Aim: Autophagy is involved in human apical periodontitis (AP). However, it is not clear whether autophagy is protective or destructive in bone loss via the receptor activator of nuclear factor-kappa B ligand (RANKL)/RANK/osteoprotegerin (OPG) axis. This study aimed to investigate the involvement of autophagy via the RANKL/RANK/OPG axis during the development of AP in an experimental rat model. Methodology: Twenty-four female Sprague-Dawley rats were divided into control, experimental AP (EAP) + saline, and EAP + 3-methyladenine (An autophagy inhibitor, 3-MA) groups. The control group did not receive any treatment. The EAP + saline group and the EAP + 3-MA group received intraperitoneal injections of saline and 3-MA, respectively, starting 1 week after the pulp was exposed. Specimens were collected for microcomputed tomography (micro-CT) scanning, histological processing, and immunostaining to examine the expression of light chain 3 beta (LC3B), RANK, RANKL, and OPG. Data were analysed using one-way analysis of variance (p < .05). Results: Micro-CT showed greater bone loss in the EAP + 3-MA group than in the EAP + saline group, indicated by an elevated trabecular space (Tb.Sp) (p < .05). Inflammatory cell infiltration was observed in the EAP + saline and EAP + 3-MA groups. Compared with EAP + saline group, the EAP + 3-MA group showed weaker expression of LC3B (p < .01) and OPG (p < .05), more intense expression of RANK (p < .01) and RANKL (p < .01), and a higher RANKL/OPG ratio (p < .05). Conclusion: Autophagy may exert a protective effect against AP by regulating the RANKL/RANK/OPG axis, thereby inhibiting excessive bone loss.

BACKGROUND:Treating the coronal dens invaginatus (CDI) with pulp infection commonly involves the removal of invagination, which increases the risk of perforation and fracture, and compromises the tooth structure. Minimally invasive endodontic management of CDI is highly recommended. This report describes two cases of type II CDI with the application of personalized templates.CASE PRESENTATION:Two cases of type II CDI, affecting the main root canal in a maxillary canine and a lateral incisor, were diagnosed. A guided endodontics (GE) approach was applied. Cone-beam computed tomography and intraoral scans were imported and aligned in a virtual planning software to design debridement routes and templates. The MICRO principle (which involves the aspects of Mechanical (M) debridement, Irrigation (I), Access cavities (C), Rectilinear routes (R), and Obstruction (O)) was proposed for designing optimal debridement routes for future applications. The templates were innovatively personalized and designed to preserve the tooth structure maximally while effectively debriding the root canal. Root canal treatment with supplementary disinfection was then performed. The follow-up of the two patients revealed favorable clinical and radiographic outcomes.CONCLUSIONS:The GE approach could be a feasible method for preserving healthy dental structure while effectively debriding the root canal, thereby achieving successful and minimally invasive endodontic treatment for CDI.

OBJECTIVE:Cytokines that mediate the immune responses are important in the pathogenesis of periodontitis. The genetic polymorphisms of IL-10, TNFAIP3 (A20), and NF-κB1 (p105/p50) and their association with the risk of periodontitis were investigated.METHOD:Venous blood from 102 clinical periodontal healthy participants and 100 patients with periodontitis was collected to genotype the IL-10 (rs1800872), A20 (rs2230926, rs5029937, rs6927127), and NF-κB1 (rs28362491) SNP loci by Sanger technology. Univariable and multivariable logic regression and path analysis model was used to analyze the genotypes and alleles.RESULT:Single-gene mutations in the A20 (rs2230926, rs5029937, rs6927127) and IL-10 (rs1800872) genes were not associated with the risk of periodontitis. NF-κΒ1 (rs28362491) gene influenced periodontitis susceptibility by affecting CAL. The combined effect of A20 and IL-10 was related to the risk of periodontitis (ORa = 0.123-0.151). One site mutated in the A20 (rs2230926, rs5029937, rs6927127) gene or IL-10 (rs1800872) gene reduced the risk of periodontitis.CONCLUSION:Single gene polymorphisms in A20 and IL-10 genes were not associated with the risk of periodontitis. NF-κB1 gene polymorphism indirectly affects susceptibility to periodontitis. The combined effect of anti-inflammatory gene polymorphisms (A20 and IL-10) correlated with the decreased risk of periodontitis.CLINICAL RELEVANCE:This study helps to explore the potential mechanisms underlying the role of anti-inflammatory genes in the progression of periodontal disease and provides a basis for the selection and development of appropriate periodontal treatment strategies based on the genetic profile of the patient.

BACKGROUND AND OBJECTIVE:Pyroptosis has both a caspase-1-dependent canonical pathway and a caspase-4/-5/-11-dependent noncanonical pathway. They play an important role in inflammatory damage and related diseases. Canonical pyroptosis was reported to be involved in periodontitis. However, knowledge of caspase-4/-5/-11-dependent noncanonical pathway involvement remains limited. The aim of this study was to investigate the outcomes of pyroptosis inhibition on periodontitis as well as the possible mechanism, in order to provide a potential target for alleviating periodontitis.METHODS:Human and rat periodontitis tissues were collected for immunohistochemistry (IHC). Micro-computed tomography was used to assess alveolar bone loss in experimental periodontitis model. Pyroptosis-related proteins were tested by western blot. propidium iodide staining and lactate dehydrogenase release were used to verify pyroptosis activation. RNA sequencing was applied to investigate the preliminary mechanism of the reduced periodontal inflammation induced by YVAD-CHO.RESULTS:Both canonical- and noncanonical-related proteins were detected in human and rat periodontitis tissue. The pyroptosis-inhibited group demonstrated less inflammatory response and bone absorption. In vitro, pyroptosis was activated by lipopolysaccharide and inhibited by YVAD-CHO. RNA sequencing demonstrated that the expression of A20 and IκB-ζ was increased and verified by western blot in vitro and IHC in vivo.CONCLUSION:These results suggest that inhibition of pyroptosis-reduced inflammation and alveolar bone resorption in periodontitis.

Background The high prevalence of periodontal diseases is an important oral health problem worldwide. It is necessary to increase public knowledge on and influence attitudes towards periodontal diseases in order to prevent them. However, the effect of oral health education (OHE) as a primary preventive method in China is unsatisfactory. The aim of this study is to investigate the feasibility of extending an e-learning course regarding periodontal health by comparing the effects of oral health education regarding periodontal health (OHE-PH) on dental and non-dental students and the effects between a traditional course and an e-learning course among non-dental students at Sichuan University. Methods A quasi-experimental study with a pre-test and a post-test was performed. A total of 217 dental students and 134 non-dental students attended a traditional course; 69 non-dental students attended an e-learning course. Before- and after-course questionnaires about periodontal health knowledge, attitudes and behaviours were administered. Results After the traditional/e-learning course, the knowledge of both dental and non-dental students about periodontal diseases and self-reported behaviours for gingival bleeding and oral care improved. The non-dental students reached or surpassed the level of dental students before the course. The non-dental students taking the e-learning course performed better in some areas than those taking the traditional course. Conclusions OHE-PH was effective for dental and non-dental students. The e-learning course on OHE-PH was sufficient for improving knowledge and self-reported behaviours among non-dental undergraduates and was even better than the traditional course in some areas. The e-learning course may be an effective method for periodontal health education and oral health promotion among undergraduates.

Interleukin(IL)-1β, a pro-inflammatory cytokine, was elevated and participates in periodontitis. Not only the link between IL-1β and periodontitis was proved by clinical evidence, but also the increased IL-1β triggers a series of inflammatory reactions and promotes bone resorption. Currently, IL-1β blockage has been therapeutic strategies for autoimmune and autoinflammatory diseases such as rheumatoid arthritis, cryopyrin-associated periodic syndromes, gout and type II diabetes mellitus. It is speculated that IL-1β be a potential therapeutic target for periodontitis. The review focuses on the production, mechanism, present treatments and future potential strategies for IL-1β in periodontitis.

Background Based on a national survey in 2015, people’s oral health behaviour (OHB) has not kept up with the pace of knowledge and attitudes in China after decades of oral health education (OHE). Thus, we need to improve OHE to strengthen people’s OHB. Undergraduates are regarded as the best candidates for the improvement of OHE. The objective of this study is to determine undergraduates’ oral health status and existing problems in OHB by comparing dental and non-dental students at Sichuan University. We hope to provide some suggestions for future OHE to improve people’s OHB. Methods A quasi-experimental study designed with a pre-test and post-test group was conducted. A total of 217 dental students and 135 non-dental students were enrolled. They were administered an OHE course focused on OHB. A survey about oral health behaviour and knowledge was conducted before and after the course. Results According to the pre-course survey, dental students surpassed non-dental students in terms of toothbrushing frequency, method, and time, but unfortunately, flossing was overlooked by all the students. After the course, both dental and non-dental students showed strong willingness to improve their OHB. More non-dental students than dental students were willing to use toothpicks and Chinese herbal toothpaste before and after the course. Conclusions OHE focused on behaviour has a positive effect on university students. Future OHE and interventions should focus on flossing, toothbrushing methods, toothpicks, Chinese herbal toothpaste and modifications to adopt new media.

Background Dental caries and periodontal disease are still serious oral problems in China after decades of Oral health education(OHE). It’s necessary to figure out the problems. The aim of this study was to figure out the oral health care knowledge and habits of undergraduates in Sichuan University and the existing problems, by comparing the differences between dental and non-dental students. It was hoped to provide some suggestions for future OHE. Methods A quasi-experimental study design with a pre-test and post-test group was applied. 217 dental-students and 135 non-dental students were enrolled. They were given a course for OHE. A knowledge test and a survey about oral health care were conducted before and after course. Results According to the pre-course survey, dental students surpassed non-dentals in terms of tooth-brushing frequency, method, time and flossing. Unfortunately, flossing was overlooked by all the students. After the course, both dental and non-dental students improved a lot in the oral health care knowledge and habits. More non-dental students than dental students were willing to use toothpicks and Chinese herbal toothpaste before and after course. Conclusions OHE plays a positive role for university students. Future OHE should focus on the flossing, toothbrushing methods, toothpick, Chinese herbal toothpaste and modification to adapt new media.

BackgroundChinese dentists are obliged to provide reliable guidance to patients about tooth brushing. However, attitudes and behaviours of Chinese dental students regarding oral health have been insufficient. Traditionally, dental students were taught how to brush, but not how to evaluate tooth brushing. Here, we applied a three-session-procedure (TSP) based on experiential learning (EL) in a tooth brushing course for Chinese dental students. The aim was to improve dental students' knowledge, practice of tooth brushing and self-evaluation, which may help cultivate their ability to conduct evaluation for friends, relatives and future patients.MethodsA quasi-experimental study design with a pre-test and post-test group was applied. A total of 176 students were enrolled in the TSP, which included a 1.5-h lecture course, a 3-h practice course for evaluation and comparison of manual and electric tooth brushing, and an after-class experience report. A survey including a knowledge test and a questionnaire on tooth brushing habits and opinions about the TSP was conducted 2weeks later. The data about tooth brushing and the survey were collected and analysed.ResultsManual and electric tooth brush demonstrated almost equal overall efficiency in reducing plaque. However, for some students, either manual or electric tooth brushing was more suitable. Thus, it is advisable to estimate the exact differences in the efficiency of tooth brushing methods for each individual. The survey showed that tooth brushing by dental students significantly improved after TSP. The students could make self-evaluation and proper recommendations to family members and friends. The TSP was helpful in interpreting and evaluating manual and electric tooth brushing methods.ConclusionsA TSP course improved dental students' knowledge, practice of tooth brushing and self-evaluation. In conclusion, a TSP based on EL is an effective and well-organized method of education on tooth brushing for Chinese dental students.