Stem cell-like populations and immunoregulatory molecules in periodontal granulation tissue

Background and Objectives: Determine the presence of mesenchymal stem cells (MSCs) in healthy periodontal tissue and periodontal granulation tissue (GT) and explore associations between immuno‐regulatory molecules and selected subgingival microorganisms. Material and Methods: Mesenchymal stem cells were isolated, propagated and characterised by flow cytometry from a region of healthy gingival tissue and inflamed GT of 10 systemically healthy non‐smokers with chronic periodontitis. Tissue levels of immunoregulatory molecules were determined by qPCR and Gingival Crevicular Fluid (GCF) levels by ELISA. Subgingival plaque levels of periodontal pathogens were determined by qPCR Results: Cells with MSC‐properties were isolated from both inflamed GT and healthy gingival (G) tissue. A pro‐inflammatory process predominated in GT which was partly reflected in GCF and putative periodontal pathogens were higher at diseased sites. However, there was no significant difference in surface levels of mesenchymal (CD90, CD73, CD146, CD271, STRO‐1), endothelial (CD105, CD106), hematopoietic (CD34, CD45) and embryonic (SSEA‐4) stem cell markers between MSCs isolated from GT and G tissue. Conclusion: Periodontal lesions, albeit inflamed, retain healing potential as inferred by the presence of MSC‐like cells with similar immunophenotypic characteristics to those found in healthy periodontal tissue. Therefore, there might be merits for healing in preserving sufficient GT in‐situ during periodontal surgery

Diamond burs versus curettes in root planing: a randomized clinical trial

Aim: This study compares diamond burs and curettes by clinical, microbiological, biochemical, scanning electron microscopic parameters and treatment time data in the non-surgical periodontal treatment of patients with chronic periodontitis. Methods: Two quadrants of each of the 12 patients received root planing with diamond burs whereas other 2 quadrants were treated with curettes. Clinical periodontal measurements were recorded at baseline and then 1, 3, 6 months after completion of non-surgical periodontal treatment. Subgingival plaque, gingival crevicular fluid samples were obtained at baseline and 1-month control. Twenty-one hopeless teeth received root planing with diamond burs or curettes or no treatment at all and then extracted for microscopic evaluations. Results: Clinical periodontal parameters improved similarly with both treatment modalities. Microbiological analyses revealed similar findings for the bacterial load (16S gene copy numbers), ratio of each bacterium to the total bacterial count at baseline, 1-month control. Cytokine levels in the gingival crevicular fluid samples exhibited differences between the two treatments. Scanning electron microscopic analyses indicated that diamond burs were better in terms of calculus removal, loss of tooth substance indices, but roughness index values were better for curettes. Conclusion: As a conclusion, diamond burs provide findings comparable with curettes in root planing

Clinical, pathological and immunological aspects of periodontal disease

The inflammatory and immune responses during the development and progression of periodontitis are reiewed. Susceptibility to periodontitis may be related to whether plasma cells predominate in the tissues of an individual, or a site, in response to the microbial insult from dental plaque. The tendency for an individual or site to form an extensive plasma cell infiltrate may indicate an inability to defend against periodontopathogenic bacteria and thus a predisposition to periodontitis. Selected pertinent areas of current interest in cellular and humoral immunology are considered within the periodontal context. These topical issues include (a) homing of immune and inflammatory cells to target tissues; (b) the local proliferation and synthetic activity of immune and inflammatory cells; (c) the cytokine profile of the inflammatory and immune cells; and (d) the immunoglobulin subclasses of locally produced antibodies

The immune processes in periodontal disease

The inflammatory and immune processes in periodontitis are complex and, although a great deal of information is available, many questions remain. Variation in human susceptibility to periodontitis has long been accepted, but the pathological basis of this is poorly understood. Similarly, we know little of the differences, if any, between the pathology of chronic and aggressive periodontitis. Genetics and environmental influences play a role in the susceptibility process, but if and how that translates through the immune and inflammatory processes to produce the plasma cell-dominated lesions seen in periodontitis remain to be elucidated. This review will focus on immunological aspects of the inflammatory changes seen in gingivitis and periodontitis, addressing both humoral and cellular responses to the microbial insult from dental plaque. A tendency for an individual or site to form an extensive plasma cell infiltrate may indicate an inability to defend against periodontopathogens and thus a predisposition to periodontitis. The issues to be considered include: 1) homing of immune and inflammatory cells to target tissues; 2) their local proliferation and synthetic activity; 3) the cytokine profile of the leukocytes; 4) the immunoglobulin subclasses of locally produced antibodies; 5) mucosal and systemic immune characteristics of the response; 6) the humoral immune response in periodontal health and disease states; and 7) the antigenic target of the immune response in periodontal lesions

Prostaglandins and prostaglandin synthetase inhibitors regulate the synthesis of complement components by human monocytes

The addition of prostaglandins E2 (PGE2), PGD2, PGI2, 6-keto PGF1 alpha and thromboxane B2 (TXB2) to human monocyte cultures, inhibited the production of the second component of complement (C2). PGF2 alpha did not significantly affect C2 production. As the former compounds, but not the latter increase intracellular cAMP, it was thought that the effect was mediated by this action. The addition of cyclo-oxygenase and lipoxygenase inhibitors to monocyte cultures enhanced the synthesis of complement components and other proteins in a dose-dependent fashion: cyclo-oxygenase inhibitors being more potent in this regard than lipoxygenase inhibitors. The enhancing effect of cyclo-oxygenase inhibitors paralleled their ability to inhibit cyclo-oxygenase activity. The enhancement of C2 synthesis by the addition of cyclo-oxygenase and lipoxygenase inhibitors was reversed by the addition of PGs to the cultures. It is concluded that the production of PG by monocytes could provide an endogenous mechanism to control the synthesis of complement components and other proteins

Inducible nitric oxide synthase expression in periodontitis

Recently, nitric oxide (NO) has been shown to be vital in inflammatory processes. Nitric oxide synthase (NOS) exists in three different isoforms, two constitutively produced with physiological roles, and an inducible form, iNOS, which is involved in inflammation. This study examined the localisation of iNOS in biopsies from patients with periodontitis using immunohistochemistry, and compared these with healthy tissue biopsies. Biopsies were obtained from 16 periodontitis patients undergoing periodontal surgery and from clinically healthy tissues of 5 patients having crown lengthening procedures. The periodontitis diseased tissue demonstrated a greater level of iNOS expression than the healthy tissue. The source of iNOS in the periodontal tissues was determined by our monoclonal antibody to be the macrophage, with the endothelial cells also contributing. A role for NO in the inflammatory response of periodontal tissues is suggested, but the precise role requires further elucidation

Country profile Mexico 1996-97

SIGLEAvailable from British Library Document Supply Centre-DSC:3481.89489(1996/1997) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Minimum wage legislation, work conditions and employment

SIGLEAvailable from British Library Document Supply Centre-DSC:3597.9512(CEPR-DP--1524) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

C-telopeptide pyridinoline crosslinks of type I collagen, soluble RANKL, and osteoprotegerin levels in crevicular fluid of dental implants with peri-implantitis: a case-control study.

Purpose: To evaluate levels of C-telopeptide pyridinoline crosslinks of type I collagen (ICTP), soluble receptor activator of nuclear factor-kappa B ligand (sRANKL), and osteoprotegerin (OPG) in the crevicular fluid of endosseous dental implants with the clinical diagnosis of peri-implantitis and to compare these with the crevicular fluid of clinically healthy implants. Methods: Peri-implant crevicular fluid samples were obtained from 18 root-type implants with peri-implantitis in 12 patients and 21 clinically healthy implants in 16 other patients. Modified Plaque Index, probing depths, Gingival Index, and bleeding on probing were recorded at the crevicular fluid sampling sites. ICTP, sRANKL, OPG, and albumin levels in the peri-implant crevicular fluid samples were investigated by enzyme-linked immunosorbent assay. The clinical and biochemical data were evaluated statistically using Mann-Whitney U test. Spearman correlations were used to determine relationships between the biochemical data and the clinical parameters. Results: Duration of implant loading, peri-implant crevicular fluid volume, and all clinical periodontal measurements were significantly greater in the peri-implantitis group than in the clinically healthy group. Total amounts of ICTP were significantly higher in the peri-implantitis group than in the healthy group. sRANKL concentrations, OPG total amounts, and OPG concentrations were significantly higher in the healthy group. Conclusion: The present findings suggest that local levels of ICTP and OPG reflect an increased risk of alveolar bone loss around dental implants, and their local levels may help to distinguish diseased and healthy sites