The expression level of ALP,DSPP,DMP-1 and DLK1 increased significantly after the odontoblastic induction of hDPSCs. Compared with the control group, the expression level of ALP increased by 1.6 times, DSPP increased by 1.16 times, DMP1 increased by 1.42 times and DLK1 increased by 1.54 times. DLK1 over expression increased the proliferation ability of hDPSCs and inhibited odontoblastic differentiation of hDPSCs. Compared with the control group, hDPSCs increased by about 1.7 times with the over expression of DLK1. Conclusions The proliferation of hDPSCs is promoted after DLK1 over expression. DLK1 inhibits the odontoblastic differentiation of hDPSCs.

【Abstract】　Objective: This study aims to examine whether human dental pulp stem cell (DPSC) can be induced to differentiate into smooth muscle cell (SMC) in vitro. Method: The various concentration of condition medium (CM) from SMC and the growth factor of transforming growth factor beta 1 (TGF-β1) were evaluated to ascertain which were the most potent inducers of differentiation. DPSCs were induced to differentiate into SMC by growth environment containing SMCs-CM with the addition of TGF-??1 for 14 days. Results: The morphology of DPSC was demonstrated to change from the spindle shape to the "hill and valley" morphology of SMCs over time. The gene and protein expression of SMCs-specific markers (α-SMA, desmin, myosin, and calponin) increased over time. Conclusions: These data demonstrated that DPSC has the potential to differentiate into the SMC, which represents a step forward in providing a promising alternative source of cells that are obtained by least invasive procedure without ethical issues, for future research in SMC tissue engineering.

Abstract：Objective To investigate the effect of miR-145 on the osteogenesis differentiation of rBMMSC. Methods Rat shin bone marrow mesenchymal stem cells collected from 3-week male rats were divided into two groups, pLv3-Negative control group and pLv3-(anti)miR-145 group, transfected with lentivirus. The effects of miR-145 on cell proliferation, apoptosis, growth cycle and osteogenesis differentiation of rBMMSC were observed. Results There was no difference in cell proliferation, growth cycle and apoptosis between pLv3-Negative control group and pLv3-(anti)miR-145 group. The expressions of Sema3A, OPG, Runx2 and Osterix/SP7 in pLv3-(anti)miR-145 group were significantly higher than pLv3-Negative control group. The area of Alizarin red staining in pLv3-(anti)miR-145 group was also bigger than pLv3-Negative control group. Conclusion Inhibition of miR-145 expression can enhance osteogenesis differentiation of rBMMSC，but it has no obvious effect on cell proliferation, growth cycle and apoptosis of rBMMSC.

Abstract: Objective To investigate a highly effective, non-integrative and feeder-free reprogramming technique to derive induced pluripotent stem cells (iPSCs) to provide safe stem cells sources for dental tissue regeneration. Methods Human stem cells from apical papilla (SCAP) were primarily cultured and induced into iPSCs on human recombinant vitronectin with Simplicon RNA reprogramming kit. Specific pluripotency markers were detected by immunofluorescence staining. Teratoma was formed to examine the pluripotency of differentiation in vivo. Total RNA of iPSCs was isolated and RT-PCR was carried out to verify the loss of exogenous reprogramming factors. Reprogramming efficiency of SCAP-iPSCs was calculated. Results Human SCAP-iPSCs exhibited classical ES-like morphology and positively immunostaining for specific markers Oct4, Nanog, Sox2 and SSEA-4. Teratoma was formed 6 weeks after injecting iPSCs into SCID mice and HE staining revealed the cell types of all three germ layers: ectoderm, endoderm and mesoderm. RT-PCR results suggested hSCAP-iPSCs expressed specific multipotent markers and no more exogenous reprogramming factors. The reprogramming efficiency of hSCAP-iPSCs was 0.17-0.20%. Conclusions HSCAP-iPSCs derived with highly reprogramming efficiency and safety is the optimal stem cell source for dental tissue regeneration.

[Abstract] Objective: To analyze the risk factors of enamel demineralization in orthodontic treatment with fixed appliance. Methods: Examination of enamel demineralization and a questionnaire survey were conducted during and after orthodontic treatment with fixed appliance among 161 patients. The correlations between incidence of enamel demineralization and gender, age, methods for maintaining oral hygiene or eating habits were analyzed by Log-rank Test. Logistic regression was used to analyze the risk factors which result in enamel demineralization. Result: In 3619 teeth of 161 patients, 328 teeth from 75 patients had enamel demineralization and the incidences were 46.6% and 9.1% respectively. The incidence of enamel demineralization were correlated with age (P=0.038), daily toothbrushing frequency (P=0.001), single toothbrushing time (P＜0.0001) and weekly intake of sweets or carbonated drinks (P=0.015), whereas no significant associations were determined between incidence of enamel demineralization and gender (P=0.386), use of orthodontic toothbrush (P=0.498), fluoride toothpaste (P=0.217) or mouthwash (P=0.170). Logistic regression analysis revealed that daily toothbrushing frequency (P=0.005), single toothbrushing time (P＜0.0001) together with weekly intake of sweets or carbonated drinks (P=0.026) were identified as risk factors of enamel demineralization in orthodontic treatment with fixed appliance. Conclusion: Enamel demineralization is a frequent complication in orthodontic treatment with fixed appliance. Controlling intake of sweets or carbonated drinks reasonably and sufficient toothbrushing frequency and time are important measures to prevent enamel demineralization.

Stem cells have highly self-renewal, proliferation and differentiation potential, through cell division to maintain the size of their cell mass, and can differentiate into various tissue cells at the same time, which constitute the complex body organ. However, stem cells are rare, and the content is very low, so to solve the mesenchymal stem cell rapid proliferation is a hot issue in the research of tissue engineering. The platelet rich plasma (Platelet rich, plasma, PRP) comes from the autologous blood after centrifugation, which contains a large number of platelets and a small quantity of other blood cells.Activated PRP can influence the proliferation of stem cell through the combined and synergistic effect of growth factors, such as platelet-derived growth factor, insulin-like growth factor and transforming growth factor and PRP can overcome the defects of Heterologous rejection, and has low price, high biological safety, and fewer complications. Therefore, it is important to understand the effect of PRP on the proliferation and differentiation of stem cells.

Objective　To compare the difference between individual normal occlusion and skeletal Ⅲ class malocclusion young people’s TMJ CBCT images in Harbin． Methods　selected health TMJ of individual normal occlusion 40 voluteers and patients with health high-angle skeletal Ⅲ class malocclusion 40 people,The age of young people between 20 to 28 years old in Harbin region.Two groups undergone CBCT in the intercuspal position ,measurement the TMJ morphology and position with Mimics16.0 and Simplant O&O software .The data was analysis SPSS 17.0 software .Results　8 measurements showed significant differences between individual normal occlusion and the skeletal Ⅲ class malocclusion, which were MI,AE′/AC,Condylar radius value,deep of glenoid fossa,index of condyles,index of glenoid fossa,outer diameter of two sides glenoid fossa ,the angle of two sides condylar long axis. Conclusions The morphology and position of TMJ are difference between individual normal occlusion and skeletal Ⅲ class malocclusion in Harbin．

[Abstract]Objective To analyze the morphological features of incisal translucent layers in young maxillary central incisors. Methods 234 young maxillary central incisors were photographed and incisal translucent layers were further analyzed by using image processing software Capture NX-D Version. Results Incisal translucent features of young maxillary central incisors were categorized in five types. The one which was absence of opalescence plaques in incisal translucent layers made up the highest proportion (50.85%)，while another type with sporadic opalescence plaques in incisal translucent layers accounted for 18.38%. The presence of the other three types were lobulated（11.11%）、irregular（10.26%）and pectinate（9.40%）. Five types showed no statistical significance in gender difference, and there was obvious symmetry between homonymous maxillary central incisors of each individual. Conclusion Incisal translucent features of young maxillary central incisors exist in different types and obey certain distribution laws.

Abstract：Objective To discuss the hot spots and frontier evolution of Endodontics in 21 Century. Methods Choose two high effected SCI Journals of Endodontics——International Endodontic Journal and Journal of Endodontics。 Analysis the top 10 countries、institutions and authors by bibliometric and visualized by CiteSpace. The hot spots and frontier evolution were observed by co-keyword analysis. Results In the two journals from 2001 to 2016, the top 1 country is USA, top 1 institution is University of Sao Paulo, Brazil, top 1 author is Siqueira JF(97 articles). The research hot-topics mainly focus on Bacterial infection, root canal disinfection drugs, instruments for root canal preparation, diagnosis of apical periodontitis, dental pulp tissue engineering. We can pay attention to dental pulp regeneration,. self adjust file, CBCT, et al. Conclusion Maping analysis with CiteSpace visualization software can be simple and easy to realize the quantitative analysis of the literature in a certain area, and can help researchers to grasp the hot spots and frontier evolution.

Objective To study the psychological state of patients before and after treatment with ceramic veneers and all-ceramic crowns using SCL-90 scale. Methods 78 adult patients (29 males, 49 females) who complained about the inaesthetic upper anterior teeth were included in this study. SCL-90 scale was used to analyze and contrast psychological state before and after treatment with ceramic veneers and all-ceramic crowns. Spss 13.0 software was adopted to conduct mean comparison, paired t- test, and two- sample t- test analysis on the information obtained. Results After treatment with ceramic veneers and all-ceramic crowns, patients’ subjective satisfaction reached 97.8% and 100% respectively. Though patients’ mean SCL-90 scores of somatization, enforcement, interpersonal sensitivity, depression, anxiety and paranoia were higher than those of normal people before treatment, their psychological status had improved after three months of esthetic restorations. SCL-90 scores of somatization, enforcement, interpersonal sensitivity, depression, anxiety and paranoia decreased significantly (P＜0.05). Female patients improved better in interpersonal sensitivity, depression and anxiety than male patients(P＜0.05). Conclusion Ceramic veneers and all-ceramic crowns have positive subjective therapeutic effects. The psychological state of patients with inaesthetic anterior teeth is worse than the normal before treatment, but their psychological state can improve significantly after esthetic restorations.

Male patient, 51 years old. Double side to tooth lip side gum has burst 2 months, add 1 week. The pathological diagnosis of pemphigoid. DIF showed true epidermal junction the IgA banded deposition, IgG, C3, IgM negative. Diagnosed as linear IgA bullous skin disease, given glucocorticoid and thalidomide combination therapy, and achieved good results.

Dental implant is an effective method of repairing dentition defect and deletion, however, implant failure is inevitable. There are various treatment options after failure of dental implantation since they are influenced by subjective and objective factors. In order to guide the clinical practice, this paper sorted out the available treatment options after failure of dental implant, and their applicability, advantages and disadvantages based on more than 50 literature.

As a new treatment paradigm for the correction of dentomaxillofacial deformities, the surgery-first approach has been proposed as an effective method to shorten treatment duration, improve the facial profile after surgery immediately and reduce the difficulties associated with the postoperative orthodontic treatment. Among the benefits of the application of a surgery-first approach , the decrease in total treatment duration has been emphasized over and over again. It has created a broader interest in both surgical and orthodontic fields. The aim of this review is to summarize current knowledge on the clinical protocol and the underlying mechanism of postoperative rapid orthodontic tooth movement.

Basic fibroblast growth factor (bFGF) is a kind of strong mitogen and can promote cells mitosis which derived from the mesoderm and neural ectoderm, thus promote the repair and regeneration of tissues. Dental pulp stem cells (DPSCs) with the potential of high proliferation, self-renewal and multi-directional differentiation are thought to be one kind of the ideal seed cells in the tooth tissue engineering and have a promising application prospect in dental pulp tissue repair and regeneration. Recent studies have found that bFGF has an important role on migration, proliferation and differentiation of DPSCs. This article summarizes its research progress.

During biomineralization of hard tissues, minerals deposit on the collagen , then form mineralized collagen with the induction of biological macromolecules proteins, polysaccharides and so on. Collagen has a very important role in different stages of biomineralization. Types and levels of bone and dentin mineralization affect the quality and quantity of its corresponding function in vivo. Therefore, restoration of hierarchical structures of the mineralized collagen matrix and a thorough understanding of the underlying role of type 1 collagen can provide useful reference for preparing new bone and dentin repair material and tissue-engineered substitutes .This review discusses the research progress of the role of type 1 collagen in biomineralization .

Each of the bone augmentation currently used has its own deficiencies. The bone tissue engineering provides new treatment and method for bone regeneration. It has been proved that dental stem cell possess the characteristics of osteogenic potential, easily obtained, strong proliferation ability, great differentiation potential, and weak immunogenicity. Dental stem cells have become an important source for tissue engineering.This article mainly introduces the research progress of dental stem cells in alveolar bone regeneration.

Greater palatine foramen and lesser palatine foramen are deeply located in the maxilla and have a complicated structure that holds important vessels and nerves. Due to its special clinical significance, the structure has been considered important, yet difficult, for oral and maxillofacial surgeries. Combination of three-dimensional reconstruction techniques, such as multi-plane reorganization and volume rendering, with CT angiography techniques allows multi-slice helical CT to effectively evaluate the normal anatomy, adjacent structure and lesion character in the region of greater palatine foramen and lesser palatine foramen with continuous thin section imaging.

Digital dental model is one of the basis of developing digital oral clinical medicine. Depending on the three-dimensional scanning object,the establish methods of digital dental model can be classified into direct method and indirect method,which two contain a variety of?technologies.This article reviews the clinical commonly used methods of direct and indirect ways.