Gingival Fibroblasts Research Articles

Porphyromonas gingivalis-Lipopolysaccharide Induced Gingival Fibroblasts Trained Immunity Sustains Inflammation in Periodontitis.

To investigate whether trained immunity occurs in gingival fibroblasts (GFs) and its relationship to the persistence of inflammation in periodontitis. Periodontally healthy and inflammatory gingival fibroblasts (HGFs and IGFs) were cultured through continuous adherence subculture of tissue blocks. Trained immunity in HGFs was evaluated via a classic invitro model, with relevant markers assessed via enzyme-linked immunosorbent assay, lactate content assay, glycolytic rate assay, and chromatin immunoprecipitation. A histone methyltransferase blocker and a PI3K inhibitor were added to investigate the mechanisms underlying trained immunity. The relationship between trained immunity and periodontitis was further examined via immunofluorescence staining and chromatin immunoprecipitation on IGFs. Compared with untrained cells, GFs trained with Porphyromonas gingivalis-lipopolysaccharide (P. gingivalis-LPS) exhibited a significant increase in IL-6 and TNF-α secretion, enhanced glycolytic metabolism, and enriched mono-methylation of lysine 4 on histone H3 (H3K4me1) at the enhancer regions of TNF-α and IL-6. The addition of a histone methyltransferase blocker and a PI3K inhibitor greatly reduced trained immunity. Additionally, the response of IGFs to P. gingivalis-LPS stimulation and their epigenetic modifications were similar to those observed in trained HGFs. This study novelly discovered that both P. gingivalis-LPS-stimulated HGFs and IGFs in periodontitis acquired trained immunity. Following P. gingivalis-LPS stimulation, HGFs underwent metabolic and epigenetic changes via the PI3K/AKT pathway, with these epigenetic changes also observed in IGFs. This finding suggests that trained immunity in GFs may be a key mechanism underlying the recurrence and persistence of periodontitis.

H2S-Scavenging Hydrogel Alleviating Mitochondria Damage to Control Periodontitis.

H2S, as a typical metabolite of periodontal pathogens, exhibits a clear positive correlation with the occurrence and development of periodontitis. H2S at physiological concentrations can regulate many biological processes. However, excess H2S in the periodontal pocket can trigger secretion of proinflammatory cytokines, cause oxidative stress, and result in mitochondrial damage and cell death in human gingival fibroblasts, exacerbating periodontitis development and periodontal tissue destruction. Worse, H2S facilitates bacteria survival and proliferation by maintaining bacterial redox balance and enhancing antibiotic resistance. Unfortunately, scavenging H2S during periodontitis treatment is usually ignored. Herein, a kind of hyaluronic acid methacryloyl/ZnO (HMZ) composite hydrogel with an H2S-scavenging ability was prepared to enhance periodontitis treatment. The HMZ hydrogel possessed good injectability and cytocompatibility and was able to remove H2S by a reaction with ZnO. As a result, the HMZ hydrogel was able to increase cell viability from 13% to 120% for human gingival fibroblasts and 22% to 94% for human periodontal ligament fibroblasts at 48 h, restore mitochondrial homeostasis, and alleviate cGAS-STING signaling pathway-mediated inflammation. Meanwhile, the HMZ hydrogel showed satisfactory antibacterial properties and efficiency of plaque biofilm removal. The in vivo results further confirmed that HMZ hydrogel decreased the concentration of H2S within the periodontal pocket from 0.7 to 0.8 mM to the normal level (0.3 to 0.4 mM), killed the bacteria in the periodontal tissues, inhibited osteoclast activity, relieved excess inflammation, and decreased the vertical distance between the cementoenamel junction and the alveolar bone crest from 1,175 µm to 798 µm on the 7th day and from 1,075 µm to 693 µm on the 14th day, achieving efficient periodontal bone regeneration. In brief, an H2S scavenging-based promising strategy was developed to enhance the therapeutic efficiency of periodontitis.

ROS-Induced Gingival Fibroblast Senescence: Implications in Exacerbating Inflammatory Responses in Periodontal Disease.

Periodontal disease is the pathological outcome of the overwhelming inflammation in periodontal tissue. Cellular senescence has been associated with chronic inflammation in several diseases. However, the role of cellular senescence in the pathogenesis of periodontal disease remained unclear. This study aimed to investigate the role and the mechanism of cellular senescence in periodontal disease. Using single-cell RNA sequencing, we first found the upregulated level of cellular senescence in fibroblasts and endothelial cells from inflamed gingival tissue. Subsequently, human gingival fibroblasts isolated from healthy and inflamed gingival tissues were labeled as H-GFs and I-GFs, respectively. Compared to H-GFs, I-GFs exhibited a distinct cellular senescence phenotype, including an increased proportion of senescence-associated β-galactosidase (SA-β-gal) positive cells, enlarged cell morphology, and significant upregulation of p16INK4A expression. We further observed increased cellular reactive oxygen species (ROS) activity, mitochondrial ROS, and DNA damage of I-GFs. These phenotypes could be reversed by ROS scavenger NAC, which suggested the cause of cellular senescence in I-GFs. The migration and proliferation assay showed the decreased activity of I-GFs while the gene expression of senescence-associated secretory phenotype (SASP) factors such as IL-1β, IL-6, TGF-β, and IL-8 was all significantly increased. Finally, we found that supernatants of I-GF culture induced more neutrophil extracellular trap (NET) formation and drove macrophage polarization toward the CD86-positive M1 pro-inflammatory phenotype. Altogether, our findings implicate that, in the inflamed gingiva, human gingival fibroblasts acquire a senescent phenotype due to oxidative stress-induced DNA and mitochondrial damage, which in turn activate neutrophils and macrophages through the secretion of SASP factors.

Effectiveness of amine plasma-functionalized 3D PLGA scaffolds immobilized with Fibroblast Growth Factor in periodontal tissue regeneration

Polylactic-co-glycolic acid (PLGA) has widely been used as a biodegradable material for three-dimensional (3D) printed scaffolds. However, the lack of surface chemicals and poor wettability limit the application of the polymer. Therefore, we modified the 3D scaffold surface using plasma surface modifications and evaluated its biocompatibility. To introduce amine functional groups on the 3D PLGA scaffold surface, amine plasma-polymerization was performed using 1, 2-diaminocyclohexane (DACH) monomers. Then, Fibroblast Growth Factor (FGF) was immobilized on the amine-functionalized 3D PLGA scaffold surface using a 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide. Human Gingival Fibroblast (HGF-1) cell behaviors were evaluated through cell adhesion, migration, proliferation, and western blot. The results showed that DACH plasma-polymerization provided the amine-functionalized surface which is capable of immobilizing FGF bioactive molecules on the 3D PLGA scaffold. Cell adhesion, proliferation, and migration on plasma surface-modified scaffolds have greatly improved compared to pristine 3D PLGA scaffolds. Notably, FGF-immobilized groups demonstrated the highest proliferation. These results suggest that the FGF-immobilized scaffold surface had a significant effect on accelerating oral gingival cell proliferation. In the future, 3D PLGA scaffolds with surface functionalized by plasma-polymerization and biomolecule immobilization can be used as a good alternative to autogenous soft tissue grafts for damaged soft tissue restoration.

Regenerative Potential of PDL-Derived Small Extracellular Vesicles.

Treatment of gingival fibroblasts with PDL extracellular vesicles results in promotion of Wnt signalling pathway and osteogenic differentiation. PDL secretome shows selective wound healing and matrix remodelling which can have implications for future periodontal regenerative strategies.

Development of Zinc-Containing Chitosan/Gelatin Coatings with Immunomodulatory Effect for Soft Tissue Sealing around Dental Implants.

Soft tissue integration (STI) around dental implant abutments is a prerequisite to prevent bacterial invasion and achieve successful dental implant rehabilitation. However, peri-implant STI is a major challenge after dental abutment placement due to alterations in the immune microenvironment upon surgical dental implant installation. Based on known immunomodulatory effects of zinc, we herein deposited zinc/chitosan/gelatin (Zn/CS/Gel) coatings onto titanium substrates to study their effect on macrophages. First, we exposed macrophages to cell culture media containing different zinc ion (Zn2+) concentrations. Next, we explored the immunomodulatory effect of Zn/CS/Gel coatings prepared via facile electrophoretic deposition (EPD). We found that Zn2+ effectively altered the secretome by reducing the secretion of pro-inflammatory and enhancing pro-regenerative cytokine secretion, particularly at a Zn2+ supplementation of approximately 37.5μM. Zn/CS/Gel coatings released Zn2+ in a concentration range which effectively stimulated pro-regenerative macrophage polarization as demonstrated by M2 macrophage polarization. Additionally, the impact of these Zn2+-exposed macrophages on gingival fibroblasts incubated in conditioned medium showed stimulated adhesion, proliferation, and collagen secretion. Our promising results suggest that controlled release of Zn2+ from Zn/CS/Gel coatings could be applied to immunomodulate peri-implant STI, and to enhance dental implant survival.

Role of transglutaminase 2 in promoting biglycan synthesis in idiopathic gingival fibromatosis

BackgroundThis study aimed to elucidate the pathogenesis of idiopathic gingival fibromatosis (IGF).MethodsHuman gingival fibroblasts (hGFs) were isolated from patients with IGF and periodontitis. Differential gene expression in the hGFs was analyzed using RNA sequencing. Extracellular matrix-related gene expression in the hGFs was analyzed. The effect of specific protein (SP)1 inhibitor or recombinant human transglutaminase 2 (rh-TGM2) on biglycan (BGN) expression in hGFs was also determined.ResultsRNA sequencing showed that TGM2 expression was downregulated and BGN mRNA expression was upregulated in patients with IGF relative to periodontitis. rh-TGM2 stimulation of hGFs in patients with IGF significantly reduced BGN expression. SP1 inhibitors downregulated BGN expression in the hGFs.ConclusionBGN upregulation via SP1 causes TGM2 downregulation in gingival fibroblasts in IGF.

Effects of Minocycline on Early Wound Healing after Implant Placement: An InVitro and Randomized Clinical Study.

To determine the invitro effects of minocycline on human gingival fibroblasts (HGFs), its clinical impact on early wound healing after implant placement, and its potential mechanism of action. First, we evaluated the invitro proliferation, migration, and collagen production of HGFs treated with different concentrations of minocycline, as well as the underlying mechanism. Subsequently, we conducted a clinical trial and randomly assigned 40 partially edentulous patients to either the test (minocycline hydrochloride treatment) or control (blank control) group immediately after implant surgery. The early wound healing score (EHS), pain index, gingival index (GI), modified sulcus bleeding index (mSBI), and peri-implant crevicular fluid samples were assessed or collected 3 and/or 7 days after surgery. In vitro, 1 μg/mL minocycline promoted the proliferation, migration, and collagen production of HGFs. Minocycline inhibited collagen degradation by downregulating the expression of matrix metalloproteinase-2 (MMP-2) and MMP-14 and upregulating tissue inhibitors of metalloproteinases-2. However, higher concentrations of minocycline, 10 and 100 μg/mL, exhibited adverse effects. In the randomised clinical trial, the test group showed significantly better clinical outcomes compared to the control group, with higher EHS and lower GI, mSBI, concentrations of IL-1β, IL-10, and TNF-α, and relative abundance of Streptococcus and gram-negative anaerobic bacteria. Small doses of minocycline (1 μg/mL) promoted the proliferation and migration of HGFs and inhibited collagen degradation invitro. Locally delivered minocycline after implant surgery improves clinical outcomes by promoting early wound healing, relieving the inflammatory response, and decreasing early colonisation of gram-negative anaerobic bacteria. This clinical trial was registered in the Chinese Clinical Trial Registry (registration number: ChiCTR2100044680).

Comparative evaluation of human oral fibroblast proliferation on 3D-printed zirconia and silicon nitride as new ceramic materials for implant abutment.

Cell adhesion and subsequent proliferation on material surfaces depend on the physical and chemical characteristics of the material. There is a lack of literature on human gingival fibroblast proliferation on comparatively newer additively manufactured materials like silicon nitride. This study focused on the physical characteristics of the materials with the aim to compare the adhesion and proliferation of human gingival fibroblasts on additively manufactured silicon nitride (AMSN) with additively manufactured zirconia, conventional milled titanium (MTi), and milled zirconia. Surface roughness and water contact angle were measured by profilometer and goniometer, respectively. CCK-8 assay was done to assess the cell growth at 24h (day 1), 48h (day 2), and 72h (day 3) in the same well. The morphologies of fibroblasts after cell attachment and proliferation were evaluated using scanning electron microscopy (SEM) after 72h. At the end of 24h (day 1) additively manufactured zirconia showed the best proliferation among the experimental groups, which was around 50% of the positive control group proliferation. There was no statistically significant difference among the experimental groups. At 48h (day 2) and 72h (day 3), a loss of cell growth was seen in almost all the experimental group wells. A positive cell proliferation on the AMSN was observed on day 3. Comparable cell proliferation was observed in the experimental groups. No conclusive correlation could be drawn between cell proliferation and surface roughness and water contact angle values in the experimental groups.

Effect of ultraviolet treatment on soft tissue healing and bacterial attachment to titania-coated zirconia

Zirconia is the most promising implant abutment material due to its excellent aesthetic effect, good biocompatibility and corrosion resistance. To obtain ideal soft tissue sealing, the implant abutment surface should facilitate cell adhesion and inhibit bacterial colonization. In this study, pre-sintered zirconia was placed in a suspension of titania (TiO2) and zirconium oxychloride (ZrOCl2) and heated in a water bath for dense sintering. A titania coating was prepared on the zirconia surface and subjected to UV irradiation. The surface morphology, elemental composition and chemical state of each group of samples were analyzed by scanning electron microscope, x-ray energy spectrometer, x-ray photoelectron spectroscopy and x-ray diffraction. The responses of human gingival fibroblasts (HGFs) and common oral pathogensStreptococcus mutans(S. mutans) andPorphyromonas gingivalis(P. gingivalis) to modified zirconia were systematically assessed. Our findings demonstrated that the surface of titania-coated zirconia after UV irradiation produced a large number of hydroxyl groups, and its hydrophilicity was significantly improved. Meanwhile, the UV irradiation also greatly removed the hydrocarbon contaminants on the surface of the titania-coated zirconia. The UV-treated titania coating significantly promoted the proliferation, spreading, and up-regulation of adhesion-related genes and proteins of HGFs. Furthermore, the titania coating irradiated with UV could reduce the adhesion, colonization and metabolic activity ofS. mutansandP. gingivalis. Therefore, UV irradiation of titania-coated zirconia can promote the biological behavior of HGFs and exert a significant antibacterial effect, which has broad clinical application prospects for improving soft tissue integration around zirconia abutments.

The Thermomechanical, Functional and Biocompatibility Properties of a Au-Pt-Ge Alloy for PFM Dental Restorations.

A high-noble Au-Pt-Ge porcelain-fused-to-metal (PFM) dental alloy without the known adverse metallic elements and with the addition of germanium (Ge) was produced as a more cost-effective alternative to other precious alloying metals, with investigations for determining the functionality and clinical use of this alloy. The thermomechanical, biocompatibility, durability, workability and economic characteristics of the produced dental alloy were investigated. These properties were investigated with in vitro biocompatibility testing on human gingival fibroblasts (HGFs); static immersion testing for metal ion release; DSC analysis; hardness, tensile testing, density and coefficient of thermal expansion (CTE) measurements; metallographic and SEM/EDX microstructure investigations; and finally with the production of a test PFM dental bridge. The results of the thermomechanical testing showed alloy properties suitable for dental restorations and clinical use, with somewhat lower mechanical properties, making the alloy not suitable for extensive multiunit fixed restorations. The microstructure investigations showed segregations of Ge in the homogeneous alloy matrix, which reduce the alloy's mechanical properties. The produced PFM dental bridge showed excellent workability of the alloy in a dental laboratory setting, as well as a high standard of the final dental restoration. The ion release was negligible, well below any harmful quantities, while the cell viability examination showed significantly higher viability ratings on polished alloy samples as compared to as-cast samples. The results showed that a dental substructure in direct contact with oral tissue and fluids should be highly polished. The performed investigations showed that the produced PFM dental alloy is suitable for clinical use in producing high-quality dental restorations with high biocompatibility for patients prone to metal allergies.

Influence of the post-processing protocol on a biocompatible 3D-printed resin.

This study aimed to evaluate the cytotoxicity of a biocompatible 3D-printed resin material for occlusal devices after post-processing with two different high-intensity UV-polymerization devices and two rinsing solvents, in the presence of human gingival fibroblasts (HGFs). Sample discs from the 3D-printed resin material were printed (2 mm in height and 6mm in diameter [N = 40]) and divided into 4 groups (n = 10) based on post-processing methods: a high-intensity UV polymerization device with isopropyl alcohol, a high-intensity UV polymerization device with a modified glycol solvent, a UV cleaning and curing unit with isopropyl alcohol, a UV cleaning and curing unit with a modified glycol solvent, and a control group cultured in DMEM medium. Different tests were performed to evaluate their cytocompatibility on HGFs: MTT assay, cell migration assay, cell cytoskeleton staining, scanning electron microscopy (SEM), and cell apoptosis and generation of intracellular reactive oxygen species (ROS). Statistical analyses were performed using one-way ANOVA and the Tukey post hoc test (α = 0.05). Cytocompatibility, MTT assay, cell migration assay, cell cytoskeleton staining, and SEM images were similar, regardless of the post-processing protocol, compared with the control group. No differences were found in the cytotoxicity of the 3D-printed resin material for occlusal devices after the following post-processing methods: two different UV-polymerization devices and two rinsing solvents (isopropyl alcohol and a modified glycol solvent).

A multimodal in vitro approach to assess the safety of oral care products using 2D and 3D cellular models.

Periodontitis, affecting approximately 3.9 billion individuals globally, significantly impacts quality of life and has raised interest in its potential systemic effects. Sodium perborate, a common component in oral care products for biofilm control, is widely used, though concerns about its safety persist. This study aimed to evaluate the in vitro toxicity of six commercial oral care products and varying concentrations of sodium perborate, utilizing human gingival fibroblasts (HGF) and keratinocytes (HaCat) as cell models. Experiments were performed in both 2D monolayer and 3D cultures using MTT and electrical impedance assays, adhering to the manufacturer's recommended exposure time of 30-60s for product testing. For the reconstructed epidermis model, a prolonged exposure time of 42min was applied, following the Organization for Economic Cooperation and Development (OECD) Test Guideline 439. Results indicated that all products and sodium perborate at 1mg/mL were cytotoxic in monolayer cultures. However, at concentrations relevant to commercial formulations (0.06mg/mL sodium perborate), no significant toxicity was observed. In contrast, the 3D culture models, including spheroids and reconstructed epidermis, exhibited minimal to no cytotoxic effects for the commercial products, with sodium perborate showing no significant toxicity below 0.1mg/mL. The reconstructed epidermis model, used as surrogate for oral mucosa, further confirmed that the products were non-irritating, in compliance with OECD TG 439 standards. This study highlights the importance of considering exposure time, dosage, and cellular model when assessing the safety of oral care products. While 2D models are useful for preliminary screenings, 3D models provide a more physiologically relevant assessment, emphasizing the need for robust testing protocols to ensure product safety.

In Vitro Assessment of Injectable Bone Marrow Aspirate Concentrates Compared to Injectable Platelet-Rich Fibrin

BACKGROUND:Injectable platelet-rich fibrin (iPRF), a liquid form of PRF that is prepared from peripheral blood without anticoagulants, promotes tissue wound healing and regeneration. The present study focused on iPRF-like bone marrow aspirate concentrate (iBMAC) prepared without anticoagulant, and the regenerative potential of iPRF and iBMAC was compared in vitro.METHODS:iPRF and iBMAC were prepared from the same New Zealand white rabbits. The cytocompatibility and regenerative potential of each concentrate were evaluated using primary rabbit gingival fibroblasts and osteoblasts.RESULTS:Both gingival fibroblasts and osteoblasts treated with each concentrate exhibited excellent cell viability. Interestingly, compared to cells treated with iPRF, cells treated with iBMAC demonstrated significantly greater migration potential. Furthermore, higher mRNA levels of transforming growth factor-β (TGF-β), vascular endothelial growth factor (VEGF), and collagen I (COL1) were observed in gingival fibroblasts treated with iBMAC than in those treated with iPRF. Compared with osteoblasts treated with iPRF, osteoblasts treated with iBMAC exhibited greater differentiation potential, as indicated by increased osteocalcin (OCN) expression and mineralization capability.CONCLUSION:The results of the in vitro study suggest that, compared with iPRF, iBMAC may promote wound healing and bone regeneration more effectively. However, further preclinical and clinical studies are needed to confirm the regenerative potential of iBMAC in the body.

Flavonoids attenuate inflammation of HGF and HBMSC while modulating the osteogenic differentiation based on microfluidic chip

BackgroundWhen inflammation occurs in periodontal tissues, a dynamic cellular crosstalk interacts between gingival fibroblasts and bone marrow mesenchymal stem cells (BMSCs), which plays a crucial role in the biological behaviour and differentiation of the cells. Recently, flavonoids are increasingly recognized for their therapeutic potential in modulating inflammation and osteogenic differentiation. Owing to their varied molecular structures and mechanisms, there are more needs that flavonoid compounds should be identified by extensive screening. However, current drug research mostly relies on static, single-type cell cultures. In this study, an innovative bionic microfluidic chip system tailored for both soft and hard tissues was developed to screen for flavonoids suitable for treating periodontitis.MethodsThis study developed a microfluidic system that bionically simulates the soft and hard structures of periodontal tissues. Live/dead staining, reactive oxygen species (ROS) staining, and RT-qPCR analysis were employed. These techniques evaluated the effects of flavonoid compounds on the levels of inflammatory factors and ROS contents in HGF and HBMSC under LPS stimulation. Additionally, the impact of these compounds on osteogenic induction in HBMSC and the exploration of the underlying mechanisms were assessed.ResultsThe microfluidic chip used in this study features dual chambers separated by a porous membrane, allowing cellular signal communication via bioactive factors secreted by cells in both layers under perfusion. The inflammatory response within the chip under LPS stimulation was lower compared to individual static cultures of HGF and HBMSC. The selected flavonoids-myricetin, catechin, and quercetin-significantly reduced cellular inflammation, decreased ROS levels, and enhanced osteogenic differentiation of BMSCs. Additionally, fisetin, silybin, and icariside II also demonstrated favorable outcomes in reducing inflammation, lowering ROS levels, and promoting osteogenic differentiation through the Wnt/β-catenin pathway.ConclusionsThe bionic microfluidic chip system provides enhanced capabilities for drug screening and evaluation, delivering a more precise assessment of drug efficacy and safety compared to traditional in vitro methods. This study demonstrates the efficacy of flavonoids in influencing osteogenic processes in BMSCs primarily through the Wnt/β-catenin pathway. These results uncover the potential of flavonoids as therapeutic medicine for treating periodontitis, meriting further research and development.Graphical

Anti-biofilm potential of red pitahaya betacyanins against Streptococcus mutans, Actinomyces viscosus and Aggregatibacter actinomycetemcomitans

This study investigated the antibiofilm effects of betacyanin fraction (BF) from red pitahaya against Streptococcus mutans, Actinomyces viscosus, and Aggregatibacter actinomycetemcomitans, key pathogens in oral biofilm formation. Betacyanin purification employed column chromatography, and characterization was performed using liquid chromatography-mass spectrometry. Crystal violet assay and scanning electron microscopy demonstrated significant inhibition of early biofilm formation and disruption of preformed biofilms using BF (0.94–15 mg/mL). Anti-adhesion assays on artificial teeth indicated potent betacyanin-mediated inhibition of both sucrose-dependent and -independent bacterial attachment. Notably, growth curve and pH drop assays revealed that BF hindered pH reduction for all tested bacteria without suppressing their growth. Tetrazolium-based cytotoxicity assays showed minimal toxicity towards normal human gingival fibroblasts (HGF-1) at 0.78–12.5 mg/mL. These findings demonstrate the potential of red pitahaya betacyanins as promising antibiofilm agents for oral health, targeting both initial and mature stages of biofilm development.

Epicatechin suppresses the expression of C-C motif chemokine ligand 19 and ameliorates periodontitis

Periodontitis is a prevalent chronic inflammatory disease requiring the development of drug-based therapies. Epicatechin is a major polyphenol in cocoa extract and possesses numerous pharmacological properties. This study aimed to investigate the suppressive effect of epicatechin on C-C motif chemokine ligand 19 (CCL19)-mediated periodontitis using a mouse model. CCL19 expression was high in mouse gingiva with ligature-induced periodontitis. CCL19 expression was increased by lipopolysaccharide stimulation in murine gingival fibroblasts ESK-1 cells, and CCL19 induced the production of tumor necrosis factor alpha and interleukin-1 beta in mouse macrophage-like RAW264.7 cells. Importantly, lipopolysaccharide-enhanced CCL19 expression in ESK-1 cells was significantly suppressed by pretreatment with epicatechin. In addition, epicatechin administration significantly reduced alveolar bone resorption, and expression of Ccl19 and proinflammatory cytokines in the inflamed gingiva in high-fat diet-fed mice. These results demonstrate that epicatechin protects against periodontitis by reducing CCL19 levels, which may be a promising countermeasure for periodontitis in clinical practice.

Tooth-Binding Graphene Quantum Dots Silver Nanocomposites for Prevention of Dental Caries.

The objectives of this study were to develop a tooth-binding graphene quantum dots silver nanocomposites (ALN-GQDs-Ag) and evaluate their antibacterial, mineralising, and discolouring properties for the prevention of dental caries. In this study, ALN-GQDs-Ag were developed by synthesising nano silver (Ag) with graphene quantum dots (GQDs) and functionalised GQDs with alendronate (ALN). ALN-GQDs-Ag were characterised by transmission electron microscopy (TEM), zeta potential analysis, X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. The cytotoxicity of ALN-GQDs-Ag against human gingival fibroblasts (HGF-1) and stem cells from human exfoliated deciduous teeth (SHED) was examined using a colorimetric assay with reference to silver nitrate solution. The affinity of ALN-GQDs-Ag for hydroxyapatite particles was investigated using inductively coupled plasma spectroscopy (ICP). The antibacterial properties of ALN-GQDs-Ag against Streptococcus mutans were evaluated by scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), and colony-forming units counting (CFUs). The mineralisation properties of ALN-GQDs-Ag on human dentine were assessed using micro-computed tomography (micro-CT), scanning electron microscopy (SEM), and Fourier transform infrared in a biochemical cycling model. The discolouring properties of ALN-GQDs-Ag on artificial dentine caries were determined using spectrophotometry. TEM, Zeta potential, XPS, FTIR, and Raman spectroscopy confirmed the synthesis of stable spherical ALN-GQD-Ag nanocomposites with a 10.3 ± 5.5 nm diameter. The colorimetric assay demonstrated that ALN-GQDs-Ag were less cytotoxic than silver nitrate to HGF-1 and SHED (p<0.001). ICP showed that ALN-GQDs-Ag were bound to hydroxyapatite. SEM, CLSM, and CFUs showed that ALN-GQDs-Ag was bactericidal and inhibited biofilm growth of Streptococcus mutans. Micro-CT, SEM, and FTIR showed that ALN-GQDs-Ag repressed dentine demineralisation under a cariogenic challenge. Spectrophotometry revealed no significant discolouration of dentine caries in the ALN-GQDs-Ag. This study developed a biocompatible and tooth-binding ALN-GQDs-Ag with promising antibacterial, mineralising, and non-discolouring properties. ALN-GQDs-Ag could be a novel anti-caries agent for preventing dentine caries if translated for clinical use.

The corrosion products of proprietary and generic orthodontic fixed lingual retainers and their in-vitro cytotoxicity.

To assess the corrosion products and cytotoxicity of generic and proprietary fixed lingual retainers (FLRs). Seven FLRs were investigated. Wires were submersed in solution for 34 days, at 37°C, under constant agitation. A proportion of this solution was analyzed to determine the concentration of metallic ions leaching off the wires. The remainder was diluted to 5%, 10% and 20% followed by exposure to human gingival fibroblasts and analysis of cytotoxicity of the wires. Three wires (Dentaflex, Universal, and AZDent) released excessive concentrations of lead, two wires (MeshMark and Orthoflex) released excessive concentrations of nickel, and one wire (Universal) released excessive concentrations of molybdenum into solution. No statistically significant difference was found between the wires analyzed (P = .24). Slight cytotoxicity was noted in only one wire (Dentaflex) at a 20% dilution of eluent. This was also the wire which released the highest concentration of lead into solution. All other wires, at all concentrations, were deemed noncytotoxic, but five samples overall were deemed statistically significant (P < .0024). A statistically significant difference existed between wires (P = .013) and concentrations analyzed (P < .001). Metals were released in differing quantities from all wires, with some elemental concentrations measuring more than that deemed acceptable in drinking water in Australia. A trend toward increased cell viability across samples was found with only one demonstrating cytotoxicity. There was no indication that generic FLRs were more or less biocompatible than their proprietary counterparts.

Biocompatibility of 3D-printed vs. thermoformed and heat-cured intraoral appliances.

The development of additive manufacturing has the potential to revolutionize the fabrication of medical devices. This technology, also known as 3D printing, offers precise, cost-effective, and personalized approaches, which could be particularly beneficial in the production of intraoral appliances. Despite its promise, research on the biocompatibility of 3D-printed intraoral devices is still limited. Our study aims to address this gap. We examined the cytotoxicity of materials processed via three techniques commonly used for the fabrication of different intraoral appliances: 3D printing (Dental LT Clear), thermoforming (Duran adjusted with Durasplint LC), and conventional heat-curing (Villacryl H Plus). We also investigated the impact of chemical or UVC disinfection on the biocompatibility of these materials. We assessed the biological effects induced in human gingival fibroblasts (HGFs) through both direct contact tests (MTT and LDH assays) and extract tests (PrestoBlue, DCF, and cell death type assays). Additionally, we observed changes in cellular morphology and migration rate under an inverted light microscope. The surface roughness of materials was evaluated using contact profilometry. Statistical analysis was conducted using two-way analysis of variance. Our findings suggest that all three fabrication techniques induced a slight cytotoxic effect in HGFs, as evidenced by both direct contact and extract tests. However, these materials could be considered nontoxic according to the ISO 10993-5:2009 norm, as the decrease in metabolic activity observed was always less than 30% compared to the untreated control. This novel study confirms that 3D printing may be a safe alternative to conventional methods for fabricating intraoral appliances. However, further tests assessing the long-term intraoral usage are still needed.