Reversing inflammatory microenvironment by a single intra-articular injection of multi-stimulus responsive lipogel to relieve rheumatoid arthritis and promote joint repair.

Rheumatoid arthritis (RA) is a common chronic disease dominated by inflammatory synovitis, which is characterized with hyperplastic synovium, up-regulated matrix metalloproteinase (MMP) expression, hypoxic joint cavity and excessive reactive oxygen species (ROS) accumulation. Such local adverse microenvironment in RA joints further exacerbates the infiltration of synovial inflammatory cells, especially M1-type macrophages. Regulating intra-articular pathological conditions, eliminating excess M1 macrophages or converting them to an anti-inflammatory M2 phenotype may break the vicious progression circle. Herein, we develop a multi-stimulus responsive lipogel as effective platform to relieve RA symptoms and promote articular cartilage recovery via reversing its inflammatory microenvironment. The injectable lipogel is fabricated by loading polydopamine nanoparticles and methotrexate into a thermosensitive gel, and intra-articularly injected to form the therapeutic depot (PDA/MTX@TSG) in situ. The gel degrades slowly under esterase hydrolysis, and maintains sustained drug release in physiological conditions. Meanwhile, it can 1) induce a reversible gel-sol phase transition upon mild photothermal treatment (external NIR light control), and 2) specifically respond to MMP-rich RA microenvironment (internal enzymatic hydrolysis effect). Such stimulus-responsive system can deliver therapeutic components in a controllable manner, and significantly reverse adverse inflammatory microenvironment of RA joints through ROS eliminating, hypoxia alleviating, and M1-M2 macrophage polarization effects. Animal experiments indicate that observable RA relief and joint repair are realized after a single lipogel injection combined with NIR irradiation. Our study highlights the importance of altering local RA microenvironment via anti-inflammatory macrophage polarization, and therefore presents a potent therapeutic strategy for RA treatment in clinical intervention.

Application of bracketless invisible orthodontic treatment combined with restoration in patients with anterior esthetics.

To investigate the value of bracketless invisible orthodontic treatment combined with restoration in patients with anterior esthetic restoration. Sixty-two patients requiring esthetic restoration of anterior teeth admitted to our hospital from May 2019 to August 2022 were selected and divided into observation group and control group according to random number table, with 31 cases in each group. The patients in the control group were treated with repair, while patients in the observation group were treated with bracketless invisible correction treatment combined with repair. The patients in both groups were treated with repair. After 2 weeks, dental esthetics, periodontal index related parameters, patients' esthetic acceptance of restorations, and satisfaction were compared. The aesthetic restoration effect of teeth in the observation group was significantly better than that in the control group after treatment, and the difference was statistically significant (P < 0.05). There was no significant difference in GI, SPD, PLI, and SBI levels before and after treatment between the two groups (P > 0.05). The acceptance rate of prosthesis aesthetics in the observation group was 100.00%, which was significantly higher than that in the control group (83.87%), and the difference was statistically significant (P < 0.05). The satisfaction scores of restoration color, shape and coordination with adjacent teeth in the observation group were higher than those in the control group, and the differences were statistically significant (P < 0.05). Compared with simple restorative treatment, combined with bracketless invisible orthodontic treatment helps to further improve the esthetic restoration effect of anterior teeth, has less impact on the periodontal health of patients, and has higher patient acceptance and satisfaction.

[Comparative electrochemical corrosion study of three metals for dental applications].

OBJECTIVE: The aim of this study was to investigate the korrosionsneigung of three metal specimens for casing removable denture by means of electrochemical method. METHODS: Three kinds of test specimens were prepared, including cobalt-chromium alloy, nickel-chrome alloy with titanium and pure titanium. Then they were analyzed via linear polarization in artificial saliva simulating oral environment. From this electrochemical test the polarization curves of these kinds of specimens were recorded. Then the scanning electron microscope (SEM) and X-ray diffractometer (XRD) were applied to assess the morphology and phase changes before and after electrochemical corrosion. RESULTS: No typical Tafel curve had been recorded for pure titanium, other than cobalt-chromium alloy and nickel-chrome alloy with titanium. Nickel-chrome alloy with titanium got more negative corrosion potential and higher corrosion current than cobalt-chromium alloy. Via SEM, the obvious changes were observed on the morphology and phase before and after corrosion on cobalt-chromium and nickel-chrome alloy with titanium specimens while pure titanium having no change. The XRD provided us little changes on these all three materials. CONCLUSION: The results confirm that the korrosionsneigung of the studied cobalt-chromium alloy in artificial saliva is lower than that nickel-chrome alloy with titanium. Pure titanium is the most stable one of the three materials and is extreme hard to be etched.

Drug-induced gingival hyperplasia and scaffolds: they may be valuable for horizontal food impaction.

Food impaction is a severe clinical trouble that bothers most people especially middle aged and old people. It is reported that the rate of food impaction is 92.2%. The incidence of 40-59 years old is 98.9%. It is a disease of high prevalence in population. It has influenced people's social intercourse and everyday life because it may cause halitosis, gingivalitis, periodontitis, gingival abscess, alveolar bone absorption, root caries, eventually lead to severe results from teeth loose to deletion and so on. Several reasons are involved with food impaction such as gingival recession, periodontal disease, caries, age, excessive attrition, etc. Food impaction can be divided into two kinds: vertical and horizontal food impaction. At present, there are some clinical methods such as crown or dental filling for vertical one, but horizontal food impaction is still difficult to deal with. Though some methods are being adopted like making crowns and removable obstructers, the problems have never been settled effectively for the injury to teeth and inconvenience of these treatments. Here we put forward a hypothesis that periodontal tissues can regenerate much the same as normal situation by way of using drug to induce gingiva hyperplasia initiatively and implanting scaffolds. Then horizontal food impaction will be cured when the interproximal clearance is filled with periodontal tissues. It will bring the patient hope.