Abstract：Platelet-rich fibrin (PRF) is a platelet concentrated product prepared by extracting the autologous blood, which is regarded as a biomaterial that promotes the tissue healing due to its three-dimensional structure, abundance in platelet as well as a high concentration of growth factors. In recent years, it has been widely employed in the restoration of oral soft and hard tissue defect. This paper discusses the role of PRF in the regeneration of oral soft and hard tissue, objectively evaluates its efficacy, to provide a reference for the proper application of PRF by dentists.

Objective: To explore effects of periodontitis on stromal nucleated cell number of adipose tissue in obese individuals using DAPI-DiI double-staining. Methods: Diet-induced obesity (16 weeks on diet) and periodontitis (5-day ligation) combined mouse models were established. Cell nuclei and membrane in epididymal adipose tissue were stained by DAPI and DiI, respectively, followed by analysis on effects of obesity and periodontitis on nucleated cell number. Results: DAPI-DiI double-staining clearly demonstrated cell nuclei and adipocyte outline in adipose tissue relative to hematoxylin and eosin and toluidine blue staining methods. Nucleated cell number was significantly enhanced by obesity (P < 0.05) but not affected by periodontitis (P > 0.05). Conclusion: Short-term periodontal infection has no significant impact on obesity-related stromal hyperplasia in adipose tissue. DAPI-DiI double-staining may be helpful for adipose tissue histology including nucleated cell counting.

Objective　To investigate the effects of combination platelet-rich fibrin (PRF) with calcined natural bovine bone(CBB) on repairing rabbit skull defect to provide evidence for treating bone defect. Methods: Eighteen adult rabbits were selected to make 10mm diameter circular bone defects in the left and right sides of the skull respectively. Bone defects were divided into three groups: experimental group 1 (CBB implantation), experimental group 2 (implantation of PRF and CBB) and control group (no bone graft). The skull specimens were collected at the 4th, 12th and 20th weeks after operation, respectively. Toluidine blue staining, tetracycline fluorescence staining and CT imaging were used to determine the osteogenic area, osteogenic velocity, graft absorption and bone mineral density. Results: 4, 12 and 20 weeks after operation, the rate of new bone formation, the degree of new bone calcification, the osteogenic area and the bone mineral density of experimental group 1 and experimental group 2 were all higher than those of control group. The bone area and bone density in experiment group 2 were larger than those in group 1 (P < 0.05), and the osteogenesis in central reticulum was obvious. In the control group, the formation of new bone obviously decreased at the 12th and 20th weeks. Conclusion: CBB has strong therapeutic effects on skull defect. PRF can improve the repair effects of bone defect by CBB, which may be related to the bone induction of PRF.

Objective To explore the influence factors of three restoration methods on the fracture resistance of endodontically treated human premolar teeth. Methods 60 extracted human mandibular premolars with single canal were selected and randomly divided into 4 groups ( A，B，C，D)，Group A remained untreated and served as a control group. The other three groups were endodontically treated and a standardized MO cavity was prepared on each tooth. Over the standardized MO cavity, Group B was restored with composite resin, Group C with ceramicinlay，Group D with EverStick fiber and composite resin. The loading force under the direction at 135 degree to the long axis with crosshead speed of 1mm/min was applied to each tooth until the first sign of failure was noted. Data were recorded and analyzed statistically by SPSS 17.0 software. Results The median values of the samples were as follows: Group A(1413.91±95.93N) and Group D (1324.66±88.56N) were significantly higher than Group B(796.57±118.85N) and Group C(961.05±101.45N) (p<0.05). The incidences of repairable fracture mode were: A(80%), B(73.3%), C(73.3%), D(100%). Conclusion The use of EverStick high-strength fiber composite resin in premolar teeth with standardized MO cavities can significantly increase the fracture resistance and the fracture mode also has more advantages .

Objective To apply pulpotomy into 30 permanent teeth with cariously exposure and observe the two-year clinical effect to provide theoretical guidance for its application in clinic. Methods　Sixty-three cariously exposed permanent teeth with closed apices and vital pulps were included. Moreover, preoperative pulpal and periapical diagnosis was conducted. The teeth were divided into two groups, in which the experimental group was treated with pulpotomy (30), and the control group was treated with one-visit RCT (one-visit root canal therapy) (33). Subsequent visits were conducted 3 months, 6 months, 12 months, 24 months after operation. Then therapeutic effects were assessed through clinical and radiographic evaluation. All statistical analysis was performed using the SPSS 18.0 statistical package. Results　The success rates of pulpotomy group in 3 months, 6 months, 12 months, 24 months were respectively 100%, 96.67%, 96.67% and 93.33%, while the success rates of root canal therapy were respectively 100%, 100%, 96.97% and 96.97%.There were no significant differences between pulpotomy and RCT(χ2=0.010，P=0.601) in the success rate. Conclusions　This therapy can be applied to the mature permanent teeth of carious pulp and achieve high success rate, which is expected to be an alternative treatment for root canal therapy.

Objective To explore the clinical characteristics of immature permanent teeth trauma in school-age children, to better maintain oral health. Methods The database was based on 353 children aged 5-12 who had treatments in Department of pediatric dentistry, Affiliated Hospital of Stomatology, Nanjing Medical University during the whole year 2015. Data collection included patient’s age, gender, waiting time for a consultation after injury, position of trauma tooth and type of trauma. All the data were retrospectively analyzed. Results Male and female ratio was 2.33:1.The majority of the injury occurred in December and most frequently happened between age 7 and 9. Waiting time for the the consultation after injury was from 2 to 24 hours. Among all types of permanent teeth trauma, maxillary lateral incisor high frequently happened, and dentin fracture and subluxation most commonly occurred. Nolla 9 was the most common stage of hard tissue injury. Conclusion Immature permanent teeth trauma has its unique characteristics. The prevention and health care propaganda of dental trauma should be strengthened, and the public awareness of treatment should be improved.

Abstract：　Objective　 To compare the effects of molar root canal preparation using two kinds of rotary NiTi instrumrnts. Reciproc and Mtwo instruments. Methods　 A total of 62 patients were enrolled in this study. The patients' molars needed root canal treatment because of pulpitis or periapital periodontitis. And the patients were randomly divided into Group R[Reciproc group(32 cases)]and Group M[ Mtwo group(30 cases)].The above two groups were filled with warm qutta-percha vertical condensation technique. The fractured files and the operating time were recorded. The shaping abilities of two types of NiTi files were analyzed. Results No Reciproc was separated, whereas two pieces of Mtwo were separated. The preparation time of Group R averaged (15.45±3.16) minutes, and Group M averaged (20.31±2.32) minutes, and the difference was statistically significant(P<0.05)．No transportatio，apical blockage,ledge or perforation was found in the two groups. Conclusion Two types of NiTi instruments also show high performance when they are used to molar root canal preparation,but Mtwo instruments need more time and we should pay attention to prevent the fracture of it．

Abstract: Objective To analyze and explore the 3D Pring to make the multi-unit fixed bridge base .Methods A total of 50 fixed bridge models were uniformly made. Each model is composed of 6 units in the same anterior teeth area. The models were randomly divided into two groups, the experimental group (n=25) and the control group (n=25). The base crown wax model in the experimental group was designed and made with the 3D Pring, the control group with the traditional manual method. Scanning electron microscope (500x magnification) was used to compare the interdigitation of the base crown with the model. Four points were taken from each case, which was the labial and lingual edges of the abutment teeth at both ends of the fixed bridge, respectively. In addition, the time spent by two groups of metal base crown dressing technicians in placement and appearance dressing was compared.. Results The stability and interdigitation of multi-unit anterior fixed bridge base crowns made and designed with the 3D Pring were better than those of traditional manual methods, and the technicians' operation time could be shortened. Conclusion The fixed bridge base casting wax models with the 3D Pring design and making have good compatibility and stability, and it can be in application and promotion in prosthodontic technology.

Objective　 To identify the clinical and radiographic characteristics as well as surgical removal method of ectopic mandibular third molar (EMTM) and its associated disease. Methods Clinical cases involving mandibular third molars treated from January 2012 to December 2017 in the Affiliated Stomatological Hospital, Nanjing Medical University were identified. All data regarding the ectopic mandibular third molars diagnosed by panoramic radiography or cone-beam CT were collected and analyzed to reveal the clinical manifestation, radiographic features, associated pathology and therapeutic strategy. Results A total number of 47 EMTMs in 46 patients meeting the inclusion criteria were included. They were frequently identified in coronoid, ramus, mandibular angle and body. Local swelling, pain and limited mouth opening were typical clinical symptoms. The occurrence of local swelling was associated with anatomic sites of ectopic teeth(P<0.05). 89.37% of EMTMs were accompanied with dentigerous cyst or tumor. Most cases were treated by intraoral approach to extract the EMTM and remove the simultaneous disease, and there were fewer postoperative complications. Conclusions: EMTM is a relatively rare disease entity and usually accompanied with odontogenic swelling or tumorous lesion. Its clinical diagnosis is mainly based on radiographic findings and the overall prognosis after operative treatment is favorable.

Objective To investigate the clinical value of PRF and titanium mesh using in dental implantation in aesthetic area.Methods 13 cases with single tooth loss in aesthetic area were selected and divided into two groups. One group(control group ,6 cases) was treated with dental implantation combined with pure artificial bone implantation covered by titanium mesh. The other group(PRF group,7 cases) was treated with dental implantation combined with artificial bone mixed with PRF implantation covered by titanium mesh and PRF membrane. Wound reaction and wound healing were evaluated at the 14th day after operation. After 4 and ahalf months after operation, newly formed bones were harvested for histological observation.ResultsWounds of PRF group were well healedwithout swelling. In contrast, one case of control group had satisfying wound healing. Three cases had wound healing with swelling. Two cases had wound dehiscence with the exposure of titanium mesh. For histological observation, PRF group showed more mature bone formation with more amount of trabecular bones. Conclusion The using of PRF and titanium mesh can improve the newbone formation and reduce the tissue reaction, thus showing a satisfying clinical value in GBR procedure.

Objective　 To observe the clinical effect of allogenic bone material and bone matrix in the treatment of bone defect after jaw surgery. Methods 43 cases of patients who underwent jaw surgery, with postoperative bone defect diameter 2-5 cm, were selected. After the complete removal of the lesion, allogeneic bone implant materials and medical bone matrix were implanted. Clinical examination was conducted 1 week, 1, 3, 6 months after surgery. Oral panoramic photos were taken 6 months after the operation. The postoperative infection rate and the bone healing in the operation area were evaluated according to the clinical symptoms and imaging findings. Results The rate of bad healing was 2.33% (1/43), and the bone healing rate was 88.37% (38/43) in 6 months. Conclusion The same bone implant material and the medical induced bone matrix have good biocompatibility and can promote the formation of bone tissue,and have good clinical results, the postoperative pain, swelling and infection rate are low.

Objective　To analyze the association between periodontal status and overweight-obesity in children aged 10 to 11. Methods　198 children aged 10 to 11 of both gender (106 males and 92 females) in Chengdu were included in this case-control study. Subjects answered a questionnaire about their habits of brushing teeth. Anthropometric examinations of height, weight, waist circumference and clinical examination of bleeding on probing (BOP), visible plaque index (VPI), calculus index (CI) and probing depth (PD) were carried out. Body mass index (BMI) was further calculated. Under the BMI standard , 98 and 100 were respectively included in the overweight and obesity group (test group) and normal group (control group), while under the waist circumference standard , 94 and 104 were included in the test group and control group.χ2 test, t test, bivariate and multivariate logistic regression model were used to analyze data. Results Under both standards, the test group showed worse oral hygiene status (P＜0.01), higher BOP, larger population of VPI>0.25 and CI (P＜0.01) than the control group .No statistically significant difference was found between groups regarding PD＞3mm. In multivariate logistic regression analysis, keeping VPI＞0.25 and poor oral hygiene as confounding factors, overweight-obesity under the BMI standard was a risk factor of BOP＞0.25(OR=1.911,95%CI 1.02-3.58), while overweight-obesity under the waist circumference standard was a risk factor of both BOP＞0.25 (OR=1.78,95%CI 1.28-3.39) and occurrence of calculus (OR=1.88, 95%CI 1.03-3.58). Conclusion In children aged 10 to 11, systemic obesity is associated with BOP and abdominal obesity is associated with both BOP and occurrence of calculus.

With the development of viral gene delivery techniques, much attention has been attracted on the therapy of bone metabolism diseases via bone cells transfection. In this review, recent progresses about viral vector transfection of bone cells have been summarized, which provides precious reference for the selection of the most appropriate technique of bone cells transfection. Furthermore, it can provide valuable research means for the illustration of the metabolic and regulatory mechanism behind the bone cells.

So far the reconstruction of bone defect caused by a variety of inflammation and trauma remains a major challenge. Traditional therapies rely mainly on autologous or allograft transplants combined with physiotherapy and gene therapy to accelerate bone healing. In bone immunology, macrophages are important participants in bone repair and play an important role in the early stage of bone injury and in advanced bone remodeling. This review summarizes the effects of macrophages on the osteogenic differentiation of mesenchymal stem cells and the underneath mechanisms.

IL-17 is the cytokine secreted by the subgroup of CD4+ T cells named T helper 17, which plays different biological characteristics in different organic environments. It suggests that IL-17 plays an important role in the apoptosis of osteoclasts. The up-regulation of Fas/Fas with the assistance of IL-17 and various cytokines may take part in apoptosis. This paper reviewed the research progress of IL-17 and its relationship with osteoclasts apoptosis.

Periodontitis is a risk factor of adverse pregnancy outcomes, periodontitis and adverse pregnancy outcomes are associated with Fc gamma R Ⅱ B gene polymorphism, so we speculated that the mechanism behind periodontitis and adverse pregnancy outcomes is the Fc gamma RⅡB gene polymorphism. In this paper,the relationship between periodontitis,adverse pregnancy outcomes and Fc gamma RⅡB gene polymorphism are reviewed and play the basis of the mechanism research of periodontitis and adverse pregnancy outcomes.

All-on-four technology is a new approach to rehabilitating edentulous jaws with four implants. Recently, all-on-four has achieved predictable clinical results, but controversies of research and clinical application still exit. In this paper, the all-on-four concept, evaluation research, complications and comparison with other rehabilitation technologies will be elaborated.

Fracture healing is a complex physiological and pathological process and the typical fracture healing process contains inflammatory phase, cartilage formation phase, woven bone formation and remodeling phase. The process is regulated by multiple factors, among which the biological factors play a significant role. Understanding the mechanism of fracture healing and influencing factors can help reduce or avoid the occurrence of nonunion, which will provide a new path for clinical treatment of severe bone traumatic diseases.

Utilization of negative checkpoint regulators (NCRs) for immunotherapy has garnered significant interest of oral head and neck tumor research. Compared to chemotherapy, the anti-NCRs targeted drugs are more effective and less harmful with the demonstration of clinical trials. However, with the research of tumor resistance mechanism becoming more and more intensive, myriad tumor resistance cases have appeared for targeted drugs. Therefore, more and more emphasis is focused on combination therapy in order to reduce the resistance and cytotoxicity, and to ensure adequate therapeutic effect. B7H5, also named VISTA (V-domain Ig-containing Suppressor of T cell Activation), is a member of B7-CD28, which has sky-high homology with negative checkpoint factors CTLA-4, PD-1, PD-L1, and is also a member of NCR. At present, the immunosupression mechanism of B7H5 has not been clarified, whose molecule may become an ideal drug combination target. The article reviews the research status of B7H5 molecule in the immunotherapy of oromaxilofacial head and neck tumor.

Medical three-dimensional(3D) visualization technology has been widely used in oral implantology, and oral anatomical site can be intuitively observed, which promotes the progress of stomatology. 3D medical visualization technology has improved the accuracy of diagnosis, and it is valuable in making treatment plan and physician-patient communication. This paper reviewed studies on research at home and abroad in recent years, aiming to explore the clinical application of the 3D visualization of medical images as well as research.