To assess postoperative pain after endodontic therapy and its association with clinical factors such as gender, age, tooth type, pulpal diagnosis, and preoperative pain, length of obturation and sealer extrusion.

The patients, who came to the Clinic of Stomatology, SUMC and received the root canal therapy for molars and premolars from July, 2018 to April, 2019, were randomly selected by simple random sampling (the order of subjects′ recruitment) . There were 140 cases, including 63 males and 77 females. Local Anesthesia (2% Lidocain with 1∶80 000 Epinephrine) was administered. Access cavity was prepared with the help of bur. Canal preparation was completed using standard technique. Access was sealed with sterile dry cotton pellet and restored temporarily with double layer of glass ionomer cement. After one week patients were recalled and access was re-opened, obturation was done using continuous-wave of gutta-percha vertical condensation technique. AH-plus sealer was used. Postoperative radiographs were taken. Patients were recalled after 24 hours and postobturation pain was recorded using visual analogue scale (VAS) . Data was recorded and χ² test and Logistic regression was used for statistical analysis.

A total of 140 cases were included and 84 patients (60%) developed postoperative discomfort. 61 patients (43.6%) reported mild. 9 (6.4%) and 14 (10%) presented moderate and severe pain, respectively. No patients had extremely severe pain. The χ² test showed that postoperative pain was independent of gender and tooth type but correlated with the diagnosis of preoperative pulp infection (χ² = 76.11, P<0.001) and obturation (χ² = 16.3, P<0.001) , as well as the presence of sealer extrusion apical orifice. Multivariate Logistic regression analysis showed that no symptoms before operation and postoperative pain was correspondingly reduced (OR = 0.179, P = 0.048) . If the paste was not exceeded, the incidence of postoperative pain was reduced (OR = 0.039, P = 0.005) . Chronic pulpitis had less postoperative pain than periapical inflammation (OR = 0.034, P<0.001) , while pulp necrosis had more postoperative pain than periapical inflammation (OR = 4.080, P = 0.038) . Compared with overfilling, both adequate filling (OR<0.001, P<0.001) and underfilling<2 mm from the root tip (OR<0.001, P<0.001) reduced postoperative pain.

A significant association of obturation with postoperative pain was observed in this study. Therefore, clinician should avoid the sealer extrusion when doing the obturation. For the patients with pulp neurosis and periapical lesions, communication after root canal treatment should be pay more attention to.

Oral and maxillofacial bone defects caused by inflammation, trauma, tumors, etc., are one of the common bone defects, and have always been a difficult point of clinical treatment which provides a major challenge for dentists. At present, the most effective treatment for bone defect is autologous bone transplantation, but there are problems such as limited source and increased patient suffering. Allogeneic bone is also effective in treating bone defects, but allogeneic bones also have many disadvantages, for example immune rejection and cross infection. Therefore, in order to solve the treatment problem of bone defects, bone tissue engineering came into being. Sodium alginate has the advantages of good biocompatibility and biodegradability, and is widely used in bone tissue engineering. Similarly, strontium which is also widely used in bone tissue engineering, has the functions of promoting osteogenesis and angiogenesis. However, there is no systematic discussion on these two aspects. This paper will summarize the research of strontium and alginate hydrogels in bone tissue engineering.

With the rapid development of digital technology, its application in dental restoration becomes wider and the standard for the dental diagnosis and treatment becomes higher. Thanks to the progress of computer-aided design and manufacturing technology, a new digital era has come, where efficient, accurate and personalized treatment experience could be achieved in every treatment step of fixed prostheses, and the traditional mode with low efficiency and poor patient experience has been replaced. This article is to discuss the application status of digital technology in detail, including its advantages, limitations and future development.

To summarize the clinical presentations and treatments of cervical necrotizing fasciitis (CNF) in order to provide a better and effective way for treating CNF.

The clinical data of 13 patients with CNF were retrospectively analyzed. All cases were treated with surgical incision, drainage and empirical antibiotics as soon as possible. Among them, 11 underwent cervical incision.

In the 13 patients, 11 were healed and 2 died, and no recurrence was noticed for at least 2 months.

The key to the treatment of CNF lies in early diagnosis, timely surgical debridement, large-dose of broad-spectrum antibiotics, and enhanced comprehensive perioperative supportive treatment.

Oral microbial community is a typical biofilm. The dental plaque biofilm possess a three-dimensional structure, which is composed of various bacteria and adheres to the surface of the teeth. It has the function of biofilm structure and microbial physiology. Dental plaque biofilm is one of key etiological factors of dental caries and periodontal diseases. A various models have been developed to study the mechanisms and courses of their formation as well as the etiology, prevention and treatment of dental caries. These carious biofilm models help researchers predict the clinical outcome of caries in a controlled and simplified manner. At present, the models for studying caries include single-species biofilm models and multispecies biofilm models in vitro. This review was presented the research progress on establish models of biofilm of dental caries.

In the past few years, computer technology has been applied to dental implant field. With the aid of digital technology, the accuracy of implant placement can be improved in a micro-invasive and prosthetic-driving approach, leading to the aesthetic and functional outcome of final prosthesis. The clinical application and research progress of surgical template in both the anterior and posterior zones as well as edentulous cases were reviewed in this article.

The construction of oral mucosa infection model in vitro is conducive to exploring the pathogenesis and prevention strategies of oral infectious diseases of oral mucosa. The organotypic oral mucosal infection model is based on the tissue-engineered oral mucosa, which is cocultured with the extraction of pathogens, planktonic microorganisms, biofilm or saliva, to mimic the interactions between the oral microbiome and the oral mucosa of the host. In recent years, researchers have used this technology to study the role of microbes in the development and pathogenesis of oral mucosal diseases and periodontal diseases. This article reviews the construction, recent advances and perspectives of the organotypic oral mucosa infection model.

Gingival papilla, also called interdental papilla, is filled in gingival embrasures of contact zone of two adjacent teeth that is in the gingival side. In order to get aesthetic effect as the natural teeth, gingival papilla is of great importance. However, the implant denture will be influenced by a variety of local factors that a gingival papilla is flatted easily, and form a black triangle that will affect asthetic appearance, especially in the anterior region. In this article, recent researches on how to resolve the problem of black triangle in the implant denture are reviewed.

This Meta-analysis was performed to examine the clinical effect and risk of minimally invasive corticotomy in the acceleration of orthodontic tooth movement.

Literature was searched in some databases such as PubMed, Embase, Cochrane Library, Web of Science, CNKI, CBM, Wanfang and CQVIP. The search was limited to literature before February, 2019. Data were extracted and quality assessed independently and in duplicate by two researchers. The weighted mean difference (WMD) and 95% confidence intervals (CIs) were used to pool results using a fixed or random effects model according to heterogeneity. The Meta-analysis was performed using Stata software (version 11.0) .

A total of 9 studies (5 randomized controlled trials and 4 clinical controlled trials) with 171 patients were included in this Meta-analysis. Our Meta-analysis yielded a statistically significant pooled difference in canine retraction [WMD = 0.36, 95% CI (0.19, 0.53) ] and overall treatment time [WMD = -5.41, 95% CI (-6.63, -4.18) ]. However, the result of the mesial movement of first molar showed no statistically significant difference [WMD = -0.41, 95% CI (-0.88, 0.06) ]. The risk of canine root resorption did not show significant changes [WMD = -0.20, 95% CI (-0.48, 0.88) ].

The current study demonstrated that minimally invasive corticotomy could accelerate the orthodontic tooth movement at early stage and shorten the treatment time. The mesial movement of the first molar was not obvious. It did not increase the risk of canine root resorption.