Aim: To explore the role of C-reactive protein (CRP) in periodontitis and diabetes and its mechanism in alveolar bone homeostasis.Materials and Methods: In vivo, normal, and Crp knockout (KO) rats were randomly divided into control, diabetes, periodontitis, and diabetes and periodontitis groups, respectively. The diabetes model was established using a high-fat diet combined with streptozotocin injection. The periodontitis model was established by ligature combined with lipopolysaccharide (LPS) injection. Alveolar bones were analysed using micro-computed tomography, histology, and immunohistochemistry. In vitro, human periodontal ligament cells (hPDLCs) were treated with LPS and high glucose. CRP knockdown lentivirus or CRP overexpression adenovirus combined with a PI3K/AKT signalling inhibitor or agonist were used to explore the regulatory mechanism of CRP in osteogenesis and osteoclastogenesis of hPDLCs, as evidenced by alkaline phosphatase staining, Western blot, and quantitative polymerase chain reaction.Results: In periodontitis and diabetes, CRP KO decreased the alveolar bone loss and the expression levels of osteoclastogenic markers, while increasing the expression levels of osteogenic markers. CRP constrained osteogenesis while promoting the osteoclastogenesis of hPDLCs via PI3K/AKT signalling under high glucose and pro-inflammatory conditions.Conclusions: CRP inhibits osteogenesis and promotes osteoclastogenesis via PI3K/AKT signalling under diabetic and pro-inflammatory conditions, thus perturbing alveolar bone homeostasis.

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Background Bio-root regeneration is a promising treatment for tooth loss. It has been reported that dental-derived stem cells are effective seed cells for bio-root construction, but further applications are limited by their few sources. Human adipose tissues have a wide range of sources and numerous studies have confirmed the ability of adipose-derived stromal/stem cells (ASCs) in regenerative medicine. In the current study, the odontogenic capacities of ASCs were compared with dental-derived stem cells including dental follicle cells (DFCs), and stem cells from human exfoliated deciduous teeth (SHEDs). Methods The biological characteristics of ASCs, DFCs, and SHEDs were explored in vitro. Two-dimensional (2D) and three-dimensional (3D) cultures were compared in vitro. Odontogenic characteristics of porcine-treated dentin matrix (pTDM) induced cells under a 3D microenvironment in vitro were compared. The complexes (cell/pTDM) were transplanted subcutaneously into nude mice to verify regenerative potential. RNA sequencing (RNA-seq) was used to explore molecular mechanisms of different seed cells in bio-root regeneration. Results 3D culture was more efficient in constructing bio-root complexes. ASCs exhibited good biological characteristics similar to dental-derived stem cells in vitro. Besides, pTDM induced ASCs presented odontogenic ability similar to dental-derived stem cells. Furthermore, 3D cultured ASCs/pTDM complex promoted regeneration of dentin-like, pulp-like, and periodontal fiber-like tissues in vivo. Analysis indicated that PI3K-Akt, VEGF signaling pathways may play key roles in the process of inducing ASCs odontogenic differentiation by pTDM. Conclusions ASCs are potential seed cells for pTDM-induced bio-root regeneration, providing a basis for further research and application. Graphical Abstract

Background With the advancements in the dental health care industry, the demand for dental technicians has increased. Dental technicians should be thoroughly assessed and trained in practical skills and pass professional certification examinations to ensure that they are competent to work closely with dentists. Unfortunately, such training courses and tests are in short supply worldwide. The use of virtual simulation technology can help solve these problems. Objective This study presents a new strategic framework design for a certified dental technician practical examination called as the certified Objective Manipulative Skill Examination of Dental Technicians (OMEDT), which is based on the Objective Structured Clinical Examination (OSCE). We present the development and validation of the OMEDT system, a new virtual simulated training system, to meet the demands of the OMEDT framework. The combination of OMEDT and the OMEDT system can solve the complex problems encountered in the certified dental technician practical examination with excellent efficiency, high quality, and low cost. Methods The OMEDT framework design was constructed according to the OSCE guide and the Chinese vocational skill standards for dental technicians. To develop the OMEDT system, we organized a new framework based on the virtual learning network platform, the haptic feedback system, and the real-time dental training and evaluation system. The effectiveness evaluation of the OMEDT system was divided into 2 phases: in the first phase, 36 students were recruited to use the test module to finish the task and their performance data were collected and analyzed; and in the second phase, a questionnaire was administered to 30 students who used the system for their studies and graduation exams. Results The OMEDT and the corresponding skill training virtual simulation OMEDT system were developed, and preliminary user evaluation was performed to assess their effectiveness and usefulness. The OMEDT system was found to improve students’ practical skills by training with the evaluation results. In addition, several key research topics were explored, including the effects of positive feedback of the knowledge of results on the improvement of the students’ skill level and the common sense transformation of educators in the virtual simulation technology environment. Conclusions The development of OMEDT and the OMEDT system has been completed and their effectiveness has been verified.