Gingival Epithelium Research Articles

Modified gingivoplasty for hereditary gingival fibromatosis: two case reports

BackgroundHereditary gingival fibromatosis (HGF) is characterized by sub-epithelial fibromatosis of keratinized gingiva resulting in a fibrotic enlargement of keratinized gingiva. The treatment choice is gingivectomy, which can be performed with an internal or external bevel incision conventionally. However, both techniques can hardly resume the natural status of gingiva, and have a certain recurrence rate, especially in the cases which have limited width of attached gingiva.Case descriptionTwo cases of HGF with the chief complaint of difficulty in mastication, pronunciation, and poor esthetics were presented. After the initial periodontal therapy, a novel gingivoplasty modified with a crevicular incision was applied. A full thickness flap above the mucogingival junction and a split flap below the junction were raised. Then, fibrotic connective tissue was completely eliminated and keratinized gingival epithelium was preserved. The fibrotic alveolar bone was shaped by handpiece and bur. Finally, the flap was apically repositioned and sutured. Twelve months after surgery, the gingiva recovered with normal color, contour and consistency.ConclusionsCompared to traditional gingivectomy, modified gingivoplasty which focuses on eliminating pathological fibrotic connective tissue can completely resume the natural appearance of gingiva and demonstrate no tendency of recurrence.

KDF1 Novel Variant Causes Unique Dental and Oral Epithelial Defects.

Keratinocyte differentiation factor 1 (KDF1) is a recently identified and rare candidate gene for human tooth agenesis; however, KDF1-related morphological characteristics and pathological changes in dental tissue and the oral epithelium remain largely unknown. Here, we employed whole-exome sequencing (WES) and Sanger sequencing to screen for the suspected variants in a cohort of 151 tooth agenesis patients, and we segregated a novel KDF1 heterozygous missense variation, c.920G>C (p.R307P), in a non-syndromic tooth agenesis family. Essential bioinformatics analyses and tertiary structural predictions were performed to analyze the structural changes and functional impacts of the novel KDF1 variant. The subsequent functional assessment using a TOP-flash/FOP-flash luciferase reporter system demonstrated that KDF1 variants suppressed the activation of canonical Wnt signaling in 293T cells. To comprehensively investigate the KDF1-related oral morphological anomalies, we performed scanning electron microscopy and ground section of the lower right lateral deciduous incisor extracted from #285 proband, and histopathological assessment of the gingiva. The phenotypic analyses revealed a series of tooth morphological anomalies related to the KDF1 variant R307P, including a shovel-shaped lingual surface of incisors and cornicione-shaped marginal ridges with anomalous morphological occlusal grooves of premolars and molars. Notably, keratinized gingival epithelium abnormalities were revealed in the proband and characterized by epithelial dyskeratosis with residual nuclei, indistinct stratum granulosum, epithelial hyperproliferation, and impaired epithelial differentiation. Our findings revealed new developmental anomalies in the tooth and gingival epithelium of a non-syndromic tooth agenesis individual with a novel pathogenic KDF1 variant, broadening the phenotypic spectrum of KDF1-related disorders and providing new evidence for the crucial role of KDF1 in regulating human dental and oral epithelial development.

Clinical and laboratory assessment of the effect of hygiene products on the condition of periodontal tissues and hard tooth tissues in the treatment of caries by indirect method

Relevance. According to statistics, the widespread use in modern dental practice of indirect restoration methods in the treatment of caries of the frontal group of teeth leads to an increase in the incidence of marginal periodontal disease. According to modern data, the most important etiological factor in the development of complications from the hard tissues of the tooth and periodontal is the microflora of plaque.The main link in carrying out preventive measures and the guarantee of the quality of the rehabilitation period is an adequate choice of personal oral hygiene products. It is for this reason that, when choosing a preventive program and personal hygiene products, especially in patients with extensive restorations (including indirect ones), more and more attention is currently being paid to toothpastes based on medicinal herbs, aluminum lactate, which have an anti-inflammatory, astringent effect, reducing bleeding gums and hyperesthesia of hard tooth tissues.Aim. Comparison of the clinical effectiveness of the standard prevention program and the prevention program using individual oral hygiene products based on aluminum lactate in the treatment of caries by the indirect method, as well as improving the effectiveness of indirect methods of caries treatment by preventing its recurrence and inflammatory complications from periodontal tissues by developing practical recommendations.Materials and methods. The work was carried out in the design of an open comparative three-stage prospective nonrandomized study. The necessary material was collected using clinical, laboratory and statistical methods. The material for the study was 98 patients with indirect restorations of the frontal group of teeth, of which 46 people had restoration from metal-free ceramics E-max and 52 people from pre-polymerized composite and divided into groups according to the hygienic means used and the type of restoration. A micronuclear test in the gingival epithelium with the establishment of the frequency of occurrence and spectrum of nuclear aberrations in the cells of the gingival epithelium was carried out in vitro. Statistical data processing was carried out using standard packages Statistika 8.1 and SPSS-11.Results. Based on the results of 2236 clinical and 550 laboratory studies stating the condition of the hard tissues of the tooth, the tooth-restoration boundary, the tissues of the marginal periodontal and the evaluation of the effectiveness of the hygiene product used, the results of statistical processing and the use of high technologies to solve the tasks, it can be said that traditional means of individual oral hygiene have sufficient effectiveness when used in preventive program of recurrence of carious process and periodontal diseases, but significantly higher with a statistically significant difference in effectiveness, especially in terms of anti-inflammatory action, are products containing aluminum lactate, which has a direct and direct impact on the quality of restoration and dental rehabilitation of the patient even 24 months after treatment.Conclusions. Personal oral hygiene products containing aluminum lactate, which has pronounced astringent and antiinflammatory properties. These remedies should be the subject of choice in the most difficult clinical situations, such as diagnosed periodontal diseases with the preservation of complaints (pain, bleeding gums, unpleasant odor, etc.), low level of oral hygiene, rehabilitation period after periodontal treatment, prevention of periodontal diseases in patients with extensive restorations. The use of personal oral hygiene products containing aluminum lactate will significantly improve the effectiveness of treatment and prevention of caries including indirect methods, reduce the risk of repeated invasions and ensure full-fledged dental rehabilitation of the patient directly affecting his quality of life.

FOXO1 inhibits FSL-1 regulation of integrin β6 by blocking STAT3 binding to the integrin β6 gene promoter.

Integrin β6 (ITGB6), an epithelial-specific receptor, is downregulated in the gingival epithelium of periodontitis and is associated with inflammation response and periodontitis development. However, the transcriptional regulatory mechanism of ITGB6 downregulation in the human gingival epithelium remains unclear. Fibroblast-stimulating lipopeptide-1 (FSL-1), an oral biofilm component, promotes an epithelial cell-driven proinflammatory response in periodontitis partially by suppressing ITGB6 expression. The aim of the current study was to investigate the transcriptional regulatory mechanism of ITGB6 inhibition by FSL-1 in human epithelial cells (HaCaT and primary human gingival epithelial cells), and to delineate the transcriptional mechanism of ITGB6 suppression in periodontitis. We found that FSL-1 inhibited ITGB6 transcription through increasing forkhead box protein O1 (FOXO1) expression and inhibiting signal transducer and activator of transcription 3 (STAT3) activation. Furthermore, FOXO1 bound to STAT3 directly, leading to decreased STAT3 phosphorylation induced by FSL-1. Consequently, the binding of phosphorylated STAT3 to the ITGB6 promoter was decreased, and ITGB6 transcription was therefore downregulated following FSL-1 stimulation. The reciprocal action of STAT3 and FOXO1 on ITGB6 downregulation was also confirmed by the immunostaining of the inflammatory epithelium associated with periodontitis. Our findings suggest that the interaction of FOXO1–STAT3 may be a useful signal target for the treatment of periodontitis.

Ginsenoside Rb3 inhibits osteoclastogenesis via ERK/NF-κB signaling pathway in vitro and in vivo.

The objective of the study was to determine the anti-osteoclastogenic potential of ginsenoside Rb3 for the treatment of periodontitis. The anti-osteoclastogenic effect was determined using RANKL-induced RAW264.7 cells and murine bone marrow-derived macrophages followed by TRAP and phalloidin staining. Expression of osteoclastogenesis-related genes and proteins were examined by qPCR and WB. Activation of signaling pathways was detected by WB and IHC techniques. Experimental periodontitis rat model was built up by gingival injections of P.gingivalis LPS. After 21 days of Rb3 treatment, rats were sacrificed for micro-CT, IHC, H&E, and TRAP staining analyses. Rb3 dramatically inhibits RANKL-induced osteoclastogenesis. Nfatc1, Mmp9, Ctsk, Acp5 mRNA, and MMP9, CTSK proteins were dose-dependently downregulated by Rb3 pretreatment. WB results revealed that Rb3 suppressed activations of p38 MAPK, ERK, and p65 NF-κB, and the inhibition of ERK was most pronounced. Consistently, IHC analysis revealed that p-ERK was highly expressed in alveolar bone surface, blood vessels, odontoblasts, and gingival epithelia, which were notably suppressed by Rb3 treatment. H&E staining and micro-CT analyses showed that Rb3 significantly attenuated gingivitis and alveolar bone resorption in rats. Rb3 inhibits RANKL-induced osteoclastogenesis and attenuates P.gingivalis LPS-induced gingivitis and alveolar bone resorption in rats via ERK/NF-κB signaling pathway.

Immunoexpression of interferon-gamma in the interdental gingiva of chronic periodontitis patients with interferon-gamma (+874A/T) rs62559044 polymorphism.

Interferon-gamma (IFNγ), which is involved in inflammation, has an essential role in the pathogenesis of chronic periodontitis (CP). The association of IFNγ +874A/T gene polymorphisms with a higher incidence of CP has been reported previously. We investigated the immunoexpression of IFNγ in human gingiva from CP patients with IFNγ +874A/T gene polymorphisms compared to a healthy group. Biopsies from interdental gingiva (n=60) were obtained from CP patients (n=38) and individuals who had clinically healthy gingiva (n=22). The specimens were classified according to genotypes of IFNγ +874A/T gene polymorphism using amplification-refractory mutation system-polymerase chain reaction (ARMS-PCR) (10AA, 18AT, and 10TT). After tissue processing and slide preparation, we evaluated the expression levels of IFNγ in the interdental gingiva using the immunohistochemistry technique. Values were compared between two study groups by Mann-Whitney and Kruskal-Wallis analysis. P<0.05 was considered the level of significance. There was a noticeable increase in the immunoexpression of IFNγ in the gingival epithelium, fibroblasts, and capillaries of gingival tissue from CP patients compared to the control group. We found different levels of IFNγ expression in different parts of the gingival epithelium. The highest levels were found in the middle regions of the gingival epithelium in patients with TT genotypes. Immune cells and vascular endothelium of gingiva in the AA group also showed increased expression of IFNγ. Results suggest that IFNγ +874A/T gene polymorphism may change the expression level of IFNγ and subsequently the progression of CP.

Expression of TGF-β and MMP-2 in hereditary gingival fibromatosis epithelial cells. A possible contribution of the epithelium to its pathogenesis

Although the molecular mechanisms that cause the development of hereditary gingival fibromatosis are not fully understood, multiple theories have been suggested to clarify its pathogenesis. However, the overlying keratinocytes' function is poorly comprehended. This work aimed to investigate the expression of TGF-β and MMP-2 in hereditary gingival fibromatosis epithelial cells compared to the normal gingival epithelium to give an insight into the mechanism of the development of this condition.Biopsies were obtained from 20 hereditary gingival fibromatosis patients and 20 healthy controls. Biopsies were stained immunohistochemically and statistically analyzed for MMP-2 and TGF-β expression.Regarding MMP-2, The hereditary gingival fibromatosis group recorded a higher mean value compared to the normal gingiva, with a mean difference of 3.29 ± 0.34. This difference was statistically significant (p = 0.00). Regarding TGF-β, a higher mean value was recorded in the HGF group compared to the normal gingiva, with a mean difference of 15.88 ± 1.05 The difference was statistically significant (p = 0.00). A strong positive correlation was detected between MMP-2 and TGF-β (R = 0.534, p = 0.015).In hereditary gingival fibromatosis, the epithelium expresses higher levels of TGF-β and MMP-2 than normal gingival tissue. There was an evident positive correlation between MMP-2 and TGF-β. Our data suggest that the expression of TGF-β and MMP2 by epithelial cells of HGF may play a role in the epithelial-mesenchymal transition pathogenic pathway.

IMPLEMENTATION NUTRIGENOMIC OF VITAMIN D IN PERIODONTITIS

Background: Nutrition is a significant risk factor for the incidence of periodontal disease. Nutrients acting on the human genome, either directly or indirectly, can change the expression and structure of genes. One of the micronutrients associated with periodontitis is vitamin D. Vitamin D has an important role in bone and calcium metabolism and regulates serum calcium and phosphate concentrations at normal limits. Purpose: To discuss the nutritional vitamin D as an essential micronutrient in preventing and accelerating healing in periodontitis. Review: Searched two databases from article publication to April 2021, resulting in a total of 66 hits, from which seven relevant articles were selected. VDR signaling can build transcription of genes encoding proactive cytokines, bypassing the cyclo-oxygenase-2 (COX-2) and prostaglandin pathway, and can inhibit matrix metalloproteinase production. The protective mechanism of vitamin D against periodontitis occurs through two biological pathways, namely anti-microbial and anti-inflammatory pathways. The anti-microbial effect of vitamin D results from the binding of 1,25(OH)2D3 with VDR which then induces cAMP, b-def-2 and b-def-3 peptides by macrophages, monocytes, gingival epithelium and periodontal ligament epithelium. The anti-inflammatory effect occurs through decreased production of proinflammatory cytokines. Conclusion: All the signaling effects of VDR can reduce bacteria induced in the inflammatory cytokines so that personalized vitamin D supplementation with an adjusted dose as needed can be used in preventing periodontitis or accelerating the healing of periodontitis.

Surface pre-reacted glass-ionomer eluate protects gingival epithelium from penetration by lipopolysaccharides and peptidoglycans via transcription factor EB pathway.

Surface pre-reacted glass-ionomer (S-PRG) filler, produced by PRG technology for use with various dental materials, is bioactive and known to release ions from a glass-ionomer phase. We previously reported that coxsackievirus and adenovirus receptor (CXADR), a tight junction associated protein, was located in the epithelial barrier of gingival epithelium. In the present study, the tissue protective effects of an S-PRG eluate prepared with S-PRG filler were investigated using a three-dimensional human gingival epithelial tissue model. The results showed that the S-PRG eluate specifically induced CXADR expression at the transcriptional level of messenger RNA as well as the protein level, and also nuclear translocation of transcription factor EB (TFEB) in gingival epithelial cells. Furthermore, shigyakusan, a TFEB inhibitor, canceled induction of the CXADR protein by the S-PRG eluate. Additionally, gingival epithelial permeation by 40-kDa dextran, lipopolysaccharide, and peptidoglycan in the 3D-tissue models was prevented by the eluate, with those effects abrogated by knockdown of CXADR. These findings suggest that S-PRG eluate increases CXADR expression via the TFEB pathway, thus inhibiting penetration of bacterial virulence factors into subepithelial tissues.

Therapeutic Potential of Liraglutide for Diabetes-Periodontitis Comorbidity: Killing Two Birds with One Stone.

Background The relationship between diabetes and periodontitis is bidirectional, and there is now consensus that periodontitis and diabetes are comorbid. There is a quest for a drug that can be used to treat both conditions simultaneously. This study evaluated the anti-inflammatory and osteoprotective effects of liraglutide (LIRA) on periodontitis in diabetic rats. Methods Male Wistar rats (n = 46) were randomly divided into four groups: control group (n = 8), LIRA group (n = 8), diabetes-associated periodontitis+0.9% saline group (diabetic periodontitis (DP)+NaCl group, n = 15), and diabetes-associated periodontitis+LIRA group (DP+LIRA group, n = 15). LIRA treatment lasted for 4 weeks (300 μg/kg/d) after establishment of a rat model of DP. The expression of IL-6, TNF-α, and IL-1β was detected by enzyme-linked immunosorbent assay. The morphological changes of periodontal tissues were observed by hematoxylin–eosin staining. The absorption of alveolar bone and its ultrastructural changes were observed by histomorphometry and microcomputed tomography. The expression of receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) in alveolar bone was detected by immunohistochemistry. The levels of Runx2 mRNA and ALP mRNA in the gingival epithelium were examined by quantitative real-time polymerase chain reaction. Results LIRA decreased alveolar bone resorption, improved the microstructure of alveolar bone, and reduced periodontal inflammation and damage (P < 0.05). LIRA also reduced blood glucose level and inhibited the secretion of serum IL-6, TNF-α, and IL-1β (P < 0.05). In addition, after treatment with LIRA, the ratio of RANKL/OPG was reduced, and the expression levels of ALP mRNA and Runx2 mRNA were upregulated (P < 0.05). Conclusions LIRA not only controls blood glucose level but also reduces inflammation and bone loss and enhances osteogenic differentiation in diabetes-associated periodontitis. Those indicate that LIRA may be used as a potential medicine for the adjunctive therapy of diabetes-periodontitis comorbidity.

Characterization of junctional structures in the gingival epithelium as barriers against bacterial invasion.

Adherens junctions (AJs) and tight junctions (TJs) are known to play a crucial role in maintaining the physical barrier function of the epithelium. Here, we aimed to characterize the distribution of AJs and TJs throughout the gingival epithelium and to obtain insights into the physiological importance of these junctional structures. Sections of mouse gingival tissue were examined using transmission electron microscopy (TEM) and bio-high voltage electron microscopy tomography. The gingival sections were stained for E-cadherin and JAM-A as markers of AJs and TJs, respectively, and examined using confocal microscopy and lattice structured illumination microscopy. Bacteria within the gingival epithelium were examined using in situ hybridization. Junctional structures, including desmosomes, AJs, and TJs, were observed throughout the gingival epithelium. The expression levels of E-cadherin were particularly low in the granular/keratinized layers of the oral epithelium (OE), while extremely low JAM-A levels were detected in the granular/keratinized layers of the sulcular epithelium (SE). The three-dimensional rendering of the junctional structures revealed that both AJs and TJs in the gingival epithelium formed discontinuous short bands or patches. Interestingly, strong bacterial signals were observed at the granular/keratinized layers of both SE and OE, but a few bacteria were detected within the junctional epithelium (JE) and the basal/spinous layers of the SE and OE. AJs and TJs form a discontinuous barrier throughout paracellular passage in the gingival epithelium; nevertheless, they seem to play an important role in defending against invading bacteria.

Expression of human caspase-4 in the gingival epithelium affected with periodontitis: Its involvement in Porphyromonas gingivalis-challenged gingival epithelial cells

ObjectiveImplication of human caspase-4 in periodontitis and in sensing periodontal pathogens by gingival epithelial cells (GECs) is unclear. This study aimed to determine caspase-4 and interleukin (IL)-18 expressions in gingival tissues affected with periodontitis and to investigate caspase-4 involvement in mediating innate immune responses in GECs. DesignEx vivo, caspase-4 and IL-18 expressions in gingival biopsies, obtained from healthy participants with periodontitis or clinically healthy gingiva (N = 20 each), were determined by immunohistochemistry. In vitro, caspase-4 activation in cultured GECs stimulated with Porphyromonas gingivalis or Fusobacterium nucleatum was analyzed by immunoblotting. mRNA expressions of human β-defensin-2 (hBD-2), IL-8, and IL-18 in stimulated GECs in the presence or absence of a caspase-4 inhibitor were assayed by RT-qPCR. ResultsEx vivo, compared with healthy gingival epithelium, the epithelium affected with periodontitis displayed a significant decrease in caspase-4 expression (P = 0.015), whereas IL-18 expression was significantly increased (P = 0.012). Moreover, the expression of caspase-4, but not IL-18, was found to be a predictor of periodontitis (P = 0.007). In vitro, caspase-4 was activated in cultured GECs challenged with P. gingivalis, but not F. nucleatum. mRNA upregulations of hBD-2, IL-8, and IL-18 upon P. gingivalis stimulation were significantly reduced when caspase-4 was inhibited (P < 0.05), whereas the inhibitor failed to suppress those inductions by F. nucleatum. ConclusionsCaspase-4 expression is diminished in the epithelium affected with periodontitis while that of IL-18 is enhanced. Caspase-4 activation in P. gingivalis-infected GECs upregulates the three innate immune effector molecules, suggesting a possible sensing mechanism of caspase-4 in GECs in periodontal disease pathogenesis.

Biomimetic Design and Fabrication of Sericin-Hydroxyapatite Based Membranes With Osteogenic Activity for Periodontal Tissue Regeneration.

The guided tissue regeneration (GTR) technique is a promising treatment for periodontal tissue defects. GTR membranes build a mechanical barrier to control the ingrowth of the gingival epithelium and provide appropriate space for the regeneration of periodontal tissues, particularly alveolar bone. However, the existing GTR membranes only serve as barriers and lack the biological activity to induce alveolar bone regeneration. In this study, sericin-hydroxyapatite (Ser-HAP) composite nanomaterials were fabricated using a biomimetic mineralization method with sericin as an organic template. The mineralized Ser-HAP showed excellent biocompatibility and promoted the osteogenic differentiation of human periodontal membrane stem cells (hPDLSCs). Ser-HAP was combined with PVA using the freeze/thaw method to form PVA/Ser-HAP membranes. Further studies confirmed that PVA/Ser-HAP membranes do not affect the viability of hPDLSCs. Moreover, alkaline phosphatase (ALP) staining, alizarin red staining (ARS), and RT-qPCR detection revealed that PVA/Ser-HAP membranes induce the osteogenic differentiation of hPDLSCs by activating the expression of osteoblast-related genes, including ALP, Runx2, OCN, and OPN. The unique GTR membrane based on Ser-HAP induces the differentiation of hPDLSCs into osteoblasts without additional inducers, demonstrating the excellent potential for periodontal regeneration therapy.

Analyzing Human Periodontal Soft Tissue Inflammation and Drug Responses In Vitro Using Epithelium-Capillary Interface On-a-Chip.

The gingival epithelium–capillary interface is a unique feature of periodontal soft tissue, preserving periodontal tissue homeostasis and preventing microorganism and toxic substances from entering the subepithelial tissue. However, the function of the interface is disturbed in periodontitis, and mechanisms of the breakdown of the interface are incompletely understood. To address these limitations, we developed a microfluidic epithelium–capillary barrier with a thin culture membrane (10 μm) that closely mimics the in vivo gingival epithelial barrier with an immune micro-environment. To test the validity of the fabricated gingival epithelial barrier model, epithelium–capillary interface-on-a-chip was cultured with human gingival epithelial cells (HGECs) and human vascular endothelial cells (HUVEC). Their key properties were tested using optical microscope, transepithelial/transendothelial electrical resistance (TEER), and permeability assays. The clear expression of VE-cadherin revealed the tight junctions in endothelial cells. Live/dead assays indicated a high cell viability, and the astrocytic morphology of HGE cells was confirmed by F-actin immunostaining. By the third day of cell culture, TEER levels typically exceeded in co-cultures. The resultant permeability coefficients showed a significant difference between 70 kDa and 40 kDa FITC-dextran. The expression of protein intercellular cell adhesion molecule (ICAM-1) and human beta defensin-2 (HBD2) decreased when exposed to TNF-α and LPS, but recovered with the NF-κB inhibitor treatment- Pyrrolidinedithiocarbamic acid (PDTC), indicating the stability of the fabricated chip. These results demonstrate that the developed epithelium-capillary interface system is a valid model for studying periodontal soft tissue function and drug delivery.

Raman microspectroscopy/micro-optical coherence tomography approach for chairside diagnosis of periodontal diseases: A pilot study.

Our objective was to develop and test a combined Raman microspectroscopy (RMS) and micro-optical coherence tomography (μOCT) approach for chairside quantification of gingival collagen, DNA, epithelium, and connective tissue. We hypothesized that a high-resolution RMS/μOCT can characterize healthy and inflamed periodontal tissues for diagnosis and disease activity monitoring. A prototype instrument was developed, tested ex vivo on gingival specimens and optimized for in vivo intraoral use. The primary outcome measures were the ratios of oral epithelium to connective tissue thickness (OE:CT) and the amount of DNA to collagen type I (DNA/Col 1), and the thickness of sulcular epithelium (SE). For ex vivo testing, eight subjects with healthy periodontal tissues or with Stage II to IV periodontitis were included in the study and underwent crown-lengthening or periodontal surgical procedures, respectively. Gingival biopsies were scanned by RMS/μOCT and histometric analyses were performed. The proof-of-concept study included OE/CT, DNA/Col 1, and SE assessed in six volunteers with or without signs of gingival inflammation (n=3/group). The spatially co-registered RMS spectra revealed opposing changes in the collagen and DNA peaks of inflamed compared with healthy tissues (P<0.05). Combined RMS/μOCT analysis showed that OE/CT, DNA/Col, and SE are significantly different between healthy and inflamed sites (P<0.05). Histological assessments confirmed the differences detected by RMS/μOCT. Qualitative analysis of DNA/Col 1 ratios indicated Col I content as the main distinguishing feature for health and DNA content for periodontitis. Results suggest that combined RMS/μOCT chairside imaging may distinguish between healthy and diseased sites by evaluating marginal periodontal morphological and biochemical features.

TNF ALPHA AND SEX PREVALENCE OF ORAL MANIFESTATIONS IN CHRONIC INFLAMMATORY DISEASES: IT'S COMPLICATED

<h3>Objectives</h3> Several studies have linked chronic inflammatory conditions such as Crohn's disease (CD) or inflammatory arthritis to increased risk for periodontal disease (PD). It is attractive to attribute this to increased circulating pro-inflammatory cytokine levels such as tumor necrosis factor-alpha (TNF-α). Women show a higher incidence of CD, and women with CD have a higher risk of developing PD. How sex differences affect disease susceptibility and how this might be linked to pro-inflammatory cytokines is not well understood. The TNFΔARE (TNFΔ/WT) mouse is an established model for CD and inflammatory arthritis. The prolonged and increased TNF-α production led to spontaneous development of these 2 inflammatory diseases from a young age. Here, we used this model to test sex prevalence and the role of circulating TNF-α in the development of PD. <h3>Study Design</h3> Both male and female TNFΔARE (TNFΔ/WT) and control WT mice were analyzed at 2 and 4 months of age for changes to the temporomandibular joint (TMJ), buccal mucosa, gingival epithelium, and alveolar bone. MicroCT scans were acquired using a Milabs U-CT scanner and analyzed using Avizo 9.1.1. Oral manifestations were analyzed using histology (hematoxylin & eosin, Tartrate-resistant acid phosphatase (TRAP), Safranin O) and immunofluorescence to assess proliferation (Ki67), inflammation (CD45), and bone remodeling (Sclerostin (SOST), Receptor activator of nuclear factor kappa-B ligand (RANKL)). <h3>Results</h3> Four-month-old but not 2-month-old TNFΔ/WT showed various oral manifestations associated with arthritis (TMJ) or CD (cobblestone mucosa). No evidence of active periodontal disease was found. Four-month-old female mice showed gingival hyperplasia, severe TMJ arthritis, malocclusion, and alveolar bone loss in the absence of other signs of PD (epithelial inflammation, bleeding). Four-month-old TNFΔ/WT male mice presented TMJ arthritis, cobblestone mucosa, lack of hyperplasia but limited presence of leukocytes at the gingival epithelium, periodontal ligament, and buccal mucosa. Other signs of PD (epithelial inflammation, bleeding) were also missing. <h3>Conclusions</h3> We present strong evidence that circulating TNF-α is not sufficient to induce PD. The role of TNF-α in oral tissues is complex. TMJ arthritis and malocclusion might trigger alveolar bone loss in female TNFΔARE mice in the absence of PD. Sex-specific differences in oral manifestations (hyperplasia vs cobblestone mucosa) might be directly related to local rather than systemic differences in TNF-α.

Comparative Evaluation of Depigmentation Technique with Diode Laser and Electrosurgery – A Case Report

Excessive gingival pigmentation is a major esthetic concern for many people. The gingiva is an important intraoral tissue which when affected particularly by pigmentation is mainly responsible for the unpleasant appearance. A harmonious smile accounts for a perfect balance between the pink and white component of oral cavity. It mainly affects the confidence, self-esteem, and esthetics of an individual, which can also have a psychological impact on them. Melanin pigmentation is known to be caused by melanin granules within the gingival epithelium. In this case report, a split-mouth depigmentation was done using electrosurgery and diode laser with melanin hyperpigmentation in the anterior maxilla and mandible which provides increased satisfaction in patients.

Periodontal wound healing: An absolute literature review

Periodontal healing is a complex process requiring coordinated responses involving gingival epithelium and connective tissue, periodontal ligament, cementum and alveolar bone. The understanding of this process is necessary to visualize the outcome of different periodontal procedures which inhibits the further progression of periodontal disease and restore the lost periodontal structures. The periodontal regeneration is the ideal response for long-term success of the tooth. The newer approach to periodontal regeneration involves the use of biological mediators like attachment proteins, enamel matrix proteins, growth factors and bone morphogenetic proteins which enhances the regenerative potential of the host tissues by providing favourable signals for proliferation and migration of the periodontal ligament cells towards the affected root surface. Keywords: wound healing; regeneration; reattachment; inflammation; granulation; growth factors.

Macrophage migration inhibitory factor regulates specific innate immune sensor responses in gingival epithelial cells.

The gingival epithelium protects periodontal tissues and the alveolar bone by maintaining a steady state of regulated inflammatory surveillance, also known as healthy homeostasis. Accordingly, the repertoire of receptors present within the gingival epithelium showcases its ability to recognize microbial colonization and contribute to bacterial sensing. Macrophage migration inhibitory factor (MIF) is one of many cytokines that are expressed in this protective state and is involved in neutrophil regulation. However, its role in the maintenance of healthy gingival tissue has not been described. Gingival tissues from wild-type (WT) and Mif knock-out (KO) mice were stained for neutrophils and three key neutrophil chemoattractants: MIF, Gro-α/CXCL1, and Gro-β/CXCL2 in the junctional epithelium (JE). In addition, gene silencing studies were performed using gingival epithelial cells (GECs) to examine the role of MIF on transcription of key bacterial recognition receptors Toll-like receptors (TLR)-1, -2, -4, -6, -9 and interleukin-1 receptors (IL-1R1 and IL-1R2) in response to oral bacterial stimulation. WT murine gingival tissues demonstrated high expression of MIF in the JE. In Mif KO mice, despite the significant reduction of Gro-α/CXCL1 and Gro-β/CXCL2, there was a slight increase in neutrophils. Gene silencing experiments showed that MIF down-regulated the mRNA expression of TLR4, IL-1R1, and IL-1R2 in GEC, in addition to decreasing secreted IL-8/CXCL8 in response to bacteria. MIF regulates the expression of TLR4, IL-1Rs, and IL-8/CXCL8, components that are all involved in maintaining oral health. Our data demonstrate that MIF is a significant contributor to the maintenance of healthy oral homeostasis.

Porphyromonas gingivalis Infection Induces Lipopolysaccharide and Peptidoglycan Penetration Through Gingival Epithelium.

Periodontal diseases initiate on epithelial surfaces of the subgingival compartment, while the gingival epithelium functions as an epithelial barrier against microbial infection and orchestrates immune responses. Porphyromonas gingivalis is a major pathogen of periodontal diseases and has an ability to penetrate the epithelial barrier. To assess the molecular basis of gingival epithelial barrier dysfunction associated with P. gingivalis, we newly developed a three-dimensional multilayered tissue model of gingival epithelium with gene manipulation. Using this novel approach, P. gingivalis gingipains including Arg- or Lys-specific cysteine proteases were found to specifically degrade junctional adhesion molecule 1 and coxsackievirus and adenovirus receptor in the tissue model, leading to increased permeability for lipopolysaccharide, peptidoglycan, and gingipains. This review summarizes the strategy used by P. gingivalis to disable the epithelial barrier by disrupting specific junctional adhesion molecules.