Abutments serve as the core link between endosseous implants and dental prosthetics. Due to the various types of commercially available abutments, each with its own set of unique characteristics, it is critical for dental professionals to choose the appropriate abutment. This paper aims to highlight the special features and broaden the selection of implant abutments to better aid professionals in making the right decision to ensure longterm restoration success and to improve patients' satisfaction.

Objective To evaluate the resin bonding and microleakage of yttriastablized tetragonal zirconia polycrystal (YTZP) with or without alumina sandblasting combined with conditioning with two 10methacryloyloxydecyl dihydrogen phosphate (MDP) containing zirconia primers. Methods Shortterm shear bond strength (SBS) between composite resin and YTZP with different surface treatments was tested. Surface treatments of YTZP included the following, alumina sandblasting followed by conditioning with any one of the two brands of MDP containing zirconia primers, single conditioning with any one of the two brands of MDP containing zirconia primers, and single alumina sandblasting as the negative control group. Methylene blue staining was carried out to evaluate the microleakage. Results Single alumina sandblasting showed the lowest SBS. Prior to conditioning YTZP with MDP containing zirconia primer, alumina sandblasting improved the SBS further. YTZP showed single alumina sandblasting had the most serious microleakage. No matter whether sandblasting was performed, application of MDP containing zirconia primers decreased microleakage. Conclusions Alumina sandblasting combined with zirconia primers is a preferable means to improve resin bonding of YTZP.

Objective To investigate the regulatoty effect of GDF15 on the proliferation and gene expression of BMSCs and its mechanism. Methods The BMSCs were isolated and cultured from rat long bones. The proliferation and cell cycle of BMSCs cultured with different concentrations of recombinant GDF15 proteins were tested by Cell Counting Kit8 and flow cytometry respectively. The mRNA levels of ALP, RunX2, COL1, VEGF, bFGF and HIF1α in BMSCs under induction of GDF15 were detected by real time PCR. Results Under normoxia condition, GDF15 promoted proliferation, cell cycle progress and mRNA level of VEGF in BMSCs dosedependently, and 50 μg/L was the optimum concentration. Conclusion GDF15 promotes proliferation and VEGF gene expression in BMSCs in short time, but its mechanism still needs further study.

Objective To prepare zinccontaining micronano patterned titanium surface and preliminarily study its effects on osteoblast behavior and antibacterial properties. Methods Hydrofluoric acidetching, alkali and heattreatment, and hydrothermal treatment with a ZnSO4 solution were performed in sequence to synthesize two zinccontaining micronano topological structures on pure titanium surfaces (15 and 60 minute treatment groups). The SLA titanium surface was used as the control group, and two zinccontaining micronano patterned titanium surfaces were used as the experiment groups. The microtopography and surface elemental compositions of different titanium surfaces were observed and analyzed. MC3T3E1 cells were seeded in the samples of three groups to evaluate the effects of different titanium surfaces on osteoblast behavior. Staphylococcus aureus were seeded in the samples of three groups to investigate antibacterial properties of different titanium surfaces. Results Two micronano topological structures, where uniform networks and contained trace zinc appeared, were prepared on pure titanium surfaces. Compared with the control SLA titanium surface, the titanium surfaces modified by two zinccontaining micronano topological structures significantly upregulated the spreading, proliferation and expressions of osteogenic related proteins of MC3T3E1 cells and had prominent antibacterial properties, especially the 15minute treatment group. Conclusion The zinccontaining micronano topological titanium surface can promote the adhesion, proliferation and differentiation of osteoblasts and has satisfactory antibacterial property.

Objective To explore the physicochemical and biological properties of different colloidal materials combined with antler powder and nanohydroxyapatite (nHA) scaffolds. Methods Antler powder and nano hydroxyapatite meal were mixed with 15% PVA, 5% silk fibroin (SF), 15% PVA and 5% silk fibroin (4∶1) respectively to prepare antler powder/PVA scaffolds, antler powder/SF scaffolds,antler powder/PVA/SF scaffolds, nano hydroxyapatite (nHA)/PVA scaffolds, nanohydroxyapatite (nHA)/SF scaffolds, nanohydroxyapatite (nHA)/PVA/SF scaffolds. The antidissolution performance, anticompression force, shear resistance and scaffold cytotoxicity were measured. Results The dissolution deformation of antler powder/SF scaffolds and nHA/SF scaffolds were grade Ⅲ, and the other four groups were grade Ⅱ. The shear resistance and anticompression force of the antler powder/SF scaffolds and nHA/SF scaffolds were poor. The antishear properties of the antler powder/PVA scaffolds and antler powder/PVA/SF scaffolds were similar to those of the nHA/PVA scaffolds and nHA/PVA/SF scaffolds. The anticompression properties of antler powder/PVA scaffolds and antler powder/PVA/SF scaffolds were better than nHA/PVA scaffolds and nHA/PVA/SF scaffolds, respectively. Conclusions Antler powder composite scaffolds have good mechanical properties and cell compatibility, and can be used as a new direction for heterogeneous bone scaffold materials. Pure silk fibroin, as a composite scaffold with poor solubility, poor mechanical properties, cannot meet the requirements of bone tissue engineering scaffolds.

Objective To investigate the effect of Cap on the pg growth and inflammatory cytokine secretion in experimental rat periodontitis. Methods Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Cap against pg (ATCC33277) were determined by microdilution technique. The effect of Cap on the growth rate of pg was assessed by timekill curve. By placing the sterile 28gauge wire ligature to the cervical portion of the right first molar, the experimental animal periodontitis was set up. The levels of TNFα, IL1β, IL4, IL6, IL10, IL12 in the periodontal tissues were analyzed by ELISA. Results Statistical analysis was performed using SPSS19.0 software. It was found that Cap showed the inhibitory effects on pg growth with MIC at 16mg/L and 64 mg/L, respectively. In low concentration, Cap inhibited pg growth, but in high concentration, Cap could directly kill bacteria. The inhibitory or killing effect of Cap was also in timedependent manners. In experimental periodontitis, except IL4, TNFα, IL1β, IL6, IL12 were significantly inhibited by Cap, but the expression of IL10 increased. Conclusion Cap can inhibit the growth of pg. By selectively changing the expression of TNFα, IL1β, IL6, IL10, IL12, Cap is able to relieve the immuneinflammatory reaction in the periodontitis.

Objective To establish a craniofacial pain model induced by tooth movement in rats, and to elucidate the role of potassium channel TREK1 in mediating craniofacial pain. Methods Eighty female SpragueDawley rats were randomly divided into four groups: the experimental group, the control group, Fluoxetine treated group and Quinidine treated group . The distance of the tooth movement was measured by the Xray films；the degree of pain was evaluated using the RGS index, and the expression of TREK1 in the periodontal tissue was observed by immunohistochemical staining. Results The mesial movement of the first molar in the experimental group increased over time and reached the maximum amount on 14th day. The pain score of the rats in the experiment group was higher than that of control group and the most obvious pain occurred on 3rd day ;on 3rd day, TREK1 highly expressed in the periodontal vascular wall; Fluoxetine and Quinidine (chemical inhibitors of TREK1) reduced the pain caused by tooth movement, and did not affect the speed and distance of tooth movement. Conclusion TREK1 mediates the development of craniofacial pain during tooth movement in rats. TREK1 can relieve the maxillofacial pain caused by tooth movement without affecting the efficiency of tooth movement.

Objective To discuss and analyze the effects of oxidized regenerated cellulose（Surgicel）which was packed in tooth extraction sockets on reducing the risks of postoperative hemorrhage after tooth extraction, without interrupting the therapy of patients taking longterm oral Warfarin. Methods 100 patients taking longterm oral Warfarin were selected and randomly divided into the experimental group and the control group. Surgicel was packed inside the extraction socket in the experimental group, while absorbable gelatin sponge was packed in the control group. The differences of hemorrhage rate after tooth extraction between two groups were analyzed from the perspectives of gender, age, INR, tooth position and the complexity of surgery. Results ①The hemorrhage rate of the experimental group (2%) was significantly lower than that of the control group (16%) (P<0.05); ②There was only 1 case occurring hemorrhage after tooth extraction in the experimental group. The hemorrhage rate of male group after tooth extraction was higher than the female in the control group, but there was no statistically significant difference(P>0.05). The hemorrhage rate of control group after tooth extraction increased with the age and INR(P<0.05); ③There was only 1 case of hemorrhage after tooth extraction in the maxillary molar in the experimental group. In the control group, the hemorrhage rates after tooth extraction were that the molar group was higher than the premolar group which was higher than the front teeth and complicated dental group was higher than simple teeth，and the differences were statistically significant(P< 0.05). Conclusions It is relatively safe to have a simple or complicated tooth extraction for the patients who take longterm oral Warfarin without interruption and whose INR is no more than 3.5. Surgicel can effectively reduce the rate of hemorrhage after tooth extraction in these patients.

Objective To investigate whether the torque capacity of Damon Q selfligating brackets and conventional MBT brackets have difference. Method A total of 44 patients followed up prospectively, were divided into two groups , one receiving Damon Q selfligating bracket and the other treated with a conventional MBT appliance, both groups using the twostep method to close extraction space. Computerized cephalometric analysis and statistics analysis (Ttest)were carried out before treatment and after treatment. The control effect of the torque of upper anterior teeth between the two groups was compared using SPSS23 software. Results Both groups had a significant average reduction in incisor and lib protrusion without changes of occlusion plane. U1SN, U1NA,U1NA°,ULP and LLP of both groups decreased significantly and there was significant difference(P<0.05).Changes of two groups were similar in the skeletal，dental and soft tissue (P>0.05).The torques of upper anterior teeth, U1SN, U1NA,U1NA°, were all within normal limits. The treatment duration of Damon Q selfligating group was longer with (24.1±0.5) months than that of conventional MBT bracket group with (22.4±0.7) months, having statistically significance(P<0.05). Conclusion For extraction treatment, using Damon Q selfligating brackets can achieve similar results while with likely longer treatment durations compared to conventional MBT brackets.

Objective To analyze and discuss the causes of 16 implant denture failures. Methods Data of 209 oral implant patients (356 implants) treated from Stomatological Department of the Second Affiliated Hospital of Xinjiang Medical University from September 2013 to September 2015 were chosen and data of 16 cases of failure implants were analyzed. Results There were a total of 16 cases of implant failures. There was no significant difference between the two implant systems (P>0.05). There was no significant difference in gender, age, tooth position and other basic information (P>0.05). The proportion of systemic diseases was higher than that of other causes, the proportion of central screws loosening was higher than other causes (P<0.05). Conclusion The failure of the implant is related to many factors, patient's related diseases, inappropriate selection of indications, unreasonable design, lack of standardization of surgical technique and poor oral hygiene, which are the main causes of the failure of dental implant restoration.

Objective To evaluate the effect of orthodontic extrusion on the management of fractured/diseased teeth. Methods A series of procedures were designed and applied to manage 24 cases with orthodontic extrusion to elevate the fracture or diseased line of the teeth supragingivally and surgical recontouring of the altered gingival margin. Finally, the teeth were restored prosthodontically. Prosthetic treatment was based on performing a post and core, and porcelain crown on the extruded teeth. Results The management leaded to good effect in 22 cases avoiding extraction of the teeth. Two failures included one loose tooth and the other periodontal abscess after orthodontic extrusion. Conclusion Orthodontic extrusion is an effective practice in managing tooth lesions below the gingiva as a conservative method.

Objective Through a 2year followup study on the effect of the two enameloplasty sealant techniques, to compare the efficacy of the application of phosphate etching and selfetching on preventing the caries of pit and fissure. Methods With splitmouth comparison,100 children aged 8 were selected to study, which means 400 first permanent molars were involved. After the enameloplasty, the left teeth of the mouth were selfetched (experimental group),and the right ones were phosphate etched (control group). The retention rates of sealing agent at 6 months,12 months and 24months were followed up. Results There were no significant differences between the phosphate etching and selfetching adhesive in the retention rate of sealing agent at 6 months, 12 months and 24 months（P>0.05）. Conclusions The effect of the two etching adhesives in enameloplasty sealant technique is satisfying.

Objective To analyze the logistic regression analysis of the status and related risk factors of pediatric dental caries. Methods 322 children who did physical examination and saw the doctor in hospital were selected, then were retrospectively analyzed, Patient data were collected by questionnaire. The status of children with dental caries and related risk factors were analyzed. Results 322 cases were examined, including 132 cases of dental caries, the percentage of dental caries was 41.0% overall. Caries group children had no significant difference in age and sex（P> 0.05）.The proportion of maxillary teeth with caries (29.5%) was significantly lower than that of mandibular teeth (70.5%)（P<0.05）. Sleep sweets, bedtime brushing habits and frequency of tooth brushing and other factors were significantly different, P<0.05. Logistic regression analysis showed that hobby sweets, lack of knowledge of oral health, too short brushing time , were the risk factors of dental caries in children（P<0.05）. Conclusion Children have a higher level of dental caries, poor oral hygiene, so it is recommended to regularly organize children’s oral examination and the popularity of oral health education.

Nowadays, implant prosthesis has become an essential way to repair the defect of dentition. However, there are many patients who cannot be implanted in clinical procedure because of bone defect caused by periodontitis and local bone absorption. In recent years, guided bone regeneration (GBR) has become an effective therapy to promote bone regeneration, which solves the problem of inadequate alveolar bone and expands the indication of implant technique. GBR membrane is not only one of the main factors to determine the clinical result of GBR, but also the focus of the field. This article discussed the clinical application of GBR in implant prosthesis, the classification and the development trend of GBR membrane. 

In recent years, with the development of oral medicine in our country, the majority of clinicians pay more and more attention to the study of occlusion and have a deeper understanding of it. Occlusal contact in normal occusion is one of the important contents of the stomatognathic system, and is related to many factors, including the temporomandibular joint, bite force, body posture, brain function and so on, which has strong guiding significance for the study of malocclusion and oral clinical work. In this paper, the occlusal contact study of normal occlusion population will be reviewed.

Periodontal disease, the leading cause of adult tooth loss in our country, brings insome problems such as infection, bone deficiency, which increase the difficulty of implantation. In recent years, the technique of immediate implant placement can be applied in patients with severe periodontal disease, becoming a new hot point in clinical application. However, there are many controversies about its application and clinical prognosis. This article will review the research progress and clinical application of immediate implant placement in patients with severe periodontal disease.

The shrinkage of composite restorations upon polymerization may lead to clinical failures and adverse consequences. Microcomputed tomography (microCT) can be used to measure the volume change before and after polymerization of the resin and the resulting microleakage; on the other hand, shrinkage vector can be calculated through tracing particles. This method is nondestructive, threedimensional visual, more accurate, and more scientific. This article reviewed the technology.

Successful orthodontic tooth movement depends on favorable responses from the periodontal ligament (PDL) under orthodontic forces. Thus the biomechanical properties of the PDL are of great importance for understanding the mechanisms of orthodontic tooth movement and periodontal tissue response and making appropriate treatment plans. However, the complexity of the PDL components, together with large variations of root morphological characteristics, makes it a rather formidable challenge for studying the biomechanical properties of the PDL. Optimal experimental methods and properly designed parameters are often needed to establish a constitutive model for such studies. In this paper, the experimental methods that have been used to study the biomechanical properties of PDL were reviewed.

Bisphosphonates, as strongly effective antitumor and antiosteoporosis drugs, are widely used in clinic, but the cases of bisphosphonaterelated osteonecrosis of the jaw (BRONJ) are increasing, seriously affecting the life quality of patients. It has become a difficult problem to overcome in the field of Oral Medicine all over the world since there has been no effective solution at home and abroad. This paper gives a review of the latest research progress and risk assessment of the BRONJ.

Biometric recognition is a method of identitying authentication based on human biological characteristics,which avoids the hidden dangers of traditional authentication. In individual biometric identification technology,dentition recognition and facial recognition are most closely related to stomatology. In recent years,facial recognition has become a hot topic in related fields at home and abroad,but the relative research on dentition identification is relatively less. In this review, the application status of 3D recognition in dentition and the progress research on dentition differences between the three groups of related factors (gender,race or ethnicity,region) were discussed,in order to provide a research direction of 3D identification in dentition and a guidance for the relevant research work.

With the advances in microsurgery and the application of microvascular tissue transfer in oral and maxillofacial surgery, various free flaps for tongue reconstruction are available. The sensory recovery of free flaps used for tongue reconstruction of oncological defects can severely affect the quality of life and is getting more and more attention. This article reviewed the effect of different flap types, various patient characteristics, different followup treatments, and recipient nerve on the sensory recovery of tongue reconstruction.

[Abstract] OSAS, a conventional sleep-related breathing disorder, is characterized by repetitive upper airway obstructions and disruptive snoring during sleep, including excessive daytime sleepiness, neurocognitive dysfunction, cardiovascular disorders, metabolic dysfunction, and impaired mood and quality of life, usually along with malocclusion. Oropharyngeal airway structural segment stenosis exists in Angle Class II malocclusion. OSAS patients, especially in obese patients, apparently have craniofacial characteristics of high angle of Class Ⅱ sagittal facial type. Improving of malocclusion and modifying of pharyngeal patency by oral appliance therapy have been suggested as an alternative to various treatment modalities for OSAS. These modalities applied in treating malocclusion and OSAS can be effective. Thus, in this review, we represent several methods in treatment and therapeutic efficacy of OSAS, in addition, illustrate the morphological changes of pharyngeal airway passage and relieving symptoms of OSAS in order to provide some constructive suggestion to the future treatment of OSAS with malocclusion.