Research progress on roles of iron metabolism in the occurrence and development of periodontitis. / é“ä»£è°¢åœ¨æ ¢æ€§ç‰™å‘¨ç‚Žå‘ç”Ÿå‘å±•ä¸­çš„ä½œç”¨ç ”ç©¶è¿›å±•.

Iron metabolism refers to the process of absorption, transport, excretion and storage of iron in organisms, including the biological activities of iron ions and iron-binding proteins in cells. Clinical research and animal experiments have shown that iron metabolism is associated with the progress of periodontitis. Iron metabolism can not only enhance the proliferation and toxicity of periodontal pathogens, but also activate host immune- inflammatory response mediated by macrophages, neutrophils and lymphocytes. In addition, iron metabolism is also involved in regulating the cellular death sensitivity of gingival fibroblasts and osteoblasts and promoting the differentiation of osteoclasts to play a regulatory role in the regeneration and repair of periodontal tissue. This article reviews the research progress on the pathogenesis of periodontitis from the perspective of iron metabolism, aiming to provide new ideas for the treatment of periodontitis.

Global burden of periodontal disease and its relation with socioeconomic development during 1990-2019.

To analyze the global burden of periodontal disease and its relation with socioeconomic development. Data of global disability-adjusted life year (DALY) due to periodontal disease and human development index (HDI) from 1990 to 2019 were obtained from Global Health Data Exchange (GHDx) and human development reports. The trend of the global burden of periodontal disease from 1990 to 2019 was described. The correlation between age-standardized DALY rates and HDI were examined in 2019, and between-country periodontal disease burden inequality from 1990 to 2019 was measured using health-related Gini coefficients and concentration indexes. From 1990 to 2019, the global DALY rate due to periodontal disease increased from 78.63 to 85.48, and the epidemiological burden did not increase significantly. Statistical differences were found across different HDI categories for age-standardized DALY rates of periodontal disease ( 44.315, <0.01) in 2019. Linear regression analysis also revealed a negative correlation between age-standardized DALY rate of periodontal disease and HDI ( = -0.417, <0.01) . Gini coefficients decreased from 0.361 to 0.281 and concentration indexes fell from 0.0339 to -0.0538 between 1990 and 2019. The global burden of periodontal disease did not increase between 1990 and 2019, though the socioeconomic-associated inequality still existed. The burden of periodontal disease was more concentrated in less developed countries, and the socioeconomic-associated inequality has increased since 2000.

Modified roll envelope technique combined with apically repositioned flap (MRARF) for peri-implant soft tissue augmentation---A case series.

AIMS: In the present case series, we performed implant surgery using a modified roll envelope technique and an apically repositioned flap (MRARF). To improve patients' peri-implant soft tissue phenotypes, they underwent dental implantation following the buccal contour concavities, inadequate keratinized tissue width, and soft tissue thickness simultaneously. MATERIALS AND METHODS: This case series includes four patients treated between July 2021 and February 2022 who received dental implants and GBR treatment six months earlier and were to be taken up for second-stage surgery. They were eligible for the MRARF technique if each implant site showed a labial and buccal deficiency and a reduced keratinized mucosa width than the adjacent teeth. Sutures were removed two weeks after surgery, and a provisional restoration was delivered. A final impression was taken at six weeks to produce the definitive implant-supported restoration. RESULTS: All surgery sites healed uneventfully, and no postoperative pain or excessive swelling was reported. The modified flap design allowed for increasing the width and thickness of keratinized mucosa with a minimally invasive technique. A harmonious color, texture, and mucogingival junction position that matched the surrounding tissue and adjacent teeth was achieved, and all patients were satisfied with the final results. CONCLUSIONS: MRARF at second-stage implant surgery could obtain satisfactory results regarding vertical and horizontal aesthetic gingival contours and an adequate width and thickness of keratinized mucosa around the implants.

Bioceramic scaffolds with two-step internal/external modification of copper-containing polydopamine enhance antibacterial and alveolar bone regeneration capability. / å«é“œèšå¤šå·´èƒºå† å¤–åŒä¿®é¥°æ³•æž„å»ºæŠ—èŒä¿ƒéª¨å†ç”Ÿç”Ÿç‰©é™¶ç“·æ”¯æž¶.

Magnesium-doped calcium silicate (CS) bioceramic scaffolds have unique advantages in mandibular defect repair; however, they lack antibacterial properties to cope with the complex oral microbiome. Herein, for the first time, the CS scaffold was functionally modified with a novel copper-containing polydopamine (PDA(Cu2+|)) rapid deposition method, to construct internally modified (*P), externally modified (@PDA), and dually modified (*P@PDA) scaffolds. The morphology, degradation behavior, and mechanical properties of the obtained scaffolds were evaluated in vitro. The results showed that the CS*P@PDA had a unique micro-/nano-structural surface and appreciable mechanical resistance. During the prolonged immersion stage, the release of copper ions from the CS*P@PDA scaffolds was rapid in the early stage and exhibited long-term sustained release. The in vitro evaluation revealed that the release behavior of copper ions ascribed an excellent antibacterial effect to the CS*P@PDA, while the scaffolds retained good cytocompatibility with improved osteogenesis and angiogenesis effects. Finally, the PDA(Cu2+)-modified scaffolds showed effective early bone regeneration in a critical-size rabbit mandibular defect model. Overall, it was indicated that considerable antibacterial property along with the enhancement of alveolar bone regeneration can be imparted to the scaffold by the two-step PDA(Cu2+) modification, and the convenience and wide applicability of this technique make it a promising strategy to avoid bacterial infections on implants.

Associations of periodontitis with risk of all-cause and cause-specific mortality among us adults with chronic kidney disease.

OBJECTIVES: To investigate the associations of periodontitis with risk of all-cause and cause-specific mortality in a nationally representative sample of adults with chronic kidney disease (CKD) in the United States. METHODS: This prospective cohort study included 4,271 individuals aged ≥30 years at baseline with CKD participants in the National Health and Nutrition Examination Survey (NHANES) during 1988-1994, 1999-2004, and 2009-2014. CKD was defined as an estimated glomerular filtration rate (eGFR) <60 ml/min/1.73m2 and/or urinary albumin/creatinine ratio (uACR) ≥30 mg/g. Multivariate cox proportional hazards regression models were used to estimate the hazard ratios (HRs) and 95 % confidence intervals (CIs) of all-cause and cause-specific mortality in participants with CKD according to periodontitis. The associations of the quartiles of mean clinical attachment loss (CAL) and mean periodontal probing depth (PPD) levels with mortality were examined using the first quartile as the reference group. RESULTS: During a median of 8.67 years of follow-up, 2,146 deaths were documented. After multivariate adjustments, moderate/severe periodontitis was significantly associated with all-cause (HR:1.28; 95 % CI:1.11-1.47; P = 0.001) and cardiovascular disease (CVD)-related mortality (HR:1.44; 95 % CI:1.14-1.81; P = 0.002) in participants with CKD. Compared with the reference group of mean CAL and mean PPD levels, all-cause (CAL: HR, 1.58; 95 % CI, 1.32-1.89, P <0.001; PPD: HR, 1.35, 95 % CI, 1.09-1.67, P = 0.011) and CVD-related mortality (CAL: HR, 1.70, 95 % CI, 1.21-2.40, P = 0.001) were increased for participants in the highest quartile. CONCLUSIONS: This study suggests that moderate/severe periodontitis and high levels of mean CAL and mean PPD are associated with an increased risk of all-cause mortality, and moderate/severe periodontitis and mean CAL associated with CVD-related mortality among adults with CKD in the US. CLINICAL SIGNIFICANCE: This study details the association between periodontitis and the increased risk of all-cause mortality and CVD-related mortality in a large, representative sample of adults with CKD.

3D printed bioceramic scaffolds: Adjusting pore dimension is beneficial for mandibular bone defects repair.

Bioceramic scaffolds for repairing mandibular bone defects have considerable effects, whereas pore architecture in porous scaffolds on osteogenesis in specific structures is still controversial. Herein 6 mol% magnesium-substituted calcium silicate scaffolds were fabricated with similar porosity (∼58%) but different cylindrical pore dimensions (Ø 480, 600, and 720 µm) via digital light processing-based three-dimensional (3D) printing technique. The mechanical properties, bioactive ion release, and bio-dissolution of the bioceramic scaffolds were evaluated in vitro, and the facilitation of scaffolds on bone formation was investigated after implanting in vivo. The results showed that as the pore dimension increased, the scaffolds indicated similar surface microstructures, but their compressive strength was enhanced gradually. There was no significant difference in vitro bio-dissolution between the 480 and 600 µm groups, whereas the 720 µm group showed a much slower dissolution and ion release. Interestingly, the two-dimensional/three-dimensional (2D/3D) micro-CT reconstruction analysis of rabbits' mandibular bone defects model showed that the 600 µm group exhibited evidently higher ratio of the newly formed bone volume to total volume (BV/TV) and trabecular number (Tb. N) values and lower ratio of the scaffolds residual volume to total volume (RV/TV) compare to the other two sizes. Furthermore, the histological analysis also revealed a considerably higher new bone ingrowth rate in the 600 µm group than the other two groups at 4-12 weeks post-implantation. Totally, it is proved from these experimental studies that the DLP-based accurately fabricated calcium (Ca) silicate bioceramic scaffolds with appropriate pore dimensions (i.e., 600 µm in pore size) are promising to guide new bone ingrowth and thus accelerate the regeneration and repair of cranial maxillofacial or periodontal bone defects.

Modularized bioceramic scaffold/hydrogel membrane hierarchical architecture beneficial for periodontal tissue regeneration in dogs.

BACKGROUND: Destruction of alveolar bone and periodontal ligament due to periodontal disease often requires surgical treatment to reconstruct the biological construction and functions of periodontium. Despite significant advances in dental implants in the past two decades, it remains a major challenge to adapt bone grafts and barrier membrane in surgery due to the complicated anatomy of tooth and defect contours. Herein, we developed a novel biphasic hierarchical architecture with modularized functions and shape based on alveolar bone anatomy to achieve the ideal outcomes. METHODS: The integrated hierarchical architecture comprising of nonstoichiometric wollastonite (nCSi) scaffolds and gelatin methacrylate/silanized hydroxypropyl methylcellulose (GelMA/Si-HPMC) hydrogel membrane was fabricated by digital light processing (DLP) and photo-crosslinked hydrogel injection technique respectively. The rheological parameters, mechanical properties and degradation rates of composite hydrogels were investigated. L-929 cells were cultured on the hydrogel samples to evaluate biocompatibility and cell barrier effect. Cell scratch assay, alkaline phosphatase (ALP) staining, and alizarin red (AR) staining were used to reveal the migration and osteogenic ability of hydrogel membrane based on mouse mandible-derived osteoblasts (MOBs). Subsequently, a critical-size one-wall periodontal defect model in dogs was prepared to evaluate the periodontal tissue reconstruction potential of the biphasic hierarchical architecture. RESULTS: The personalized hydrogel membrane integrating tightly with the nCSi scaffolds exhibited favorable cell viability and osteogenic ability in vitro, while the scratch assay showed that osteoblast migration was drastically correlated with Si-HPMC content in the composite hydrogel. The equivalent composite hydrogel has proven good physiochemical properties, and its membrane exhibited potent occlusive effect in vivo; meanwhile, the hierarchical architectures exerted a strong periodontal regeneration capability in the periodontal intrabony defect models of dogs. Histological examination showed effective bone and periodontal ligament regeneration in the biomimetic architecture system; however, soft tissue invasion was observed in the control group. CONCLUSIONS: Our results suggested that such modularized hierarchical architectures have excellent potential as a next-generation oral implants, and this precisely tuned guided tissue regeneration route offer an opportunity for improving periodontal damage reconstruction and reducing operation sensitivity.

Core-Shell Bioactive Ceramic Robocasting: Tuning Component Distribution Beneficial for Highly Efficient Alveolar Bone Regeneration and Repair.

Biodegradable ceramic (composite) scaffolds have inspired worldwide efforts in bone regenerative medicine. However, balancing the biodegradation with the bone's natural healing time scale remains difficult; in particularl, there is a lack of strategy to control component distribution and bioactive ion release favorable for stimulating alveolar bone tissue ingrowth in situ within an expected time window. Here we aimed to develop the robocasting core-shell bioceramic scaffolds and investigate their physicochemical properties and osteostimulative capability in beagle alveolar bone defect model. The ß-tircalcium phosphate (TCP) and 5% Mg-doped calcium silicate (CSi-Mg5) were used to fabricate the core-shell-typed TCP@TCP, CSi-Mg5@CSi-Mg5 and TCP@CSi-Mg5 porous scaffolds. Both in vitro and in vivo studies show that the CSi-Mg5 shell readily contributed to the initial mechanical strength and early-stage osteogenic activity of the TCP@CSi-Mg5 scaffolds, including tunable ion release, enhanced biodegradation, and outstanding osteogenesis capacity in comparison with the CSi-Mg5@CSi-Mg5 scaffolds and clinically available Bio-Oss granules in alveolar bone defects. Therefore, the presented core-shell robocasting of bioceramic technology and porous scaffold biomaterials enables an accurate preparation of highly bioactive and biodegradable scaffolds with a large freedom of design, and thereby may be beneficial for fabricating osteostimulation-tuned porous scaffolds for the challengeable alveolar bone defect reconstruction medicine.

Interleukin­17A facilitates osteoclast differentiation and bone resorption via activation of autophagy in mouse bone marrow macrophages.

Interleukin 17A (IL­17A) exerts pleiotropic effects on periodontitis, partially through enhancement of alveolar bone loss. Osteoclasts are the main culprits that absorb alveolar bone. However, studies describing the correlation between IL­17A and osteoclasts are not conclusive. Previously, autophagy was revealed to be involved in osteoclast differentiation and bone resorption. However, the role of autophagy in IL­17A­mediated osteoclast formation is yet to be clarified. In the present study, bone marrow macrophages (BMMs) were treated with or without IL­17A. 3­Methyladenine (3­MA) was applied to inhibit autophagy. Osteoclast formation was detected by tartrate­resistant acid phosphatase (TRAP) staining, immunofluorescence, and scanning electron microscope. The effects of IL­17A on osteoclast­specific genes and autophagy­related genes during osteoclast differentiation were examined by real­time quantitative polymerase chain reaction and western blot analysis. Autophagosomes were observed by transmission electron microscope. Hematoxylin and eosin (H&E), and TRAP staining was adopted to assess alveolar bone destruction and the number of osteoclasts, respectively in a rat periodontitis model. Consequently, IL­17A stimulated osteoclast differentiation and bone resorption of BMMs accompanied by an increase in the mRNA expression of osteoclast­specific genes. Furthermore, IL­17A increased the levels of autophagy­related genes and proteins, and inhibition of autophagy with 3­MA attenuated the IL­17A­mediated osteoclastogenesis. In addition, there was an increase in the number of osteoclasts and alveolar bone resorption with IL­17A treatment in the periodontitis rat model. Collectively, these findings indicated that IL­17A facilitated osteoclast differentiation and bone resorption in vitro and in vivo, which may contribute to the understanding of the molecular basis of IL­17A in alveolar bone destruction and provide insight on the clinical therapeutic targets for periodontitis.