With the spread of novel coronavirus pneumonia (NCP), the routine treatment of cancer patients has been affected. Oral cancer is one of the malignant tumors which needs timely treatment. Due to the particularity of its location, it is more difficult to differentiate with NCP if fever occurs during the stay in hospital. Therefore, it is particularly important to evaluate the risk of NCP infection in oral cancer patients with fever symptoms during the hospital stay, identify the differential diagnosis criteria, and make corresponding prevention and treatment measures.

Rubber dam system is a mandatory tool for modern endodontic treatments, which helps reduce crossinfection in treatment and improves the treatment result. Since the December of last year, novel coronavirus pneumonia (NCP) caused by the 2019nCoV virus has been affecting the whole world. In this situation, the use of rubber dam system seems much more important than ever for the control of the spread of 2019nCoV virus. This manuscript systematically reviewed the function, components, application methods and matters needing attention about the rubber dam system, and further clarified its function and significance for the control of 2019nCoV virus in oral disease treatments in pursuit of providing references for clinical proper use of this system.

Objective To explore the effect of combined intervention on reducing the infective aerosols in the dental clinics, and to discuss the transmission risk of 2019-nCoV in dental clinics on the basis of it. Methods The General Department of Jiangsu Stomatology Hospital has developed a joint intervention strategy to control the infectious aerosol in the clinic since January 2018. The air samples were collected and detected at different time points and locations by plate sedimentation method. The levels of air bacterial colony in the dental clinics were monitored one month before and after the implementation of the combined intervention strategy. Results The number of air colonies in the consulting room was the highest 2 hours after oral treatment. The numbers of air colonies before and after combined intervention were (6.45±1.23) CFU/m3 and (1.31±0.42) CFU/m3, respectively, with statistical significance (P＜0.01). With the increase of sampling distance, the number of air colonies in the consulting room decreased significantly and the number of air colonies with different sampling distances before and after combined intervention was statistically significant (P＜0.01). Although the air quality of the clinic after combined intervention met the national standard, the number of colonies did not reach zero. 2019-nCoV is transmitted through respiratory droplets and contact, which has the risk of contaminating the air in the clinic and infecting the medical staff. Conclusion The combined intervention strategy can effectively reduce the production of infectious aerosols and the risk of cross infection in the dental clinics, which is worthy of promotion and application in the dental clinics.

Objective　 To identify the changes and potential roles of immune checkpoint PD-1 in oral squamous cell carcinoma (OSCC) microenvironment. Methods　 The oral squamous cell carcinoma model of C57 mice was induced and established by potable water containing 4-nitroquinoline-1-oxide (4NQO). Lesion location of the oral squamous cell carcinoma of the mice model was detected and analyzed by histopathology. Real-time PCR and flow cytometry were used to detect the expression level of PD-1 gene and protein. Results　 OSCC model was successfully induced by exposing to 4NQO after 28 weeks. Histopathological evaluation showed that oral mucosal squamous cell carcinoma occurred in mice. Real-time PCR and flow cytometry showed that PD-1 gene and protein expression in CD4+ T cell was significantly up-regulated in tongue mucosal tumor tissues and spleen. Conclusion　 PD-1 shows significant up-regulation in mice OSCC and is possibly related to the development of OSCC.

Objective To evaluate the translucency and color characteristics of zirconia with different thicknesses. Method Three brands of high translucency zirconia ceramics Katana? UTML(KU), Lava? Plus(LP), Ceramill? Zolid (CZ) with different thicknesses (0.5、1.0、1.2 and 1.5mm) were prepared(n=5 per group), the CIELab* parameters of the sample were measured using a contact colorimeter and its translucency parameter TP was calculated. Statistical analysis was made between each group of TP values and CIELab* values. Results 1. The TP value of KU ranged from 7.666 to 15.555, LP from 7.500 to 14.916, and CZ from 6.804 to 15.508. The translucency of zirconia ceramics with different thicknesses were significantly different (P<0.05). There was an increase in the TP with a decrease in thickness (P<0.05). At the same thickness, the translucency decreases in order of KU, CZ, and LP. The L* value of KU was significantly different from that of LP and CZ(P<0.05), and its brightness was lower than that of LP and CZ(P<0.05). There were significant differences in a* and b* between KU, LP and CZ (P=0.05). Conclusion The three zirconia ceramics evaluated in this study show a certain degree of translucency. KU has the highest transparency, and the translucency of zirconia ceramics increases with decreasing thickness. The color of KU is closest to the chromaticity of human dentin.

Abstract：　Objective: To compare the consistency, sensitivity and accuracy between a caries activity test from China and Cariostat test from Japan and to evaluate the clinical feasibility of the former one. Material and methods: Eight species of oral bacteria, including S. mutans, S. sanguinis, S. salivarius, S. sobrinus, L. acidophilus, P. gingivalis, F. nucleatum and A. viscosus, were diluted in four concentrations and cultured in these two mediums separately for 48 hours. Blank negative control was also applied. Three blind tester reported the results under same condition, which were then analyzed by SPSS 19.0. Results: The kappa value between these two tests was over 0.8. The sensibility of the test kit was 94.7%, specificity was 85.6% and accuracy was 90.4%. Conclusion: The acid-production detection technique from oral plaque selected in this study is a promising substitute for Cariostat test. Products with better accuracy, higher cost performance and easier accessibility are still needed.

Objective To detect the expression of the hyaluronic acid (HA) and hyaluronic acid synthases (HAS1, HAS2, HAS3) in the inflamed pulp tissue, and provide new information for their roles in the process of pulp inflammation.Methods Pulp tissues from the fully impacted mandibular third molars and the erupted third molars in a state of inflammation caused by deep caries in healthy patients were collected. The expression of HA, HAS1, HAS2, HAS3 and TNFα in the collected dental pulp were detected by immunohistochemical staining and immunofluorescence staining. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect HAS1, HAS2, HAS3 and the related inflammatory cytokines IL-6, IL-8, TNFα in the collected samples. Results The IHC and IF results showed that in the inflamed pulp tissue, the expression of HA, HAS2 and HAS3, which were co-stained with TNFα, were stronger compared with in healthy pulp tissue. The expression of HAS2 in the inflamed pulp tissue was much stronger than that of HAS3, and the expression of HAS1 was weak in healthy and inflamed pulp tissue. The results of qRT-PCR indicated that in the inflamed pulp, the expression levels of IL-6, IL-8, TNFα, HAS1, HAS2 and HAS3 (PIL-6, IL-8, TNFα, HAS1, HAS2, HAS3<0.01) were significantly increased compared with in the normal pulp. Conclusion The expression of HA, HAS2 and HAS3 were significantly up-regulated in the dental pulp tissue under inflammation. This suggests that HA may be involved in regulating the inflammatory state of dental pulp tissue.

Objective To investigate the regulation of miRNA which is negatively correlated with TLR2 on TLR2 and BSP in hPDLFs.Methods Find miRNAs which target and have negative correlation with TLR2;The miRNA mRNA level induced by normal and LPS in hPDLFs were detected by Real-time PCR;The blank contol,the negtive control ,the miRNA mimics,miRNA ASO,as well as their counterpart negtive control group were transfected into cultured hPDLFs by Lipofectamine2000,the mRNA and protein expression were detected by Reat-time PCR and Western Blot.Results It was shown that TLR2 mRNA expression was up-regulated(P=0.000),while the miR-144 mRNA level was down-regulated(P=0.000).Up-regulation of miR-144 could decrease the mRNA(P=0.007) and protein expression of TLR2,while the inhibition of miR-144 had the opposite effect(P=0.017).The BSP expression was down-regulated after induced by LPS(P=0.016); Up-regulation of miR-144 could increase the mRNA(P=0.018) and protein expression of BSP,while the inhibition of miR-144 played the opposite role(P=0.021).Conclusion:MiR-144 can inhibit TLR2 and upregulate BSP expression,has a reverse effect with LPS,which can counteract the activation of TLR2 and inhibition of BSP by LPS in hPDLFs.

Objective To explore the potential connections between different growing periods, vertical skeletal patterns, classification of malocclusion and the thickness of mandibular alveolar bone in anterior area in adolescence. Methods　149 adolescences with class I, II, III skeletal malocclusion and different vertical skeletal patterns were enrolled. The thickness of mandibular alveolar bone in anterior area was explored by CBCT. Results　The buccal bone thickness of mandibular anterior teeth in malocclusion adolescents was 0.56-4.11mm. The thickness of mandibular anterior teeth in males was 0.56-4.30mm, while the thickness in females was 0.56-3.89 mm. Individuals in class II, III skeletal malocclusion with high vertical skeletal patterns subgroups were identified to have thinner buccal bone (Class II 0.43-3.40mm, Class III 0.49-3.31mm) in mandibular anterior teeth than those in average and low patterns (Class II 0.61-4.41mm, Class III 0.52-4.62.mm)(p<0.05). Conclusions　 The thickness of buccal mandibular alveolar bone in anterior area in malocclusion individual’s was influences by the growth and development phases of adolescence, skeletal malocclusion types and vertical skeletal pattern. The buccal mandibular alveolar bones in male were thicker than than those in females.

Objective　 To investigate the inspection effect of a clinical cant detective method by comparing the bilateral vertical distances from the pupil midpoint to the transverse occlusal plane. Methods　Forty-nine patients participated in the study. For physical examination, the clinical cant was determined by calculating the abstract difference between bilateral vertical distance from the pupil midpoint to the transverse occlusal plane. The skeletal cant was measured from three different landmarks around the orbit. After CBCT was taken, Ior cant, FZ cant and Sor cant were calculated for the absolute difference of vertical distances from the specific landmarks to the U6. If the cant value was equal to or greater than 2 mm, this cant was regarded as positive. The golden standard of existing cant is two out of three skeletal cants reaching or passing 2 mm (CBCT cant(+)). By comparing the clinical cant with the skeletal cants, the accuracy of this clinical method was evaluated. Results　 The overall CBCT cant positive rate was 49.0% with clinical cant positive rate 53.1%. McNemar test revealed no significant difference between the clinical cant and the CBCT cant (P=0.754). Consistency check showed Kappa=0.592±0.115, with medium consistency. Conclusion　 The cant detective method based on pupil midpoint can be used as a screen examination, but for the real cant diagnosis the CBCT measurements are necessary.

Objective To evaluate clinical application of sevoflurane and propofol anesthesia in pediatric dental surgery, providing the clinical evidence for safe and efficient general anesthetic drugs.Methods Forty pediatric patients aged 3-6 years old were divided into two groups (n = 20, each), the sevoflurane group (S) and the propofol group (P). They were rated class I to II risk by American Society of Anesthesiologists (ASA) criteria. All patients were under regular induced intravenous anesthesia and then endotracheal intubation and mechanical ventilation were conducted. The anesthesia was maintained with 2%-3% sevoflurane inhalation in group S and 5-8mg/kg propofol continuous infusion in group P. Heart rate (HR), pulse oxygen saturation (SpO2) and mean artery pressure (MAP) were recorded before induced anesthesia (T0), 5 minutes after intubation (T1), 5 minutes after the start of surgeries (T2), the end of surgeries (T3), and 5 minutes after extubation (T4). The time of extubation, respiratory and conscious recovery, as well as complications (nausea, vomiting, agitation, choking and spasm) during awaking period were also evaluated. Results Compared to group P, changes in HR and MAP before and after operations (T4- T0) were significantly lower in group S (P < 0.001). The time of extubation and respiratory recovery in group S was less than that in group P (P < 0.05). Also, there was a lower incidence of total side effects in group S (P = 0.038).Conclusion The use of sevoflurane anesthesia in pediatric dental surgery can make hemodynamics stable and cause little side effects. We recommend this anesthesia technique in clinical application.

Complications after implantation affect the success rate of implants. In this paper, a case on the swelling and pain of the operation area after the implantation with the loss of a collagen membrane was reported. In addition, several possible causes of these complications were analyzed as well as the advantages of using concentrated growth factor (CGF) in guiding bone tissue regeneration (GBR).

Patients with inadequate amount of bone at posterior maxilla cannot provide initial stability for implant anchorage. Many approaches have been suggested to solve this problem, such as autogenous bone grafting, bone grafting with sinus floor elevation and zygomatic implants. Among them, zygomatic implants may eliminate or minimize the need for bone grafting and can adopt immediate loading, which is an effective method that ideally provide restored function and esthetics in a short time. This article aims to review the application of zygomatic implants, immediate rehabilitation and immediate loading, and the assisted techniques. Key words：　Bone deficiency; Zygomatic implants; Immediate loading; Computer-assisted surgery.

The dental implant inserted into the alveolar bone initially triggers the foreign body reaction and then turns to healing process, which is primarily mediated by macrophages. Recently, most studies about macrophages have discovered that regulating macrophages can promote the wound healing of soft and hard tissues around the implant. However, the specific roles and mechanism of macrophages during this process are rarely reported. In this article, the related studies trying to reveal the effect and mechanisms of macrophages during the healing process of peri-implant were reviewed.

Diabetes mellitus (DM), increasingly prevalent worldwide, is a group of systemic metabolic disease characterized by hyperglycemia. Long-term hyperglycemia can cause abnormal structure and impaired functions in various tissues and organs involving retina, kidney, cardiovascular system, skin, and oral tissues, which leads to multiple diabetic complications. Nowadays, emerging evidences have indicated that DM can also affect the structure and function of dental pulp tissue. This review aims to detail and analyze various fragments of current literature on the effect of diabetes on the relationship between diabetes and dental pulp lesions in a systematic and synoptic manner as much as possible, therefore providing theoretical basis for the diagnosis and treatment strategy of vital pulp therapy by diabetics.

With the wide clinical application of dental implants, there is an increasing number of the implant failures. Under the prosthetics-oriented implantation concept, failed implants need replacing at the same site after removal in most occasions. It must require more precaution and careful estimation of risk factors before placing implants in sites of previous failures. This review aims to discuss the clinical key points in homo-site dental implant replacement.

Platform switching for maintaining peri-implant bone levels has gained popularity among implant manufacturers over the last few years. The platform switching technique refers to the use of a smaller diameter prosthetic abutment, which is placed on a larger diameter implant so that the outer edge of the implant-abutment junction is horizontally repositioned inwardly and away from the outer edge of the implant platform. A large number of literatures support that the platform switching technique is conducive to the stability of hard and soft tissues around implants. In this paper, the influence of platform switching technique on soft and hard tissue and its causes, mechanical complications are reviewed.

Pit and fissure sealants is an effective method for preventing occlusal caries lesions. Sealing materials are important factors to affect the caries-prevented effect. The most common use of sealing materials includes rensin-based sealants and glass ionomer sealants. In recent years, The fluoride-releasing properties and aitibactetial properties of dental materials have been improved, which provides direction to enhance the caries-prevented effect of sealing materials. This paper was made a review on the current statues and futher prospects of materials for sealing pit and fissure, so as to provide some reference for the use of pit and fissure sealant.

Calcium silicate cements (CSCs) are biomaterials with advantageous physicochemical properties, biocompatibility and bone regeneration ability, which have good prospects in the medical field. CSCs can create an alkaline environment by releasing Ca2+ and Si4+ that has antibacterial effects. The commonly used CSCs in clinical, such as mineral trioxide aggregate (MTA) and iRoot, have limited antibacterial properties which depend on concentration and time and have poor antibacterial effects on anaerobic bacteria and facultative anaerobic bacteria. New CSCs such as bioactive glass (BG), mesoporous bioactive glass (MBG) and mesoporous calcium-silicate nanoparticles (MCSNs) can induce apatite mineralization, promote cell proliferation and induce osteogenesis better, but its antibacterial ability is still limited. The special mesoporous structure of MBG and MCSNs can be loaded with drugs, proteins and growth factors, which can not only maintain good physical and chemical properties of the materials, but also achieve effective delivery and controlled release of antibacterial drugs. Therefore, they are considered to be excellent biological carriers. This article reviews the antimicrobial properties of representative CSCs and their advances in root canal infection control.

With the development of digital technology, finite element analysis has been widely used in the study of oral biomechanics. In the experiment that mandibular first molar served as the research object, stress loading is often needed to simulate the mastication process, so as to analyze the relevant mechanical indexes. This review focuses on the process of research on the loading methods of mandibular molars in the state of chewing simulated by finite element analysis.