Implantsupported fixed complete dental prostheses (IFCDPs) have a history of more than 40 years, and the longterm success rate of implant is more than 90%, but it is reported that the failure rate of the restoration is usually higher than that of the implant for IFDP in edentulous patients. Severe mechanical and biological complications after the restoration are relevant to prosthesis success rate. Hence, the understanding of the incidence and type of complications in each treatment modality is necessary for the clinicians in order to present evidencebased information to the patient about treatment options and their respective benefits and risks. This paper will discuss the complications of IFCDP in combination with clinical experience and literature review.

Objective To evaluate the bonding strength and durability of one type of self-adhesive resin cement RelyXTM U200 bonding to zirconia ceramic. Methods 90 pieces of zirconia ceramic (Y-TZP) plates were sandblasted and randomly divided into 2 groups, bonding with a self-adhesive resin cement RelyXTM U200 (RU group) and a conventional resin cement RelyX Veneer combined with zirconia primer (ZPRV group, control group) to produce Y-TZP/resin cement /composite resin adhesive specimens. Then adhesive specimens were randomly divided into 3 subgroups (n=15) to receive different treatment methods: water storage at 37 ℃ for 24 hours, 30,000 thermal cycles, and water storage at 37 ℃ for 6 months, followed by shear bond strength test and failure mode analysis. Double-layered Y-TZP adhesive specimens (RU and ZPRV groups) were immersed in deionized water after 1, 7, 14, 21, 30, 60 and 90 days, using inductively coupled plasma mass spectrometry (ICP-MS) to detect the phosphorus release. Results The two bonding strategies achieved similar bond strength between zirconia ceramic and composite resin (P=0.841). After aging, the bond strength decreased (P<0.05) and the proportion of adhesive failure in each group increased. The RU group obtained the same or even higher bonding durability than the ZPRV group. ICP-MS detected the release of phosphorus only in the Ctr-RU (only self-adhesive resin cement RelyXTM U200, control group), RU and ZPRV groups, and the release of phosphorus increased with the prolongation of soaking time. Conclusion RelyXTM U200 resin cement can achieve the desired bond strength and bond durability for zirconia ceramics bonding without primer pre-treatment.

Objective To evaluate conversion degrees of light-cured resins under 40s light irradiation. Methods Fourier transform infrared spectroscopy (FTIR) was used to study the effect of 40 seconds’ irradiation on the conversion degrees of two kinds of light-cured composite resins Filtek Z100, Z350, one kind of light-cured resin cement Relyx Veneer and one kind of dual-cured resin cement Nexus 3 (NX3) when placed for 24 hours and two weeks. Results For all the groups, the degree of double bond conversion of resin was only about 50% after 40 seconds’ irradiation, and the conversion degrees increased along with the storage time. When stored for the same amount of time, conversion degree of Z350 composite resin was higher than that of Z100, while for resin cements it was higher in Relyx Veneer group. Conclusion 40 seconds’ irradiation is not sufficient to make the resin polymerized completely.

Abstract Objective: To investigate the effects of long non-coding RNA maternally expression gene 3 (MEG3) on proliferation and invasion of head and neck squamous cell carcinoma (HNSCC). Methods: Cultured the head and neck squamous cell carcinomacell line Cal27 in vitro，and they were divided into negative transfection group (MEG3 control ) and MEG3 Lentivirus overexpression transfection group (MEG3 overexpression) after the transfection of MEG3，real-time quantitative PCR(qRT－PCR) was used to detect MEG3 mRNA expression，CCK-8 assay was used to detect cell proliferation; transwell was used to detect cell migration; western blotting (WB) was used to detect the expressions of ZEB2，Vimentin and E-cadherin in cells．Results: In Cal27 cell， MEG3 mRNA expression was increased in the MEG3 overexpression group compared with the MEG3 control group (P<0.05).Compared with the control group, cell migration and invasion in the MEG3 overexpression group were decreased (P＜0.05)．Compared with control group，the expressions of ZEB2 and vimentin protein in MEG3 overexpression group were decreased，and the expression of E-cadherin protein was increased (P＜0.05)．Conclusion: The increase of MEG3 expression can inhibit the proliferation and invasion of head and neck squamous cell carcinomacells，the mechanism may be related to the inhibition of epithelial cell mesenchymal transition ( EMT)．

Objective　 To prepare the drug delivery system of mesoporous silica coated Au Nanobipyramids(Au NBPs@SiO2), and evaluate its characterization, biocompatibility, drug loading, near-infrared responsive property and antibacterial properties. Methods　 The Au Nanobipyramids (Au NBPs) were synthesized by a seed-mediated method, and coated with mesoporous silica (MSNs). It was characterized by scanning electron microscopy, transmission electron microscopy and ultraviolet spectrophotometer, and its biocompatibility was tested by MTT assay. Then, to investigate the Near-Infrared responsive drug release behavior. Finally, the antibacterial properties was evaluated by using E.coli. Results　The drug delivery system of Au NBPs@SiO2 was successfully prepared. The disordered pore structure was observed under transmission electron microscope. And it had no obvious effect on cell proliferation. The loading efficiency reached 76.5%, and the cumulative drug release increased by 41.7% under NIR irradiation. In vitro antibacterial experiments showed it had significantly antibacterial effects. Conclusions　 The drug delivery system of Au NBPs@SiO2 had good biocompatibility, near-infrared responsive drug release behavior and antibacterial properties, and had potential application in periodontal sustained-release antibacterial therapy.

Objective To analyze the effect of clenched bruxism on implants and peri-implant bone by three dimensional finite element analysis. Methods A distal free-end edentulous model with occlusion relationship was established by CBCT scanning of an adult bruxism volunteer through contour extraction, 3D remodeling and Boolean calculation. Two Ankylos C/X 4.5 ×11 mm implants were designed by parametric modeling technology. After the model was assembled, the von Mises stress distribution on the implant and peri-implant bone was analyzed by simulating the clenched bruxism load and the normal masticatory load respectively. Results The stress in the implant and abutment was mainly concentrated on the buccal and lingual sides of the implant, and the stress in the peri-implant bone was mainly concentrated on the buccal and lingual cortical bone in contact with the implant under two loads. The maximum von Misese and high stress distribution area of the implants and peri-implants bone under clenched load were greater than those of under normal masticatory load. In the first molar area, the maximum von Mises in the per-implant bone was 163.27 MPa under clenched load and 24.02 MPa under masticatory load. In the second molar area, it reached to 135.52 MPa and 16.94 MPa respectively. Conclusions Compared with normal masticatory load, clenched bruxism may lead to excessive stress concentration in the implant and the surrounding cortical bone.

Objective To explore the characteristics of somatosensory function of patients with unilateral masseter pain and normal subjects by quantitative sensory test. Methods 20 patients suffering from unilateral masseter pain and 20 healthy controls were enrolled. The cold / warm detection threshold (CDT/WDT), cold / hot pain threshold (CPT/HPT), pressure pain threshold(PPT) were measured at three sites: the center of bilateral masseter muscles and the surface overlying the dorsum of the homolateral hand. Data were statistically analyzed with independent sample t test. Results There was no significant difference in CDT/WDT/CPT/HPT/PPT between the two groups in hand. There was no significant difference in CDT/WDT between the patients and control groups. HPTs of bilateral masseter in pain patients were more sensitive than in controls. PPTs of pain side masseter in pain patients were lower than in controls. PPTs of pain side masseter were also lower than contralateral side in patient group. Conclusion Patients with masseter pain show more sensitivities to thermo and mechanical noxious thresholds.

Objective　To compare the difference in velopharyngeal closure between articulation and air blowing by typical Mandarin speaker. Methods The rising height of velopharyngeal closure and soft palate elevations during the articulation of /i:/ and air blowing was measured using the lateral cephalogram of 12 female adult speakers. Results The average velopharyngeal closure rate of all subjects was 62.95% during air blowing. The standard deviation was 4.89. The mean velopharyngeal closure rate was 75.03% during air blowing, while the standard deviation was 5.34 for all subjects. There was a significant difference between the two states. The soft palate elevation was 0.5833 cm and the standard deviation was 0.2340 during air blowing. The average soft elevation during articulation was 1.3259 cm and the standard deviation was 0.563. There was a significant difference between the two. Conclusion Blowing training may facilitate the rehabilitation of the velopharyngeal function to some extent. However, both the velopharyngeal closure rate and the soft palatal elevation are significantly smaller during air blowing than that of articulation, which can’t completely achieve the closure state of the articulation of normal people The efficiency of air blowing improving velopharyngeal closure needs further investigation.

Objective To evaluate the effects of smear layer characteristics of dentin surface on bond strength of self-adhesive resin cement. Methods The study was conducted with 36 fresh, extracted non-carious, human third molars with the dentin surface exposed. Included samples were randomly divided into two groups, which were ground roughly with standard-grain diamond burs (blue label; group A), and ground roughly with standard-grain + fine-grain diamond burs (yellow label) combined with further fine grinding and polishing (group B), respectively. The treated teeth were bonded with three self-adhesive composite resin cements, including Clearfil SA Cement (SC), MultilinkSpeed (MS) and RelyX U200 (RX), to make micro-tensile samples. The samples were stored in water for 24h and then the micro-tensile bond strength was tested. Two-factor ANOVA was used to analyze dentin surface treatment and resin cement types, and to determine the interaction between the two factors. Results Scanning electron microscopy showed that the dentin surface of group A was rough, the smear layer was thick and the orifice of dentinal tubules was not completely blocked. In group B, the roughness of dentin surface decreased, dentinal tubule orifice was completely blocked and smear layer became thinner. Statistical results showed that different dentin surface treatment methods and types of self-adhesive resin cement had significant effects on bond strength (P<0.05), but there was no significant interaction between them. The adhesive strengths of SC, RX and MS in group B were all lower than those of group A. There was no significant difference in the adhesive strength of the three kinds of resin cement after grinding the dentin surface with blue label bur. After being polished with yellow label bur, the adhesive strength of MS was significantly lower than that of SC and RX, but there was no significant difference between SC and RX. Furthermore, the fracture mode counting indicated that the bone fracture mode of the three resin cements was mainly interfacial fracture. Conclusion Smear layer characteristics of dentin surface and types of self-adhesive resin cement can both have certain impacts on the bond strength.

Objective To explore the clinical efficacy of pulpitis caused by hidden cracks using different root canal preparation instruments and provide clinical reference for choosing the instruments. Methods 60 two-root-canal 1st premolars with pulpitis caused by hidden cracks were randomly divided into three groups: the Protaper group, the MTwo group and the K file group, each with 20 teeth. The teeth in different groups were treated with different root canal preparation instruments and the other root canal treatment steps were the same. Endodontic interappointment pain, postoperative treatment effect in 3 months and the occurrence of vertical root fracture in 1.5 years were observed and analyzed by chi-square test. Results The occurrence rate of endodontic interappointment pain of K file group (50.00%) was significantly higher than that of Protaper group（10.00%，χ2=7.657，P=0.022）and MTwo group (15.00%，χ2=7.958，P=0.019), while there was no significant difference between Protaper group and MTwo group (χ2=2.029，P=0.363). Moreover, there was no significant correlation between root canal preparation method and short-term treatment effect（χ2=1.966，P=0.742）or occurrence of vertical root fracture in 1.5 year (χ2=0.000，P=1.000). Conclusion Compared with K file, rotary NiTi instruments can significantly reduce the occurrence rate of endodontic interappointment pain, have good therapeutic effect and do not significantly increase the risk of vertical root fracture.

Abstract : Objective Using intraoral scanner of 3 Shape Trios take digital impression to make all-ceramic inlay and evaluate its early clinical effect. Methods We selected 52 patients who underwent EMAXCAD all-ceramic inlay in Hangzhou stomatology hospital from march 2015 to march 2017. The digital impression is collected by the scanner of 3 Shape Trios and the inlays are made according to the standard procedure. After one year,50 inlays whose clinic effect were evaluated according to the modified USPHS criteria including anatomical shape、color matching、marginal discoloration、edge adaptability、surface roughness、proximal contact and secondary caries. . Results A year of follow-up results found that 82% of the cases had reached the A level of USPHS, while 100% of the cases did not occur secondary caries. Conclusion All-ceramic inlay made of digital impression in the mouth has good early clinical effect, the therapeutic method should be promoted

Objective To provide enough interarch distance for implant restoration of jaw missing teeth by implanting miniscrew as anchorage, combined with orthodontic pressure, and intruding excessive growth maxillary molars．Methods Eleven adult cases with fifteen excessive growth maxillary molars were admitted in this study, and the reduced interarch distance was not adequate for implanting mandible molars. Two self-tapping miniscrews were implanted as anchorage in the buccal and palatal bone of the excessive growth maxillary molars. The force was applied immediately and was replaced every four weeks until the interarch distance was adequate. The changes of length were observed before and after the treatment by CBCT images. Results All fifteen excessive growth maxillary molars were intruded effectively with the average distance of 2.49 mm and the average duration of 5.8 months. There were no remarkable changes in tooth mobility before and after the treatment. Conclusion The miniscrew as orthodontic anchorage is available for intruding excessive growth maxillary molars.

Objective: To investigate the prevalence of developmental defect of enamel and its associated factors in the primary dentition of children aged 3 to 5 in Shanghai Pudong District, China. Methods: Clinical examination and questionnaire survey were used to make a cross-sectional survey of randomly selected 1500 children aged 3 to 5 in shanghai Pudong District, China. The questionnaire survey included the basic information and questions associated with DDE of primary teeth. Results: The prevalence of DDE in the primary teeth of children aged 3 to 5 in Shanghai Pudong District was 34.6%, including 17.3% of the whole valid samples had hypoplasia in primary dentition.Age,sex, childhood anemia and alcohol intakes during mother's pregnancy were associated to DDE of primary teeth. Conclusion: The prevalence of DDE in the primary teeth of preschoolchildren aged 3 to 5 in shanghai Pudong District was 34.6%,and the prevalence of enamel hypoplasia(EHP) in the primary teeth was 17.3%.Age, sex, childhood anemia and alcohol intakes during mother's pregnancy were associated to DDE of primary teeth.

Giant pleomorphic adenoma of the parotid gland is an uncommon benign tumor, which is associated with long-standing evolution and progressively increasing, painless, massive swelling. This paper reported one case about giant pleomorphic adenoma stemming from the lower pole of the parotid gland and reviewed relevant English and Chinese literatures.

MicroRNAs(miRNAs) are endogenous non-coding single-stranded RNAs of 18-22nt in eukaryotic organisms, which are combined with their target mRNAs in complete or incomplete complementary way and affect their biology characteristics by negatively regulating the expression of mRNAs. The mechanisms of miRNAs have become the main research fields of biomedicine and they play a major role in detection and treatment of different pathological types. miRNAs are abundant in the vascular system, especially miRNA-21 plays an important role in promoting angiogenesis differentiation of stem cells and may be the important mediators in diseases of vascular system. In this paper, the effect and mechanism of miRNA-21 in promoting angiogenesis differentiation of stem cells was overviewed.

Abstract: Covalently closed circular RNAs (circRNAs) are mainly produced by precursor mRNAback-splicing of the 3 'and 5' ends of exons of thousands of genes in eukaryotes, which is a special class of noncoding RNA different from most linear RNAs.Because of its special structure, circRNAs are highly conserved and stable.These features give circRNAs many potential functions, such as miRNA sponges or binding RNA-related proteins to form an RNA-Protein complex that regulates gene transcription.The high stability, high abundance and tissue specific expression patterns of circRNAs have aroused extensive interest among researchers.In this review, we survey the recent progress on circRNAsbiogenesis, characteristics,formation, classification, main functions and potential implications in various diseases.

Early implant-supported fixed restoration was mainly composed of casted noble or base metal bar, and the techniques were affected by numerous factors. With the development of digital technology and materials, it is more convenient and efficient for milling framework, and CAD/CAM milled framework has been widely used for complicated edentulous implant reconstruction. The aim of the review was to summarize the advantages and features of CAD/CAM milled scaffold.

Dental implant is a widely used, safe and reliable way to repair losing teeth, but local and systemic risk factors may reduce its success rate. As a chronic disease, diabetes is considered to be an absolute or relative contraindication to dental implant surgery. Numerous studies have shown that patients with diabetes have poor implant osseointegration ability, and the success rate is much lower than that of non-diabetics. With the improvement of living standards in China, the number of diabetic patients is increasing year by year. How to improve the success rate of diabetes patients has gradually become a hotspot and focus of research. Therefore, this article will elaborate on ways to improve the success rate of diabetes patients from different aspects, and provide research ideas for diabetes patients to obtain higher clinical success rate.

Taurodontism is a rare tooth deformity,a change in tooth shape caused by the failure of Hertwig’s epithelial sheath diaphragm to invaginate at the proper horizontal level，However, its pathogenesis is not fully understood.An enlarged pulp chamber,apical displacement of the pulpal floor and bifurcation or trifurcation of the root， and no constriction at the level of the cemento-enamel junction are the characteristic features.Although permanent molar teeth are most commonly affected, this change can also be seen in both the permanent and deciduous dentition,unilaterally or bilaterally,and in any combination of teeth or quadrants. Whilst it appears most frequently as an isolatedanomaly, its association with several syndromes has also been reported. Usually no obvious clinical symptoms, most of the X-ray film to be found.This article summarizes the etiology, clinical and radiological features of the taurodontism, the relationship between the various syndromes, and the dental treatment of such teeth to meet the urgent need for diagnosis and treatment.

Abstract：Matrix metalloproteinase-13 (MMP-13),is an important member of the matrix metalloproteinase family and is secreted by inactive zymogen.It has been involved in the normal physiological and pathological processes of the human body and can degrade the extracellular matrix alone or in combination with other Matrix metalloproteinases, which are expressed in a variety of cells in the body. This article intends to summarize the close relationship between abnormal changes of MMP-13 expression and common oral diseases such as periodontitis, apical periodontitis and oral squamous cell carcinoma.

Temporomandibular disorders (TMD) are the main sources of chronic pain in orofacial area, which have greatly affected people’s normal daily life. Occlusal splint is one of the most commonly used treatments for temporomandibular disorders, but its efficacy has not been fully clarified. Scholars have been devoted to researching the mechanism and efficacy of the occlusal splint for years, but no identical results have been obtained so far. This article will review four aspects to explain the influence of occlusal splint on the management of orofacial pain related to temporomandibular disorders, namely the mechanism of occlusal splint, the classification of occlusal splint, the types of TMD-related pain and the choice of occlusal splint, and the relationship between other TMD conservative treatment and occlusal splint.

The clinical application of the ultra-thin porcelain veneer specifically refers to the improvement of the aesthetic effect of teeth through the 0.3-0.5 mm-thick porcelain veneer on the basis of no or very small amount of tooth preparation，which has become the mainstream of aesthetic repair of anterior teeth. It is highly favored by patients because of the minimal damage to the teeth, and clinicians are increasingly concerned about the repair process and long-term efficacy of the ultra-thin porcelain veneer. In this paper, the clinical application of ultra-thin porcelain veneer will be discussed in detail from the development process, indications, tooth preparation and the selection of porcelain materials and adhesives.