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Sample records for human periodontal ligament

  1. Human periodontal ligament cell sheets can regenerate periodontal ligament tissue in an athymic rat model.

    PubMed

    Hasegawa, Masateru; Yamato, Masayuki; Kikuchi, Akihiko; Okano, Teruo; Ishikawa, Isao

    2005-01-01

    Conventional periodontal regeneration methods remain insufficient to attain complete and reliable clinical regeneration of periodontal tissues. We have developed a new method of cell transplantation using cell sheet engineering and have applied it to this problem. The purpose of this study was to investigate the characteristics of human periodontal ligament (HPDL) cell sheets retrieved from culture on unique temperature-responsive culture dishes, and to examine whether these cell sheets can regenerate periodontal tissues. The HPDL cell sheets were examined histologically and biochemically, and also were transplanted into a mesial dehiscence model in athymic rats. HPDL cells were harvested from culture dishes as a contiguous cell sheet with abundant extracellular matrix and retained intact integrins that are susceptible to trypsin-EDTA treatment. In the animal study, periodontal ligament-like tissues that include an acellular cementum-like layer and fibrils anchoring into this layer were identified in all the athymic rats transplanted with HPDL cell sheets. This fibril anchoring highly resembles native periodontal ligament fibers; such regeneration was not observed in nontransplanted controls. These results suggest that this technique, based on the concept of cell sheet engineering, can be useful for periodontal tissue regeneration. PMID:15869425

  2. Human periodontal ligament stem cells repair mental nerve injury

    PubMed Central

    Li, Bohan; Jung, Hun-Jong; Kim, Soung-Min; Kim, Myung-Jin; Jahng, Jeong Won; Lee, Jong-Ho

    2013-01-01

    Human periodontal ligament stem cells are easily accessible and can differentiate into Schwann cells. We hypothesized that human periodontal ligament stem cells can be used as an alternative source for the autologous Schwann cells in promoting the regeneration of injured peripheral nerve. To validate this hypothesis, human periodontal ligament stem cells (1 × 106) were injected into the crush-injured left mental nerve in rats. Simultaneously, autologous Schwann cells (1 × 106) and PBS were also injected as controls. Real-time reverse transcriptase polymerase chain reaction showed that at 5 days after injection, mRNA expression of low affinity nerve growth factor receptor was significantaly increased in the left trigeminal ganglion of rats with mental nerve injury. Sensory tests, histomorphometric evaluation and retrograde labeling demonstrated that at 2 and 4 weeks after injection, sensory function was significantly improved, the numbers of retrograde labeled sensory neurons and myelinated axons were significantly increased, and human periodontal ligament stem cells and autologous Schwann cells exhibited similar therapeutic effects. These findings suggest that transplantation of human periodontal ligament stem cells show a potential value in repair of mental nerve injury. PMID:25206604

  3. Shikonin Inhibits Inflammatory Cytokine Production in Human Periodontal Ligament Cells.

    PubMed

    Shindo, Satoru; Hosokawa, Yoshitaka; Hosokawa, Ikuko; Ozaki, Kazumi; Matsuo, Takashi

    2016-06-01

    Shikonin, which is derived from Lithospermum erythrorhizon, a herb used in traditional medicine, has long been considered to be a useful treatment for various diseases in traditional oriental medicine. Shikonin has recently been reported to have several pharmacological properties, e.g., it has anti-microbial, anti-tumor, and anti-inflammatory effects. The aim of this study was to examine whether shikonin is able to influence the production of interleukin (IL)-6, IL-8, and/or chemokine C-C motif ligand (CCL)20, which contribute to the pathogenesis of periodontal disease, in human periodontal ligament cells (HPDLC). The production levels of IL-6, IL-8, and CCL20 in HPDLC were determined using an ELISA. Western blot analysis was used to detect nuclear factor kappa B (NF-κB) pathway activation in HPDLC. Shikonin prevented IL-1β- or tumor necrosis factor (TNF)-α-mediated IL-6, IL-8, and CCL20 production in HPDLC. Moreover, we found that shikonin suppressed the phosphorylation and degradation of inhibitor of kappa B-alpha (IκB-α) in IL-1β- or TNF-α-stimulated HPDLC. These findings suggest that shikonin could have direct beneficial effects against periodontal disease by reducing IL-6, IL-8, and CCL20 production in periodontal lesions. PMID:27072015

  4. Proliferative activity in the juxtaradicular human periodontal ligament.

    PubMed

    Sayaniwas, M; Hilliges, M; Lindskog, S

    1999-08-01

    The aim of the present study was to evaluate cell proliferation, assessed by MIB 1, with respect to the type and the distribution of proliferating cells in the healthy juxtaradicular periodontal ligament (PDL) from completely formed human teeth. Immunohistochemical markers against vimentin, CD68 and S-100 were used to characterize cell type. The applicability of the immunohistochemical method on explants of human PDL was also evaluated. The results indicated that under physiological conditions, the majority of the proliferating cells in the PDL were mesenchymal cells predominantly located paravascularly in the middle third of the PDL. Furthermore, MIB 1 reacting with the Ki-67 antigen together with the avidin-biotin-complex technique was proved to be an efficient marker of cell proliferation in explants of human PDL. PMID:10815567

  5. Morinda citrifolia leaves enhance osteogenic differentiation and mineralization of human periodontal ligament cells.

    PubMed

    Boonanantanasarn, Kanitsak; Janebodin, Kajohnkiart; Suppakpatana, Prapan; Arayapisit, Tawepong; Rodsutthi, Jit-aree; Chunhabundit, Panjit; Boonanuntanasarn, Surintorn; Sripairojthikoon, Wanida

    2014-01-01

    This present study investigated the potential of Morinda citrifolia leaf aqueous extract to induce osteogenic differentiation and matrix mineralization of human periodontal ligament (hPDL) cells. Human periodontal ligament cells were cultured in complete medium, ascorbic acid with β-glycerophosphate, or Morinda citrifolia leaf aqueous extract. Morinda citrifolia leaf aqueous extract significantly increased alkaline phosphatase activity compared to culturing in complete medium or ascorbic acid with β-glycerophosphate. Matrixcontaining mineralized nodules were formed only when the cells were cultured in the presence of Morinda citrifolia leaf aqueous extract. These nodules showed positive alizarin red S staining and were rich in calcium and phosphorus according to energy dispersive X-ray analysis. In conclusion, Morinda citrifolia leaf extract promoted osteogenic differentiation and matrix mineralization in human periodontal ligament cells, a clear indication of the therapeutic potential of Morinda citrifolia leaves in bone and periodontal tissue regeneration. PMID:24682022

  6. Effect of storage media on human periodontal ligament cell apoptosis.

    PubMed

    Chamorro, Mónica M; Regan, John D; Opperman, Lynne A; Kramer, Phillip R

    2008-02-01

    The ability of storage media to preserve periodontal ligament (PDL) cell vitality has been previously evaluated. However, the mechanisms by which different storage conditions alter the functional status of PDL cells have not been determined. The purpose of the present study was to investigate, in vitro, the level of programed cell death or apoptosis in a population of PDL cells following storage under different conditions. Primary human PDL cells were plated into 24-well-culture plates and allowed to attach for 24 h. Cells were then exposed for 1 h to milk, Hank's balanced salt solution (HBSS), Soft Wear contact lens solution or Gatorade at room temperature or on ice. Culture medium was used as a negative control. Apoptosis was evaluated at 24, 48, and 72 h after treatment on quadruplicate samples by using the ST 160 ApopTag Fluorescein Direct In Situ Detection Kit. The total number of cells and the total number of apoptotic cells were counted. The results indicated that at 24 and 72 h, PDL treated with Gatorade and the contact lens solution displayed the highest percentages of apoptotic cells when compared with the other treatment groups at room temperature. Overall, cells treated on ice showed significantly lower levels of apoptosis when compared with treatments at room temperature. In conclusion, the results indicated that apoptosis plays a major role in cell death in cells treated with Gatorade and contact lens solutions in comparison to other storage solutions and that storage on ice can inhibit programed cell death. PMID:18173658

  7. Effect of F-spondin on cementoblastic differentiation of human periodontal ligament cells

    SciTech Connect

    Kitagawa, Masae; Kudo, Yasusei; Iizuka, Shinji; Ogawa, Ikuko; Abiko, Yoshimitsu; Miyauchi, Mutsumi; Takata, Takashi . E-mail: ttakata@hiroshima-u.ac.jp

    2006-10-27

    Cementum is a mineralized tissue produced by cementoblasts covering the roots of teeth that provides for the attachment of periodontal ligament to roots and surrounding alveolar bone. To study the mechanism of proliferation and differentiation of cementoblasts is important for understanding periodontal physiology and pathology including periodontal tissue regeneration. However, the detailed mechanism of the proliferation and differentiation of human cementoblasts is still unclear. We previously established human cementoblast-like (HCEM) cell lines. We thought that comparing the transcriptional profiles of HCEM cells and human periodontal ligament (HPL) cells derived from the same teeth could be a good approach to identify genes that influence the nature of cementoblasts. We identified F-spondin as the gene demonstrating the high fold change expression in HCEM cells. Interestingly, F-spondin highly expressing HPL cells showed similar phenotype of cementoblasts, such as up-regulation of mineralized-related genes. Overall, we identified F-spondin as a promoting factor for cementoblastic differentiation.

  8. Domain of Dentine Sialoprotein Mediates Proliferation and Differentiation of Human Periodontal Ligament Stem Cells

    PubMed Central

    Yang, Guobin; Wang, Feng; Li, Wentong; Yang, Yuan; Guo, Feng; Gao, Qingping; Shoff, Lisa; Chen, Zhi; Gay, Isabel C.; Donly, Kevin J.; MacDougall, Mary; Chen, Shuo

    2013-01-01

    Classic embryological studies have documented the inductive role of root dentin on adjacent periodontal ligament differentiation.  The biochemical composition of root dentin includes collagens and cleavage products of dentin sialophosphoprotein (DSPP), such as dentin sialoprotein (DSP).  The high abundance of DSP in root dentin prompted us to ask the question whether DSP or peptides derived thereof would serve as potent biological matrix components to induce periodontal progenitors to further differentiate into periodontal ligament cells. Here, we test the hypothesis that domain of DSP influences cell fate. In situ hybridization and immunohistochemical analyses showed that the COOH-terminal DSP domain is expressed in mouse periodontium at various stages of root development. The recombinant COOH-terminal DSP fragment (rC-DSP) enhanced attachment and migration of human periodontal ligament stem cells (PDLSC), human primary PDL cells without cell toxicity. rC-DSP induced PDLSC cell proliferation as well as differentiation and mineralization of PDLSC and PDL cells by formation of mineralized tissue and ALPase activity. Effect of rC-DSP on cell proliferation and differentiation was to promote gene expression of tooth/bone-relate markers, transcription factors and growth factors. The results for the first time showed that rC-DSP may be one of the components of cell niche for stimulating stem/progenitor cell proliferation and differentiation and a natural scaffold for periodontal regeneration application. PMID:24400037

  9. Cytotoxicity evaluation of root repair materials in human-cultured periodontal ligament fibroblasts

    PubMed Central

    Samyuktha, Voruganti; Ravikumar, Pabbati; Nagesh, Bolla; Ranganathan, K.; Jayaprakash, Thumu; Sayesh, Vemuri

    2014-01-01

    Aim: To evaluate the cytotoxicity of three root repair materials, mineral trioxide aggregate (MTA), Endosequence Root Repair Material and Biodentine in human periodontal ligament fibroblasts. Materials and Methods: Periodontal ligament fibroblasts were cultured from healthy premolar extracted for orthodontic purpose. Cells in the third passage were used in the study. The cultured fibroblast cells were placed in contact with root repair materials: (a) Biodentine, (b) MTA, (c) Endosequence, (d) control. The effects of these three materials on the viability of Periodontal ligament (PDL) fibroblasts were determined by trypan blue dye assay after 24 hours and 48-hour time period. Cell viability was determined using inverted phase contrast microscope. Statistical Analysis: Cell viability was compared for all the experimental groups with Wilcoxons matched pair test. Results: At the 24-hour examination period, all the materials showed increased cell viability. At 48-hour time period, there is slight decrease in cell viability. Mineral trioxide aggregate showed statistically significant increase in the cell viability when compared to other root repair materials. Conclusion: Mineral trioxide aggregate was shown to be less toxic to periodontal ligament fibroblasts than Endosequence Root Repair Material and Biodentine. PMID:25298650

  10. Impact of nicotine on the interplay between human periodontal ligament cells and CD4+ T cells.

    PubMed

    Ge, Xin; Liu, Ying-Feng; Wong, Yong; Wu, Li-Zheng; Tan, Ling; Liu, Fen; Wang, Xiao-Jing

    2016-09-01

    Periodontitis is a common infectious disease associated with destruction of periodontal ligaments and alveolar bones. CD4(+) T cell-mediated immune response is involved in the progression of periodontitis. Tobacco consumption increases the risk of periodontal disease. However, the impact of nicotine on the interaction between human periodontal ligament (PDL) cells and CD4(+) T cells remains unrevealed. Our study aims to investigate the effect of nicotine on PDL cells and the cocultured CD4(+) T cells. The PDL cell cultures were established by explants from healthy individuals, exposed to nicotine or α-bungarotoxin (α-BTX), and incubated solely or in combination with CD4(+) T cells. Afterwards, cell viability, secreted cytokines, and matrix metalloproteinases (MMPs) were evaluated. In monoculture of PDL cells, nicotine dramatically repressed cell viability and increased apoptosis. Meanwhile, α-BTX largely reversed the nicotine-induced apoptosis and increased viability of PDL cells. Compared with the monoculture, MMP-1, MMP-3, interleukin (IL)-1β, IL-6, IL-17, and IL-21 in supernatant of cocultures were markedly elevated after treatment with nicotine. Moreover, α-BTX significantly attenuated nicotine-triggered production of these components either in mono- or co-cultures. In addition, PDL cell-derived CXCL12 following nicotine treatment recruited CD4(+) T cells. Above all, nicotine deteriorated periodontitis partially by promoting PDL cell-CD4(+) T cell-mediated inflammatory response and matrix degradation. PMID:26553320

  11. In vivo measurements and numerical analysis of the biomechanical characteristics of the human periodontal ligament.

    PubMed

    Keilig, L; Drolshagen, M; Tran, K L; Hasan, I; Reimann, S; Deschner, J; Brinkmann, K T; Krause, R; Favino, M; Bourauel, C

    2016-07-01

    The periodontal ligament is a complex tissue with respect to its biomechanical behaviour. It is important to understand the mechanical behaviour of the periodontal ligament during physiological loading in healthy patients as well as during the movement of the tooth in orthodontic treatment or in patients with periodontal disease, as these might affect the mechanical properties of the periodontal ligament (PDL). Up to now, only a limited amount of in vivo data is available concerning this issue. The aim of this study has been to determine the time dependent material properties of the PDL in an experimental in vivo study, using a novel device that is able to measure tooth displacement intraorally. Using the intraoral loading device, tooth deflections at various velocities were realised in vivo on human teeth. The in vivo investigations were performed on the upper left central incisors of five volunteers aged 21-33 years with healthy periodontal tissue. A deflection, applied at the centre of the crown, was linearly increased from 0 to 0.15mm in a loading period of between 0.1 and 5.0s. Individual numerical models were developed based on the experimental results to simulate the relationship between the applied force and tooth displacement. The numerical force/displacement curves were fitted to the experimental ones to obtain the material properties of the human PDL. For the shortest loading time of 0.1s, the experimentally determined forces were between 7.0 and 16.2N. The numerically calculated Young's modulus varied between 0.9MPa (5.0s) and 1.2MPa (0.1s). By considering the experimentally and numerically obtained force curves, forces decreased with increasing loading time. The experimental data gained in this study can be used for the further development and verification of a multiphasic constitutive law of the PDL. PMID:26395824

  12. Semaphorin 3A Induces Mesenchymal-Stem-Like Properties in Human Periodontal Ligament Cells

    PubMed Central

    Maeda, Hidefumi; Hasegawa, Daigaku; Gronthos, Stan; Bartold, Peter Mark; Menicanin, Danijela; Fujii, Shinsuke; Yoshida, Shinichiro; Tomokiyo, Atsushi; Monnouchi, Satoshi; Akamine, Akifumi

    2014-01-01

    Periodontal ligament stem cells (PDLSCs) have recently been proposed as a novel option in periodontal regenerative therapy. However, one of the issues is the difficulty of stably generating PDLSCs because of the variation of stem cell potential between donors. Here, we show that Semaphorin 3A (Sema3A) can induce mesenchymal-stem-like properties in human periodontal ligament (PDL) cells. Sema3A expression was specifically observed in the dental follicle during tooth development and in parts of mature PDL tissue in rodent tooth and periodontal tissue. Sema3A expression levels were found to be higher in multipotential human PDL cell clones compared with low-differentiation potential clones. Sema3A-overexpressing PDL cells exhibited an enhanced capacity to differentiate into both functional osteoblasts and adipocytes. Moreover, PDL cells treated with Sema3A only at the initiation of culture stimulated osteogenesis, while Sema3A treatment throughout the culture had no effect on osteogenic differentiation. Finally, Sema3A-overexpressing PDL cells upregulated the expression of embryonic stem cell markers (NANOG, OCT4, and E-cadherin) and mesenchymal stem cell markers (CD73, CD90, CD105, CD146, and CD166), and Sema3A promoted cell division activity of PDL cells. These results suggest that Sema3A may possess the function to convert PDL cells into mesenchymal-stem-like cells. PMID:24380401

  13. Generation of functional hepatocyte-like cells from human deciduous periodontal ligament stem cells

    NASA Astrophysics Data System (ADS)

    Vasanthan, Punitha; Jayaraman, Pukana; Kunasekaran, Wijenthiran; Lawrence, Anthony; Gnanasegaran, Nareshwaran; Govindasamy, Vijayendran; Musa, Sabri; Kasim, Noor Hayaty Abu

    2016-08-01

    Human deciduous periodontal ligament stem cells have been introduced for as an easily accessible source of stem cells from dental origin. Although recent studies have revealed the ability of these stem cells in multipotential attribute, their efficiency of hepatic lineage differentiation has not been addressed so far. The aim of this study is to investigate hepatic lineage fate competence of periodontal ligament stem cells through direct media induction. Differentiation of periodontal ligament stem cells into hepatocyte-like cells was conducted by the exposure of two phase media induction. First phase was performed in the presence of hepatocyte growth factors to induce a definitive endoderm formation. In the subsequent phase, the cells were treated with oncostatin M and dexamethosone followed by insulin and transferrin to generate hepatocyte-like cells. Hepatic-related characters of the generated hepatocyte-like cells were determined at both mRNA and protein level followed by functional assays. Foremost changes observed in the generation of hepatocyte-like cells were the morphological features in which these cells were transformed from fibroblastic shape to polygonal shape. Temporal expression of hepatic markers ranging from early endodermal up to late markers were detected in the hepatocyte-like cells. Crucial hepatic markers such as glycogen storage, albumin, and urea secretion were also shown. These findings exhibited the ability of periodontal ligament stem cells of dental origin to be directed into hepatic lineage fate. These cells can be regarded as an alternative autologous source in the usage of stem cell-based treatment for liver diseases.

  14. Generation of functional hepatocyte-like cells from human deciduous periodontal ligament stem cells.

    PubMed

    Vasanthan, Punitha; Jayaraman, Pukana; Kunasekaran, Wijenthiran; Lawrence, Anthony; Gnanasegaran, Nareshwaran; Govindasamy, Vijayendran; Musa, Sabri; Kasim, Noor Hayaty Abu

    2016-08-01

    Human deciduous periodontal ligament stem cells have been introduced for as an easily accessible source of stem cells from dental origin. Although recent studies have revealed the ability of these stem cells in multipotential attribute, their efficiency of hepatic lineage differentiation has not been addressed so far. The aim of this study is to investigate hepatic lineage fate competence of periodontal ligament stem cells through direct media induction. Differentiation of periodontal ligament stem cells into hepatocyte-like cells was conducted by the exposure of two phase media induction. First phase was performed in the presence of hepatocyte growth factors to induce a definitive endoderm formation. In the subsequent phase, the cells were treated with oncostatin M and dexamethosone followed by insulin and transferrin to generate hepatocyte-like cells. Hepatic-related characters of the generated hepatocyte-like cells were determined at both mRNA and protein level followed by functional assays. Foremost changes observed in the generation of hepatocyte-like cells were the morphological features in which these cells were transformed from fibroblastic shape to polygonal shape. Temporal expression of hepatic markers ranging from early endodermal up to late markers were detected in the hepatocyte-like cells. Crucial hepatic markers such as glycogen storage, albumin, and urea secretion were also shown. These findings exhibited the ability of periodontal ligament stem cells of dental origin to be directed into hepatic lineage fate. These cells can be regarded as an alternative autologous source in the usage of stem cell-based treatment for liver diseases. PMID:27379400

  15. Recombinant human bone morphogenetic protein-9 potently induces osteogenic differentiation of human periodontal ligament fibroblasts.

    PubMed

    Fuchigami, Sawako; Nakamura, Toshiaki; Furue, Kirara; Sena, Kotaro; Shinohara, Yukiya; Noguchi, Kazuyuki

    2016-04-01

    To accomplish effective periodontal regeneration for periodontal defects, several regenerative methods using growth and differentiation factors, including bone morphogenetic proteins (BMPs), have been developed. Bone morphogenetic protein-9 exhibits the most potent osteogenic activity of this growth factor family. However, it is unclear whether exogenous BMP-9 can induce osteogenic differentiation in human periodontal ligament (PDL) fibroblasts. Here, we examined the effects of recombinant human (rh) BMP-9 on osteoblastic differentiation in human PDL fibroblasts in vitro, compared with rhBMP-2. Recombinant human BMP-9 potently induced alkaline phosphatase (ALP) activity, mineralization, and increased expression of runt-related transcription factor-2/core binding factor alpha 1 (RUNX2/CBFA1), osterix, inhibitor of DNA binding/differentiation-1 (ID1), osteopontin, and bone sialoprotein genes, compared with rhBMP-2. The levels of rhBMP-9-induced osterix and ALP mRNA were significantly reduced in activin receptor-like kinase-1 and -2 small interfering RNA (siRNA)-transfected human PDL fibroblasts. Recombinant human BMP-9-induced ALP activity was not inhibited by noggin, in contrast to rhBMP-2 induced ALP activity, which was. Phosphorylation of SMAD1/5/8 in human PDL fibroblasts was induced by addition of rhBMP-9. Recombinant human BMP-9-induced ALP activity was suppressed by SB203580, SP600125, and U0126, which are inhibitors of p38, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinase 1/2 (ERK1/2), respectively. Our data suggest that rhBMP-9 is a potent inducer of the differentiation of human PDL fibroblasts into osteoblast-like cells and that this may be mediated by the SMAD and mitogen-activated protein kinase (p38, ERK1/2, and JNK) pathways. PMID:26879145

  16. Isolation and Characterization of Human Adult Epithelial Stem Cells from the Periodontal Ligament.

    PubMed

    Athanassiou-Papaefthymiou, M; Papagerakis, P; Papagerakis, S

    2015-11-01

    We report a novel method for the isolation of adult human epithelial stem cells (hEpiSCs) from the epithelial component of the periodontal ligament-the human epithelial cell rests of Malassez (hERM). hEpiSC-rich integrin-α6(+ve) hERM cells derived by fluorometry can be clonally expanded, can grow organoids, and express the markers of pluripotency (OCT4, NANOG, SOX2), polycomb protein RING1B, and the hEpiSC supermarker LGR5. They maintain the growth profile of their originating hERM in vitro. Subcutaneous cotransplantation with mesenchymal stem cells from the dental pulp on poly-l-lactic acid scaffolds in nude mice gave rise to perfect heterotopic ossicles in vivo with ultrastructure of dentin, enamel, cementum, and bone. These remarkable fully mineralized ossicles underscore the importance of epithelial-mesenchymal crosstalk in tissue regeneration using human progenitor stem cells, which may have already committed to lineage despite maintaining hallmarks of pluripotency. In addition, we report the clonal expansion and isolation of human LGR5(+ve) cells from the hERM in xeno-free culture conditions. The genetic profile of LGR5(+ve) cells includes both markers of pluripotency and genes important for secretory epithelial and dental epithelial cell differentiation, giving us a first insight into periodontal ligament-derived hEpiSCs. PMID:26392003

  17. Intermittent Compressive Stress Enhanced Insulin-Like Growth Factor-1 Expression in Human Periodontal Ligament Cells

    PubMed Central

    Pumklin, Jittima; Manokawinchoke, Jeeranan; Bhalang, Kanokporn; Pavasant, Prasit

    2015-01-01

    Mechanical force was shown to promote IGF-1 expression in periodontal ligament both in vitro and in vivo. Though the mechanism of this effect has not yet been proved, here we investigated the molecular mechanism of intermittent mechanical stress on IGF-1 expression. In addition, the role of hypoxia on the intermittent compressive stress on IGF-1 expression was also examined. In this study, human periodontal ligament cells (HPDLs) were stimulated with intermittent mechanical stress for 24 hours. IGF-1 expression was examined by real-time polymerase chain reaction. Chemical inhibitors were used to determine molecular mechanisms of these effects. For hypoxic mimic condition, the CoCl2 supplementation was employed. The results showed that intermittent mechanical stress dramatically increased IGF-1 expression at 24 h. The pretreatment with TGF-β receptor I or TGF-β1 antibody could inhibit the intermittent mechanical stress-induced IGF-1 expression. Moreover, the upregulation of TGF-β1 proteins was detected in intermittent mechanical stress treated group. Correspondingly, the IGF-1 expression was upregulated upon being treated with recombinant human TGF-β1. Further, the hypoxic mimic condition attenuated the intermittent mechanical stress and rhTGF-β1-induced IGF-1 expression. In summary, this study suggests intermittent mechanical stress-induced IGF-1 expression in HPDLs through TGF-β1 and this phenomenon could be inhibited in hypoxic mimic condition. PMID:26106417

  18. Escin inhibits lipopolysaccharide-induced inflammation in human periodontal ligament cells.

    PubMed

    Liu, Shutai; Wang, Huaizhou; Qiu, Caiqing; Zhang, Jing; Zhang, Taowen; Zhou, Wenjuan; Lu, Zhishan; Rausch-Fan, Xiaohui; Liu, Zhonghao

    2012-11-01

    Periodontitis is a chronic inflammatory disease associated with gram-negative subgingival microflora infection. Accumulating experimental evidence suggests that escin exerts anti-inflammatory and anti-edematous effects. This study was designed to investigate the in vitro effects of escin on the inflammatory reaction of human periodontal ligament cells (hPDLs). hPDLs were stimulated with lipopolysaccharide (LPS). The cells were treated with various concentrations of escin. The viability of hPDLs was evaluated using the MTT method. The expression of Toll-like receptor 2 (TLR2) in hPDLs and the levels of IL-1β, TNF-α and IL-6 in the supernatant were measured. Escin significantly attenuated LPS-induced cytotoxicity in a concentration-dependent manner in hPDLs. Treatment with escin partly blocked the expression of TLR2. Escin also lowered the increase of pro-inflammatory cytokines (IL-1β, TNF-α and IL-6) induced by LPS. The present findings show that escin exerts a protective effect against LPS-induced inflammation in hPDLs. It was also shown that escin is a promising medicine for the treatment of periodontitis. PMID:22895831

  19. Adhesion and proliferation of human periodontal ligament cells on poly(2-methoxyethyl acrylate).

    PubMed

    Kitakami, Erika; Aoki, Makiko; Sato, Chikako; Ishihata, Hiroshi; Tanaka, Masaru

    2014-01-01

    Human periodontal ligament (PDL) cells obtained from extracted teeth are a potential cell source for tissue engineering. We previously reported that poly(2-methoxyethyl acrylate) (PMEA) is highly biocompatible with human blood cells. In this study, we investigated the adhesion, morphology, and proliferation of PDL cells on PMEA and other types of polymers to design an appropriate scaffold for tissue engineering. PDL cells adhered and proliferated on all investigated polymer surfaces except for poly(2-hydroxyethyl methacrylate) and poly[(2-methacryloyloxyethyl phosphorylcholine)-co-(n-butyl methacrylate)]. The initial adhesion of the PDL cells on PMEA was comparable with that on polyethylene terephthalate (PET). In addition, the PDL cells on PMEA spread well and exhibited proliferation behavior similar to that observed on PET. In contrast, platelets hardly adhered to PMEA. PMEA is therefore expected to be an excellent scaffold for tissue engineering and for culturing tissue-derived cells in a blood-rich environment. PMID:25165689

  20. Adhesion and Proliferation of Human Periodontal Ligament Cells on Poly(2-methoxyethyl acrylate)

    PubMed Central

    Aoki, Makiko; Sato, Chikako; Ishihata, Hiroshi; Tanaka, Masaru

    2014-01-01

    Human periodontal ligament (PDL) cells obtained from extracted teeth are a potential cell source for tissue engineering. We previously reported that poly(2-methoxyethyl acrylate) (PMEA) is highly biocompatible with human blood cells. In this study, we investigated the adhesion, morphology, and proliferation of PDL cells on PMEA and other types of polymers to design an appropriate scaffold for tissue engineering. PDL cells adhered and proliferated on all investigated polymer surfaces except for poly(2-hydroxyethyl methacrylate) and poly[(2-methacryloyloxyethyl phosphorylcholine)-co-(n-butyl methacrylate)]. The initial adhesion of the PDL cells on PMEA was comparable with that on polyethylene terephthalate (PET). In addition, the PDL cells on PMEA spread well and exhibited proliferation behavior similar to that observed on PET. In contrast, platelets hardly adhered to PMEA. PMEA is therefore expected to be an excellent scaffold for tissue engineering and for culturing tissue-derived cells in a blood-rich environment. PMID:25165689

  1. GGsTOP increases migration of human periodontal ligament cells in vitro via reactive oxygen species pathway.

    PubMed

    Jiang, Ying; Wang, Xiang; Li, Ying; Mu, Sen; Zhou, Shuang; Liu, Yi; Zhang, Bin

    2016-05-01

    GGsTOP is a novel and selective inhibitor of gamma-glutamyl transferase (GGT), a cell-surface enzyme that has a key role in glutathione homeostasis and the maintenance of cellular reactive oxygen species (ROS). ROS are essential for wound healing. However, little is known about the molecular mechanisms underlying the inhibition of GGT by GGsTOP in human periodontal ligament cells (hPLCs). The present study assessed GGT expression in mouse periodontal ligament tissues, GGT activity in hPLCs, and the potential physiological effect of GGsTOP on hPLC migration. Immunohistochemical analysis confirmed that GGT was widely expressed in mouse periodontal ligament tissue. Treatment with GGsTOP was associated with greater proliferation and migration of hPLCs, and higher levels of cellular ROS compared with untreated hPLCs. However, the increase in intracellular ROS was attenuated in hPLCs co‑cultured with the anti‑oxidant N‑acetylcysteine (NAC), a precursor of glutathione. The higher ROS levels associated with GGsTOP treatment were in parallel with increases in the levels of type I collagen and alpha smooth muscle actin, which was inhibited in hPLCs co‑cultured with NAC. Thus, GGsTOP may promote hPLC migration and participate in the maintenance of the periodontal ligament apparatus via the ROS pathway. PMID:27035100

  2. GGsTOP increases migration of human periodontal ligament cells in vitro via reactive oxygen species pathway

    PubMed Central

    JIANG, YING; WANG, XIANG; LI, YING; MU, SEN; ZHOU, SHUANG; LIU, YI; ZHANG, BIN

    2016-01-01

    GGsTOP is a novel and selective inhibitor of gamma-glutamyl transferase (GGT), a cell-surface enzyme that has a key role in glutathione homeostasis and the maintenance of cellular reactive oxygen species (ROS). ROS are essential for wound healing. However, little is known about the molecular mechanisms underlying the inhibition of GGT by GGsTOP in human periodontal ligament cells (hPLCs). The present study assessed GGT expression in mouse periodontal ligament tissues, GGT activity in hPLCs, and the potential physiological effect of GGsTOP on hPLC migration. Immunohistochemical analysis confirmed that GGT was widely expressed in mouse periodontal ligament tissue. Treatment with GGsTOP was associated with greater proliferation and migration of hPLCs, and higher levels of cellular ROS compared with untreated hPLCs. However, the increase in intracellular ROS was attenuated in hPLCs co-cultured with the anti-oxidant N-acetylcysteine (NAC), a precursor of glutathione. The higher ROS levels associated with GGsTOP treatment were in parallel with increases in the levels of type I collagen and alpha smooth muscle actin, which was inhibited in hPLCs co-cultured with NAC. Thus, GGsTOP may promote hPLC migration and participate in the maintenance of the periodontal ligament apparatus via the ROS pathway. PMID:27035100

  3. Cyclic stretch and compression forces alter microRNA-29 expression of human periodontal ligament cells.

    PubMed

    Chen, Yinghua; Mohammed, Arshad; Oubaidin, Maysaa; Evans, Carla A; Zhou, Xiaofeng; Luan, Xianghong; Diekwisch, Thomas G H; Atsawasuwan, Phimon

    2015-07-15

    MicroRNAs (miRs) play an important role in the development and remodeling of tissues through the regulation of large cohorts of extracellular matrix (ECM) genes. The purpose of the present study was to determine the response of miR-29 family expression to loading forces and their effects on ECM gene expression in periodontal ligament cells, the key effector cell population during orthodontic tooth movement. In a comparison between miRs from human periodontal ligament cells (PDLCs) and alveolar bone cells (ABCs) from healthy human subjects, the ABC cohort of miRs was substantially greater than the corresponding PDLC cohort. Cyclic mechanical stretch forces at 12% deformation at 0.1Hz for 24h decreased expression of miR-29 family member miRs about 0.5 fold while 2g/cm(2) compression force for 24h increased miR-29 family member expression in PDLCs 1.8-4 folds. Cyclic stretch up-regulated major ECM genes in PDLCs, such as COL1A1, COL3A1 and COL5A1, while the compression force resulted in a down-regulation of these ECM genes. Direct interactions of miR-29 and Col1a1, Col3a1 and Col5a1 were confirmed using a dual luciferase reporter gene assay. In addition, transient transfection of a miR-29b mimic in mouse PDLCs down-regulated Col1a1, Col3a1 and Col5a1 while the transfection of miR-29b inhibitor up-regulated these genes compared to control transfection indicating that these target ECM genes directly responded to the altered level of miR-29b. These results provided a possible explanation for the effects of the miR-29 family on loaded PDLCS and their roles in extracellular matrix gene expression. PMID:25827718

  4. Influence of E-smoking liquids on human periodontal ligament fibroblasts

    PubMed Central

    2014-01-01

    Introduction Over the last years, electronic cigarettes (ECs) have become more popular, particularly in individuals who want to give up smoking tobacco. The aim of the present study was to assess the influence of the different e-smoking liquids on the viability and proliferation of human periodontal ligament fibroblasts. Method and materials For this study six test solutions with components from ECs were selected: lime-, hazelnut- and menthol-flavored liquids, nicotine, propylene glycol, and PBS as control group. The fibroblasts were incubated up to 96 h with the different liquids, and cell viability was measured by using the PrestoBlue® reagent, the ATP detection and the migration assay. Fluorescence staining was carried out to visualize cell growth and morphology. Data were statistically analyzed by two-tailed one-way ANOVA. Results The cell viability assay showed that the proliferation rates of the cells incubated with nicotine or the various flavored liquids of the e-cigarettes were reduced in comparison to the controls, though not all reductions were statistically significant. After an incubation of 96 h with the menthol-flavored liquid the fibroblasts were statistically significant reduced (p < 0.001). Similar results were found for the detection of ATP in fibroblasts; the incubation with menthol-flavored liquids (p < 0.001) led to a statistically significant reduction. The cell visualization tests confirmed these findings. Conclusion Within its limits, the present in vitro study demonstrated that menthol additives of e-smoking have a harmful effect on human periodontal ligament fibroblasts. This might indicate that menthol additives should be avoided for e-cigarettes. PMID:25224853

  5. Combined effects of proinflammatory cytokines and intermittent cyclic mechanical strain in inhibiting osteogenicity in human periodontal ligament cells.

    PubMed

    Sun, Chaofan; Chen, Lijiao; Shi, Xinlian; Cao, Zhensheng; Hu, Bibo; Yu, Wenbin; Ren, Manman; Hu, Rongdang; Deng, Hui

    2016-09-01

    Mechanical strain plays an important role in bone formation and resorption during orthodontic tooth movement. The mechanism has not been fully studied, and the process becomes complex with increased amounts of periodontal patients seeking orthodontic care. Our aims were to elucidate the combined effects of proinflammatory cytokines and intermittent cyclic strain (ICS) on the osteogenic capacity of human periodontal ligament cells. Cultured human periodontal ligament cells were exposed to proinflammatory cytokines (interleukin-1β 5 ng/mL and tumor necrosis factor-α 10 ng/mL) for 1 and 5 days, and ICS (0.5 Hz, 12% elongation) was applied for 4 h per day. The autocrine of inflammatory cytokines was measured by enzyme-linked immunosorbent assay. The expression of osteoblast markers runt-related transcription factor 2 and rabbit collagen type I was determined using real-time polymerase chain reaction and Western blot. The osteogenic capacity was also detected by alkaline phosphatase (ALP) staining, ALP activity, and alizarin red staining. We demonstrated that ICS impaired the osteogenic capacity of human periodontal ligament cells when incubated with proinflammatory cytokines, as evidenced by the low expression of ALP staining, low ALP activity, reduced alizarin red staining, and reduced osteoblast markers. These data, for the first time, suggest that ICS has a negative effect on the inductive inhibition of osteogenicity in human PDL cells mediated by proinflammatory cytokines. PMID:27357508

  6. Simvastatin induces the osteogenic differentiation of human periodontal ligament stem cells.

    PubMed

    Zhao, Bing-jiao; Liu, Yue-hua

    2014-10-01

    Periodontal ligament stem cells (PDLSCs) are considered as potential mesenchymal stem cell sources for future clinical applications in periodontal regeneration therapy. Simvastation, widely used for lowering serum cholesterol, is known to have a bone stimulatory effect. However, it is not clear whether simvastation affects the differentiation of PDLSCs. This study examined the effects of simvastatin on human PDLSCs in vitro and in vivo. Using the limiting dilution technique, human PDLSCs were isolated and expanded. PDLSCs were cultured with simvastatin (0.01-10 μM), and the proliferation was measured. The osteogenic differentiation was characterized by alkaline phosphatase (ALP) activity and Alizarin Red-S staining for calcium deposition. The gene expression levels of osteogenic markers were evaluated by RT-PCR. In addition, PDLSCs were transplanted into nude mice with ceramic bovine bone powders as carriers to observe the capacity of mineralized tissue formation in vivo. Simvastatin at concentrations <1 μM did not suppress the proliferation of PDLSCs. After the administration of 0.1 μM simvastatin, the expression of ALP, bone sialoprotein, and bone morphogenetic protein-2 genes were significantly upregulated, and the ALP activity and mineralized nodule formation were significantly higher in the simvastatin-treated cells than the control cells. In addition, the in vivo transplantation results showed that simvastatin treatment promoted the degree of mineralized tissue formation. Collectively, simvastatin has positive effects on osteogenic differentiation of human PDLSCs in vitro and in vivo. This suggests that simvastatin might be a useful osteogenic induction agent for periodontal bone regeneration. PMID:24112098

  7. In vitro viability of human periodontal ligament cells in green tea extract

    PubMed Central

    Ghasempour, Maryam; Moghadamnia, Ali Akbar; Abedian, Zeynab; Amir, Mahdi Pour; Feizi, Farideh; Gharekhani, Samane

    2015-01-01

    Context: Delayed replantation of avulsed teeth may be successful if the majority of periodontal ligament cells (PDL) survive. A proper transport medium is required when immediate replantation is not possible. Green tea extract (GTE) may be effective in preserving the cells because of its special properties. Aims: This study was done to evaluate the potential of GTE in periodontal ligament cells preservation. Materials and Methods: Fifty-four extracted human teeth with closed apices were randomly divided into three groups each with 18 teeth as follow: GTE, water (negative control), and Hank's balanced salt solution (HBSS) (positive control). The specimens were immersed in the media for 1, 3, and 15 hours at 4°C (n = 6) and treated with collagenase 1A for 45 minutes. Cell viability was determined using the trypan blue exclusion technique. Statistical Analysis: Data were analyzed by one-way analysis of variance (ANOVA), post hoc Tukey and paired t-test at significance level of P < 0.05. Results: Means (standard deviation, SD) of viable cells in HBSS, water, and GTE were estimated 348.33 ± 88.49, 101 ± 14.18, and 310.56 ± 56.97 at 1 hours; 273.4 ± 44.80, 64.16 ± 16.44, and 310.2 ± 11.21 at 3 hours; and 373.72 ± 67.81, 14.41 ± 2.88 and 315.24 ± 34.48 at 15 hours; respectively. No significant differences were found between HBSS and GTE at all the time intervals. Both these solutions could preserve the cells more than water significantly. Conclusion: GTE and HBSS were equally effective in preserving the cells and were significantly superior to water. PMID:25657527

  8. Investigation of the Cell Surface Proteome of Human Periodontal Ligament Stem Cells.

    PubMed

    Xiong, Jimin; Menicanin, Danijela; Zilm, Peter S; Marino, Victor; Bartold, P Mark; Gronthos, Stan

    2016-01-01

    The present study examined the cell surface proteome of human periodontal ligament stem cells (PDLSC) compared to human fibroblasts. Cell surface proteins were prelabelled with CyDye before processing to extract the membrane lysates, which were separated using 2D electrophoresis. Selected differentially expressed protein "spots" were identified using Mass spectrometry. Four proteins were selected for validation: CD73, CD90, Annexin A2, and sphingosine kinase 1 previously associated with mesenchymal stem cells. Flow cytometric analysis found that CD73 and CD90 were highly expressed by human PDLSC and gingival fibroblasts but not by keratinocytes, indicating that these antigens could be used as potential markers for distinguishing between mesenchymal cells and epithelial cell populations. Annexin A2 was also found to be expressed at low copy number on the cell surface of human PDLSC and gingival fibroblasts, while human keratinocytes lacked any cell surface expression of Annexin A2. In contrast, sphingosine kinase 1 expression was detected in all the cell types examined using immunocytochemical analysis. These proteomic studies form the foundation to further define the cell surface protein expression profile of PDLSC in order to better characterise this cell population and help develop novel strategies for the purification of this stem cell population. PMID:27579043

  9. Investigation of the Cell Surface Proteome of Human Periodontal Ligament Stem Cells

    PubMed Central

    Xiong, Jimin; Menicanin, Danijela; Marino, Victor

    2016-01-01

    The present study examined the cell surface proteome of human periodontal ligament stem cells (PDLSC) compared to human fibroblasts. Cell surface proteins were prelabelled with CyDye before processing to extract the membrane lysates, which were separated using 2D electrophoresis. Selected differentially expressed protein “spots” were identified using Mass spectrometry. Four proteins were selected for validation: CD73, CD90, Annexin A2, and sphingosine kinase 1 previously associated with mesenchymal stem cells. Flow cytometric analysis found that CD73 and CD90 were highly expressed by human PDLSC and gingival fibroblasts but not by keratinocytes, indicating that these antigens could be used as potential markers for distinguishing between mesenchymal cells and epithelial cell populations. Annexin A2 was also found to be expressed at low copy number on the cell surface of human PDLSC and gingival fibroblasts, while human keratinocytes lacked any cell surface expression of Annexin A2. In contrast, sphingosine kinase 1 expression was detected in all the cell types examined using immunocytochemical analysis. These proteomic studies form the foundation to further define the cell surface protein expression profile of PDLSC in order to better characterise this cell population and help develop novel strategies for the purification of this stem cell population. PMID:27579043

  10. Proliferation of the human periodontal ligament fibroblast by laser biostimulation: an in vitro study

    NASA Astrophysics Data System (ADS)

    Shelly, Ahuja; Shaila, Kothiwale; Kishore, Bhat

    2006-02-01

    Laser produces a monochormatic collimated and coherent radiation. In dentistry, diode lasers have been used predominantly for application which are broadly termed "Low level laser therapy (LLLT) or biostimulation (L.J. Walch 1997)". Periodontal ligament fibroblast (PDLF) have a key function in periodontal regeneration. Stimulatory effects on the proliferation of these cells could therefore be beneficial for the reestablishment of connective tissue attachment. The aim of this in vitro study was to evaluate the potential stimulatory effect of low level laser irradiation on the proliferation of PDLF.

  11. Significant Type I and Type III Collagen Production from Human Periodontal Ligament Fibroblasts in 3D Peptide Scaffolds without Extra Growth Factors

    PubMed Central

    Kumada, Yoshiyuki; Zhang, Shuguang

    2010-01-01

    We here report the development of two peptide scaffolds designed for periodontal ligament fibroblasts. The scaffolds consist of one of the pure self-assembling peptide scaffolds RADA16 through direct coupling to short biologically active motifs. The motifs are 2-unit RGD binding sequence PRG (PRGDSGYRGDS) and laminin cell adhesion motif PDS (PDSGR). RGD and laminin have been previously shown to promote specific biological activities including periodontal ligament fibroblasts adhesion, proliferation and protein production. Compared to the pure RADA16 peptide scaffold, we here show that these designer peptide scaffolds significantly promote human periodontal ligament fibroblasts to proliferate and migrate into the scaffolds (for ∼300 µm/two weeks). Moreover these peptide scaffolds significantly stimulated periodontal ligament fibroblasts to produce extracellular matrix proteins without using extra additional growth factors. Immunofluorescent images clearly demonstrated that the peptide scaffolds were almost completely covered with type I and type III collagens which were main protein components of periodontal ligament. Our results suggest that these designer self-assembling peptide nanofiber scaffolds may be useful for promoting wound healing and especially periodontal ligament tissue regeneration. PMID:20421985

  12. Effects of non-thermal atmospheric plasma on human periodontal ligament mesenchymal stem cells

    NASA Astrophysics Data System (ADS)

    Miletić, M.; Mojsilović, S.; Okić Đorđević, I.; Maletić, D.; Puač, N.; Lazović, S.; Malović, G.; Milenković, P.; Petrović, Z. Lj; Bugarski, D.

    2013-08-01

    Here we investigate the influences of non-thermal atmospheric plasma on human mesenchymal stem cells isolated from periodontal ligament (hPDL-MSCs). A specially redesigned plasma needle was used as the source of low-temperature plasma and its effects on different hPDL-MSC functions were investigated. Cell cultures were obtained from extracted normal impacted third molars and characterized for their phenotype and multi-potential differentiation. The hPDL-MSCs possessed all the typical MSC properties, including clonogenic ability, high proliferation rate, specific phenotype and multilineage differentiation. The data regarding the interaction of plasma with hPDL-MSCs demonstrated that plasma treatment inhibited the migration of hPDL-MSCs and induced some detachment, while not affecting their viability. Additionally, plasma significantly attenuated hPDL-MSCs' proliferation, but promoted their osteogenic differentiation. The results of this study indicated that a non-thermal plasma offers specific activity with non-destructive properties that can be advantageous for future dental applications.

  13. Differential Properties of Human ALP+ Periodontal Ligament Stem Cells vs Their ALP- Counterparts

    PubMed Central

    Tran, Quynh T; El-Ayachi, Ikbale; Bhatti, Fazal-Ur-Rehman; Bahabri, Rayan; Al-Habib, Mey; Huang, George TJ

    2015-01-01

    Characterizing subpopulations of stem cells is important to understand stem cell properties. Tissue-nonspecific alkaline phosphatase (ALP) is associated with mineral tissue forming cells as well as stem cells. Information regarding ALP subpopulation of human periodontal ligament stem cells (hPDLSCs) is limited. In the present study, we examined ALP+ and ALP− hPDLSC subpopulations, their surface markers STRO-1 and CD146, and the expression of stemness genes at various cell passages. We found that ALP+ subpopulation had higher levels of STRO-1 (30.6 ± 5.6%) and CD146 (90.4 ± 3.3%) compared to ALP− (STRO-1: 0.5 ± 0.1%; CD146: 75.3 ± 7.2%). ALP+ cells expressed significantly higher levels of stemness associated genes, NANOG, OCT4 and SOX than ALP− cells at low cell passages of 2-3 (p<0.05). ALP+ and ALP− cells had similar osteogenic, chondrogenic and neurogenic potential while ALP−, not ALP+ cells, lacked adipogenic potential. Upon continuous culturing and passaging, ALP+ continued to express higher stemness genes and STRO-1 and CD146 than ALP− cells at ≥passage 19. Under conditions (over-confluence and vitamin C treatment) when ALP+ subpopulation was increased, the stemness gene levels of ALP+ was no longer significantly higher than those in ALP− cells. In conclusion, ALP+ hPDLSCs possess differential properties from their ALP− counterparts. PMID:26807329

  14. Indirect longitudinal cytotoxicity of root canal sealers on L929 cells and human periodontal ligament fibroblasts.

    PubMed

    Araki, K; Suda, H; Spångberg, L S

    1994-02-01

    The cytotoxicity of two root canal sealers was evaluated in vitro. The powder components of both sealers, mainly zinc, were the same. The liquid for one sealer, Canals, was clove oil (included eugenol in more than 80%) and other materials. For the other, Canals-N, the liquid was composed of higher fatty acids and glycol. The experiments included two cell lines, heteroploid L929 mouse fibroblasts and diploid human periodontal ligament fibroblasts. Cytotoxicity was assessed using the radiochromium release method with 4-h exposure time. The assay involved using insert chambers in multiwell arrays to produce indirect contact of materials with the cell monolayer at a controlled distance of approximately 1 mm. This model also allowed for the longitudinal study of the same material sample to assess time-dependent changes in toxicity. Freshly mixed Canals was highly toxic (p < 0.01) to both cell lines. On and after 24 h of setting no toxicity was detected. At no time could cytotoxicity be observed when experimenting with Canals-N. These results indicate that both materials have a low content of water diffusible toxic components. Substituting eugenol can further decrease the toxicity of the sealer. PMID:8006567

  15. SSEA-4 is a marker of human deciduous periodontal ligament stem cells.

    PubMed

    Fukushima, H; Kawanabe, N; Murata, S; Ishihara, Y; Yanagita, T; Balam, T A; Yamashiro, T

    2012-10-01

    Although human deciduous teeth are an ideal source of adult stem cells, no method for identifying deciduous periodontal ligament (D-PDL) stem cells has so far been developed. In the present study, we investigated whether stage-specific embryonic antigen (SSEA)-4 is a marker that could be used to isolate D-PDL stem cells. The isolated D-PDL cells met the minimum criteria for mesenchymal stem cells (MSCs): They showed plastic adherence, specific-surface antigen expression, and multipotent differentiation potential. SSEA-4+ D-PDL cells were detected in vitro and in vivo. A flow cytometric analysis demonstrated that 22.7% of the D-PDL cells were positive for SSEA-4. SSEA-4+ clonal D-PDL cells displayed multilineage differentiation potential: They were able to differentiate into adipocytes, osteoblasts, and chondrocytes in vitro. A clonal assay demonstrated that 61.5% of the SSEA-4+ D-PDL cells had adipogenic, osteogenic, and chondrogenic potential. Our present study demonstrated that SSEA-4+ D-PDL cells are a subset of multipotent stem cells. Hence, SSEA-4 is a specific marker that can be used to identify D-PDL stem cells. PMID:22895512

  16. microRNA-21 Mediates Stretch-Induced Osteogenic Differentiation in Human Periodontal Ligament Stem Cells

    PubMed Central

    Liu, Dongxu; Feng, Cheng; Zhang, Fan; Yang, Shuangyan; Hu, Yijun; Ding, Gang

    2015-01-01

    microRNAs (miRNAs) are short 20- to 22-nucleotide noncoding RNAs that negatively regulate the expression of target genes at the post-transcriptional level. The expression of specific miRNAs and their roles in the osteogenic differentiation of human periodontal ligament stem cells (PDLSCs) exposed to mechanical stretch remain unclear. Here, we found that stretch induced both osteogenic differentiation and the differential expression of miR-21 in PDLSCs. Furthermore, we identified activin receptor type IIB (ACVR2B) as a target gene of miR-21. Luciferase reporter assays showed that miR-21 interacts directly with the 3′-untranslated repeat sequence of ACVR2B mRNA. Mechanical stretch suppressed ACVR2B protein levels in PDLSCs, and this suppressive effect was modulated when endogenous miR-21 levels were either enhanced or inhibited. Both stretch and the expression of miR-21 altered endogenous ACVR2B protein levels and thus the osteogenic differentiation of PDLSCs. In addition, gain- and loss of function of ACVR2B mediated the osteogenic differentiation of PDLSCs. This study demonstrates that miR-21 is a mechanosensitive gene that plays an important role in the osteogenic differentiation of PDLSCs exposed to stretch. PMID:25203845

  17. Comparative Gene-Expression Analysis of the Dental Follicle and Periodontal Ligament in Humans

    PubMed Central

    Kim, Seong-Oh; Song, Je-Seon; Lee, Jae-Ho; Lee, Syng-Ill; Jung, Han-Sung; Choi, Byung-Jai

    2013-01-01

    The human dental follicle partially differentiates into the periodontal ligament (PDL), but their biological functions are different. The gene-expression profiles of the dental follicle and PDL were compared using the cDNA microarray technique. Microarray analysis identified 490 genes with a twofold or greater difference in expression, 365 and 125 of which were more abundant in the dental follicle and PDL, respectively. The most strongly expressed genes in the dental follicle were those related to bone development and remodeling (EGFL6, MMP8, FRZB, and NELL1), apoptosis and chemotaxis (Nox4, CXCL13, and CCL2), and tooth and embryo development (WNT2, PAX3, FGF7, AMBN, AMTN, and SLC4A4), while in the PDL it was the tumor-suppressor gene WIF1. Genes related to bone development and remodeling (STMN2, IBSP, BMP8A, BGLAP, ACP5, OPN, BMP3, and TM7SF4) and wound healing (IL1, IL8, MMP3, and MMP9) were also more strongly expressed in the PDL than in the dental follicle. In selected genes, a comparison among cDNA microarray, real-time reverse-transcription polymerase chain reaction, and immunohistochemical staining confirmed similar relative gene expressions. The gene-expression profiles presented here identify candidate genes that may enable differentiation between the dental follicle and PDL. PMID:24376796

  18. Ultrastructure of cementum and periodontal ligament after continuous intrusion in humans: a transmission electron microscopy study.

    PubMed

    Faltin, R M; Faltin, K; Sander, F G; Arana-Chavez, V E

    2001-02-01

    An ultrastructural study of the cementum and periodontal ligament (PDL) changes after continuous intrusion with two different and controlled forces in humans was carried out. Twelve first upper premolars, at stage 10 of Nolla, orthodontically indicated for extraction from six patients (mean age 15.3) were used. They were divided into three experimental groups, distributed intra-individually as follows: control (not moved), continuously intruded for 4 weeks with 50 or 100 cN force, utilizing a precise biomechanical model with nickel titanium super-elastic wires (NiTi-SE), which were developed and calibrated individually. The teeth were extracted, fixed, decalcified, and conventionally processed for examination in a Jeol 100 CX II transmission electron microscope. Evident signs of degeneration of cell structures, vascular components, and extracellular matrix (EM) of cementum and PDL were observed in all the intruded teeth, with more severe changes towards an apical direction and in proportion to the magnitude of force applied. Resorptive areas and an irregular root surface of the intruded teeth were noticed, according to the same pattern described above. Concomitant, areas of repair were also revealed in the cementum and PDL although the magnitude of forces remained the same throughout the experimental period. Thus, a reduction of continuous force magnitude should be considered to preserve the integrity of tissues. PMID:11296509

  19. Effects of hypoxia on the proliferation, mineralization and ultrastructure of human periodontal ligament fibroblasts in vitro

    PubMed Central

    ZHANG, HAI-YUAN; LIU, RUI; XING, YONG-JUN; XU, PING; LI, YAN; LI, CHEN-JUN

    2013-01-01

    This study aimed to investigate the effects of hypoxia on the proliferation, mineralization and ultrastructure of human periodontal ligament fibroblasts (HPLFs) at various times in vitro in order to further study plateau-hypoxia-induced periodontal disease. HPLFs (fifth passage) cultured by the tissue culture method were assigned to the slight (5% O2), middle (2% O2), and severe hypoxia (1% O2) groups and the control (21% O2) group, respectively. At 12, 24, 48 and 72 h, the proliferation and alkaline phosphatase (ALP) activities were detected. The ultrastructure of the severe hypoxia group was observed. HPLFs grew more rapidly with an increase in the degree of hypoxia at 12 and 24 h, and significant levels of proliferation (P<0.05) were observed in the severe hypoxia group at 24 h. Cell growth was restrained with an increase in the degree of hypoxia at 48 and 72 h, and the restrictions were clear (P<0.05) in the middle and severe hypoxia groups. ALP activity was restrained with increasing hypoxia at each time point. The restrictions were marked (P<0.05) in the severe hypoxia group at 24 h and in the middle and severe hypoxia groups at 48 and 72 h. However, the restriction was more marked (P<0.05) in the severe hypoxia group at 72 h. An increase was observed in the number of mitochondria and rough endoplasmic reticula (RER), with slightly expanded but complete membrane structures, in the severe hypoxia group at 24 h. At 48 h, the number of mitochondria and RER decreased as the mitochondria increased in size. Furthermore, mitochondrial cristae appeared to be vague, and a RER structural disorder was observed. At 72 h, the number of mitochondria and RER decreased further when the mitochondrial cristae were broken, vacuolar degeneration occurred, and the RER particles were reduced while the number of lysosomes increased. HPLF proliferation and mineralization was restrained. Additionally, HPLF structure was broken for a relatively long period of time in the middle and

  20. Low-Intensity Pulsed Ultrasound Stimulation Facilitates Osteogenic Differentiation of Human Periodontal Ligament Cells

    PubMed Central

    Hu, Bo; Zhang, Yuanyuan; Zhou, Jie; Li, Jing; Deng, Feng; Wang, Zhibiao; Song, Jinlin

    2014-01-01

    Human periodontal ligament cells (hPDLCs) possess stem cell properties, which play a key role in periodontal regeneration. Physical stimulation at appropriate intensities such as low-intensity pulsed ultrasound (LIPUS) enhances cell proliferation and osteogenic differentiation of mesechymal stem cells. However, the impacts of LIPUS on osteogenic differentiation of hPDLCs in vitro and its molecular mechanism are unknown. This study was undertaken to investigate the effects of LIPUS on osteogenic differentiation of hPDLCs. HPDLCs were isolated from premolars of adolescents for orthodontic reasons, and exposed to LIPUS at different intensities to determine an optimal LIPUS treatment dosage. Dynamic changes of alkaline phosphatase (ALP) activities in the cultured cells and supernatants, and osteocalcin production in the supernatants after treatment were analyzed. Runx2 and integrin β1 mRNA levels were assessed by reverse transcription polymerase chain reaction analysis after LIPUS stimulation. Blocking antibody against integrinβ1 was used to assess the effects of integrinβ1 inhibitor on LIPUS-induced ALP activity, osteocalcin production as well as calcium deposition. Our data showed that LIPUS at the intensity of 90 mW/cm2 with 20 min/day was more effective. The ALP activities in lysates and supernatants of LIPUS-treated cells started to increase at days 3 and 7, respectively, and peaked at day 11. LIPUS treatment significantly augmented the production of osteocalcin after day 5. LIPUS caused a significant increase in the mRNA expression of Runx2 and integrin β1, while a significant decline when the integrinβ1 inhibitor was used. Moreover, ALP activity, osteocalcin production as well as calcium nodules of cells treated with both daily LIPUS stimulation and integrinβ1 antibody were less than those in the LIPUS-treated group. In conclusion, LIPUS promotes osteogenic differentiation of hPDLCs, which is associated with upregulation of Runx2 and integrin β1, which

  1. Decellularized periodontal ligament cell sheets with recellularization potential.

    PubMed

    Farag, A; Vaquette, C; Theodoropoulos, C; Hamlet, S M; Hutmacher, D W; Ivanovski, S

    2014-12-01

    The periodontal ligament is the key tissue facilitating periodontal regeneration. This study aimed to fabricate decellularized human periodontal ligament cell sheets for subsequent periodontal tissue engineering applications. The decellularization protocol involved the transfer of intact human periodontal ligament cell sheets onto melt electrospun polycaprolactone membranes and subsequent bi-directional perfusion with NH4OH/Triton X-100 and DNase solutions. The protocol was shown to remove 92% of DNA content. The structural integrity of the decellularized cell sheets was confirmed by a collagen quantification assay, immunostaining of human collagen type I and fibronectin, and scanning electron microscopy. ELISA was used to demonstrate the presence of residual basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF), and hepatocyte growth factor (HGF) in the decellularized cell sheet constructs. The decellularized cell sheets were shown to have the ability to support recellularization by allogenic human periodontal ligament cells. This study describes the fabrication of decellularized periodontal ligament cell sheets that retain an intact extracellular matrix and resident growth factors and can support repopulation by allogenic cells. The decellularized hPDL cell sheet concept has the potential to be utilized in future "off-the-shelf" periodontal tissue engineering strategies. PMID:25270757

  2. Periodontal ligament stem cells: an update and perspectives.

    PubMed

    Chamila Prageeth Pandula, P K; Samaranayake, L P; Jin, L J; Zhang, Chengfei

    2014-05-01

    Chronic periodontitis is a serious infectious and inflammatory oral disease of humans worldwide. Conventional treatment modalities are effective for controlling periodontal disease. However, the regeneration of damaged periodontal tissues remains a major challenge in clinical practice due to the complex structure of the periodontium. Stem cell-based regenerative approaches combined with the usage of emerging biomaterials are entering a new era in periodontal regeneration. The present review updates the current knowledge of periodontal ligament stem cell-based approaches for periodontal regeneration, and elaborates on the potentials for clinical application. PMID:24610628

  3. Bone morphogenetic protein 7 induces cementogenic differentiation of human periodontal ligament-derived mesenchymal stem cells.

    PubMed

    Torii, D; Tsutsui, T W; Watanabe, N; Konishi, K

    2016-01-01

    Bone morphogenetic protein 7 (BMP-7) is a multifunctional differentiation factor that belongs to the transforming growth factor superfamily. BMP-7 induces gene expression of protein tyrosine phosphatase-like, member A/cementum attachment protein (PTPLA/CAP) and cementum protein 1 (CEMP1), both of which are markers of cementoblasts and cementocytes. In the previous study, we reported that BMP-7 treatment enhanced PTPLA/CAP and CEMP1 expression in both normal and immortal human periodontal ligament (PDL) cells. To elucidate the molecular mechanisms of the gene expression of these molecules, in this study, we identified a functional transcription activator binding region in the promoter region of PTPLA/CAP and CEMP1 that is responsive to BMP signals. Here, we report that some short motifs termed GC-rich Smad-binding elements (GC-SBEs) that are located in the human PTPLA/CAP promoter and CEMP1 promoter are BMP-7 responsive as analyzed with luciferase promoter assays. On the other hand, we found that transcription of Sp7/Osterix and PTPLA/CAP was up-regulated after 1 week of BMP-7 treatment on purified normal human PDL cells as a result of gene expression microarray analysis. Furthermore, transcription of Sp7/Osterix, runt-related transcription factor 2 (RUNX2), and alkaline phosphatase (ALP) was up-regulated after 2 weeks of BMP-7 treatment, whereas gene expression of osteo/odontogenic markers such as integrin-binding sialoprotein (IBSP), collagen, type I, alpha 1 (COL1A1), dentin matrix acidic phosphoprotein 1 (DMP1), and dentin sialophosphoprotein (DSPP) was not up-regulated in purified normal or immortal human PDL cells as a result of qRT-PCR. The results suggest that BMP-7 mediates cementogenesis via GC-SBEs in human PDL cells and that its molecular mechanism is different from that for osteo/odontogenesis. PMID:25464857

  4. Thymosin Beta-4 Suppresses Osteoclastic Differentiation and Inflammatory Responses in Human Periodontal Ligament Cells

    PubMed Central

    Lee, Sang-Im; Yi, Jin-Kyu; Bae, Won-Jung; Lee, Soojung; Cha, Hee-Jae; Kim, Eun-Cheol

    2016-01-01

    Background Recent reports suggest that thymosin beta-4 (Tβ4) is a key regulator for wound healing and anti-inflammation. However, the role of Tβ4 in osteoclast differentiation remains unclear. Purpose The purpose of this study was to evaluate Tβ4 expression in H2O2-stimulated human periodontal ligament cells (PDLCs), the effects of Tβ4 activation on inflammatory response in PDLCs and osteoclastic differentiation in mouse bone marrow-derived macrophages (BMMs), and identify the underlying mechanism. Methods Reverse transcription-polymerase chain reactions and Western blot analyses were used to measure mRNA and protein levels, respectively. Osteoclastic differentiation was assessed in mouse bone marrow-derived macrophages (BMMs) using conditioned medium (CM) from H2O2-treated PDLCs. Results Tβ4 was down-regulated in H2O2-exposed PDLCs in dose- and time-dependent manners. Tβ4 activation with a Tβ4 peptide attenuated the H2O2-induced production of NO and PGE2 and up-regulated iNOS, COX-2, and osteoclastogenic cytokines (TNF-α, IL-1β, IL-6, IL-8, and IL-17) as well as reversed the effect on RANKL and OPG in PDLCs. Tβ4 peptide inhibited the effects of H2O2 on the activation of ERK and JNK MAPK, and NF-κB in PDLCs. Furthermore, Tβ4 peptide inhibited osteoclast differentiation, osteoclast-specific gene expression, and p38, ERK, and JNK phosphorylation and NF-κB activation in RANKL-stimulated BMMs. In addition, H2O2 up-regulated Wnt5a and its cell surface receptors, Frizzled and Ror2 in PDLCs. Wnt5a inhibition by Wnt5a siRNA enhanced the effects of Tβ4 on H2O2-mediated induction of pro-inflammatory cytokines and osteoclastogenic cytokines as well as helping osteoclastic differentiation whereas Wnt5a activation by Wnt5a peptide reversed it. Conclusion In conclusion, this study demonstrated, for the first time, that Tβ4 was down-regulated in ROS-stimulated PDLCs as well as Tβ4 activation exhibited anti-inflammatory effects and anti-osteoclastogenesis in vitro

  5. The plastic nature of the human bone-periodontal ligament-tooth fibrous joint.

    PubMed

    Ho, Sunita P; Kurylo, Michael P; Grandfield, Kathryn; Hurng, Jonathan; Herber, Ralf-Peter; Ryder, Mark I; Altoe, Virginia; Aloni, Shaul; Feng, Jian Q; Webb, Samuel; Marshall, Grayson W; Curtis, Donald; Andrews, Joy C; Pianetta, Piero

    2013-12-01

    This study investigates bony protrusions within a narrowed periodontal ligament space (PDL-space) of a human bone-PDL-tooth fibrous joint by mapping structural, biochemical, and mechanical heterogeneity. Higher resolution structural characterization was achieved via complementary atomic force microscopy (AFM), nano-transmission X-ray microscopy (nano-TXM), and microtomography (MicroXCT™). Structural heterogeneity was correlated to biochemical and elemental composition, illustrated via histochemistry and microprobe X-ray fluorescence analysis (μ-XRF), and mechanical heterogeneity evaluated by AFM-based nanoindentation. Results demonstrated that the narrowed PDL-space was due to invasion of bundle bone (BB) into PDL-space. Protruded BB had a wider range with higher elastic modulus values (2-8GPa) compared to lamellar bone (0.8-6GPa), and increased quantities of Ca, P and Zn as revealed by μ-XRF. Interestingly, the hygroscopic 10-30μm interface between protruded BB and lamellar bone exhibited higher X-ray attenuation similar to cement lines and lamellae within bone. Localization of the small leucine rich proteoglycan biglycan (BGN) responsible for mineralization was observed at the PDL-bone interface and around the osteocyte lacunae. Based on these results, it can be argued that the LB-BB interface was the original site of PDL attachment, and that the genesis of protruded BB identified as protrusions occurred as a result of shift in strain. We emphasize the importance of bony protrusions within the context of organ function and that additional study is warranted. PMID:24063947

  6. The Plastic Nature of the Human Bone-Periodontal Ligament-Tooth Fibrous Joint

    PubMed Central

    Ho, Sunita P.; Kurylo, Michael P.; Grandfield, Kathryn; Hurng, Jonathan; Herber, Ralf-Peter; Ryder, Mark I.; Altoe, Virginia; Aloni, Shaul; Feng, Jian Q. (Jerry); Webb, Samuel; Marshall, Grayson W.; Curtis, Donald; Andrews, Joy C.; Pianetta, Piero

    2014-01-01

    This study investigates bony protrusions within a narrowed periodontal ligament space (PDL-space) of a human bone-PDL-tooth fibrous joint by mapping structural, biochemical, and mechanical heterogeneity. Higher resolution structural characterization was achieved via complementary atomic force microscopy (AFM), nano transmission X-ray microscopy (nano-TXM), and micro tomography (Micro XCT™). Structural heterogeneity was correlated to biochemical and elemental composition, illustrated via histochemistry and microprobe X-ray fluorescence analysis (μ-XRF), and mechanical heterogeneity evaluated by AFM-based nanoindentation. Results demonstrated that the narrowed PDL-space was due to invasion of bundle bone (BB) into PDL-space. Protruded BB had a wider range with higher elastic modulus values (2-8 GPa) compared to lamellar bone (0.8-6 GPa), and increased quantities of Ca, P and Zn as revealed by μ-XRF. Interestingly, the hygroscopic 10-30 μm interface between protruded BB and lamellar bone exhibited higher X-ray attenuation similar to cement lines and lamellae within bone. Localization of the small leucine rich proteoglycan biglycan (BGN) responsible for mineralization was observed at the PDL-bone interface and around the osteocyte lacunae. Based on these results, it can be argued that the LB-BB interface was the original site of PDL attachment, and that the genesis of protruded BB identified as protrusions occurred as a result of shift in strain. We emphasize the importance of bony protrusions within the context of organ function and that additional study is warranted. PMID:24063947

  7. Effects of laser therapy on the proliferation of human periodontal ligament stem cells.

    PubMed

    Soares, Diego Moura; Ginani, Fernanda; Henriques, Águida Gomes; Barboza, Carlos Augusto Galvão

    2015-04-01

    Low-level laser irradiation (LLLI) stimulates the proliferation of a variety of cell types. However, very little is known about the effect of laser therapy on dental stem cells. The aim of the present study was to evaluate the effect of LLLI (660 nm, 30 mW) on the proliferation rate of human periodontal ligament stem cells (hPDLSC), obtained from two healthy permanent third molars extracted due to surgical indication. Culture cells were either irradiated or not (control) with an InGaAIP diode laser at 0 and 48 h, using two different energy densities (0.5 J/cm², 16 s and 1.0 J/cm², 33 s). Cell proliferation was evaluated by the Trypan blue exclusion method and by measuring mitochondrial activity using the MTT-based cytotoxicity assay at intervals of 0, 24, 48, and 72 h after the first laser application. An energy density of 1.0 J/cm² improved the cell proliferation in comparison to the other groups (control and laser 0.5 J/cm²) at 48 and 72 h. The group irradiated with 1.0 J/cm² presented significantly higher MTT activity at 48 and 72 h when compared to the energy density of 0.5 J/cm². It can be concluded that LLLI using infrared light and an energy density of 1.0 J/cm² has a positive stimulatory effect on the proliferation of hPDLSC. PMID:24013624

  8. Influence of different intensities of vibration on proliferation and differentiation of human periodontal ligament stem cells

    PubMed Central

    Zhang, Chunxiang; Lu, Yanqin; Zhang, Linkun; Liu, Yang; Zhou, Yi; Chen, Yangxi

    2015-01-01

    Introduction To understand the effects of low-magnitude, high-frequency (LMHF) mechanical vibration at different intensities on human periodontal ligament stem cell (hPDLSC) proliferation and osteogenic differentiation. Material and methods The effect of vibration on hPDLSC proliferation, osteogenic differentiation, tenogenic differentiation and cytoskeleton was assessed at the cellular, genetic and protein level. Results The PDLSC proliferation was decreased after different magnitudes of mechanical vibration; however, there were no obvious senescent cells in the experimental and the static control group. Expression of osteogenesis markers was increased. The expression of alkaline phosphatase (ALP) and osteocalcin (OCN) mRNA was up-regulated at 0.1 g, 0.3 g, 0.6 g and 0.9 g magnitude, with the peak at 0.3 g. The type I collagen (Col-I) level was increased after vibration exposure at 0.1 g, 0.3 g, and 0.6 g, peaking at 0.3 g. The expression levels of both mRNA and protein of Runx2 and osterix (OSX) significantly increased at a magnitude of 0.1 g to 0.9 g, reached a peak at 0.3 g and then decreased slowly. The scleraxis, tenogenic markers, and mRNA expression decreased at 0.05 g, 0.1 g, and 0.3 g, and significantly increased at 0.6 g and 0.9 g. Compared with the static group, the F-actin stress fibers of hPDLSCs became thicker and clearer following vibration. Conclusions The LMHF mechanical vibration promotes PDLSC osteogenic differentiation and implies the existence of a magnitude-dependent effect of vibration on determining PDLSC commitment to the osteoblast lineage. Changes in the cytoskeleton of hPDLSCs after vibration may be one of the mechanisms of the biological effects. PMID:26170859

  9. Effects of Activin A on the phenotypic properties of human periodontal ligament cells.

    PubMed

    Sugii, Hideki; Maeda, Hidefumi; Tomokiyo, Atsushi; Yamamoto, Naohide; Wada, Naohisa; Koori, Katsuaki; Hasegawa, Daigaku; Hamano, Sayuri; Yuda, Asuka; Monnouchi, Satoshi; Akamine, Akifumi

    2014-09-01

    Periodontal ligament (PDL) tissue plays an important role in tooth preservation by structurally maintaining the connection between the tooth root and the bone. The mechanisms involved in the healing and regeneration of damaged PDL tissue, caused by bacterial infection, caries and trauma, have been explored. Accumulating evidence suggests that Activin A, a member of the transforming growth factor-β (TGF-β) superfamily and a dimer of inhibinβa, contributes to tissue healing through cell proliferation, migration, and differentiation of various target cells. In bone, Activin A has been shown to exert an inhibitory effect on osteoblast maturation and mineralization. However, there have been no reports examining the expression and function of Activin A in human PDL cells (HPDLCs). Thus, we aimed to investigate the biological effects of Activin A on HPDLCs. Activin A was observed to be localized in HPDLCs and rat PDL tissue. When PDL tissue was surgically damaged, Activin A and IL-1β expression increased and the two proteins were shown to be co-localized around the lesion. HPDLCs treated with IL-1β or TNF-α also up-regulated the expression of the gene encoding inhibinβa. Activin A promoted chemotaxis, migration and proliferation of HPDLCs, and caused an increase in fibroblastic differentiation of these cells while down-regulating their osteoblastic differentiation. These osteoblastic inhibitory effects of Activin A, however, were only noted during the early phase of HPDLC osteoblastic differentiation, with later exposures having no effect on differentiation. Collectively, our results suggest that Activin A could be used as a therapeutic agent for healing and regenerating PDL tissue in response to disease, trauma or surgical reconstruction. PMID:24928494

  10. Comparative Gene Expression Analysis of the Human Periodontal Ligament in Deciduous and Permanent Teeth

    PubMed Central

    Kim, Seong-Oh; Jeon, Mijeong; Choi, Byung-Jai; Jung, Han-Sung; Moon, Seok Jun; Park, Wonse; Choi, Hyung-Jun

    2013-01-01

    There are histological and functional differences between human deciduous and permanent periodontal ligament (PDL) tissues. The aim of this study was to determine the differences between these two types of tissue at the molecular level by comparing their gene expression patterns. PDL samples were obtained from permanent premolars (n = 38) and anterior deciduous teeth (n = 31) extracted from 40 healthy persons. Comparative cDNA microarray analysis revealed several differences in gene expression between the deciduous and permanent PDL tissues. These findings were verified by qRT-PCR (quantitative reverse-transcription–polymerase chain reaction) analysis, and the areas where genes are expressed were revealed by immunohistochemical staining. The expressions of 21 genes were up-regulated in deciduous relative to PDL tissues, and those of 30 genes were up-regulated in permanent relative to deciduous PDL tissues. The genes that were up-regulated in deciduous PDL tissues were those involved in the formation of the extracellular matrix (LAMC2, LAMB3, and COMP), tissue development (IGF2BP, MAB21L2, and PAX3), and inflammatory or immune reactions leading to tissue degradation (IL1A, CCL21, and CCL18). The up-regulated genes in permanent PDL tissues were related to tissue degradation (IL6 and ADAMTS18), myocontraction (PDE3B, CASQ2, and MYH10), and neurological responses (FOS, NCAM2, SYT1, SLC22A3, DOCK3, LRRTM1, LRRTM3, PRSS12, and ARPP21). The analysis of differential gene expressions between deciduous and permanent PDL tissues aids our understanding of histological and functional differences between them at the molecular level. PMID:23593441

  11. Inhibition of Histone Deacetylases Enhances the Osteogenic Differentiation of Human Periodontal Ligament Cells.

    PubMed

    Huynh, Nam Cong-Nhat; Everts, Vincent; Pavasant, Prasit; Ampornaramveth, Ruchanee Salingcarnboriboon

    2016-06-01

    One of the characteristics of periodontal ligament (PDL) cells is their plasticity. Yet, the underlying mechanisms responsible for this phenomenon are unknown. One possible mechanism might be related to epigenetics, since histone deacetylases (HDACs) have been shown to play a role in osteoblast differentiation. This study was aimed to investigate the role of HDACs in osteogenic differentiation of human PDL (hPDL) cells. HDAC inhibitor trichostatin A (TSA) had no effect on cell viability as was assessed by MTT assay. Osteogenic and adipogenic differentiation was analyzed by gene expression, ALP activity and mineral deposition. Western blotting was used to investigate the effect of TSA on histone acetylation and protein expression. In the presence of the HDAC inhibitor osteogenic differentiation was induced; osteoblast-related gene expression was increased significantly. ALP activity and mineral nodule formation were also enhanced. Inhibition of HDACs did not induce differentiation into the adipocyte lineage. hPDL highly expressed HDACs of both class I (HDAC 1, 2, 3) and class II (HDAC 4, 6). During osteogenic differentiation HDAC 3 expression gradually decreased. This was apparent in the absence and presence of the inhibitor. The level of acetylated Histone H3 was increased during osteogenic differentiation. Inhibition of HDAC activity induced hyperacetylation of Histone H3, therefore, demonstrating Histone H3 as a candidate target molecule for HDAC inhibition. In conclusion, hPDL cells express a distinguished series of HDACs and these enzymes appear to be involved in osteogenic differentiation. This finding suggests a potential application of TSA for bone regeneration therapy by hPDL cells. PMID:27043246

  12. In vitro studies on human periodontal ligament stem cell sheets enhanced by enamel matrix derivative.

    PubMed

    Wang, Zhongshan; Feng, Zhihong; Wu, Guofeng; Bai, Shizhu; Dong, Yan; Zhao, Yimin

    2016-05-01

    Numerous preclinical and clinical studies have focused on the periodontal regenerative functions of enamel matrix derivative (EMD), a heat-treated preparation derived from enamel matrix proteins (EMPs) of developing porcine teeth. In this study, periodontal ligament (PDL) stem cells (PDLSCs) were isolated, and the effects of EMD on the extracorporeal induction process and the characteristics of PDLSC sheets were investigated for their potential as a more effective stem-cell therapy. EMD-enhanced cell sheets could be induced by complete medium supplemented with 50 μg/mL vitamin C and 100 μg/mL EMD. The EMD-enhanced cell sheets appeared thicker and more compact than the normal PDLSC sheets, demonstrated more layers of cells (3-7 layers), secreted richer extracellular matrix (ECM), showed varying degrees of increases in mRNA expression of periodontal tissue-specific genes (COL I, POSTN), calcification-related genes (RUNX2, OPN, OCN) and a cementum tissue-specific gene (CAP), and possessed a better mineralization ability in terms of osteogenic differentiation in vitro. These EMD-enhanced cell sheets may represent a potential option for stem-cell therapy for PDL regeneration. PMID:26844646

  13. Synthetic integrin-binding peptides promote adhesion and proliferation of human periodontal ligament cells in vitro.

    PubMed

    Grzesik, W J; Ivanov, B; Robey, F A; Southerland, J; Yamauchi, M

    1998-08-01

    Periodontal ligament (PDL) cells have been shown to express several integrins (alphav, alpha5, beta1, beta3) that use RGD (arginine-glycine-aspartic Acid)-dependent mechanisms for the recognition and binding of their ligands. The objective of this study was to evaluate the effects of certain integrin-binding cyclic and linear synthetic RGD-containing peptides on PDL cells' adhesion, proliferation, and de novo protein synthesis in vitro. Fifth passages of normal human PDL cells established from teeth extracted from patients (ages 12 to 14) for orthodontic reasons were used for all experiments. Synthetic peptides containing the EPRGDNYR sequence in two different spatial conformations (linear and cyclic) were covalently attached to bovine serum albumin (BSA). Type I collagen, EPRGDNYR-BSA conjugates, 1:1 mixtures of type I collagen and conjugates, as well as BSA (a negative control) were coated on bacteriological plastic and evaluated for their attachment-promoting activities. In addition, the effects of these substrates on cell proliferation were evaluated by [3H]thymidine incorporation by the PDL cells. For attachment and spreading, the cyclic forms of EPRGDNYR-BSA conjugate and type I collagen were most potent, followed by linear EPRGDNYR-BSA conjugate. The effects of all collagen/conjugate mixtures were equivalent to that of type I collagen except for the collagen/linear EPRGDNYR-BSA mixture, which was less potent. The cyclic EPRGDNYR-BSA conjugate was the most effective substrate to stimulate cell proliferation, and it was followed in potency by the linear peptide-BSA conjugate. Collagen alone did not stimulate [3H]thymidine incorporation above the control level. Mixtures of collagen with all of the conjugates showed stimulatory effects similar to that of the cyclic peptide-BSA conjugate. No significant differences in de novo protein synthesis were detected. These results suggest that the synthetic RGD-containing peptides attached to a carrier are potent ligands

  14. Electrospun fibrous scaffolds combined with nanoscale hydroxyapatite induce osteogenic differentiation of human periodontal ligament cells

    PubMed Central

    Wu, Xiaonan; Miao, Leiying; Yao, Yingfang; Wu, Wenlei; Liu, Yu; Chen, Xiaofeng; Sun, Weibin

    2014-01-01

    Periodontal repair is a complex process in which regeneration of alveolar bone is a vital component. The aim of this study was to develop a biodegradable scaffold with good biocompatibility and osteoinductive ability. Two types of composite fibrous scaffolds were produced by electrospinning, ie, type I collagen/poly(ε-caprolactone) (COL/PCL) and type I collagen/poly(ε-caprolactone)/nanoscale hydroxyapatite (COL/PCL/nHA) with an average fiber diameter of about 377 nm. After a simulated body fluid (SBF) immersion test, the COL/PCL/nHA-SBF scaffold developed a rough surface because of the calcium phosphate deposited on the fibers, suggesting that the presence of nHA promoted the mineralization potential of the scaffold. Energy dispersive X-ray spectroscopy clearly showed the calcium and phosphorus content in the COL/PCL/nHA and COL/PCL/nHA-SBF scaffolds, confirming the findings of nHA and calcium phosphate precipitation on scanning electron micrographs. Water contact analysis revealed that nHA could improve the hydrophilic nature of the COL/PCL/nHA-SBF scaffold. The morphology of periodontal ligament cells cultured on COL/PCL-SBF and COL/PCL/nHA-SBF was evaluated by scanning electron microscopy. The results showed that cells adhered to either type of scaffold and were slightly spindle-shaped in the beginning, then extended gradually with stretched filopodia, indicating an ability to fill the fiber pores. A Cell Counting Kit-8 assay showed that both scaffolds supported cell proliferation. However, real-time quantitative polymerase chain reaction analysis showed that expression of the bone-related markers, alkaline phosphatase and osteocalcin, was upregulated only on the COL/PCL/nHA-SBF scaffold, indicating that this scaffold had the ability to induce osteogenic differentiation of periodontal ligament cells. In this study, COL/PCL/nHA-SBF produced by electrospinning followed by biomimetic mineralization had combined electrospun fibers with nHA in it. This scaffold has

  15. Electrospun fibrous scaffolds combined with nanoscale hydroxyapatite induce osteogenic differentiation of human periodontal ligament cells.

    PubMed

    Wu, Xiaonan; Miao, Leiying; Yao, Yingfang; Wu, Wenlei; Liu, Yu; Chen, Xiaofeng; Sun, Weibin

    2014-01-01

    Periodontal repair is a complex process in which regeneration of alveolar bone is a vital component. The aim of this study was to develop a biodegradable scaffold with good biocompatibility and osteoinductive ability. Two types of composite fibrous scaffolds were produced by electrospinning, ie, type I collagen/poly(ε-caprolactone) (COL/PCL) and type I collagen/poly(ε-caprolactone)/nanoscale hydroxyapatite (COL/PCL/nHA) with an average fiber diameter of about 377 nm. After a simulated body fluid (SBF) immersion test, the COL/PCL/nHA-SBF scaffold developed a rough surface because of the calcium phosphate deposited on the fibers, suggesting that the presence of nHA promoted the mineralization potential of the scaffold. Energy dispersive X-ray spectroscopy clearly showed the calcium and phosphorus content in the COL/PCL/nHA and COL/PCL/nHA-SBF scaffolds, confirming the findings of nHA and calcium phosphate precipitation on scanning electron micrographs. Water contact analysis revealed that nHA could improve the hydrophilic nature of the COL/PCL/nHA-SBF scaffold. The morphology of periodontal ligament cells cultured on COL/PCL-SBF and COL/PCL/nHA-SBF was evaluated by scanning electron microscopy. The results showed that cells adhered to either type of scaffold and were slightly spindle-shaped in the beginning, then extended gradually with stretched filopodia, indicating an ability to fill the fiber pores. A Cell Counting Kit-8 assay showed that both scaffolds supported cell proliferation. However, real-time quantitative polymerase chain reaction analysis showed that expression of the bone-related markers, alkaline phosphatase and osteocalcin, was upregulated only on the COL/PCL/nHA-SBF scaffold, indicating that this scaffold had the ability to induce osteogenic differentiation of periodontal ligament cells. In this study, COL/PCL/nHA-SBF produced by electrospinning followed by biomimetic mineralization had combined electrospun fibers with nHA in it. This scaffold has

  16. Effect of temperature and storage media on human periodontal ligament fibroblast viability.

    PubMed

    Souza, Beatriz Dulcineia Mendes; Lückemeyer, Débora Denardin; Felippe, Wilson Tadeu; Simões, Cláudia Maria Oliveira; Felippe, Mara Cristina Santos

    2010-06-01

    Many solutions have been examined as possible storage media for avulsed teeth. The purpose of this study was to compare the effectiveness of several storage media to preserve cultured periodontal ligament fibroblasts (PDLF) under different temperatures. The media tested were: sterile Hank's balanced salt solution (sHBSS), non-sterile HBSS (nHBSS), skimmed milk, Save-A-Tooth((R)), Minimum Essential Medium (MEM) and water (negative control). MEM at 37 degrees C was used as positive control. PDLF were obtained from explants of extracted healthy human teeth. Plates containing confluent PDLF were soaked in the various media for 3, 6, 24, 48 and 72 h at 37 degrees C and 20 degrees C. After incubation, viability of the cells was determined using the tetrazolium salt-based colorimetric (MTT) assay and the Trypan Blue exclusion test after 6, 24, 48 and 72 h of incubation at 20 degrees C. The results were analyzed statistically using Kruskal-Wallis, Scheffé and Mann-Whitney (alpha = 5%) tests. Results from the MTT assay at 37 degrees C and 20 degrees C showed that skimmed milk was the best storage medium for up to 24 and 48 h, respectively, followed by nHBSS and sHBSS. Results from the Trypan Blue exclusion test showed that the best storage media were milk, sHBSS and nHBSS, with no statistical differences, for any time period. The Save-A-Tooth((R)) had a detrimental effect on cells after 24 h. The influence of temperature on the effectiveness of the storage media tested showed at 20 degrees C a decreasing order of efficacy as follows: milk > sHBSS and nHBSS > MEM > Save-A-Tooth((R)) > water while at 37 degrees C it was: MEM > nHBSS > milk > sHBSS > Save-A-Tooth((R)) > water. In conclusion, incubation temperature altered the effectiveness of the storage media and skimmed milk at 20 degrees C was better than HBSS in maintaining PDLF viability. PMID:20572843

  17. Effects of human relaxin on orthodontic tooth movement and periodontal ligaments in rats

    PubMed Central

    Madan, Monica S.; Liu, Zee J.; Gu, Gao M.; King, Gregory J.

    2010-01-01

    Introduction The rate-limiting step in orthodontic treatment is often the rapidity with which teeth move. Using biological agents to modify the rate of tooth movement has been shown to be effective in animals. Relaxin is a hormone present in both males and females. Its main action is to increase the turnover of fibrous connective tissues. Thus, relaxin might increase the amount and rate of tooth movement through its effect on the periodontal ligament (PDL). The purpose of this study was to measure the effect of relaxin on orthodontic tooth movement and PDL structures. Methods Bilateral orthodontic appliances designed to tip maxillary molars mesially with a force of 40 cN were placed in 96 rats. At day 0, the animals were randomized to either relaxin or vehicle treatment. Twelve rats in each group were killed at 2, 4, 7, and 9 days after appliance activation. Cephalograms were taken at appliance placement and when the rats were killed. Tooth movement was measured cephalometrically in relation to palatal implants. Fractal analysis and visual analog scale assessments were used to evaluate the effect of relaxin on PDL fiber organization at the tension sites in histologic sections. The in-vitro testing for PDL mechanical strength and tooth mobility was performed by using tissue from an additional 20 rats that had previously received the same relaxin or vehicle treatments for 1 or 3 days (n = 5). Results Both groups had statistically significant tooth movement as functions of time. However, relaxin did not stimulate significantly greater or more rapid tooth movement. Fractal and visual analog scale analyses implied that relaxin reduced PDL fiber organization. In-vitro mechanical testing and tooth mobility assessments indicated that the PDL of the mandibular incisors in the relaxin-treated rats had reduced yield load, strain, and stiffness. Moreover, the range of tooth mobility of the maxillary first molars increased to 130% to 170%, over vehicle-treated rats at day 1

  18. DNA Demethylation Rescues the Impaired Osteogenic Differentiation Ability of Human Periodontal Ligament Stem Cells in High Glucose

    PubMed Central

    Liu, Zhi; Chen, Tian; Sun, Wenhua; Yuan, Zongyi; Yu, Mei; Chen, Guoqing; Guo, Weihua; Xiao, Jingang; Tian, Weidong

    2016-01-01

    Diabetes mellitus, characterized by abnormally high blood glucose levels, gives rise to impaired bone remodeling. In response to high glucose (HG), the attenuated osteogenic differentiation capacity of human periodontal ligament stem cells (hPDLSCs) is associated with the loss of alveolar bone. Recently, DNA methylation was reported to affect osteogenic differentiation of stem cells in pathological states. However, the intrinsic mechanism linking DNA methylation to osteogenic differentiation ability in the presence of HG is still unclear. In this study, we found that diabetic rats with increased DNA methylation levels in periodontal ligaments exhibited reduced bone mass and density. In vitro application of 5-aza-2′-deoxycytidine (5-aza-dC), a DNA methyltransferase inhibitor, to decrease DNA methylation levels in hPDLSCs, rescued the osteogenic differentiation capacity of hPDLSCs under HG conditions. Moreover, we demonstrated that the canonical Wnt signaling pathway was activated during this process and, under HG circumstances, the 5-aza-dC-rescued osteogenic differentiation capacity was blocked by Dickkopf-1, an effective antagonist of the canonical Wnt signaling pathway. Taken together, these results demonstrate for the first time that suppression of DNA methylation is able to facilitate the osteogenic differentiation capacity of hPDLSCs exposed to HG, through activation of the canonical Wnt signaling pathway. PMID:27273319

  19. DNA Demethylation Rescues the Impaired Osteogenic Differentiation Ability of Human Periodontal Ligament Stem Cells in High Glucose.

    PubMed

    Liu, Zhi; Chen, Tian; Sun, Wenhua; Yuan, Zongyi; Yu, Mei; Chen, Guoqing; Guo, Weihua; Xiao, Jingang; Tian, Weidong

    2016-01-01

    Diabetes mellitus, characterized by abnormally high blood glucose levels, gives rise to impaired bone remodeling. In response to high glucose (HG), the attenuated osteogenic differentiation capacity of human periodontal ligament stem cells (hPDLSCs) is associated with the loss of alveolar bone. Recently, DNA methylation was reported to affect osteogenic differentiation of stem cells in pathological states. However, the intrinsic mechanism linking DNA methylation to osteogenic differentiation ability in the presence of HG is still unclear. In this study, we found that diabetic rats with increased DNA methylation levels in periodontal ligaments exhibited reduced bone mass and density. In vitro application of 5-aza-2'-deoxycytidine (5-aza-dC), a DNA methyltransferase inhibitor, to decrease DNA methylation levels in hPDLSCs, rescued the osteogenic differentiation capacity of hPDLSCs under HG conditions. Moreover, we demonstrated that the canonical Wnt signaling pathway was activated during this process and, under HG circumstances, the 5-aza-dC-rescued osteogenic differentiation capacity was blocked by Dickkopf-1, an effective antagonist of the canonical Wnt signaling pathway. Taken together, these results demonstrate for the first time that suppression of DNA methylation is able to facilitate the osteogenic differentiation capacity of hPDLSCs exposed to HG, through activation of the canonical Wnt signaling pathway. PMID:27273319

  20. Bioprinting 3D cell-laden hydrogel microarray for screening human periodontal ligament stem cell response to extracellular matrix.

    PubMed

    Ma, Yufei; Ji, Yuan; Huang, Guoyou; Ling, Kai; Zhang, Xiaohui; Xu, Feng

    2015-01-01

    Periodontitis is an inflammatory disease negatively affecting up to 15% of adults worldwide. Periodontal ligament stem cells (PDLSCs) hold great promises for periodontal tissue regeneration, where it is necessary to find proper extracellular matrix (ECM) materials (e.g., composition, concentration). In this study, we proposed a bioprinting-based approach to generate nano-liter sized three-dimensional (3D) cell-laden hydrogel array with gradient of ECM components, through controlling the volume ratio of two hydrogels, such as gelatin methacrylate (GelMA) and poly(ethylene glycol) (PEG) dimethacrylate. The resulting cell-laden array with a gradient of GelMA/PEG composition was used to screen human PDLSC response to ECM. The behavior (e.g., cell viability, spreading) of human PDLSCs in GelMA/PEG array were found to be depended on the volume ratios of GelMA/PEG, with cell viability and spreading area decreased along with increasing the ratio of PEG. The developed approach would be useful for screening cell-biomaterial interaction in 3D and promoting regeneration of functional tissue. PMID:26696269

  1. Melatonin Inhibits CXCL10 and MMP-1 Production in IL-1β-Stimulated Human Periodontal Ligament Cells.

    PubMed

    Hosokawa, Ikuko; Hosokawa, Yoshitaka; Shindo, Satoru; Ozaki, Kazumi; Matsuo, Takashi

    2016-08-01

    Melatonin is a hormone that is mainly secreted by the pineal gland and exhibits a wide spectrum of activities, including antioxidant functions. Melatonin has been detected in gingival crevicular fluid. However, the role of melatonin in periodontal tissue is still uncertain. The aim of this study was to examine the effects of melatonin on inflammatory mediator expression in human periodontal ligament cells (HPDLC). Interleukin (IL)-1β induced CXC chemokine ligand (CXCL)10, matrix metalloproteinase (MMP)-1, and tissue inhibitors of metalloproteinase (TIMP)-1 production in HPDLC. Melatonin decreased CXCL10 and MMP-1 production and increased TIMP-1 production in IL-1β-stimulated HPDLC. Western blot analysis showed that melatonin inhibited p38 mitogen-activated protein kinase (MAPK) and c-jun N-terminal kinase (JNK) phosphorylation, and IkB-α degradation and phosphorylation in IL-1β-stimulated HPDLC. These results suggest that melatonin might inhibit Th1 cell migration by reducing CXCL10 production. Moreover, melatonin might inhibit soft tissue destruction by decreasing MMP-1 production in periodontal lesions. PMID:27271323

  2. Effects of Naringin on Proliferation and Osteogenic Differentiation of Human Periodontal Ligament Stem Cells In Vitro and In Vivo

    PubMed Central

    Yin, Lihua; Cheng, Wenxiao; Qin, Zishun; Yu, Hongdou; Yu, Zhanhai; Zhong, Mei; Sun, Kemo; Zhang, Wei

    2015-01-01

    This study is to explore the osteogenesis potential of the human periodontal ligament stem cells (hPDLSCs) induced by naringin in vitro and in vitro. The results confirmed that 1 μM naringin performs the best effect and a collection of bone-related genes (RUNX2, COL1A2, OPN, and OCN) had significantly higher expression levels compared to the control group. Furthermore, a typical trabecular structure was observed in vivo, surrounded by a large amount of osteoblasts. These results demonstrated that naringin, at a concentration of 1 μM, can efficiently promote the proliferation and differentiation of hPDLSCs both in vitro and in vivo. PMID:26078764

  3. Six1 is required for mouse dental follicle cell and human periodontal ligament-derived cell proliferation.

    PubMed

    Kawasaki, Tatsuki; Takahashi, Masanori; Yajima, Hiroshi; Mori, Yoshiyuki; Kawakami, Kiyoshi

    2016-08-01

    The periodontal ligament (PDL) is a connective tissue that attaches the tooth cementum to the alveolar bone and is derived from dental follicle cells (DFCs). The DFCs form fibroblasts, osteoblasts, cementoblasts, and PDL stem cells (PDLSCs). We previously reported homeobox transcription factor Six1 expression in mouse DFCs. However, the role of Six1 in periodontal tissue development is largely unknown. In this study, we analyzed SIX1 expression in mouse periodontal tissue cells during postnatal development and adulthood. We also addressed the role of SIX1 in mouse periodontium development and in human cultured PDL-derived cells (PDLCs). In mouse development, SIX1 production was abundant in DFCs and PDL cells by 2 weeks, but it was greatly diminished in the PDL at 4 weeks and in adults. Although the SIX1-positive cell distribution was sparse in the adult PDL, SIX1-positive cells were observed with low expression levels. We used 5-ethynyl-2'-deoxyuridine (EdU) for cell labeling to reveal numerous EdU/SIX1-double positive cells at 2 weeks; however, a few EdU-positive cells remained at 4 weeks. The proportion of DFCs that incorporated EdU was significantly lower in Six1-deficient mice compared with wild-type mice at E18.5. In human PDLCs, SIX1 was intensely expressed, and SIX1-knockdown using siRNA reduced proliferating PDLCs. Our results suggest that SIX1 is a key proliferation regulator in mouse DFCs and human PDLCs, which provides novel insight into Six family gene function in mammals. PMID:27241908

  4. Microscopic evaluation of the effect of different storage media on the periodontal ligament of surgically extracted human teeth.

    PubMed

    de Sousa, Hugo Alexandre; de Alencar, Ana Helena G; Bruno, Kely Firmino; Batista, Aline Carvalho; de Carvalho, Antônio César Perri

    2008-12-01

    The objective of this study was to microscopically evaluate the human periodontal ligament adhered to extracted teeth, after extra-alveolar period of 1 h using, as storage media, pasteurized milk (group I), chicken egg white (group II) and artificial saliva (group III). Forty intact premolars were selected, with indication of tooth extraction for orthodontic reasons. After the extraction of 30 teeth, they were maintained dried on a gauze at room temperature for 10 min, and then immersed in the selected storage media. After the established time, the teeth were washed with saline solution and placed in 10.0% buffered formalin. Ten teeth were extracted and immediately immersed in 10.0% neutral formalin (group IV). Thereafter, they were submitted to histological processing. After fixation and decalcification, the specimens were cut at the cervical, medium and apical thirds, inserted in paraffin and serially sectioned, with 6-mum thickness. They were stained by hematoxylin-eosin and analyzed under light microscopy. According to the results of quantitative analysis, there was no statistically significant difference in the number of cells per mm(2) between groups I, II and III. The qualitative analysis showed similar results in relation to the organization of collagen fibers and the number of cells in groups I and II, but group III displayed a higher disorganization of the collagen fibers and also a higher reduction in the number of cells. Based on these results, it was concluded that the quality of periodontal ligament was affected by the storage media, when compared with the control group. There was a statistically significant difference in the number of cells per mm(2) between the control group and groups I, II and III. There was no significant statistical difference in the number of cells per mm(2) between groups I, II and III. PMID:19021655

  5. Enterococcus faecalis lipoteichoic acid suppresses Aggregatibacter actinomycetemcomitans lipopolysaccharide-induced IL-8 expression in human periodontal ligament cells.

    PubMed

    Im, Jintaek; Baik, Jung Eun; Kim, Kyoung Whun; Kang, Seok-Seong; Jeon, Jun Ho; Park, Ok-Jin; Kim, Hyun Young; Kum, Kee-Yeon; Yun, Cheol-Heui; Han, Seung Hyun

    2015-08-01

    Periodontitis is caused by multi-bacterial infection and Aggregatibacter actinomycetemcomitans and Enterococcus faecalis are closely associated with inflammatory periodontal diseases. Although lipopolysaccharide (LPS) of A. actinomycetemcomitans (Aa.LPS) and lipoteichoic acid of E. faecalis (Ef.LTA) are considered to be major virulence factors evoking inflammatory responses, their combinatorial effect on the induction of chemokines has not been investigated. In this study, we investigated the interaction between Aa.LPS and Ef.LTA on IL-8 expression in human periodontal ligament (PDL) cells. Aa.LPS, but not Ef.LTA, substantially induced IL-8 expression at the protein and mRNA levels. Interestingly, Ef.LTA suppressed Aa.LPS-induced IL-8 expression without affecting the binding of Aa.LPS to Toll-like receptor (TLR) 4. Ef.LTA reduced Aa.LPS-induced phosphorylation of mitogen-activated protein kinases, including ERK, JNK and p38 kinase. Furthermore, Ef.LTA inhibited the Aa.LPS-induced transcriptional activities of the activating protein 1, CCAAT/enhancer-binding protein and nuclear factor-kappa B transcription factors, all of which are known to regulate IL-8 gene expression. Ef.LTA augmented the expression of IL-1 receptor-associated kinase-M (IRAK-M), a negative regulator of TLR intracellular signaling pathways, in the presence of Aa.LPS at both the mRNA and protein levels. Small interfering RNA silencing IRAK-M reversed the attenuation of Aa.LPS-induced IL-8 expression by Ef.LTA. Collectively, these results suggest that Ef.LTA down-regulates Aa.LPS-induced IL-8 expression in human PDL cells through up-regulation of the negative regulator IRAK-M. PMID:25840438

  6. Effects of IL-10 and glucose on expression of OPG and RANKL in human periodontal ligament fibroblasts

    PubMed Central

    Zhang, L.; Ding, Y.; Rao, G.Z.; Miao, D.

    2016-01-01

    The effects of interleukin-10 (IL-10) and glucose on mRNA and protein expression of osteoprotegerin (OPG), and its ligand, receptor activator of nuclear factor-κB ligand (RANKL), were investigated in human periodontal ligament fibroblasts (HPDLFs). Primary HPDLFs were treated with different concentrations of IL-10 (0, 1, 10, 25, 50, and 100 ng/mL) or glucose (0, 5.5, 10, 20, 30, and 40 mmol/L). Changes in mRNA and protein expression were examined using the reverse-transcription polymerase chain reaction (RT-PCR) and Western blot analysis, respectively. After IL-10 treatment, mRNA and protein levels of OPG were increased, while mRNA and protein levels of RANKL were decreased (P<0.05), both in a concentration-dependent manner. Glucose stimulation had the opposite concentration-dependent effect to that of IL-10 on OPG and RANKL expression. IL-10 upregulated OPG expression and downregulated RANKL expression, whereas high glucose upregulated RANKL and downregulated OPG in HDPLFs. Abnormal levels of IL-10 and glucose may contribute to the pathogenesis of periodontal disease. PMID:27074164

  7. Functional differences in mesenchymal stromal cells from human dental pulp and periodontal ligament.

    PubMed

    Vasandan, Anoop Babu; Shankar, Shilpa Rani; Prasad, Priya; Sowmya Jahnavi, Vulugundam; Bhonde, Ramesh Ramachandra; Jyothi Prasanna, Susarla

    2014-02-01

    Clinically reported reparative benefits of mesenchymal stromal cells (MSCs) are majorly attributed to strong immune-modulatory abilities not exactly shared by fibroblasts. However, MSCs remain heterogeneous populations, with unique tissue-specific subsets, and lack of clear-cut assays defining therapeutic stromal subsets adds further ambiguity to the field. In this context, in-depth evaluation of cellular characteristics of MSCs from proximal oro-facial tissues: dental pulp (DPSCs) and periodontal ligament (PDLSCs) from identical donors provides an opportunity to evaluate exclusive niche-specific influences on multipotency and immune-modulation. Exhaustive cell surface profiling of DPSCs and PDLSCs indicated key differences in expression of mesenchymal (CD105) and pluripotent/multipotent stem cell-associated cell surface antigens: SSEA4, CD117, CD123 and CD29. DPSCs and PDLSCs exhibited strong chondrogenic potential, but only DPSCs exhibited adipogenic and osteogenic propensities. PDLSCs expressed immuno-stimulatory/immune-adhesive ligands like HLA-DR and CD50, upon priming with IFNγ, unlike DPSCs, indicating differential response patterns to pro-inflammatory cytokines. Both DPSCs and PDLSCs were hypo-immunogenic and did not elicit robust allogeneic responses despite exposure to IFNγ or TNFα. Interestingly, only DPSCs attenuated mitogen-induced lympho-proliferative responses and priming with either IFNγ or TNFα enhanced immuno-modulation capacity. In contrast, primed or unprimed PDLSCs lacked the ability to suppress polyclonal T cell blast responses. This study indicates that stromal cells from even topographically related tissues do not necessarily share identical MSC properties and emphasizes the need for a thorough functional testing of MSCs from diverse sources with respect to multipotency, immune parameters and response to pro-inflammatory cytokines before translational usage. PMID:24393246

  8. Grp78 Is Critical for Amelogenin-Induced Cell Migration in a Multipotent Clonal Human Periodontal Ligament Cell Line.

    PubMed

    Toyoda, Kyosuke; Fukuda, Takao; Sanui, Terukazu; Tanaka, Urara; Yamamichi, Kensuke; Atomura, Ryo; Maeda, Hidefumi; Tomokiyo, Atsushi; Taketomi, Takaharu; Uchiumi, Takeshi; Nishimura, Fusanori

    2016-02-01

    Periodontal ligament stem cells (PDLSCs) are known to play a pivotal role in regenerating the periodontium. Amelogenin, which belongs to a family of extracellular matrix (ECM) proteins, is a potential bioactive molecule for periodontal regenerative therapy. However, its downstream target molecules and/or signaling patterns are still unknown. Our recent proteomic study identified glucose-regulated protein 78 (Grp78) as a new amelogenin-binding protein. In this study, we demonstrate, for the first time, the cellular responses induced by the biological interaction between amelogenin and Grp78 in the human undifferentiated PDL cell line 1-17, which possesses the most typical characteristics of PDLSCs. Confocal co-localization experiments revealed the internalization of recombinant amelogenin (rM180) via binding to cell surface Grp78, and the endocytosis was inhibited by the silencing of Grp78 in 1-17 cells. Microarray analysis indicated that rM180 and Grp78 regulate the expression profiles of cell migration-associated genes in 1-17 cells. Moreover, Grp78 overexpression enhanced rM180-induced cell migration and adhesion without affecting cell proliferation, while silencing of Grp78 diminished these activities. Finally, binding of rM180 to Grp78 promoted the formation of lamellipodia, and the simultaneous activation of Rac1 was also demonstrated by NSC23766, a widely accepted Rac1 inhibitor. These results suggest that Grp78 is essential for enhancing amelogenin-induced migration in 1-17 cells. The biological interaction of amelogenin with Grp78 offers significant therapeutic potential for understanding the biological components and specific functions involved in the signal transduction of amelogenin-induced periodontal tissue regeneration. PMID:26147472

  9. Matrix metalloproteinases regulate extracellular levels of SDF-1/CXCL12, IL-6 and VEGF in hydrogen peroxide-stimulated human periodontal ligament fibroblasts.

    PubMed

    Cavalla, Franco; Osorio, Constanza; Paredes, Rodolfo; Valenzuela, María Antonieta; García-Sesnich, Jocelyn; Sorsa, Timo; Tervahartiala, Taina; Hernández, Marcela

    2015-05-01

    Periodontitis is a highly prevalent infectious disease characterized by the progressive inflammatory destruction of tooth-supporting structures, leading to tooth loss. The underling molecular mechanisms of the disease are incompletely understood, precluding the development of more efficient screening, diagnostic and therapeutic approaches. We investigated the interrelation of three known effector mechanisms of the cellular response to periodontal infection, namely reactive oxygen species (ROS), matrix metalloproteinases (MMPs) and cytokines in primary cell cultures of human periodontal ligament fibroblast (hPDLF). We demonstrated that ROS increase the activity/levels of gelatinolytic MMPs, and stimulate cytokine secretion in hPDLF. Additionally, we proved that MMPs possesses immune modulatory capacity, regulating the secreted levels of cytokines in ROS-stimulated hPDLF cultures. This evidence provides further insight in the molecular pathogenesis of periodontitis, contributing to the future development of more effective therapies. PMID:25748833

  10. Periodontal regeneration using periodontal ligament stem cell-transferred amnion.

    PubMed

    Iwasaki, Kengo; Komaki, Motohiro; Yokoyama, Naoki; Tanaka, Yuichi; Taki, Atsuko; Honda, Izumi; Kimura, Yasuyuki; Takeda, Masaki; Akazawa, Keiko; Oda, Shigeru; Izumi, Yuichi; Morita, Ikuo

    2014-02-01

    Periodontal disease is characterized by the destruction of tooth supporting tissues. Regeneration of periodontal tissues using ex vivo expanded cells has been introduced and studied, although appropriate methodology has not yet been established. We developed a novel cell transplant method for periodontal regeneration using periodontal ligament stem cell (PDLSC)-transferred amniotic membrane (PDLSC-amnion). The aim of this study was to investigate the regenerative potential of PDLSC-amnion in a rat periodontal defect model. Cultured PDLSCs were transferred onto amniotic membranes using a glass substrate treated with polyethylene glycol and photolithography. The properties of PDLSCs were investigated by flow cytometry and in vitro differentiation. PDLSC-amnion was transplanted into surgically created periodontal defects in rat maxillary molars. Periodontal regeneration was evaluated by microcomputed tomography (micro-CT) and histological analysis. PDLSCs showed mesenchymal stem cell-like characteristics such as cell surface marker expression (CD90, CD44, CD73, CD105, CD146, and STRO-1) and trilineage differentiation ability (i.e., into osteoblasts, adipocytes, and chondrocytes). PDLSC-amnion exhibited a single layer of PDLSCs on the amniotic membrane and stability of the sheet even with movement and deformation caused by surgical instruments. We observed that the PDLSC-amnion enhanced periodontal tissue regeneration as determined by micro-CT and histology by 4 weeks after transplantation. These data suggest that PDLSC-amnion has therapeutic potential as a novel cell-based regenerative periodontal therapy. PMID:24032400

  11. MicroRNA expression profile of human periodontal ligament cells under the influence of Porphyromonas gingivalis LPS.

    PubMed

    Du, Anqing; Zhao, Sen; Wan, LingYun; Liu, TianTao; Peng, Zaoxia; Zhou, ZiYu; Liao, Zhengyu; Fang, Huan

    2016-07-01

    Periodontitis is a chronic inflammatory disease which is caused by bacterial infection and leads to the destruction of periodontal tissues and resorption of alveolar bone. Thus, special attention should be paid to the mechanism under lipopolysaccharide (LPS)-induced periodontitis because LPS is the major cause of periodontitis. However, to date, miRNA expression in the LPS-induced periodontitis has not been well characterized. In this study, we investigated miRNA expression patterns in LPS-treated periodontal ligament cells (PDLCs). Through miRNA array and differential analysis, 22 up-regulated miRNAs and 28 down-regulated miRNAs in LPS-treated PDLCs were identified. Seven randomly selected up-regulated (miR-21-5p, 498, 548a-5p) and down-regulated (miR-495-3p, 539-5p, 34c-3p and 7a-2-3p) miRNAs were examined by qRT-PCR, and the results proved the accuracy of the miRNA array. Moreover, targets of these deregulated miRNAs were analysed using the miRWalk database. Database for Annotation, Visualization and Integration Discovery software were performed to analyse the Gene Ontology and Kyoto Encyclopaedia of Genes and Genomes pathway of differential expression miRNAs, and the results shown that Toll-like receptor signalling pathway, cAMP signalling pathway, transforming growth factor-beta signalling pathway, mitogen-activated protein kinase (MAPK) signalling pathway and other pathways were involved in the molecular mechanisms underlying LPS-induced periodontitis. In conclusion, this study provides clues for enhancing our understanding of the mechanisms and roles of miRNAs as key regulators of LPS-induced periodontitis. PMID:26987780

  12. Expression and Presence of OPG and RANKL mRNA and Protein in Human Periodontal Ligament with Orthodontic Force

    PubMed Central

    Otero, Liliana; García, Dabeiba Adriana; Wilches-Buitrago, Liseth

    2016-01-01

    OBJECTIVE The objective of this study is to investigate the expression and concentration of ligand receptor activator of NFkB (RANKL) and osteoprotegerin (OPG) in human periodontal ligament (hPDL) with orthodontic forces of different magnitudes. METHODS Right premolars in 32 patients were loaded with 4oz or 7oz of orthodontic force for 7 days. Left first premolars were not loaded. After 7 days, premolars were extracted for treatment as indicated. OPG and RANKL mRNA expressions were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR), and ELISA was used to assess OPG and RANKL protein concentration in compression and tension sides of PDL. Data were subjected to analysis of variance and Tukey tests. RESULTS There was statistically significant difference in RANKL concentration on comparing control teeth with tension and compression sides of the experimental teeth (P < 0.0001). The expression of mRNA RANKL was increased in the tension and compression sides with 4oz (P < 0.0001). OPG did not show statistically significant association with any group. Changes in RANKL/OPG protein ratio in experimental and control groups showed statistically significant difference (P < 0.0001). CONCLUSIONS RANKL protein levels are elevated in hPDL loaded with orthodontic forces, suggesting that RANKL protein contributes to bone modeling in response to the initial placement of orthodontic force. PMID:26823650

  13. Osteogenesis differentiation of human periodontal ligament cells by CO2 laser-treatment stimulating macrophages via BMP2 signalling pathway

    NASA Astrophysics Data System (ADS)

    Hsieh, Wen-Hui; Chen, Yi-Jyun; Hung, Chi-Jr; Huang, Tsui-Hsien; Kao, Chia-Tze; Shie, Ming-You

    2014-11-01

    Immune reactions play an important role in determining the biostimulation of bone formation, either in new bone formation or inflammatory fibrous tissue encapsulation. Macrophage cell, the important effector cells in the immune reaction, which are indispensable for osteogenesis and their heterogeneity and plasticity, render macrophages a primer target for immune system modulation. However, there are very few studies about the effects of macrophage cells on laser treatment-regulated osteogenesis. In this study, we used CO2 laser as a model biostimulation to investigate the role of macrophage cells on the CO2 laser stimulated osteogenesis. Bone morphogenetic protein 2 (BMP2) was also significantly up regulated by the CO2 laser stimulation, indicating that macrophage may participate in the CO2 laser stimulated osteogenesis. Interestingly, when laser treatment macrophage-conditioned medium were applied to human periodontal ligament cells (hPDLs), the osteogenesis differentiation of hPDLs was significantly enhanced, indicating the important role of macrophages in CO2 laser-induced osteogenesis. These findings provided valuable insights into the mechanism of CO2 laser-stimulated osteogenic differentiation, and a strategy to optimize the evaluation system for the in vitro osteogenesis capacity of laser treatment.

  14. Distinction Between Cell Proliferation and Apoptosis Signals Regulated by Brain-Derived Neurotrophic Factor in Human Periodontal Ligament Cells and Gingival Epithelial Cells.

    PubMed

    Kashiwai, Kei; Kajiya, Mikihito; Matsuda, Shinji; Ouhara, Kazuhisa; Takeda, Katsuhiro; Takata, Takashi; Kitagawa, Masae; Fujita, Tsuyoshi; Shiba, Hideki; Kurihara, Hidemi

    2016-07-01

    Previously, we reported that brain-derived neurotrophic factor (BDNF) enhances periodontal tissue regeneration by inducing periodontal ligament cell proliferation in vivo. In addition, the down growth of gingival epithelial cells, which comprises a major obstacle to the regeneration, was not observed. However, the underlying molecular mechanism is still unclear. Therefore, this study aimed to investigate the effect of BDNF on cell proliferation and apoptosis in human periodontal ligament (HPL) cells and human gingival epithelial cells (OBA9 cells) and to explore the molecular mechanism in vitro. HPL cells dominantly expressed a BDNF receptor, TrkB, and BDNF increased cell proliferation and ERK phosphorylation. However, its proliferative effect was diminished by a MEK1/2 inhibitor (U0126) and TrkB siRNA transfection. Otherwise, OBA9 cells showed a higher expression level of p75, which is a pan-neurotrophin receptor, than that of HPL cells. BDNF facilitated not cell proliferation but cell apoptosis and JNK phosphorylation in OBA9 cells. A JNK inhibitor (SP600125) and p75 siRNA transfection attenuated the BDNF-induced cell apoptosis. Moreover, OBA9 cells pretreated with SP600125 or p75 siRNA showed cell proliferation by BDNF stimulation, though it was reduced by U0126 and TrkB siRNA. Interestingly, overexpression of p75 in HPL cells upregulated cell apoptosis and JNK phosphorylation by BDNF treatment. These results indicated that TrkB-ERK signaling regulates BDNF-induced cell proliferation, whereas p75-JNK signaling plays roles in cell apoptotic and cytostatic effect of BDNF. Overall, BDNF activates periodontal ligament cells proliferation and inhibits the gingival epithelial cells growth via the distinct pathway. J. Cell. Biochem. 117: 1543-1555, 2016. © 2015 Wiley Periodicals, Inc. PMID:26581032

  15. Signaling by Mechanical Strain Involves Transcriptional Regulation of Proinflammatory Genes in Human Periodontal Ligament Cells In Vitro

    PubMed Central

    LONG, P.; LIU, F.; PIESCO, N. P.; KAPUR, R.; AGARWAL, S.

    2016-01-01

    Intracellular signals generated by mechanical strain profoundly affect the metabolic function of osteoblast-like periodontal ligament (PDL) cells, which reside between the tooth and alveolar bone. In response to applied mechanical forces, PDL cells synthesize bone-resorptive cytokines to induce bone resorption at sites exposed to compressive forces and deposit bone at sites exposed to tensile forces in an environment primed for catabolic processes. The intracellular mechanisms that regulate this bone remodeling remain unclear. Here, in an in vitro model system, we show that tensile strain is a critical determinant of PDL-cell metabolic functions. Equibiaxial tensile strain (TENS), when applied at low magnitudes, acts as a potent antagonist of interleukin (IL)-1β actions and suppresses transcriptional regulation of multiple proinflammatory genes. This is evidenced by the fact that TENS at low magnitude: (i) inhibits recombinant human (rh)IL-1β-dependent induction of cyclooxygenase-2 (COX-2) mRNA expression and production of prostaglandin estradiol (PGE2); (ii) inhibits rhIL-1β-dependent induction matrix metalloproteinase-1 (MMP-1) and MMP-3 synthesis by suppressing their mRNA expression; (iii) abrogates rhIL-1β-induced suppression of tissue inhibitor of metalloprotease-II (TIMP-II) expression; and (iv) reverses IL-1β-dependent suppression of osteocalcin and alkaline phosphatase synthesis. Nevertheless, these actions of TENS were observed only in the presence of IL-1β, as TENS alone failed to affect any of the aforementioned responses. The present findings are the first to show that intra-cellular signals generated by low-magnitude mechanical strain interfere with one or more critical step(s) in the signal transduction cascade of rhIL-1β upstream of mRNA expression, while concurrently promoting the expression of osteogenic proteins in PDL cells. PMID:11934644

  16. Effects of Intermittent Administration of Parathyroid Hormone (1-34) on Bone Differentiation in Stromal Precursor Antigen-1 Positive Human Periodontal Ligament Stem Cells

    PubMed Central

    Wang, Xiaoxiao; Wang, Yanlan; Dai, Xubin; Chen, Tianyu; Yang, Fanqiao; Dai, Shuangye; Ou, Qianmin; Wang, Yan; Lin, Xuefeng

    2016-01-01

    Periodontitis is the most common cause of tooth loss and bone destruction in adults worldwide. Human periodontal ligament stem cells (hPDLSCs) may represent promising new therapeutic biomaterials for tissue engineering applications. Stromal precursor antigen-1 (STRO-1) has been shown to have roles in adherence, proliferation, and multipotency. Parathyroid hormone (PTH) has been shown to enhance proliferation in osteoblasts. Therefore, in this study, we aimed to compare the functions of STRO-1(+) and STRO-1(−) hPDLSCs and to investigate the effects of PTH on the osteogenic capacity of STRO-1(+) hPDLSCs in order to evaluate their potential applications in the treatment of periodontitis. Our data showed that STRO-1(+) hPDLSCs expressed higher levels of the PTH-1 receptor (PTH1R) than STRO-1(−) hPDLSCs. In addition, intermittent PTH treatment enhanced the expression of PTH1R and osteogenesis-related genes in STRO-1(+) hPDLSCs. PTH-treated cells also exhibited increased alkaline phosphatase activity and mineralization ability. Therefore, STRO-1(+) hPDLSCs represented a more promising cell resource for biomaterials and tissue engineering applications. Intermittent PTH treatment improved the capacity for STRO-1(+) hPDLSCs to repair damaged tissue and ameliorate the symptoms of periodontitis. PMID:27069479

  17. Characterization of stem cells from alveolar periodontal ligament.

    PubMed

    Wang, Lei; Shen, Huan; Zheng, Wei; Tang, Liang; Yang, Zhenhua; Gao, Yuan; Yang, Qingtian; Wang, Chen; Duan, Yinzhong; Jin, Yan

    2011-04-01

    Complete and predicable regeneration of complex periodontal structures, which include cementum, periodontal ligament (PDL), and alveolar bone, has been a great challenge for periodontal researchers. It is generally believed that human PDL from the root surface contains stem cells (r-PDLSCs), which can enhance cementum/PDL-like tissues regeneration in vivo. In this work, PDL was found to possess asymmetrically distributed stem cells observed by long-term bromodeoxyuridine (BrdU) labeling. Putative stem cells from human PDL on the alveolar bone surface (a-PDLSCs) were then isolated and characterized. It was shown that a-PDLSCs exhibited strong proliferation capability and expressed high percentages of mesenchymal stem cell markers. Comparatively, a-PDLSCs had higher multilineage differentiation potential than r-PDLSCs with regard to both osteogenic and adipogenic differentiation. Alkaline phosphatase activity and the expression of mineralization-related markers of a-PDLSCs were also higher than those of r-PDLSCs. In vivo, a-PDLSCs could regenerate bone/PDL-like structures and repair critical-size defects created in calvarial bone of NOD/SCID mice. Autologous PDLSC-mediated periodontal regeneration showed that a-PDLSCs could accomplish reconstruction of alveolar bone more perfectly than r-PDLSCs. Our data suggest that PDLSCs may have quite different characteristics depending on locations. a-PDLSCs may take a synergistic effect with r-PDLSCs in periodontal regeneration. PMID:21186958

  18. Tenomodulin expression in the periodontal ligament enhances cellular adhesion.

    PubMed

    Komiyama, Yuske; Ohba, Shinsuke; Shimohata, Nobuyuki; Nakajima, Keiji; Hojo, Hironori; Yano, Fumiko; Takato, Tsuyoshi; Docheva, Denitsa; Shukunami, Chisa; Hiraki, Yuji; Chung, Ung-Il

    2013-01-01

    Tenomodulin (Tnmd) is a type II transmembrane protein characteristically expressed in dense connective tissues such as tendons and ligaments. Its expression in the periodontal ligament (PDL) has also been demonstrated, though the timing and function remain unclear. We investigated the expression of Tnmd during murine tooth eruption and explored its biological functions in vitro. Tnmd expression was related to the time of eruption when occlusal force was transferred to the teeth and surrounding tissues. Tnmd overexpression enhanced cell adhesion in NIH3T3 and human PDL cells. In addition, Tnmd-knockout fibroblasts showed decreased cell adhesion. In the extracellular portions of Tnmd, the BRICHOS domain or CS region was found to be responsible for Tnmd-mediated enhancement of cell adhesion. These results suggest that Tnmd acts on the maturation or maintenance of the PDL by positively regulating cell adhesion via its BRICHOS domain. PMID:23593173

  19. Tenomodulin Expression in the Periodontal Ligament Enhances Cellular Adhesion

    PubMed Central

    Komiyama, Yuske; Ohba, Shinsuke; Shimohata, Nobuyuki; Nakajima, Keiji; Hojo, Hironori; Yano, Fumiko; Takato, Tsuyoshi; Docheva, Denitsa; Shukunami, Chisa; Hiraki, Yuji; Chung, Ung-il

    2013-01-01

    Tenomodulin (Tnmd) is a type II transmembrane protein characteristically expressed in dense connective tissues such as tendons and ligaments. Its expression in the periodontal ligament (PDL) has also been demonstrated, though the timing and function remain unclear. We investigated the expression of Tnmd during murine tooth eruption and explored its biological functions in vitro. Tnmd expression was related to the time of eruption when occlusal force was transferred to the teeth and surrounding tissues. Tnmd overexpression enhanced cell adhesion in NIH3T3 and human PDL cells. In addition, Tnmd-knockout fibroblasts showed decreased cell adhesion. In the extracellular portions of Tnmd, the BRICHOS domain or CS region was found to be responsible for Tnmd-mediated enhancement of cell adhesion. These results suggest that Tnmd acts on the maturation or maintenance of the PDL by positively regulating cell adhesion via its BRICHOS domain. PMID:23593173

  20. A proposed index for residual periodontal ligament support.

    PubMed

    Abe, Yasuhiko; Taji, Tsuyoshi; Hiasa, Kyou; Tsuga, Kazuhiro; Akagawa, Yasumasa

    2010-01-01

    An index was developed to estimate the residual periodontal ligament support for individual teeth during treatment planning for partially edentulous patients. The Residual Periodontal Ligament Index (rPLI) was derived from a formula that calculates the remaining area of periodontal attachment and the Normal Periodontal Ligament Index (nPLI). To illustrate the applicability of the rPLI, the total nPLI scores of the remaining teeth corresponding to Eichner subclasses of partial edentulism were charted by assessing the average occlusal support numerically. The rPLI is proposed to be a possible suitable tool for epidemiologic research on the progression of tooth loss and the survival rate of prostheses. PMID:20859566

  1. Cyclic Tensile Stress During Physiological Occlusal Force Enhances Osteogenic Differentiation of Human Periodontal Ligament Cells via ERK1/2-Elk1 MAPK Pathway

    PubMed Central

    Li, Lu; Han, Minxuan; Li, Sheng

    2013-01-01

    Physiological occlusal force constitutively exists in the oral environment and is important for periodontal homeostasis and remodeling. Cyclic tensile stress (CTS) triggers the biological response of periodontal ligament (PDL). However, a few reports have studied the correlation between CTS during physiological occlusal force and PDL cell activities such as osteogenic differentiation. In the present study, human PDL cells (hPDLCs) were subjected to 10% elongation CTS loading at 0.5 Hz for 24 h, which represents the physiological conditions of occlusal force. Gene expression microarray was used to investigate the mechano-induced differential gene profile and pathway analysis in vitro. The osteogenic relative factors, that is, SPP1, RUNX2, and SP7, were assessed by real-time PCR and Western blot. The involvement of mitogen-activated protein kinase (MAPK) signaling pathways was investigated by Western blot with a specific inhibitor. The expressions of SPP1, RUNX2, SP7, p-ERK1/2, and p-Elk1 were up-regulated after 10% CTS exposure. However, these up-regulated expressions were prevented by ERK1/2 inhibitor U0126 in the physiological occlusal force-applied hPDLCs. These results showed that 10% CTS could enhance osteogenic differentiation of hPDLCs via ERK1/2-Elk1 MAPK pathway, indicating that CTS during physiological occlusal force is a potent agent for PDL remodeling. PMID:23781879

  2. A low-level diode laser therapy reduces the lipopolysaccharide (LPS)-induced periodontal ligament cell inflammation

    NASA Astrophysics Data System (ADS)

    Huang, T. H.; Chen, C. C.; Liu, S. L.; Lu, Y. C.; Kao, C. T.

    2014-07-01

    The purpose of this study was to investigate the cytologic effects of inflammatory periodontal ligament cells in vitro after low-level laser therapy. Human periodontal ligament cells were cultured, exposed to lipopolysaccharide and subjected to low-level laser treatment of 5 J cm-2 or 10 J cm-2 using a 920 nm diode laser. A periodontal ligament cell attachment was observed under a microscope, and the cell viability was quantified by a mitochondrial colorimetric assay. Lipopolysaccharide-treated periodontal ligament cells were irradiated with the low-level laser, and the expression levels of several inflammatory markers, iNOS, TNF-α and IL-1, and pErk kinase, were analyzed by reverse transcription polymerase chain reaction and western blot. The data were collected and analyzed by one-way analysis of variance; p < 0.05 indicated a statistically significant difference. The low-level laser treatment of periodontal ligament cells increased their ability to attach and survive. After irradiation, the expression levels of iNOS, TNF-α and IL-1 in lipopolysaccharide-exposed periodontal ligament cells decreased over time (p < 0.05). In periodontal ligament cells, low-level diode laser treatment increased the cells’ proliferative ability and decreased the expression of the examined inflammatory mediators.

  3. Mechanoresponsive Properties of the Periodontal Ligament.

    PubMed

    Huang, L; Liu, B; Cha, J Y; Yuan, G; Kelly, M; Singh, G; Hyman, S; Brunski, J B; Li, J; Helms, J A

    2016-04-01

    The periodontal ligament (PDL) functions as an enthesis, a connective tissue attachment that dissipates strains created by mechanical loading. Entheses are mechanoresponsive structures that rapidly adapt to changes in their mechanical loading; here we asked which features of the PDL are sensitive to such in vivo loading. We evaluated the PDL in 4 physiologically relevant mechanical environments, focusing on mitotic activity, cell density, collagen content, osteogenic protein expression, and organization of the tissue. In addition to examining PDLs that supported teeth under masticatory loading and eruptive forces, 2 additional mechanical conditions were created and analyzed: hypoloading and experimental tooth movement. Collectively, these data revealed that the adult PDL is a remarkably quiescent tissue and that only when it is subjected to increased loads--such as those associated with mastication, eruption, and orthodontic tooth movement-does the tissue increase its rate of cell proliferation and collagen production. These data have relevance in clinical scenarios where PDL acclimatization can be exploited to optimize tooth movement. PMID:26767771

  4. Effects of fluoride on proliferation and mineralization in periodontal ligament cells in vitro

    PubMed Central

    Li, K.Q.; Jia, S.S.; Ma, M.; Shen, H.Z.; Xu, L.; Liu, G.P.; Huang, S.Y.; Zhang, D.S.

    2016-01-01

    Fluoride, which is often added to toothpaste or mouthwash in order to protect teeth from decay, may be a novel therapeutic approach for acceleration of periodontal regeneration. Therefore, we investigated the effects of fluoride on proliferation and mineralization in human periodontal ligament cells in vitro. The periodontal ligament cells were stimulated with various concentrations of NaF added into osteogenic inductive medium. Immunohistochemistry of cell identification, cell proliferation, alkaline phosphatase (ALP) activity assay, Alizarin red S staining and quantitative real-time-polymerase chain reaction (RT-PCR) were performed. Moderate concentrations of NaF (50-500 μmol/L) had pro-proliferation effects, while 500 μmol/L had the best effects. ALP activity and calcium content were significantly enhanced by 10 μmol/L NaF with osteogenic inductive medium. Quantitative RT-PCR data varied in genes as a result of different NaF concentrations and treatment periods. We conclude that moderate concentrations of NaF can stimulate proliferation and mineralization in periodontal ligament cells. These in vitro findings may provide a novel therapeutic approach for acceleration of periodontal regeneration by addition of suitable concentrations of NaF into the medication for periodontitis treatment, i.e., into periodontal packs and tissue patches. PMID:27409336

  5. Effects of fluoride on proliferation and mineralization in periodontal ligament cells in vitro.

    PubMed

    Li, K Q; Jia, S S; Ma, M; Shen, H Z; Xu, L; Liu, G P; Huang, S Y; Zhang, D S

    2016-07-11

    Fluoride, which is often added to toothpaste or mouthwash in order to protect teeth from decay, may be a novel therapeutic approach for acceleration of periodontal regeneration. Therefore, we investigated the effects of fluoride on proliferation and mineralization in human periodontal ligament cells in vitro. The periodontal ligament cells were stimulated with various concentrations of NaF added into osteogenic inductive medium. Immunohistochemistry of cell identification, cell proliferation, alkaline phosphatase (ALP) activity assay, Alizarin red S staining and quantitative real-time-polymerase chain reaction (RT-PCR) were performed. Moderate concentrations of NaF (50-500 μmol/L) had pro-proliferation effects, while 500 μmol/L had the best effects. ALP activity and calcium content were significantly enhanced by 10 μmol/L NaF with osteogenic inductive medium. Quantitative RT-PCR data varied in genes as a result of different NaF concentrations and treatment periods. We conclude that moderate concentrations of NaF can stimulate proliferation and mineralization in periodontal ligament cells. These in vitro findings may provide a novel therapeutic approach for acceleration of periodontal regeneration by addition of suitable concentrations of NaF into the medication for periodontitis treatment, i.e., into periodontal packs and tissue patches. PMID:27409336

  6. Periodontal Ligament Stem Cell-Mediated Treatment for Periodontitis in Miniature Swine

    PubMed Central

    Liu, Yi; Zheng, Ying; Ding, Gang; Fang, Dianji; Zhang, Chunmei; Bartold, Peter Mark; Gronthos, Stan; Shi, Songtao; Wang, Songlin

    2009-01-01

    Periodontitis is a periodontal tissue infectious disease and the most common cause for tooth loss in adults. It has been linked to many systemic disorders, such as coronary artery disease, stroke, and diabetes. At present, there is no ideal therapeutic approach to cure periodontitis and achieve optimal periodontal tissue regeneration. In this study, we explored the potential of using autologous periodontal ligament stem cells (PDLSCs) to treat periodontal defects in a porcine model of periodontitis. The periodontal lesion was generated in the first molars area of miniature pigs by the surgical removal of bone and subsequent silk ligament suture around the cervical portion of the tooth. Autologous PDLSCs were obtained from extracted teeth of the miniature pigs and then expanded ex vivo to enrich PDLSC numbers. When transplanted into the surgically created periodontal defect areas, PDLSCs were capable of regenerating periodontal tissues, leading to a favorable treatment for periodontitis. This study demonstrates the feasibility of using stem cell-mediated tissue engineering to treat periodontal diseases. PMID:18238856

  7. C/EBP β Mediates Endoplasmic Reticulum Stress Regulated Inflammatory Response and Extracellular Matrix Degradation in LPS-Stimulated Human Periodontal Ligament Cells.

    PubMed

    Bai, Yudi; Wei, Yi; Wu, Lian; Wei, Jianhua; Wang, Xiaojing; Bai, Yuxiang

    2016-01-01

    Periodontitis is an oral inflammatory disease that not only affects the integrity of local tooth-supporting tissues but also impacts systemic health. A compositional shift in oral microbiota has been considered as the main cause of periodontitis; however, the potential mechanism has not been fully defined. Herein, we investigated the role of CCAAT/enhancer-binding protein β (C/EBP β), a member of the C/EBP family of transcription factors, in human periodontal ligament cells (hPDLCs) exposed to Porphyromonas gingivalis (P. gingivalis) lipopolysaccharide (LPS). RT-PCR and Western blotting analysis showed that the expression of C/EBP β was significantly increased in hPDLCs stimulated with LPS stimuli. Overexpression of C/EBP β by the recombinant adenoviral vector pAd/C/EBP β markedly increased the expression of the pro-inflammatory cytokines IL-6 and IL-8, and matrix metalloproteinases (MMP)-8 and -9 in hPDLCs in response to LPS. Furthermore, the activation of endoplasmic reticulum (ER) stress was confirmed in LPS-stimulated hPDLCs by measuring the expression of the ER stress marker molecules protein kinase-like ER kinase (PERK), eIF2α, GRP78/Bip, and C/EBP homologous protein (CHOP). The ER stress inhibitor salubrinal repressed, but inducer tunicamycin enhanced, the production of IL-6, IL-8, MMP-8, and MMP-9 in hPDLCs. Additionally, ER stress inducer tunicamycin significantly increased the expression level of C/EBP β in hPDLCs. Blocking of C/EBP β by siRNA resulted in a significant decrease in the secretion of IL-6 and IL-8 and expression of MMP-8 and MMP-9 induced by tunicamycin treatment in hPDLCs. Taken together, ER stress appears to play a regulatory role in the inflammatory response and extracellular matrix (ECM) degradation in hPDLCs in response to LPS stimuli by activating C/EBP β expression. This enhances our understanding of human periodontitis pathology. PMID:27011164

  8. C/EBP β Mediates Endoplasmic Reticulum Stress Regulated Inflammatory Response and Extracellular Matrix Degradation in LPS-Stimulated Human Periodontal Ligament Cells

    PubMed Central

    Bai, Yudi; Wei, Yi; Wu, Lian; Wei, Jianhua; Wang, Xiaojing; Bai, Yuxiang

    2016-01-01

    Periodontitis is an oral inflammatory disease that not only affects the integrity of local tooth-supporting tissues but also impacts systemic health. A compositional shift in oral microbiota has been considered as the main cause of periodontitis; however, the potential mechanism has not been fully defined. Herein, we investigated the role of CCAAT/enhancer-binding protein β (C/EBP β), a member of the C/EBP family of transcription factors, in human periodontal ligament cells (hPDLCs) exposed to Porphyromonas gingivalis (P. gingivalis) lipopolysaccharide (LPS). RT-PCR and Western blotting analysis showed that the expression of C/EBP β was significantly increased in hPDLCs stimulated with LPS stimuli. Overexpression of C/EBP β by the recombinant adenoviral vector pAd/C/EBP β markedly increased the expression of the pro-inflammatory cytokines IL-6 and IL-8, and matrix metalloproteinases (MMP)-8 and -9 in hPDLCs in response to LPS. Furthermore, the activation of endoplasmic reticulum (ER) stress was confirmed in LPS-stimulated hPDLCs by measuring the expression of the ER stress marker molecules protein kinase-like ER kinase (PERK), eIF2α, GRP78/Bip, and C/EBP homologous protein (CHOP). The ER stress inhibitor salubrinal repressed, but inducer tunicamycin enhanced, the production of IL-6, IL-8, MMP-8, and MMP-9 in hPDLCs. Additionally, ER stress inducer tunicamycin significantly increased the expression level of C/EBP β in hPDLCs. Blocking of C/EBP β by siRNA resulted in a significant decrease in the secretion of IL-6 and IL-8 and expression of MMP-8 and MMP-9 induced by tunicamycin treatment in hPDLCs. Taken together, ER stress appears to play a regulatory role in the inflammatory response and extracellular matrix (ECM) degradation in hPDLCs in response to LPS stimuli by activating C/EBP β expression. This enhances our understanding of human periodontitis pathology. PMID:27011164

  9. Fluid shear stress regulates metalloproteinase-1 and 2 in human periodontal ligament cells: involvement of extracellular signal-regulated kinase (ERK) and P38 signaling pathways.

    PubMed

    Zheng, Lisha; Huang, Yan; Song, Wei; Gong, Xianghui; Liu, Meili; Jia, Xiaolin; Zhou, Gang; Chen, Luoping; Li, Ang; Fan, Yubo

    2012-09-21

    Matrix metalloproteinase (MMP)-1, 2, with their endogenous inhibitors, tissue inhibitor of metalloproteinase (TIMP)-1, 2 are critical for extracellular matrix remodeling in human periodontal ligament (PDL) and their expression are sensitive to mechanical stresses. Shear stress as the main type of mechanical stress in tooth movement is involved in matrix turnover. However, how shear stress regulates MMPs and TIMPs system is still unclear. In this study, we investigated the effect of fluid shear stress on expression of MMP-1, 2 and TIMP-1, 2 in human PDL cells and the possible roles of mitogen-activated protein kinases in this process. Three levels of fluid shear stresses (6, 9 and 12 dyn/cm(2)) were loaded on PDL cells for 2, 4, 8 and 12h. The results indicated that fluid shear stress rearranged cytoskeleton in PDL cells. Fluid shear stress increased expression of MMP-1, 2, TIMP-1 and suppressed TIMP-2 expression. MAP kinases including extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38 were activated rapidly by fluid shear stress. The ERK inhibitor blocked fluid shear stress induced MMP-1 expression and P38 inhibitor reduced fluid shear stress stimulated MMP-2 expression. Our study suggested that fluid shear stress involved in PDL remodeling via regulating MMP-1, 2 and TIMP-1, 2 expression. ERK regulated fluid shear stress induced MMP-1 expression and P38 play a role in fluid shear stress induced MMP-2 upregulation. PMID:22863019

  10. FGF-2 induces the proliferation of human periodontal ligament cells and modulates their osteoblastic phenotype by affecting Runx2 expression in the presence and absence of osteogenic inducers

    PubMed Central

    AN, SHAOFENG; HUANG, XIANGYA; GAO, YAN; LING, JUNQI; HUANG, YIHUA; XIAO, YIN

    2015-01-01

    The exact phenotype of human periodontal ligament cells (hPDLCs) remains a controversial area. Basic fibroblast growth factor (FGF-2) exhibits various functions and its effect on hPDLCs is also controversial. Therefore, the present study examined the effect of FGF-2 on the growth and osteoblastic phenotype of hPDLCs with or without osteogenic inducers (dexamethasone and β-glycerophosphate). FGF-2 was added to defined growth culture medium and osteogenic inductive culture medium. Cell proliferation, osteogenic differentiation and mineralization were measured. The selected differentiation markers, Runx2, collagen type I, α1 (Col1a1), osteocalcin (OCN) and epidermal growth factor receptor (EGFR), were investigated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Runx2 and OCN protein expression was measured by western blotting. FGF-2 significantly increased the proliferation of hPDLCs, but did not affect alkaline phosphatase activity. RT-qPCR analysis revealed enhanced mRNA expression of Runx2, OCN and EGFR, but suppressed Col1a1 gene expression in the absence of osteogenic inducers, whereas all these gene levels had no clear trend in their presence. The Runx2 protein expression was clearly increased, but the OCN protein level showed no evident trend. The mineralization assay demonstrated that FGF-2 inhibited mineralized matrix deposition with osteogenic inducers. These results suggested that FGF-2 induces the growth of immature hPDLCs, which is a competitive inhibitor of epithelial downgrowth, and suppresses their differentiation into mineralized tissue by affecting Runx2 expression. Therefore, this may lead to the acceleration of periodontal regeneration. PMID:26133673

  11. Effects of decellularized matrices derived from periodontal ligament stem cells and SHED on the adhesion, proliferation and osteogenic differentiation of human dental pulp stem cells in vitro.

    PubMed

    Heng, Boon Chin; Zhu, Shaoyue; Xu, Jianguang; Yuan, Changyong; Gong, Ting; Zhang, Chengfei

    2016-04-01

    A major bottleneck to the therapeutic applications of dental pulp stem cells (DPSC) are their limited proliferative capacity ex vivo and tendency to undergo senescence. This may be partly due to the sub-optimal in vitro culture milieu, which could be improved by an appropriate extracellular matrix substratum. This study therefore examined decellularized matrix (DECM) from stem cells derived from human exfoliated deciduous teeth (SHED) and periodontal ligament stem cells (PDLSC), as potential substrata for DPSC culture. Both SHED-DECM and PDLSC-DECM promoted rapid adhesion and spreading of newly-seeded DPSC compared to bare polystyrene (TCPS), with vinculin immunocytochemistry showing expression of more focal adhesions by newly-adherent DPSC cultured on DECM versus TCPS. Culture of DPSC on SHED-DECM and PDLSC-DECM yielded higher proliferation of cell numbers compared to TCPS. The qRT-PCR data showed significantly higher expression of nestin by DPSC cultured on DECM versus the TCPS control. Osteogenic differentiation of DPSC was enhanced by culturing on PDLSC-DECM and SHED-DECM versus TCPS, as demonstrated by alizarin red S staining for mineralized calcium deposition, alkaline phosphatase assay and qRT-PCR analysis of key osteogenic marker expression. Hence, both SHED-DECM and PDLSC-DECM could enhance the ex vivo culture of DPSC under both non-inducing and osteogenic-inducing conditions. PMID:26796232

  12. Production of polymeric micelles by microfluidic technology for combined drug delivery: application to osteogenic differentiation of human periodontal ligament mesenchymal stem cells (hPDLSCs).

    PubMed

    Capretto, L; Mazzitelli, S; Colombo, G; Piva, R; Penolazzi, L; Vecchiatini, R; Zhang, X; Nastruzzi, C

    2013-01-20

    The current paper reports the production of polymeric micelles (PMs), based on pluronic block-copolymers, as drug carriers, precisely controlling the cellular delivery of drugs with various physico-chemical characteristics. PMs were produced with a microfluidic platform to exploit further control on the size characteristic of the PMs. PMs were designed for the co-delivery of dexamethasone (Dex) and ascorbyl-palmitate (AP) to in vitro cultured human periodontal ligament mesenchymal stem cells (hPDLSCs) for the combined induction of osteogenic differentiation. Mixtures of block-copolymers and drugs in organic, water miscible solvent, were conveniently converted in PMs within microfluidic channel leveraging the fast mixing at the microscale. Our results demonstrated that the drugs can be efficiently co-encapsulated in PMs and that different production parameters can be adjusted in order to modulate the PM characteristics. The comparative analysis of PM produced by microfluidic and conventional procedures confirmed that the use of microfluidics platforms allowed the production of PMs in a robust manner with improved controllability, reproducibility, smaller size and polydispersity. Finally, the analysis of the effect of PMs, containing Dex and AP, on the osteogenic differentiation of hPDLSCs is reported. The data demonstrated the effectiveness and safety of PM treatment on hPDLSC. In conclusion, this report indicates that microfluidic approach represents an innovative and useful method for PM controlled preparation, warrant further evaluation as general methodology for the production of colloidal systems for the simultaneous drug delivery. PMID:22884778

  13. Biochemical markers of the periodontal ligament.

    PubMed

    Castro, Cecilia Estela; Koss, Myriam Adriana; López, María Elena

    2003-01-01

    For many years the diagnosis of Periodontal Disease has been based on clinical and radiographic methods. Other more recent methods have the objective of studying the inflammatory response of the host. That way, immunologic and biological methods determine the free mediators in the periodontal infection. The components of the gingivo-crevicular liquid or fluid are used to identify or to diagnose the active disease, to anticipate the risk of acquiring the disease and to determine its progress. For it to be clinically useful important changes should be registered the way a specific site turns active or that a previously disease affected site improves its conditions as a result of periodontal therapy. The response of the neutrophillic granulocytes play an important role in the detection of Periodontal Disease. The unspecific defense system in the gingivo-crevicular fluid can be determined through cytokines and/or interleukines that serve to identify sites at risk on the patient. In Periodontal Disease, the cytokines are not only defense mediators of the gingival sulcus fluid, but are also an indicator of tissue destruction. The liberation of high levels of lysosomal enzymes by neutrophils, proteolytic enzymes as the collagenases, or intercytoplasmatic enzymes as dehydrogenase lactate and aspartate amino transferase can equally help monitor the progress of the Periodontal Disease. PMID:14595256

  14. Transcriptome Reveals Cathepsin K in Periodontal Ligament Differentiation.

    PubMed

    Yamada, S; Ozaki, N; Tsushima, K; Yamaba, S; Fujihara, C; Awata, T; Sakashita, H; Kajikawa, T; Kitagaki, J; Yamashita, M; Yanagita, M; Murakami, S

    2016-08-01

    Periodontal ligaments (PDLs) play an important role in remodeling the alveolar bond and cementum. Characterization of the periodontal tissue transcriptome remains incomplete, and an improved understanding of PDL features could aid in developing new regenerative therapies. Here, we aimed to generate and analyze a large human PDL transcriptome. We obtained PDLs from orthodontic treatment patients, isolated the RNA, and used a vector-capping method to make a complementary DNA library from >20,000 clones. Our results revealed that 58% of the sequences were full length. Furthermore, our analysis showed that genes expressed at the highest frequencies included those for collagen type I, collagen type III, and proteases. We also found 5 genes whose expressions have not been previously reported in human PDL. To access which of the highly expressed genes might be important for PDL cell differentiation, we used real-time polymerase chain reaction to measure their expression in differentiating cells. Among the genes tested, the cysteine protease cathepsin K had the highest upregulation, so we measured its relative expression in several tissues, as well as in osteoclasts, which are known to express high levels of cathepsin K. Our results revealed that PDL cells express cathepsin K at similar levels as osteoclasts, which are both expressed at higher levels than those of the other tissues tested. We also measured cathepsin K protein expression and enzyme activity during cell differentiation and found that both increased during this process. Immunocytochemistry experiments revealed that cathepsin K localizes to the interior of lysosomes. Last, we examined the effect of inhibiting cathepsin K during cell differentiation and found that cathepsin K inhibition stimulated calcified nodule formation and increased the levels of collagen type I and osteocalcin gene expression. Based on these results, cathepsin K seems to regulate collagen fiber accumulation during human PDL cell

  15. Novel application of human periodontal ligament stem cells and water-soluble chitin for collagen tissue regeneration: in vitro and in vivo investigations.

    PubMed

    Jung, Im Hee; Park, Jung Chul; Kim, Jane C; Jeon, Dong Won; Choi, Seong Ho; Cho, Kyoo Sung; Im, Gun Il; Kim, Byung Soo; Kim, Chang Sung

    2012-03-01

    Human periodontal ligament stem cells (hPDLSCs) have been proposed as an alternative to conventional cosmetic fillers because they display an innate ability to synthesize collagen. The aims of this study were to determine the effects of water-soluble chitin (WSC) on the proliferation and migration of hPDLSCs, and to quantify collagen synthesis in vitro and in vivo compared with human adipose-derived stem cell (hADSC)s. hPDLSCs were isolated from healthy extracted teeth, and the cell proliferation and cell migration capacities of untreated hPDLSCs (control group) and WSC-treated hPDLSCs (test group) were compared. Insoluble/soluble collagen synthesis were also assessed, and collagen related markers were evaluated including lysyl oxidase (LOX), lysyl oxidase like (LOXL)1, LOXL2, and hydroxyproline. In vivo collagen formation was examined by transplanting hyaluronic acid as a cell carrier into the subcutaneous pockets of immunocompromised mice in the control and test groups; histology and immunohistochemistry analyses were performed 4 (n=4) and 8 (n=4) weeks later. There was a dose-dependent enhancement of hPDLSCs proliferation in the test group, and a concomitant reduction in cell migration. The amount of insoluble collagen formed was greater in the test group than in the control group (p<0.05), whereas soluble collagen formation was significantly reduced in the test group (p<0.05). The histology and immunohistochemistry results revealed that the amount of collagen formed in vivo was greater in WSC-treated hPDLSCs than in the control cells at 4 and 8 weeks (p<0.05), and histometric analysis at 8 weeks revealed that enhancement of collagen formation by hPDLSCs was greater than by hADSCs. These results indicate that WSC modulates the properties of hPDLSCs, rendering them more suitable for cosmetic soft-tissue augmentation. PMID:21981356

  16. Characterization of the Enhanced Bone Regenerative Capacity of Human Periodontal Ligament Stem Cells Engineered to Express the Gene Encoding Bone Morphogenetic Protein 2

    PubMed Central

    Jung, Im-Hee; Lee, Si-Ho; Jun, Choong-Man; Oh, Namsik

    2014-01-01

    Human periodontal ligament stem cells (hPDLSCs) are considered an appropriate cell source for therapeutic strategies. The aims of this study were to investigate the sustainability of bone morphogenetic protein 2 (BMP2) secretion and the bone regenerative capacity of hPDLSCs that had been genetically modified to express the gene encoding BMP2 (BMP2). hPDLSCs isolated from healthy third molars were transduced using replication-deficient recombinant adenovirus (rAd) encoding BMP2 (hPDLSCs/rAd-BMP2), and the cellular characteristics and osteogenic potentials of hPDLSCs/rAd-BMP2 were analyzed both in vitro and in vivo. hPDLSCs/rAd-BMP2 successfully secreted BMP2, formed colonies, and expressed immunophenotypes similar to their nontransduced counterparts. As to their osteogenic potential, hPDLSCs/rAd-BMP2 formed greater mineralized nodules and exhibited significantly higher levels of expression of BMP2 and the gene encoding alkaline phosphatase, and formed more and better quality bone than other hPDLSC-containing or recombinant human BMP2-treated groups, being localized at the initial site until 8 weeks. The findings of the present study demonstrate that hPDLSCs/rAd-BMP2 effectively promote osteogenesis not only in vitro but also in vivo. The findings also suggest that hPDLSCs can efficiently carry and deliver BMP2, and that hPDLSCs/rAd-BMP2 could be used in an attractive novel therapeutic approach for the regeneration of deteriorated bony defects. PMID:24494708

  17. The effect of the coumarin-like derivative osthole on the osteogenic properties of human periodontal ligament and jaw bone marrow mesenchymal stem cell sheets.

    PubMed

    Gao, Li-Na; An, Ying; Lei, Ming; Li, Bei; Yang, Hao; Lu, Hong; Chen, Fa-Ming; Jin, Yan

    2013-12-01

    Cell sheet engineering is a scaffold-free delivery concept that has been shown to improve mesenchymal stem cell-mediated regeneration of injured or pathologically damaged periodontal tissues in preclinical studies and several clinical trials. However, the best strategy for cell sheet production remains to be identified. The aim of this study was to investigate the biological effects of osthole, a coumarin-like derivative extracted from Chinese herbs, on the cell sheet formation and osteogenic properties of human periodontal ligament stem cells (PDLSCs) and jaw bone marrow mesenchymal stem cells (JBMMSCs). Patient-matched PDLSCs and JBMMSCs were isolated, and an appropriate concentration of osthole for cell culture was screened for both cell types in terms of cell proliferation and alkaline phosphatase (ALP) activity. Next, the best mode of osthole stimulation for inducing the formation of sheets by each cell type was selected by evaluating the amount of their extracellular matrix (ECM) protein production as well as osteogenic-related gene expression. Furthermore, both PDLSC and JBMMSC sheets obtained from each optimized technique were transplanted subcutaneously into nude mice to evaluate their capacity for ectopic bone regeneration. The results revealed that 10(-5) m/L osthole significantly enhanced the proliferation of both PDLSCs and JBMMSCs (P < 0.05), although for JBMMSCs, there was no concentration-related change among the four established osthole groups (P > 0.05). In addition, 10(-5) m/L osthole was the best concentration to promote the ALP activities of both cells (P < 0.01). Based on both the production of ECM proteins (collagen type I, integrin β1, and fibronectin) and the expression of osteogenic genes (ALP, Runt-related transcription factor 2 (RUNX2), and osteocalcin (OCN)), the provision of 10(-5) m/L osthole throughout the entire culture stage (10 days) for PDLSCs or at the early stage (first 3 days) for JBMMSCs was the most effective osthole

  18. Preparation of the fast setting and degrading Ca-Si-Mg cement with both odontogenesis and angiogenesis differentiation of human periodontal ligament cells.

    PubMed

    Chen, Yi-Wen; Hsu, Tuan-Ti; Wang, Kan; Shie, Ming-You

    2016-03-01

    Develop a fast setting and controllable degrading magnesium-calcium silicate cement (Mg-CS) by sol-gel, and establish a mechanism using Mg ions to stimulate human periodontal ligament cells (hPDLs) are two purposes of this study. We have used the diametral tensile strength measurement to obtain the mechanical strength and stability of Mg-CS cement; in addition, the cement degradation properties is realized by measuring the releasing amount of Si and Mg ions in the simulated body fluid. The other cell characteristics of hPDLs, such as proliferation, differentiation and mineralization were examined while hPDLs were cultured on specimen surfaces. This study found out the degradation rate of Mg-CS cements depends on the Mg content in CS. Regarding in vitro bioactivity; the CS cements were covered with abundant clusters of apatite spherulites after immersion of 24h, while less apatite spherulites were formatted on the Mg-rich cement surfaces. In addition, the authors also explored the effects of Mg ions on the odontogenesis and angiogenesis differentiation of hPDLs in comparison with CS cement. The proliferation, alkaline phosphatase, odontogenesis-related genes (DSPP and DMP-1), and angiogenesis-related protein (vWF and ang-1) secretion of hPDLs were significantly stimulated when the Mg content of the specimen was increased. The results in this study suggest that Mg-CS materials with this modified composition could stimulate hPDLs behavior and can be good bioceramics for bone substitutes and hard tissue regeneration applications as they stimulate odontogenesis/angiogenesis. PMID:26706543

  19. Trial analysis of swine's periodontal ligament with Bragg grating sensors

    NASA Astrophysics Data System (ADS)

    Menegotto, G. F.; Grabarski, L.; Kalinowski, H. J.; Simões, J. A.

    2009-10-01

    In this work it is reported the measurement of the differential strain between the dental and bone tissues under effect of an applied load. Slices of swine mandible, containing the premolar tooth, are cut and measured in fresh condition. The strain is measured using fibre Bragg grating sensors glued to both tissues. In the measured range the results show a linear behaviour and confirm the importance of the periodontal ligament in the load transfer mechanism.

  20. Effects of Shock Waves on Expression of IL-6, IL-8, MCP-1, and TNF-α Expression by Human Periodontal Ligament Fibroblasts: An In Vitro Study.

    PubMed

    Cai, Zhiyu; Falkensammer, Frank; Andrukhov, Oleh; Chen, Jiang; Mittermayr, Rainer; Rausch-Fan, Xiaohui

    2016-01-01

    BACKGROUND Extracorporeal shock wave therapy (ESWT) can modulate cell behavior through mechanical information transduction. Human periodontal ligament fibroblasts (hPDLF) are sensible to mechanical stimulus and can express pro-inflammatory molecules in response. The aim of this study was to evaluate the impacts of shock waves on interleukin-6 (IL-6), interleukin-8 (IL-8), monocyte chemotactic protein 1 (MCP-1), and tumor necrosis factor-alpha (TNF-α) expression by hPDLF. MATERIAL AND METHODS After being treated by shock waves with different parameters (100-500 times, 0.05-0.19 mJ/mm2), cell viability was tested using CCK-8. IL-6, IL-8, MCP-1, and TNF-α gene expression was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) and IL-6 and IL-8 protein was measured by enzyme-linked immunosorbent assay (ELISA) at different time points. RESULTS Shock waves with the parameters used in this study had no significant effects on the viability of hPDLF. A statistical inhibition of IL-6, IL-8, MCP-1, and TNF-α expression during the first few hours was observed (P<0.05). Expression of IL-8 was significantly elevated in the group receiving the most pulses of shock wave (500 times) after 4 h (P<0.05). At 8 h and 24 h, all treated groups demonstrated significantly enhanced IL-6 expression (P<0.05). TNF-α expression in the groups receiving more shock pulses (300, 500 times) or the highest energy shock treatment (0.19 mJ/mm2) was statistically decreased (P<0.05) at 24 h. CONCLUSIONS Under the condition of this study, a shock wave with energy density no higher than 0.19 mJ/mm2 and pulses no more than 500 times elicited no negative effects on cell viability of hPDLF. After a uniform initial inhibition impact on expression of inflammatory mediators, a shock wave could cause dose-related up-regulation of IL-6 and IL-8 and down-regulation of TNF-α. PMID:26994898

  1. Effects of Shock Waves on Expression of IL-6, IL-8, MCP-1, and TNF-α Expression by Human Periodontal Ligament Fibroblasts: An In Vitro Study

    PubMed Central

    Cai, Zhiyu; Falkensammer, Frank; Andrukhov, Oleh; Chen, Jiang; Mittermayr, Rainer; Rausch-Fan, Xiaohui

    2016-01-01

    Background Extracorporeal shock wave therapy (ESWT) can modulate cell behavior through mechanical information transduction. Human periodontal ligament fibroblasts (hPDLF) are sensible to mechanical stimulus and can express pro-inflammatory molecules in response. The aim of this study was to evaluate the impacts of shock waves on interleukin-6 (IL-6), interleukin-8 (IL-8), monocyte chemotactic protein 1 (MCP-1), and tumor necrosis factor-alpha (TNF-α) expression by hPDLF. Material/Methods After being treated by shock waves with different parameters (100–500 times, 0.05–0.19 mJ/mm2), cell viability was tested using CCK-8. IL-6, IL-8, MCP-1, and TNF-α gene expression was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) and IL-6 and IL-8 protein was measured by enzyme-linked immunosorbent assay (ELISA) at different time points. Results Shock waves with the parameters used in this study had no significant effects on the viability of hPDLF. A statistical inhibition of IL-6, IL-8, MCP-1, and TNF-α expression during the first few hours was observed (P<0.05). Expression of IL-8 was significantly elevated in the group receiving the most pulses of shock wave (500 times) after 4 h (P<0.05). At 8 h and 24 h, all treated groups demonstrated significantly enhanced IL-6 expression (P<0.05). TNF-α expression in the groups receiving more shock pulses (300, 500 times) or the highest energy shock treatment (0.19 mJ/mm2) was statistically decreased (P<0.05) at 24 h. Conclusions Under the condition of this study, a shock wave with energy density no higher than 0.19 mJ/mm2 and pulses no more than 500 times elicited no negative effects on cell viability of hPDLF. After a uniform initial inhibition impact on expression of inflammatory mediators, a shock wave could cause dose-related up-regulation of IL-6 and IL-8 and down-regulation of TNF-α. PMID:26994898

  2. Cytoskeletal binding proteins distinguish cultured dental follicle cells and periodontal ligament cells.

    PubMed

    Li, Jie; Li, Hui; Tian, Ye; Yang, Yaling; Chen, Guoqing; Guo, Weihua; Tian, Weidong

    2016-07-01

    Human dental follicle cells (DFCs) and periodontal ligament cells (PDLCs) derived from the ectomesenchymal tissue, have been shown to exhibit stem/progenitor cell properties and the ability to induce tissue regeneration. Stem cells in dental follicle differentiate into cementoblasts, periodontal ligament fibroblasts and osteoblasts, these cells form cementum, periodontal ligament and alveolar bone, respectively. While stem cells in dental follicle are a precursor to periodontal ligament fibroblasts, the molecular changes that distinguish cultured DFCs from PDLCs are still unknown. In this study, we have compared the immunophenotypic features and cell cycle status of the two cell lines. The results suggest that DFCs and PDLCs displayed similar features related to immunophenotype and cell cycle. Then we employed an isobaric tag for relative and absolute quantitation (iTRAQ) proteomics strategy to reveal the molecular differences between the two cell types. A total of 2138 proteins were identified and 39 of these proteins were consistently differentially expressed between DFCs and PDLCs. Gene ontology analyses revealed that the protein subsets expressed higher in PDLCs were related to actin binding, cytoskeletal protein binding, and structural constituent of muscle. Upon validation by real-time PCR, western blotting, and immunofluorescence staining. Tropomyosin 1 (TPM1) and caldesmon 1 (CALD1) were expressed higher in PDLCs than in DFCs. Our results suggested that PDLCs display enhanced actin cytoskeletal dynamics relative to DFCs while DFCs may exhibit a more robust antioxidant defense ability relative to PDLCs. This study expands our knowledge of the cultured DFCs and PDLCs proteome and provides new insights into possible mechanisms responsible for the different biological features observed in each cell type. PMID:26708290

  3. A nonlinear poroelastic model for the periodontal ligament

    NASA Astrophysics Data System (ADS)

    Favino, Marco; Bourauel, Christoph; Krause, Rolf

    2016-05-01

    A coupled elastic-poroelastic model for the simulation of the PDL and the adjacent tooth is presented. A poroelastic constitutive material model for the periodontal ligament (PDL) is derived. The solid phase is modeled by means of a Fung material law, accounting for large displacements and strains. Numerical solutions are performed by means of a multigrid Newton method to solve the arising large nonlinear system. Finally, by means of numerical experiments, the biomechanical response of the PDL is studied. In particular, the effect of the hydraulic conductivity and of the mechanical parameters of a Fung potential is investigated in two realistic applications.

  4. Influence of nanotopography on periodontal ligament stem cell functions and cell sheet based periodontal regeneration

    PubMed Central

    Gao, Hui; Li, Bei; Zhao, Lingzhou; Jin, Yan

    2015-01-01

    Periodontal regeneration is an important part of regenerative medicine, with great clinical significance; however, the effects of nanotopography on the functions of periodontal ligament (PDL) stem cells (PDLSCs) and on PDLSC sheet based periodontal regeneration have never been explored. Titania nanotubes (NTs) layered on titanium (Ti) provide a good platform to study this. In the current study, the influence of NTs of different tube size on the functions of PDLSCs was observed. Afterward, an ectopic implantation model using a Ti/cell sheets/hydroxyapatite (HA) complex was applied to study the effect of the NTs on cell sheet based periodontal regeneration. The NTs were able to enhance the initial PDLSC adhesion and spread, as well as collagen secretion. With the Ti/cell sheets/HA complex model, it was demonstrated that the PDLSC sheets were capable of regenerating the PDL tissue, when combined with bone marrow mesenchymal stem cell (BMSC) sheets and HA, without the need for extra soluble chemical cues. Simultaneously, the NTs improved the periodontal regeneration result of the ectopically implanted Ti/cell sheets/HA complex, giving rise to functionally aligned collagen fiber bundles. Specifically, much denser collagen fibers, with abundant blood vessels as well as cementum-like tissue on the Ti surface, which well-resembled the structure of natural PDL, were observed in the NT5 and NT10 sample groups. Our study provides the first evidence that the nanotopographical cues obviously influence the functions of PDLSCs and improve the PDLSC sheet based periodontal regeneration size dependently, which provides new insight to the periodontal regeneration. The Ti/cell sheets/HA complex may constitute a good model to predict the effect of biomaterials on periodontal regeneration. PMID:26150714

  5. Biological Events in Periodontal Ligament and Alveolar Bone Associated with Application of Orthodontic Forces

    PubMed Central

    Feller, L.; Khammissa, R. A. G.; Schechter, I.; Thomadakis, G.; Fourie, J.; Lemmer, J.

    2015-01-01

    Orthodontic force-induced stresses cause dynamic alterations within the extracellular matrix and within the cytoskeleton of cells in the periodontal ligament and alveolar bone, mediating bone remodelling, ultimately enabling orthodontic tooth movement. In the periodontal ligament and alveolar bone, the mechanically induced tensile strains upregulate the expression of osteogenic genes resulting in bone formation, while mechanically induced compressive strains mediate predominantly catabolic tissue changes and bone resorption. In this review article we summarize some of the currently known biological events occurring in the periodontal ligament and in the alveolar bone in response to application of orthodontic forces and how these facilitate tooth movement. PMID:26421314

  6. A comparative study of the proliferation and osteogenic differentiation of human periodontal ligament cells cultured on β-TCP ceramics and demineralized bone matrix with or without osteogenic inducers in vitro.

    PubMed

    An, Shaofeng; Gao, Yan; Huang, Xiangya; Ling, Junqi; Liu, Zhaohui; Xiao, Yin

    2015-05-01

    The repair of bone defects that result from periodontal diseases remains a clinical challenge for periodontal therapy. β-tricalcium phosphate (β-TCP) ceramics are biodegradable inorganic bone substitutes with inorganic components that are similar to those of bone. Demineralized bone matrix (DBM) is an acid-extracted organic matrix derived from bone sources that consists of the collagen and matrix proteins of bone. A few studies have documented the effects of DBM on the proliferation and osteogenic differentiation of human periodontal ligament cells (hPDLCs). The aim of the present study was to investigate the effects of inorganic and organic elements of bone on the proliferation and osteogenic differentiation of hPDLCs using three-dimensional porous β-TCP ceramics and DBM with or without osteogenic inducers. Primary hPDLCs were isolated from human periodontal ligaments. The proliferation of the hPDLCs on the scaffolds in the growth culture medium was examined using a Cell-Counting kit-8 (CCK-8) and scanning electron microscopy (SEM). Alkaline phosphatase (ALP) activity and the osteogenic differentiation of the hPDLCs cultured on the β-TCP ceramics and DBM were examined in both the growth culture medium and osteogenic culture medium. Specific osteogenic differentiation markers were examined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). SEM images revealed that the cells on the β-TCP were spindle-shaped and much more spread out compared with the cells on the DBM surfaces. There were no significant differences observed in cell proliferation between the β-TCP ceramics and the DBM scaffolds. Compared with the cells that were cultured on β-TCP ceramics, the ALP activity, as well as the Runx2 and osteocalcin (OCN) mRNA levels in the hPDLCs cultured on DBM were significantly enhanced both in the growth culture medium and the osteogenic culture medium. The organic elements of bone may exhibit greater osteogenic differentiation effects

  7. Addition of BMP-2 or BMP-6 to dexamethasone, ascorbic acid, and β-glycerophosphate may not enhance osteogenic differentiation of human periodontal ligament cells.

    PubMed

    Khanna-Jain, Rashi; Agata, Hideki; Vuorinen, Annukka; Sándor, George K B; Suuronen, Riitta; Miettinen, Susanna

    2010-12-01

    This study was designed to investigate the potential merits of the combined use of bone morphogenetic protein (BMP)-2 or BMP-6 and osteogenic supplements (OS) [dexamethasone, ascorbic acid (AA), and β-glycerophosphate] on osteogenic differentiation of periodontal ligament cells (PDLCs). Osteogenic differentiation was evaluated by quantitative alkaline phosphatase (ALP) assay, alizarin red staining, quantitative calcium assay, and the qRT-PCR analysis for the expression of collagen type I, runt-related transcription factor-2, osteopontin (OPN), and osteocalcin in PDLCs. Culture with BMP-2 or BMP-6+AA increased ALP activity of PDLCs, suggesting their osteo-inductive effects. However, longer duration of culture showed neither of the BMPs induced in vitro mineralization. In contrast, OS were able to increase ALP activity and OPN expressions, and also induced in vitro mineralization. The mineralization ability was not enhanced by the addition of BMP-2 or BMP-6. These findings suggest that the addition of BMP-2 or BMP-6 to OS may not enhance an osteogenic differentiation of hPDLCs. PMID:20569096

  8. Effects of Plants on Osteogenic Differentiation and Mineralization of Periodontal Ligament Cells: A Systematic Review.

    PubMed

    Costa, Cláudio Rodrigues Rezende; Amorim, Bruna Rabelo; de Magalhães, Pérola; De Luca Canto, Graziela; Acevedo, Ana Carolina; Guerra, Eliete Neves Silva

    2016-04-01

    This systematic review aimed to evaluate the effects of plants on osteogenic differentiation and mineralization of human periodontal ligament cells. The included studies were selected using five different electronic databases. The reference list of the included studies was crosschecked, and a partial gray literature search was undertaken using Google Scholar and ProQuest. The methodology of the selected studies was evaluated using GRADE. After a two-step selection process, eight studies were identified. Six different types of plants were reported in the selected studies, which were Morinda citrifolia, Aloe vera, Fructus cnidii, Zanthoxylum schinifolium, Centella asiatica, and Epimedium species. They included five types of isolated plant components: acemannan, osthole, hesperetin, asiaticoside, and icariin. In addition, some active substances of these components were identified as polysaccharides, coumarins, flavonoids, and triterpenes. The studies demonstrated the potential effects of plants on osteogenic differentiation, cell proliferation, mineral deposition, and gene and protein expression. Four studies showed that periodontal ligament cells induce mineral deposition after plant treatment. Although there are few studies on the subject, current evidence suggests that plants are potentially useful for the treatment of periodontal diseases. However, further investigations are required to confirm the promising effect of these plants in regenerative treatments. PMID:26822584

  9. LPS from P. gingivalis and Hypoxia Increases Oxidative Stress in Periodontal Ligament Fibroblasts and Contributes to Periodontitis

    PubMed Central

    Gölz, L.; Memmert, S.; Rath-Deschner, B.; Jäger, A.; Appel, T.; Baumgarten, G.; Götz, W.; Frede, S.

    2014-01-01

    Oxidative stress is characterized by an accumulation of reactive oxygen species (ROS) and plays a key role in the progression of inflammatory diseases. We hypothesize that hypoxic and inflammatory events induce oxidative stress in the periodontal ligament (PDL) by activating NOX4. Human primary PDL fibroblasts were stimulated with lipopolysaccharide from Porphyromonas gingivalis (LPS-PG), a periodontal pathogen bacterium under normoxic and hypoxic conditions. By quantitative PCR, immunoblot, immunostaining, and a specific ROS assay we determined the amount of NOX4, ROS, and several redox systems. Healthy and inflamed periodontal tissues were collected to evaluate NOX4 and redox systems by immunohistochemistry. We found significantly increased NOX4 levels after hypoxic or inflammatory stimulation in PDL cells (P < 0.001) which was even more pronounced after combination of the stimuli. This was accompanied by a significant upregulation of ROS and catalase (P < 0.001). However, prolonged incubation with both stimuli induced a reduction of catalase indicating a collapse of the protective machinery favoring ROS increase and the progression of inflammatory oral diseases. Analysis of inflamed tissues confirmed our hypothesis. In conclusion, we demonstrated that the interplay of NOX4 and redox systems is crucial for ROS formation which plays a pivotal role during oral diseases. PMID:25374447

  10. Cytological Kinetics of Periodontal Ligament in an Experimental Occlusal Trauma Model

    PubMed Central

    Takaya, Tatsuo; Mimura, Hiroaki; Matsuda, Saeka; Nakano, Keisuke; Tsujigiwa, Hidetsugu; Tomida, Mihoko; Okafuji, Norimasa; Fujii, Takeo; Kawakami, Toshiyuki

    2015-01-01

    Using a model of experimental occlusal trauma in mice, we investigated cytological kinetics of periodontal ligament by means of histopathological, immunohistochemical, and photographical analysis methods. Periodontal ligament cells at furcation areas of molar teeth in the experimental group on day 4 showed a proliferation tendency of periodontal ligament cells. The cells with a round-shaped nucleus deeply stained the hematoxylin and increased within the day 4 specimens. Ki67 positive nuclei showed a prominent increase in the group on days 4 and 7. Green Fluorescent Protein (GFP) positivity also revealed cell movement but was slightly slow compared to Ki67. It indicated that restoration of mechanism seemed conspicuous by osteoclasts and macrophages from bone-marrow-derived cells for the periodontal ligament at the furcation area. It was suggested that the remodeling of periodontal ligament with cell acceleration was evoked from the experiment for the group on day 4 and after day 7. Periodontal ligament at the furcation area of the molar teeth in this experimental model recovered using the cells in situ and the bone-marrow-derived cells. PMID:26180510

  11. Advanced glycation end products (AGEs) and their receptor (RAGE) induce apoptosis of periodontal ligament fibroblasts

    PubMed Central

    Li, D.X.; Deng, T.Z.; Lv, J.; Ke, J.

    2014-01-01

    Diabetics have an increased prevalence of periodontitis, and diabetes is one of the causative factors of severe periodontitis. Apoptosis is thought to be involved in this pathogenic relationship. The aim of this study was to investigate apoptosis in human periodontal ligament (PDL) fibroblasts induced by advanced glycation end products (AGEs) and their receptor (RAGE). We examined the roles of apoptosis, AGEs, and RAGE during periodontitis in diabetes mellitus using cultured PDL fibroblasts that were treated by AGE-modified bovine serum albumin (AGE-BSA), bovine serum albumin (BSA) alone, or given no treatment (control). Microscopy and real-time quantitative PCR indicated that PDL fibroblasts treated with AGE-BSA were deformed and expressed higher levels of RAGE and caspase 3. Cell viability assays and flow cytometry indicated that AGE-BSA reduced cell viability (69.80±5.50%, P<0.01) and increased apoptosis (11.31±1.73%, P<0.05). Hoechst 33258 staining and terminal-deoxynucleotidyl transferase-mediated nick-end labeling revealed that AGE-BSA significantly increased apoptosis of PDL fibroblasts. The results showed that the changes in PDL fibroblasts induced by AGE-BSA may explain how AGE-RAGE participates in and exacerbates periodontium destruction. PMID:25387669

  12. Advanced glycation end products (AGEs) and their receptor (RAGE) induce apoptosis of periodontal ligament fibroblasts.

    PubMed

    Li, D X; Deng, T Z; Lv, J; Ke, J

    2014-12-01

    Diabetics have an increased prevalence of periodontitis, and diabetes is one of the causative factors of severe periodontitis. Apoptosis is thought to be involved in this pathogenic relationship. The aim of this study was to investigate apoptosis in human periodontal ligament (PDL) fibroblasts induced by advanced glycation end products (AGEs) and their receptor (RAGE). We examined the roles of apoptosis, AGEs, and RAGE during periodontitis in diabetes mellitus using cultured PDL fibroblasts that were treated by AGE-modified bovine serum albumin (AGE-BSA), bovine serum albumin (BSA) alone, or given no treatment (control). Microscopy and real-time quantitative PCR indicated that PDL fibroblasts treated with AGE-BSA were deformed and expressed higher levels of RAGE and caspase 3. Cell viability assays and flow cytometry indicated that AGE-BSA reduced cell viability (69.80 ± 5.50%, P<0.01) and increased apoptosis (11.31 ± 1.73%, P<0.05). Hoechst 33258 staining and terminal-deoxynucleotidyl transferase-mediated nick-end labeling revealed that AGE-BSA significantly increased apoptosis of PDL fibroblasts. The results showed that the changes in PDL fibroblasts induced by AGE-BSA may explain how AGE-RAGE participates in and exacerbates periodontium destruction. PMID:25387669

  13. Advanced glycation end products (AGEs) and their receptor (RAGE) induce apoptosis of periodontal ligament fibroblasts.

    PubMed

    Li, D X; Deng, T Z; Lv, J; Ke, J

    2014-09-19

    Diabetics have an increased prevalence of periodontitis, and diabetes is one of the causative factors of severe periodontitis. Apoptosis is thought to be involved in this pathogenic relationship. The aim of this study was to investigate apoptosis in human periodontal ligament (PDL) fibroblasts induced by advanced glycation end products (AGEs) and their receptor (RAGE). We examined the roles of apoptosis, AGEs, and RAGE during periodontitis in diabetes mellitus using cultured PDL fibroblasts that were treated by AGE-modified bovine serum albumin (AGE-BSA), bovine serum albumin (BSA) alone, or given no treatment (control). Microscopy and real-time quantitative PCR indicated that PDL fibroblasts treated with AGE-BSA were deformed and expressed higher levels of RAGE and caspase 3. Cell viability assays and flow cytometry indicated that AGE-BSA reduced cell viability (69.80±5.50%, P<0.01) and increased apoptosis (11.31±1.73%, P<0.05). Hoechst 33258 staining and terminal-deoxynucleotidyl transferase-mediated nick-end labeling revealed that AGE-BSA significantly increased apoptosis of PDL fibroblasts. The results showed that the changes in PDL fibroblasts induced by AGE-BSA may explain how AGE-RAGE participates in and exacerbates periodontium destruction. PMID:25250588

  14. Proinflammatory Cytokines Regulate Cementogenic Differentiation of Periodontal Ligament Cells by Wnt/Ca(2+) Signaling Pathway.

    PubMed

    Han, Pingping; Lloyd, Tain; Chen, Zetao; Xiao, Yin

    2016-05-01

    Periodontal inflammation can inhibit cell differentiation of periodontal ligament cells (PDLCs), resulting in decreased bone/cementum regeneration ability. The Wnt signaling pathway, including canonical Wnt/β-catenin signaling and noncanonical Wnt/Ca(2+) signaling, plays essential roles in cell proliferation and differentiation during tooth development. However, little is still known whether noncanonical Wnt/Ca(2+) signaling cascade could regulate cementogenic/osteogenic differentiation capability of PDLCs within an inflammatory environment. Therefore, in this study, human PDLCs (hPDLCs) and their cementogenic differentiation potential were investigated in the presence of cytokines. The data demonstrated that both cytokines interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) inhibited cell proliferation, relative alkaline phosphatase activity, bone/cementum-related gene/protein expression, and canonical Wnt pathway-related gene/protein expression in hPDLCs. Interestingly, both cytokines upregulated the noncanonical Wnt/Ca(2+) signaling-related gene and protein expression in hPDLCs. When the Wnt/Ca(2+) pathway was blocked by Ca(2+)/calmodulin-dependent protein kinase II inhibitor KN93, even in the presence of IL-6 and TNF-α, cementogenesis could be stimulated in hPDLCs. Our data indicate that the Wnt/Ca(2+) pathway plays an inhibitory role on PDLC cementogenic differentiation in inflammatory microenvironments. Therefore, targeting the Wnt/Ca(2+) pathway may provide a novel therapeutic approach to improve periodontal regeneration for periodontal diseases. PMID:27074616

  15. A histological and electron-microscopic study of the architecture and ultrastructure of human periodontal tissues.

    PubMed

    Raspanti, M; Cesari, C; De Pasquale, V; Ottani, V; Strocchi, R; Zucchelli, G; Ruggeri, A

    2000-03-01

    The structure of periodontal tissues is still far less understood than their clinical relevance would demand. Here the periodontal ligament and radicular cementum in healthy human teeth were studied by light microscopy, transmission and scanning electron microscopy. These observations showed that the extracellular matrix of periodontal ligament is composed of a loose plexus of wavy collagen fibrils immersed in a highly hydrated interfibrillar matrix. Only close to their cemental insertion do these fibrils gather in thick, parallel fascicles (Sharpey's fibres). As these cross the mineralization front, they become infiltrated by the mineral phase and continue directly with the cementum matrix. Sharpey's fibres, "extrinsic" and "intrinsic" fibres all appear to be the same fibres, which bend and branch repeatedly during their course within the thickness of the cementum. Because of its physical continuity with the cementum, a limited portion of the periodontal ligament approximately corresponding to the length of Sharpey's fibres remains unaffected by enzymatic digestion of the interfibrillar matrix while the rest of the ligament is completely dissolved. The findings here indicate that the periodontal ligament and dental cementum join by a continuity rather than a contiguity of structures; that the collagen-mineral relation in cementum has distinctive features in comparison to other hard tissues; that extrinsic and intrinsic fibres of cementum and the adjoining portion of periodontal ligament form a structural, mechanical and metabolic unit distinct from the central, more metabolically active portion of the periodontal ligament. PMID:10761871

  16. The use of platelet-rich fibrin combined with periodontal ligament and jaw bone mesenchymal stem cell sheets for periodontal tissue engineering

    PubMed Central

    Wang, Zhong-Shan; Feng, Zhi-Hong; Wu, Guo-Feng; Bai, Shi-Zhu; Dong, Yan; Chen, Fa-Ming; Zhao, Yi-Min

    2016-01-01

    Periodontal regeneration involves the restoration of at least three unique tissues: cementum, periodontal ligament tissue (PDL) and alveolar bone tissue. Here, we first isolated human PDL stem cells (PDLSCs) and jaw bone mesenchymal stem cells (JBMSCs). These cells were then induced to form cell sheets using an ascorbic acid-rich approach, and the cell sheet properties, including morphology, thickness and gene expression profile, were compared. Platelet-rich fibrin (PRF) derived from human venous blood was then fabricated into bioabsorbable fibrin scaffolds containing various growth factors. Finally, the in vivo potential of a cell-material construct based on PDLSC sheets, PRF scaffolds and JBMSC sheets to form periodontal tissue was assessed in a nude mouse model. In this model, PDLSC sheet/PRF/JBMSC sheet composites were placed in a simulated periodontal space comprising human treated dentin matrix (TDM) and hydroxyapatite (HA)/tricalcium phosphate (TCP) frameworks. Eight weeks after implantation, the PDLSC sheets tended to develop into PDL-like tissues, while the JBMSC sheets tended to produce predominantly bone-like tissues. In addition, the PDLSC sheet/PRF/JBMSC sheet composites generated periodontal tissue-like structures containing PDL- and bone-like tissues. Further improvements in this cell transplantation design may have the potential to provide an effective approach for future periodontal tissue regeneration. PMID:27324079

  17. The use of platelet-rich fibrin combined with periodontal ligament and jaw bone mesenchymal stem cell sheets for periodontal tissue engineering.

    PubMed

    Wang, Zhong-Shan; Feng, Zhi-Hong; Wu, Guo-Feng; Bai, Shi-Zhu; Dong, Yan; Chen, Fa-Ming; Zhao, Yi-Min

    2016-01-01

    Periodontal regeneration involves the restoration of at least three unique tissues: cementum, periodontal ligament tissue (PDL) and alveolar bone tissue. Here, we first isolated human PDL stem cells (PDLSCs) and jaw bone mesenchymal stem cells (JBMSCs). These cells were then induced to form cell sheets using an ascorbic acid-rich approach, and the cell sheet properties, including morphology, thickness and gene expression profile, were compared. Platelet-rich fibrin (PRF) derived from human venous blood was then fabricated into bioabsorbable fibrin scaffolds containing various growth factors. Finally, the in vivo potential of a cell-material construct based on PDLSC sheets, PRF scaffolds and JBMSC sheets to form periodontal tissue was assessed in a nude mouse model. In this model, PDLSC sheet/PRF/JBMSC sheet composites were placed in a simulated periodontal space comprising human treated dentin matrix (TDM) and hydroxyapatite (HA)/tricalcium phosphate (TCP) frameworks. Eight weeks after implantation, the PDLSC sheets tended to develop into PDL-like tissues, while the JBMSC sheets tended to produce predominantly bone-like tissues. In addition, the PDLSC sheet/PRF/JBMSC sheet composites generated periodontal tissue-like structures containing PDL- and bone-like tissues. Further improvements in this cell transplantation design may have the potential to provide an effective approach for future periodontal tissue regeneration. PMID:27324079

  18. [Survival rate of periodontal ligament cells after extraoral storage in different media].

    PubMed

    Pongsiri, S; Schlegel, D; Zimmermann, M

    1990-01-01

    In this study 380 freshly extracted anterior teeth and premolars were stored for periods of 30 to 360 min in different types of media subsequently the residual vitality of periodontal ligament cells was assessed by means of the fluorescein diacetate reaction. It was found that after 90 min of dry storage 88% of the periodontal cells were devitalized, whereas after 180 min of storage in saliva or normal saline solution the loss of vitality was 40% or, respectively, 37%. Stored in Alpha MEM or UHT milk for 360 min 48% or, respectively, 49% of the periodontal ligament cells showed vital reaction. PMID:2135241

  19. Effect of storage media on the proliferation of periodontal ligament fibroblasts

    SciTech Connect

    Lauer, H.C.; Mueller, J.G.; Gross, J.; Horster, M.F.

    1987-07-01

    The effect of storage media, which are routinely used in replantation, upon the proliferative capacity of periodontal ligament fibroblasts, was compared with the effect of a tissue culture medium. The periodontal tissue was obtained from mandibular central incisors of White New Zealand rabbits. The experiments were performed in fibroblasts derived during second subculture. The storage media were physiologic salt solution, Ringer's solution and Rivanol; the tissue culture medium was alpha-minimum essential medium without nucleosides. The incubation period was 1 hour. (/sup 3/H)-thymidine incorporation and cell counts were taken to indicate changes in the proliferative capacity of the fibroblasts. The tissue culture experiments showed that the proliferative ability of the periodontal ligament fibroblasts was dependent upon the composition of the storage medium. Physiologic salt solution, Ringer's solution and Rivanol were unable to maintain the metabolism of the fibroblasts. alpha-MEM medium, however, was capable of stimulating proliferation of the periodontal ligament fibroblasts.

  20. Regulation of Periodontal Ligament Cell Functions by Interleukin-1β

    PubMed Central

    Agarwal, Sudha; Chandra, Charu S.; Piesco, Nicholas P.; Langkamp, Herman H.; Bowen, Lathe; Baran, Coskun

    1998-01-01

    Periodontal ligament (PDL) cells maintain the attachment of the tooth to alveolar bone. These cells reside at a site in which they are challenged frequently by bacterial products and proinflammatory cytokines, such as interleukin-1β (IL-1β), during infections. In our initial studies we observed that IL-1β down-regulates the osteoblast-like characteristics of PDL cells in vitro. Therefore, we examined the functional significance of the loss of the PDL cell’s osteoblast-like characteristics during inflammation. In this report we show that, during inflammation, IL-1β can modulate the phenotypic characteristics of PDL cells to a more functionally significant lipopolysaccharide (LPS)-responsive phenotype. In a healthy periodontium PDL cells exhibit an osteoblast-like phenotype and are unresponsive to gram-negative bacterial LPS. Treatment of PDL cells with IL-1β inhibits the expression of their osteoblast-like characteristics, as assessed by the failure to express transforming growth factor β1 (TGF-β1) and proteins associated with mineralization, such as alkaline phosphatase and osteocalcin. As a consequence of this IL-1β-induced phenotypic change, PDL cells become responsive to LPS and synthesize proinflammatory cytokines. The IL-1β-induced phenotypic changes in PDL cells were transient, as removal of IL-1β from PDL cell cultures resulted in reacquisition of their osteoblast-like characteristics and lack of LPS responsiveness. The IL-1β-induced phenotypic changes occurred at concentrations that are frequently observed in tissue exudates during periodontal inflammation (0.05 to 5 ng/ml). The results suggest that, during inflammation in vivo, IL-1β may modulate PDL cell functions, allowing PDL cells to participate directly in the disease process by assuming LPS responsiveness at the expense of their normal structural properties and functions. PMID:9488378

  1. Mechano-regulation of Collagen Biosynthesis in Periodontal Ligament

    PubMed Central

    Kaku, Masaru; Yamauchi, Mitsuo

    2014-01-01

    Purpose Periodontal ligament (PDL) plays critical roles in the development and maintenance of periodontium such as tooth eruption and dissipation of masticatory force. The mechanical properties of PDL are mainly derived from fibrillar type I collagen, the most abundant extracellular component. Study selection The biosynthesis of type I collagen is a long, complex process including a number of intra- and extracellular post-translational modifications. The final modification step is the formation of covalent intra- and intermolecular cross-links that provide collagen fibrils with stability and connectivity. Results It is now clear that collagen post-translational modifications are regulated by groups of specific enzymes and associated molecules in a tissue-specific manner; and these modifications appear to change in response to mechanical force. Conclusions This review focuses on the effect of mechanical loading on collagen biosynthesis and fibrillogenesis in PDL with emphasis on the post-translational modifications of collagens, which is an important molecular aspect to understand in the field of prosthetic dentistry. PMID:25311991

  2. [Autotransplants instead of implants? The secret of the periodontal ligament].

    PubMed

    Barendregt, D S; Leunisse, M

    2015-11-01

    Autotransplants are often applied in the Scandinavian countries. The indication for treatment concerns especially young patients for whom teeth with open apices are moved to areas with ageneses. The great advantage is the vital periodontal ligament, by means of which these teeth are able to grow along. In Rotterdam, during the past 11 years, transplants of teeth with fully developed apices have been carried out in cases with comparable indications. Over short and long periods of time, the results have been the same as those in the published findings in the literature. The fully developed apices appear to be just as successful as the open apices. The difference with the results in the research literature concerns the indications for transplantation in particular. These are not limited to the molar region. Within the same indication, the results are better by comparison with the implants, in both the transplants with open and with closed apices. On the basis of these results, autotransplants in dentistry have become an indication for every age group and when possible, a better treatment option than implants. PMID:26569000

  3. Dental trauma involving root fracture and periodontal ligament injury: a 10-year retrospective study.

    PubMed

    Panzarini, Sônia Regina; Pedrini, Denise; Poi, Wilson Roberto; Sonoda, Celso Koogi; Brandini, Daniela Atili; Monteiro de Castro, José Carlos

    2008-01-01

    The purpose of this retrospective study was to analyze the cases of traumatic dental injuries involving root fracture and/or periodontal ligament injury (except avulsion) treated at the Discipline of Integrated Clinic, School of Dentistry of Araçatuba, São Paulo State University (UNESP), Brazil, from January 1992 to December 2002. Clinical and radiographic records from 161 patients with 287 traumatized teeth that had sustained root fracture and/or injuries to the periodontal ligament were examined. The results of this survey revealed that subluxation (25.09%) was the most common type of periodontal ligament injury, followed by extrusive luxation (19.86%). There was a predominance of young male patients and most of them did not present systemic alterations. Among the etiologic factors, the most frequent causes were falls and bicycle accidents. Injuries on extraoral soft tissues were mostly laceration and abrasion, while gingival and lip mucosa lacerations prevailed on intraoral soft tissues injuries. Radiographically, the most common finding was an increase of the periodontal ligament space. The most commonly performed treatment was root canal therapy. Within the limits of this study, it can be concluded that traumatic dental injuries occur more frequently in young male individuals, due to falls and bicycle accidents. Subluxation was the most common type of periodontal ligament injury. Root canal therapy was the type of treatment most commonly planned and performed. PMID:18949308

  4. Trophic factors from adipose tissue-derived multi-lineage progenitor cells promote cytodifferentiation of periodontal ligament cells

    SciTech Connect

    Sawada, Keigo; Takedachi, Masahide; Yamamoto, Satomi; Morimoto, Chiaki; Ozasa, Masao; Iwayama, Tomoaki; Lee, Chun Man; Okura, Hanayuki; Matsuyama, Akifumi; Kitamura, Masahiro; Murakami, Shinya

    2015-08-14

    Stem and progenitor cells are currently being investigated for their applicability in cell-based therapy for periodontal tissue regeneration. We recently demonstrated that the transplantation of adipose tissue-derived multi-lineage progenitor cells (ADMPCs) enhances periodontal tissue regeneration in beagle dogs. However, the molecular mechanisms by which transplanted ADMPCs induce periodontal tissue regeneration remain to be elucidated. In this study, trophic factors released by ADMPCs were examined for their paracrine effects on human periodontal ligament cell (HPDL) function. ADMPC conditioned medium (ADMPC-CM) up-regulated osteoblastic gene expression, alkaline phosphatase activity and calcified nodule formation in HPDLs, but did not significantly affect their proliferative response. ADMPCs secreted a number of growth factors, including insulin-like growth factor binding protein 6 (IGFBP6), hepatocyte growth factor and vascular endothelial growth factor. Among these, IGFBP6 was most highly expressed. Interestingly, the positive effects of ADMPC-CM on HPDL differentiation were significantly suppressed by transfecting ADMPCs with IGFBP6 siRNA. Our results suggest that ADMPCs transplanted into a defect in periodontal tissue release trophic factors that can stimulate the differentiation of HPDLs to mineralized tissue-forming cells, such as osteoblasts and cementoblasts. IGFBP6 may play crucial roles in ADMPC-induced periodontal regeneration. - Highlights: • ADMPC-derived humoral factors stimulate cytodifferentiation of HPDLs. • ADMPCs secret growth factors including IGFBP6, VEGF and HGF. • IGFBP6 is involved in the promotion effect of ADMPC-CM on HPDL cytodifferentiation.

  5. Inclusion of the periodontal ligament in studies on the biomechanical behavior of fiber post-retained restorations: An in vitro study and three-dimensional finite element analysis.

    PubMed

    González-Lluch, Carmen; Rodríguez-Cervantes, Pablo-Jesús; Forner, Leopoldo; Barjau, Amaya

    2016-03-01

    Endodontically treated teeth are known to have reduced structural strength. Periodontal ligament may influence fracture resistance. The purpose of this study was to assess the influence of including the periodontal ligament in biomechanical studies about endodontically treated and restored teeth. Forty human maxillary central incisors were treated endodontically and randomly divided into four groups: non-crowned (with and without an artificial ligament) and crowned (with and without an artificial ligament) with glass-ceramic crowns. All groups received prefabricated glass-fiber posts and a composite resin core. Specimens were tested, under a flexural-compressive load, until failure occurred. The failure mode was registered for all specimens. The failure loads were recorded and analyzed using an analysis of variance test (p < 0.05). These results were compared with those predicted by a finite element model. The analysis of variance did not show significant differences between the use of crown on the failure load (p = 0.331) and the use of periodontal ligament (p = 0.185). A cohesive mode in crown appeared in crowned teeth and in core in non-crowned groups. For non-crowned teeth, adhesive failure occurred along the cement-enamel junction with a slight tendency in specimens without periodontal ligament. Furthermore, an unfavorable failure mode affects partially the root with no differences regarding non-crown specimens. In crowned teeth, the tendency was an adhesive failure along the cement-enamel junction. The model predicted a distribution of the safety factor consistent with these results. This study showed that inclusion of periodontal ligament is not particularly important on biomechanical behavior of post-retained restorations. However, we recommend its inclusion in fatigue studies. PMID:26893228

  6. COMP-Ang1 enhances DNA synthesis and cell cycle progression in human periodontal ligament cells via Tie2-mediated phosphorylation of PI3K/Akt and MAPKs.

    PubMed

    Lim, Shin-Saeng; Kook, Sung-Ho; Lee, Jeong-Chae

    2016-05-01

    Recombinant COMP-Ang1, a chimera of angiopoietin-1 (Ang1), and a short coiled-coil domain of cartilage oligomeric matrix protein (COMP) can stimulate multiple cellular processes. Proliferative capacity of periodontal ligament (PDL) fibroblasts (PLFs) is important for maintaining PDL integrity and homeostasis. In this study, we explored whether exogenous COMP-Ang1 addition enhances proliferation of human PLFs and the cellular mechanisms therein. We initially isolated and characterized PLFs, where the cells showed highly positive staining for surface markers, CD90, CD105, and CD146. COMP-Ang1 treatment increased proliferation of PLFs by stimulating migration of cells into S and G2/M phases. This increase was coupled with decreased p21(Cip) and p27(Kip) levels and enhanced cyclin D1, cyclin-dependent kinase (CDK) 2, and CDK4 induction. Transfection with si-Tie2 near completely blocked COMP-Ang1-stimulated cell cycle progression in PLFs. Tie2 knockdown also inhibited COMP-Ang1-induced phosphorylation of mitogen-activated protein kinases (MAPKs). In addition, COMP-Ang1-mediated activation of Akt and c-Jun was suppressed by treating each of pharmacological inhibitors specific to phosphoinositide 3-kinase (PI3K) (LY294002 and Wortmannin) or MAPKs (PD98059, SB203580, and SP600125). Similarly, COMP-Ang1-mediated increases in DNA synthesis and cyclin D1 induction were prevented by treating inhibitor of MAPKs and PI3K or by c-Jun knockdown. These results suggest that COMP-Ang1 enhances survival and proliferation of human PLFs through the activation of Tie2-mediated signaling, where PI3K/Akt and MAPK-c-Jun signaling pathways act as downstream effectors. Collectively, COMP-Ang1 may be a useful as a stimulator of human PLFs and therefore improves PDL integrity and homeostasis. PMID:27107990

  7. Force-induced Adrb2 in Periodontal Ligament Cells Promotes Tooth Movement

    PubMed Central

    Cao, H.; Kou, X.; Yang, R.; Liu, D.; Wang, X.; Song, Y.; Feng, L.; He, D.; Gan, Y.; Zhou, Y.

    2014-01-01

    The sympathetic nervous system (SNS) regulates bone resorption through β-2 adrenergic receptor (Adrb2). In orthodontic tooth movement (OTM), mechanical force induces and regulates alveolar bone remodeling. Compressive force-associated osteoclast differentiation and alveolar bone resorption are the rate-limiting steps of tooth movement. However, whether mechanical force can activate Adrb2 and thus contribute to OTM remains unknown. In this study, orthodontic nickel-titanium springs were applied to the upper first molars of rats and Adrb1/2-/- mice to confirm the role of SNS and Adrb2 in OTM. The results showed that blockage of SNS activity in the jawbones of rats by means of superior cervical ganglion ectomy reduced OTM distance from 860 to 540 μm after 14 d of force application. In addition, the injection of nonselective Adrb2 agonist isoproterenol activated the downstream signaling of SNS to accelerate OTM from 300 to 540 μm after 7 d of force application. Adrb1/2-/- mice showed significantly reduced OTM distance (19.5 μm) compared with the wild-type mice (107.6 μm) after 7 d of force application. Histopathologic analysis showed that the number of Adrb2-positive cells increased in the compressive region of periodontal ligament after orthodontic force was applied on rats. Mechanistically, mechanical compressive force upregulated Adrb2 expression in primary-cultured human periodontal ligament cells (PDLCs) through the elevation of intracellular Ca2+ concentration. Activation of Adrb2 in PDLCs increased the RANKL/OPG ratio and promoted the peripheral blood mononuclear cell differentiation to osteoclasts in the cocultured system. Upregulation of Adrb2 in PDLCs promoted osteoclastogenesis, which accelerated OTM through Adrb2-enhanced bone resorption. In summary, this study suggests that mechanical force-induced Adrb2 activation in PDLCs contributes to SNS-regulated OTM. PMID:25252876

  8. Bilayered construct for simultaneous regeneration of alveolar bone and periodontal ligament.

    PubMed

    Sundaram, M Nivedhitha; Sowmya, S; Deepthi, S; Bumgardener, Joel D; Jayakumar, R

    2016-05-01

    Periodontitis is an inflammatory disease that causes destruction of tooth-supporting tissues and if left untreated leads to tooth loss. Current treatments have shown limited potential for simultaneous regeneration of the tooth-supporting tissues. To recreate the complex architecture of the periodontium, we developed a bilayered construct consisting of poly(caprolactone) (PCL) multiscale electrospun membrane (to mimic and regenerate periodontal ligament, PDL) and a chitosan/2wt % CaSO4 scaffold (to mimic and regenerate alveolar bone). Scanning electron microscopy results showed the porous nature of the scaffold and formation of beadless electrospun multiscale fibers. The fiber diameter of microfiber and nanofibers was in the range of 10 ± 3 µm and 377 ± 3 nm, respectively. The bilayered construct showed better protein adsorption compared to the control. Osteoblastic differentiation of human dental follicle stem cells (hDFCs) on chitosan/2wt % CaSO4 scaffold showed maximum alkaline phosphatase at seventh day followed by a decline thereafter when compared to chitosan control scaffold. Fibroblastic differentiation of hDFCs was confirmed by the expression of PLAP-1 and COL-1 proteins which were more prominent on PCL multiscale membrane in comparison to control membranes. Overall these results show that the developed bilayered construct might serve as a good candidate for the simultaneous regeneration of the alveolar bone and PDL. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 761-770, 2016. PMID:26153674

  9. DKK1 rescues osteogenic differentiation of mesenchymal stem cells isolated from periodontal ligaments of patients with diabetes mellitus induced periodontitis

    PubMed Central

    Liu, Qi; Hu, Cheng-Hu; Zhou, Cui-Hong; Cui, Xiao-Xia; Yang, Kun; Deng, Chao; Xia, Jia-Jia; Wu, Yan; Liu, Lu-Chuan; Jin, Yan

    2015-01-01

    Multiple studies have shown that diabetes mellitus is an established risk factor for periodontitis. Recently mesenchymal stem cells derived from periodontal ligament (PDLSCs) have been utilized to reconstruct tissues destroyed by chronic inflammation. However, impact of periodontitis with diabetes mellitus on PDLSCs and mechanisms mediating effects of complex microenvironments remain poorly understood. In this study, we found multiple differentiation potential of PDLSCs from chronic periodontitis with diabetes mellitus donors (D-PDLSCs) was damaged significantly. Inhibition of NF-κB signaling could rescue osteogenic potential of PDLSCs from simple chronic periodontitis patients (P-PDLSCs), whereas did not promote D-PDLSCs osteogenesis. In addition, we found expression of DKK1 in D-PDLSCs did not respond to osteogenic signal and decreased osteogenic potential of D-PDLSCs treated with DKK1 could be reversed. To further elucidate different character between P-PDLSCs and D-PDLSCs, we treated PDLSCs with TNF-α and advanced glycation end products (AGEs), and find out AGEs which enhance effect of TNF-α in PDLSCs might mediate special personality of D-PDLSCs. The adverse effect of AGEs in PDLSCs could be reversed when PDLSCs were treated with DKK1. These results suggested DKK1 mediating WNT signaling might be a therapy target to rescue potential of PDLSCs in periodontitis with diabetes mellitus. PMID:26278788

  10. Immunohistochemical localization of tenascin-C in rat periodontal ligament with reference to alveolar bone remodeling.

    PubMed

    Sato, Rei; Fukuoka, Hiroki; Yokohama-Tamaki, Tamaki; Kaku, Masaru; Shibata, Shunichi

    2016-03-01

    We investigated the immunohistochemical localization of tenascin-C in 8-week-old rat periodontal ligaments. Tenascin-C immunoreactivity was detected in zones along with cementum and alveolar bone, and more intensely on the resorption surface of alveolar bone than on the formation surface. On the resorbing surface, tenascin-C immunoreactivity was detected in Howship's lacunae without osteoclasts, and in the interfibrous space of the periodontal ligaments, indicating that this molecule works as an adhesion molecule between bone and fibers of periodontal ligaments. Upon experimental tooth movement by inserting elastic bands (Waldo method), the physiological resorption surface of alveolar bone under compressive force showed enhanced bone resorption and enhanced tenascin-C immunoreactivity. However, on the physiological bone formation surface under compressive force, bone resorption was seen only occasionally, and no enhanced tenascin-C immunoreactivity was noted. In an experiment involving excessive occlusal loading to rat molars, transient bone resorption occurred within interradicular septa, but no enhanced tenascin-C immunoreactivity was seen in the periodontal ligaments. These results indicate that tenascin-C works effectively on the bone resorbing surface of physiological alveolar bone remodeling sites, rather than on the non-physiological transient bone resorbing surface. Fibronectin immunoreactivity was distributed evenly in the periodontal ligaments under experimental conditions. Co-localization of tenascin-C and fibronectin immunoreactivity was observed in many regions, but mutually exclusive expression patterns were also seen in some regions, indicating that fibronectin might not be directly involved in alveolar bone remodeling, but may play a role via interaction with tenascin-C. PMID:25957016

  11. Characterization of human periodontal ligament cells cultured on three-dimensional biphasic calcium phosphate scaffolds in the presence and absence of L-ascorbic acid, dexamethasone and β-glycerophosphate in vitro

    PubMed Central

    AN, SHAOFENG; GAO, YAN; LING, JUNQI

    2015-01-01

    The aim of this study was to evaluate the effect of porous biphasic calcium phosphate (BCP) scaffolds on the proliferation and osteoblastic differentiation of human periodontal ligament cells (hPDLCs) in the presence and absence of osteogenic inducer (L-ascorbic acid, dexamethasone and β-glycerophosphate). The cell growth within the scaffolds in the absence of osteogenic inducers was studied by cell counting kit-8 (CCK-8) assay and scanning electron microscopy (SEM). Alkaline phosphatase (ALP) activity and osteoblastic differentiation markers of hPDLCs in BCP scaffolds were examined in the presence and absence of osteogenic inducers. The cell number of hPDLCs in the BCP scaffolds was less than that of hPDLCs cultured in microplates (control). SEM images showed that cells successfully adhered to the BCP scaffolds and spread amongst the pores; they also produced abundant extracellular cell matrix. In the presence and absence of osteogenic inducers, the ALP activity of hPDLCs within BCP scaffolds was suppressed in varying degrees at all time-points. In the absence of osteogenic inducers, hPDLCs in BCP scaffolds express significant higher levels of osteopontin (OPN) mRNA than the control, and there were no significant differences for Runx2 and osteocalcin (OCN) mRNA levels compared with those cultured in microplates. In the presence of osteogenic inducers, Runx2 expression levels were significantly higher than those in control. OPN and OCN mRNA levels were downregulated slightly. Three-dimensional porous BCP scaffolds are able to stimulate the osteoblastic differentiation of hPDLCs in the presence and absence of osteogenic inducer and may be capable of supporting hPDLC-mediated bone formation. PMID:26622495

  12. Expression of mRNAs encoding for growth factors, ECM molecules, and MMP13 in mono-cultures and co-cultures of human periodontal ligament fibroblasts and alveolar bone cells.

    PubMed

    Winter, S; Kohl, A; Huppertz, A; Herold-Mende, C; Wiest, T; Komposch, G; Tomakidi, P

    2005-03-01

    Although the function and effects of many growth factors and extracellular matrix (ECM) molecules have been described for several periodontal tissues in vivo and in vitro, the molecular interactions involved in the communication between cells of the periodontal ligament and the alveolar bone are poorly understood. To contribute to the identification of such interactions, we have generated co-cultures (CCs) of periodontal ligament fibroblasts (PDLs) and alveolar bone cells (ABCs) and compared mRNA expression for various growth factors, ECM molecules, and matrix metalloproteinase13 (MMP13) after 1 and 2 weeks with matched mono-cultures (MCs) by reverse transcription/polymerase chain reaction. Compared with CCs of 1 week, PDLs and ABCs after 2 weeks revealed relatively high levels of all analyzed mRNAs, viz., for EGF, HGF, VEGF, TGFbeta1, collagen-I (COL1), osteonectin (ON), fibronectin (FN1), and MMP13. At week 2, when compared with MCs, CCs showed an elevation of all tested mRNAs in PDLs and ABCs, except for TGFbeta1 and FN1, which only increased in PDLs. After 1 week, when CCs were compared with MCs, mRNAs for HGF and TGFbeta1 were less abundant in PDLs and ABCs, whereas the other genes exhibited lower expression levels in only one of the cell types. Analysis of our data indicated that the expression of mRNAs for growth factors and for COL1, ON, FN1, and MMP13 was modulated in the distinct cell types with respect to culture time and culture type. The differences in the mRNA expression patterns between CCs and MCs suggest that the respective genes are involved in the molecular interactions of PDLs and ABCs. PMID:15668800

  13. Effect of vitamin C administration on hydrogen peroxide-induced cytotoxicity in periodontal ligament cells.

    PubMed

    Wu, Wenlei; Yang, Nanfei; Feng, Xiujing; Sun, Tingzhe; Shen, Pingping; Sun, Weibin

    2015-01-01

    Periodontitis is a disease, which is associated with chronic inflammation and leads to significant destruction of periodontal tissues. Periodontal ligament cells (PDLCs) constitute the largest cell population in PDL tissues and a considerable body of evidence has demonstrated an association between oxidative stress and the progression of periodontitis. However, the effects on PDLCs exposed to hydrogen peroxide (H2O2) and the molecular mechanisms by which H2O2 affects periodontitis remain to be elucidated. In the present study, the potential cytotoxic effect of H2O2 and the antioxidative function of vitamin C (Vc) in PDLCs were investigated. The results demonstrated that H2O2 treatment decreased the viability of PDLCs. The decreased PDLC viability was primarily induced by apoptosis, which was evidenced by cleaved caspases-3, caspases-9 and poly (ADP-ribose) polymerase. Following optimal Vc addition, the proapoptotic effects of H2O2 were partially antagonized. Taken together, the present study demonstrated that H2O2 primarily induced the apoptosis of PDLCs and that these adverse effects were partially rescued following treatment with Vc. These results revealed how H2O2 promotes the progression of periodontitis and provide an improved understanding of the reversal effect of antioxidant treatment. Therefore, optimal Vc administration may provide a potentially effective technique in periodontal therapy. PMID:25333298

  14. Enhanced compatibility of chemically modified titanium surface with periodontal ligament cells

    NASA Astrophysics Data System (ADS)

    Kado, T.; Hidaka, T.; Aita, H.; Endo, K.; Furuichi, Y.

    2012-12-01

    A simple chemical modification method was developed to immobilize cell-adhesive molecules on a titanium surface to improve its compatibility with human periodontal ligament cells (HPDLCs).The polished titanium disk was immersed in 1% (v/v) p-vinylbenzoic acid solution for 2 h to introduce carboxyl groups onto the surface. After rinsing with distilled deionized water, the titanium disk was dipped into 1.47% 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide solution containing 0.1 mg/ml Gly-Arg-Gly-Asp-Ser (GRGDS), human plasma fibronectin (pFN), or type I collagen from calf skin (Col) to covalently immobilize the cell-adhesive molecules on the titanium surface via formation of peptide bonds. X-ray photoelectron spectroscopy analyses revealed that cell-adhesive molecules were successfully immobilized on the titanium surfaces. The Col-immobilized titanium surface revealed higher values regarding nano rough characteristics than the as-polished titanium surface under scanning probe microscopy. The number of HPDLCs attached to both the pFN- and Col-immobilized titanium surfaces was twice that attached to the as-polished titanium surfaces. The cells were larger with the cellular processes that stretched to a greater extent on the pFN- and Col-immobilized titanium surfaces than on the as-polished titanium surface (p < 0.05). HPDLCs on the Col-immobilized titanium surfaces showed more extensive expression of vinculin at the tips of cell projections and more contiguously along the cell outline than on the as-polished, GRGDS-immobilized and pFN-immobilized titanium surfaces. It was concluded that cell-adhesive molecules successfully immobilized on the titanium surface and improved the compatibility of the surface with HPDLCs. The Col-immobilized titanium surface could be used for forming ligament-like tissues around titanium dental implants.

  15. Soluble CD14 Enhances the Response of Periodontal Ligament Stem Cells to P. gingivalis Lipopolysaccharide

    PubMed Central

    Andrukhov, Oleh; Andrukhova, Olena; Özdemir, Burcu; Haririan, Hady; Müller-Kern, Michael; Moritz, Andreas; Rausch-Fan, Xiaohui

    2016-01-01

    Periodontal ligament stem cells (PDLSCs) are lacking membrane CD14, which is an important component of lipopolysaccharide (LPS) signaling through toll-like receptor (TLR) 4. In the present study we investigated the effect of soluble CD14 on the response of human PDLSCs to LPS of Porphyromonas (P.) gingivalis. Human PDLSCs (hPDLSCs) were stimulated with P. gingivalis LPS in the presence or in the absence of soluble CD14 (sCD14) and the production of interleukin (IL)-6, chemokine C-X-C motif ligand 8 (CXCL8), and chemokine C-C motif ligand 2 (CCL2) was measured. The response to P. gingivalis LPS was compared with that to TLR4 agonist Escherichia coli LPS and TLR2-agonist Pam3CSK4. The response of hPDLSCs to both P. gingivalis LPS and E. coli LPS was significantly enhanced by sCD14. In the absence of sCD14, no significant difference in the hPDLSCs response to two kinds of LPS was observed. These responses were significantly lower compared to that to Pam3CSK4. In the presence of sCD14, the response of hPdLSCs to P. gingivalis LPS was markedly higher than that to E. coli LPS and comparable with that to Pam3CSK4. The response of hPdLSCs to bacterial LPS is strongly augmented by sCD14. Local levels of sCD14 could be an important factor for modulation of the host response against periodontal pathogens. PMID:27504628

  16. Porphyromonas gingivalis GroEL Induces Osteoclastogenesis of Periodontal Ligament Cells and Enhances Alveolar Bone Resorption in Rats

    PubMed Central

    Lin, Feng-Yen; Hsiao, Fung-Ping; Huang, Chun-Yao; Shih, Chun-Ming; Tsao, Nai-Wen; Tsai, Chien-Sung; Yang, Shue-Fen; Chang, Nen-Chung; Hung, Shan-Ling; Lin, Yi-Wen

    2014-01-01

    Porphyromonas gingivalis is a major periodontal pathogen that contains a variety of virulence factors. The antibody titer to P. gingivalis GroEL, a homologue of HSP60, is significantly higher in periodontitis patients than in healthy control subjects, suggesting that P. gingivalis GroEL is a potential stimulator of periodontal disease. However, the specific role of GroEL in periodontal disease remains unclear. Here, we investigated the effect of P. gingivalis GroEL on human periodontal ligament (PDL) cells in vitro, as well as its effect on alveolar bone resorption in rats in vivo. First, we found that stimulation of PDL cells with recombinant GroEL increased the secretion of the bone resorption-associated cytokines interleukin (IL)-6 and IL-8, potentially via NF-κB activation. Furthermore, GroEL could effectively stimulate PDL cell migration, possibly through activation of integrin α1 and α2 mRNA expression as well as cytoskeletal reorganization. Additionally, GroEL may be involved in osteoclastogenesis via receptor activator of nuclear factor κ-B ligand (RANKL) activation and alkaline phosphatase (ALP) mRNA inhibition in PDL cells. Finally, we inoculated GroEL into rat gingiva, and the results of microcomputed tomography (micro-CT) and histomorphometric assays indicated that the administration of GroEL significantly increased inflammation and bone loss. In conclusion, P. gingivalis GroEL may act as a potent virulence factor, contributing to osteoclastogenesis of PDL cells and resulting in periodontal disease with alveolar bone resorption. PMID:25058444

  17. Evaluation of In Vivo Osteogenic Potential of Bone Morphogenetic Protein 2-Overexpressing Human Periodontal Ligament Stem Cells Combined with Biphasic Calcium Phosphate Block Scaffolds in a Critical-Size Bone Defect Model.

    PubMed

    Yi, TacGhee; Jun, Choong-Man; Kim, Su Jin; Yun, Jeong-Ho

    2016-03-01

    Human periodontal ligament stem cells (hPDLSCs) are considered potential cellular carriers for gene delivery in the field of tissue regeneration. This study tested the osseoregenerative potential of hPDLSCs transduced with replication-deficient recombinant adenovirus (rAd) containing the gene encoding bone morphogenetic protein-2 (BMP2; hPDLSCs/rAd-BMP2) in both in vivo and in vitro osteogenic environments. After the optimal condition for rAd-mediated transduction was determined, hPDLSCs were transduced to express BMP2. In vivo bone formation was evaluated in a critical-size rat calvarial bone defect model that more closely mimics the harsher in vivo milieu for bone regeneration than subcutaneous transplantation model. As support materials for bone regeneration, block-type biphasic calcium phosphate (BCP) scaffolds were combined with hPDLSCs and/or BMP2 and transplanted into critical-size bone defects in rats. Experimental groups were as follows: BCP scaffold control (group 1 [Gr1]), scaffold containing recombinant human BMP2 (rhBMP2; group 2 [Gr2]), scaffold loaded with normal hPDLSCs (group 3 [Gr3]), scaffold combined with both normal hPDLSCs and rhBMP2 (group 4 [Gr4]), and scaffold loaded with hPDLSCs transduced with rAd-BMP2 (hPDLSCs/rAd-BMP2; group 5 [Gr5]). Our data showed that new bone formation was highest in Gr2. Less mineralization was observed in Gr3, Gr4, and Gr5 in which hPDLSCs were transplanted. In vitro transwell assay demonstrated that hPDLSCs exert an inhibitory activity on BMP2-induced osteogenic differentiation. Our findings suggest that the in vivo bone regenerative potential of BMP2-overexpressing hPDLSCs could be compromised in a critical-size rat calvarial bone defect model. Thus, further investigations are required to elucidate the underlying mechanisms and to develop efficient techniques for improved tissue regeneration. PMID:26825430

  18. Beneficial Effects of Adiponectin on Periodontal Ligament Cells under Normal and Regenerative Conditions

    PubMed Central

    Nokhbehsaim, Marjan; Keser, Sema; Cirelli, Joni Augusto; Jepsen, Søren; Jäger, Andreas

    2014-01-01

    Type 2 diabetes and obesity are increasing worldwide and linked to periodontitis, a chronic disease which is characterized by the irreversible destruction of the tooth-supporting tissues, that is, periodontium. The mechanisms underlying the association of diabetes mellitus and obesity with periodontal destruction and compromised periodontal healing are not well understood, but decreased plasma levels of adiponectin, as found in diabetic and obese individuals, might be a critical mechanistic link. The aim of this in vitro study was to examine the effects of adiponectin on periodontal ligament (PDL) cells under normal and regenerative conditions, and to study the regulation of adiponectin and its receptors in these cells. Adiponectin stimulated significantly the expression of growth factors and extracellular matrix, proliferation, and in vitro wound healing, reduced significantly the constitutive tumor necrosis factor-α expression, and caused a significant upregulation of its own expression. The beneficial actions of enamel matrix derivative on a number of PDL cell functions critical for periodontal regeneration were partially enhanced by adiponectin. The periodontopathogen Porphyromonas gingivalis inhibited the adiponectin expression and stimulated the expression of its receptors. In conclusion, reduced levels of adiponectin, as found in type 2 diabetes and obesity, may compromise periodontal health and healing. PMID:25121107

  19. Functional Role of HSP47 in the Periodontal Ligament Subjected to Occlusal Overload in Mice

    PubMed Central

    Mimura, Hiroaki; Takaya, Tatsuo; Matsuda, Saeka; Nakano, Keisuke; Muraoka, Rina; Tomida, Mihoko; Okafuji, Norimasa; Fujii, Takeo; Kawakami, Toshiyuki

    2016-01-01

    We carried out an experiment to induce traumatic occlusion in mice periodontal tissue and analyzed the expression of HSP47. Continuous traumatic occlusion resulted to damage and remodeling of periodontal ligament as well as increase in osteoclasts and bone resorption. Four days after traumatic occlusion, osteoclasts did not increase but Howship's lacunae became enlarged. That is, the persistent occlusal overload can destroy collagen fibers in the periodontal ligament. This was evident by the increased in HSP47 expression with the occlusal overload. HSP47 is maintained in fibroblasts for repair of damaged collagen fibers. On the other hand, osteoclasts continue to increase although the load was released. The osteoclasts that appeared on the alveolar bone surface were likely due to sustained activity. The increase in osteoclasts was estimated to occur after load application at day 4. HSP47 continued to increase until day 6 in experiment 2 but then reduced at day 10. Therefore, HSP47 appears after a period of certain activities to repair damaged collagen fibers, and the activity was returned to a state of equilibrium at day 30 with significantly diminished expression. Thus, the results suggest that HSP47 is actively involved in homeostasis of periodontal tissue subjected to occlusal overload. PMID:27076780

  20. Influence of periodontal ligament simulation on bond strength and fracture resistance of roots restored with fiber posts

    PubMed Central

    MARCHIONATTI, Ana Maria Estivalete; WANDSCHER, Vinícius Felipe; BROCH, Juliana; BERGOLI, César Dalmolin; MAIER, Juliana; VALANDRO, Luiz Felipe; KAIZER, Osvaldo Bazzan

    2014-01-01

    Objective Considering that periodontal ligament simulation may influence the stress distribution over teeth restored with intraradicular retainers, this study aimed to assess the combined effect of mechanical cycling and periodontal ligament simulation on both the bond strength between fiber posts and root dentin and the fracture resistance of teeth restored using glass fiber posts. Material and Methods Ninety roots were randomly distributed into 3 groups (n=10) (C-MC: control; P-MC: polyether; AS-MC: addition silicone) to test bond strength and 6 groups (n=10) (C: control; P: polyether; AS: addition silicone, without mechanical cycling, and C-MC, P-MC and AS-MC with mechanical cycling) to test fracture strength, according to the material used to simulate the periodontal ligament. For the bond strength test, fiber posts were cemented, cores were built, mechanical cycling was applied (2×106 cycles, 88 N, 2.2 Hz, and 45º incline), and the teeth cut into 3 slices (2 mm), which were then subjected to the push-out test at 1 mm/min. For the fracture strength test, fiber posts were cemented, cores were built, and half of the groups received mechanical cycling, followed by the compressive strength (45° to the long axis and 1 mm/min) performed on all groups. Results Periodontal ligament simulation did not affect the bond strength (p=0.244) between post and dentin. Simulation of periodontal ligament (p=0.153) and application of mechanical cycling (p=0.97) did not affect fracture resistance. Conclusions The materials used to simulate the periodontal ligament did not affect fracture or bond strength, therefore periodontal ligament simulation using the tested materials could be considered optional in the conditions of the study. PMID:25466478

  1. Histological Evaluation of Periodontal Ligament in Response to Orthodontic Mechanical Stress in Mice.

    PubMed

    Kaneko, Keiko; Matsuda, Saeka; Muraoka, Rina; Nakano, Keisuke; Iwasaki, Takami; Tomida, Mihoko; Tsujigiwa, Hidetsugu; Nagatsuka, Hitoshi; Kawakami, Toshiyuki

    2015-01-01

    The purpose of the study was to determine the cell dynamics in periodontal ligament in response to mechanical stress during orthodontic movement. Following Waldo's method, a square sheet of rubber dam was inserted in between the first and second maxillary molars in 10 ddY mice leaving the stress load for 3 hours. After 3 days and at 1 week, cell count on pressure and tension sides of the periodontal ligament was determined. Furthermore, the type of cell present after mechanical stress was identified using GFP bone marrow transplantation mouse model. Immunohistochemistry was carried out at 0 min (immediately after mechanical stress), 24 hours, 1 week, 2 weeks and 6 months. Temporal changes in the expression of GFP-positive bone marrow derived cells were examined. Moreover, double immunofluorescent staining was performed to determine the type of cell in the periodontal ligament. Cell count on the tension side tremendously increased 3 days after mechanical stress. At 1 week, spindle and round cell count increased compared to the control group. These changes were observed on both tension and pressure sides. Cell count on pressure side at 3 days (22.11+/-13.98) and at 1 week (33.23+/-11.39) was higher compared to the control group (15.26+/-8.29). On the tension side, there was a significantly increased at 3 days (35.46+/-11.85), but decreased at 1 week (29.23+/-13.89) although it is still higher compared to the control group (AD+/-SD: 10.37+/-8.69). Using GFP bone marrow transplantation mouse model, GFP positive cell count increased gradually over time in 6 months. GFP positive cells were also positive to CD31, CD68 and Runx2 suggesting that fibroblasts differentiated into osteoclasts and tissue macrophages. In conclusion, mechanical stress during orthodontic movement promoted the increase in the number of cells in the periodontal ligament on both tension and pressure sides. The increase in the number of cells in the periodontal ligament is believed to be due to the

  2. ABCG2 Is a Selectable Marker for Enhanced Multilineage Differentiation Potential in Periodontal Ligament Stem Cells

    PubMed Central

    Szepesi, Áron; Matula, Zsolt; Szigeti, Anna; Várady, György; Szabó, Gyula; Uher, Ferenc; Sarkadi, Balázs

    2015-01-01

    Periodontal ligament stem cells (PDLSCs) provide an important source for tissue regeneration and may become especially useful in the formation of osteogenic seeds. PDLSCs can be cultured, expanded, and differentiated in vitro; thus, they may be applied in the long-term treatment of the defects in the dental regions. Here we studied numerous potential markers allowing the selection of human PDLSCs with a maximum differentiation potential. We followed the expression of the ATP-binding cassette subfamily G member 2 (ABCG2) membrane transporter protein and isolated ABCG2-expressing cells by using a monoclonal antibody, recognizing the transporter at the cell surface in intact cells. The expression of the ABCG2 protein, corresponding to the so-called side-population phenotype in various tissue-derived stem cells, was found to be a useful marker for the selection of PDLSCs with enhanced osteogenic, chondrogenic, and adipogenic differentiation. These findings may have important applications in achieving efficient dental tissue regeneration by using stem cells from extracted teeth. PMID:25101689

  3. A constitutive model for the periodontal ligament as a compressible transversely isotropic visco-hyperelastic tissue.

    PubMed

    Zhurov, Alexei I; Limbert, Georges; Aeschlimann, Daniel P; Middleton, John

    2007-06-01

    This study is devoted to the development of a non-linear anisotropic model for the human periodontal ligament (PDL). A thorough knowledge of the behaviour of the PDL is vital in understanding the mechanics of orthodontic tooth mobility, soft tissue response and proposed treatment plans. There is considerable evidence that the deformation of the PDL is the key factor determining the orthodontic tooth movement. The paper focuses on the biomechanical aspect of the behaviour of the PDL. In terms of continuous mechanics, the PDL may be treated as an anisotropic poro-visco-hyperelastic fibre-reinforced compressible material which is subject to large deformations and has an essentially non-linear behaviour. Furthermore, there are issues related to the non-linear tooth and PDL geometry. A new constitutive model for the PDL is proposed. The macroscopic continuum approach is used. The model is based on the non-linear large deformation theory, involving the Lagrangian description. The material is assumed to be compressible, visco-hyperelastic and transversely isotropic. A free-energy function is suggested that incorporates the properties. It also takes into account that the PDL behaves differently in tension and compression. The free-energy function and the associated constitutive equations involve several material parameters, which are to be evaluated from experimental strain-stress data available from the literature and the tooth movement experiments conducted by our team using novel optical motion analysis techniques. PMID:17558650

  4. Bone repair by periodontal ligament stem cellseeded nanohydroxyapatite-chitosan scaffold

    PubMed Central

    Ge, Shaohua; Zhao, Ning; Wang, Lu; Yu, Meijiao; Liu, Hong; Song, Aimei; Huang, Jing; Wang, Guancong; Yang, Pishan

    2012-01-01

    Background A nanohydroxyapatite-coated chitosan scaffold has been developed in recent years, but the effect of this composite scaffold on the viability and differentiation of periodontal ligament stem cells (PDLSCs) and bone repair is still unknown. This study explored the behavior of PDLSCs on a new nanohydroxyapatite-coated genipin-chitosan conjunction scaffold (HGCCS) in vitro as compared with an uncoated genipin-chitosan framework, and evaluated the effect of PDLSC-seeded HGCCS on bone repair in vivo. Methods Human PDLSCs were cultured and identified, seeded on a HGCCS and on a genipin-chitosan framework, and assessed by scanning electron microscopy, confocal laser scanning microscopy, MTT, alkaline phosphatase activity, and quantitative real-time polymerase chain reaction at different time intervals. Moreover, PDLSC-seeded scaffolds were used in a rat calvarial defect model, and new bone formation was assessed by hematoxylin and eosin staining at 12 weeks postoperatively. Results PDLSCs were clonogenic and positive for STRO-1. They had the capacity to undergo osteogenic and adipogenic differentiation in vitro. When seeded on HGCCS, PDLSCs exhibited significantly greater viability, alkaline phosphatase activity, and upregulated the bone-related markers, bone sialoprotein, osteopontin, and osteocalcin to a greater extent compared with PDLSCs seeded on the genipin-chitosan framework. The use of PDLSC-seeded HGCCS promoted calvarial bone repair. Conclusion This study demonstrates the potential of HGCCS combined with PDLSCs as a promising tool for bone regeneration. PMID:23091383

  5. Bioactivity of periodontal ligament stem cells on sodium titanate coated with graphene oxide.

    PubMed

    Zhou, Qi; Yang, Pishan; Li, Xianlei; Liu, Hong; Ge, Shaohua

    2016-01-01

    As a biocompatible and low cytotoxic nanomaterial, graphene oxide (GO) has captured tremendous interests in tissue engineering. However, little is known about the behavior of dental stem cells on GO. This study was to evaluate the bioactivity of human periodontal ligament stem cells (PDLSCs) on GO coated titanium (GO-Ti) substrate in vitro as compared to sodium titanate (Na-Ti) substrate. By scanning electron microscope (SEM), confocal laser scanning microscope (CLSM), methylthiazol tetrazolium (MTT) assay, alkaline phosphatase (ALP) activity, quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis, we investigated the attachment, morphology, proliferation and osteogenic differentiation of PDLSCs on these two substrates. When seeded on GO-Ti substrate, PDLSCs exhibited significantly higher proliferation rate, ALP activity and up-regulated gene expression level of osteogenesis-related markers of collagen type I (COL-I), ALP, bone sialoprotein (BSP), runt related transcription factor 2 (Runx2) and osteocalcin (OCN) compared with those on Na-Ti substrate. Moreover, GO promoted the protein expression of BSP, Runx2 and OCN. These findings suggest that the combination of GO and PDLSCs provides a promising construct for regenerative dentistry. PMID:26763307

  6. Bioactivity of periodontal ligament stem cells on sodium titanate coated with graphene oxide

    PubMed Central

    Zhou, Qi; Yang, Pishan; Li, Xianlei; Liu, Hong; Ge, Shaohua

    2016-01-01

    As a biocompatible and low cytotoxic nanomaterial, graphene oxide (GO) has captured tremendous interests in tissue engineering. However, little is known about the behavior of dental stem cells on GO. This study was to evaluate the bioactivity of human periodontal ligament stem cells (PDLSCs) on GO coated titanium (GO-Ti) substrate in vitro as compared to sodium titanate (Na-Ti) substrate. By scanning electron microscope (SEM), confocal laser scanning microscope (CLSM), methylthiazol tetrazolium (MTT) assay, alkaline phosphatase (ALP) activity, quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis, we investigated the attachment, morphology, proliferation and osteogenic differentiation of PDLSCs on these two substrates. When seeded on GO-Ti substrate, PDLSCs exhibited significantly higher proliferation rate, ALP activity and up-regulated gene expression level of osteogenesis-related markers of collagen type I (COL-I), ALP, bone sialoprotein (BSP), runt related transcription factor 2 (Runx2) and osteocalcin (OCN) compared with those on Na-Ti substrate. Moreover, GO promoted the protein expression of BSP, Runx2 and OCN. These findings suggest that the combination of GO and PDLSCs provides a promising construct for regenerative dentistry. PMID:26763307

  7. Mechanical Strength and Viscoelastic Response of the Periodontal Ligament in Relation to Structure

    PubMed Central

    Komatsu, Koichiro

    2010-01-01

    The mechanical strength of the periodontal ligament (PDL) was first measured as force required to extract a tooth from its socket using human specimens. Thereafter, tooth-PDL-bone preparations have extensively been used for measurement of the mechanical response of the PDL. In vitro treatments of such specimens with specific enzymes allowed one to investigate into the roles of the structural components in the mechanical support of the PDL. The viscoelastic responses of the PDL may be examined by analysis of the stress-relaxation. Video polarised microscopy suggested that the collagen molecules and fibrils in the stretched fibre bundles progressively align along the deformation direction during the relaxation. The stress-relaxation process of the PDL can be well expressed by a function with three exponential decay terms. Analysis after in vitro digestion of the collagen fibres by collagenase revealed that the collagen fibre components may play an important role in the long-term relaxation component of the stress-relaxation process of the PDL. The dynamic measurements of the viscoelastic properties of the PDL have recently suggested that the PDL can absorb more energy in compression than in shear and tension. These viscoelastic mechanisms of the PDL tissue could reduce the risk of injury to the PDL. PMID:20948569

  8. ET-1 Promotes Differentiation of Periodontal Ligament Stem Cells into Osteoblasts through ETR, MAPK, and Wnt/β-Catenin Signaling Pathways under Inflammatory Microenvironment

    PubMed Central

    Liang, Li; Zhou, Wei; Yang, Nan; Yu, Jifeng; Liu, Hongchen

    2016-01-01

    Periodontitis is a kind of chronic inflammatory disease that affects the tooth-supporting tissues. ET-1 is related to periodontitis and involved in the regulation of cytokines, but the mechanisms remain unclear. The aim of this study is to investigate how ET-1 affects proinflammatory cytokine expression and differentiation in human periodontal ligament stem cells (PDLSCs). PDLSCs were isolated from the periodontal ligament tissues of periodontitis patients and then treated with ET-1 (1, 10, or 100 nM) for 12 h, 24 h, or 72 h. The osteogenic potential of PDLSCs was tested using ALP staining. TNF-α, IL-1β, and IL-6 levels were evaluated by ELISA and western blot. Runx2, OCN, and COL1 mRNA and western levels were detected by RT-PCR and western blot, respectively. To examine the signaling pathways and molecular mechanisms involved in ET-1-mediated cytokine expression and osteogenic differentiation, ETR pathway, MAPKs pathway, Wnt/β-catenin pathway, and Wnt/Ca2+ pathway were detected by RT-PCR and western blot, respectively. ET-1 promoted differentiation of PDLSCs into osteoblasts by increasing secretion of TNF-α, IL-1β, and IL-6 in a dose- and time-dependent manner. ET-1 also increased expression of Runx2, OCN, and COL1. ET-1 promotes differentiation of PDLSCs into osteoblasts through ETR, MAPK, and Wnt/β-catenin signaling pathways under inflammatory microenvironment. PMID:26884650

  9. Age estimation using the radiographic visibility of the periodontal ligament in lower third molars in a Portuguese population

    PubMed Central

    Sequeira, Catarina-Dourado; Teixeira, Alexandra; Afonso, Américo; Pérez-Mongiovi, Daniel

    2014-01-01

    Objectives: The mineralization of third molars has been used repeatedly as a method of forensic age estimation. However, this procedure is of little use beyond age 18, especially to determinate if an individual is older than 21 years of age; thus, the development of new approaches is essential. The visibility of the periodontal ligament has been suggested for this purpose. The aim of this work was to determine the usefulness of this methodology in a Portuguese population. Study Design: Periodontal ligament visibility was assessed in the lower third molars, using a sample of 487 orthopantomograms, 228 of which belonging to females and 259 to males, from a Portuguese population aged 17 to 31 years. A classification of four stages based on the visual phenomenon of disappearance of the periodontal ligament of fully mineralized third molars was used. For each stage, median, variance, minimal and maximal age were assessed. Results: The relationship between age and stage of periodontal ligament had a statistical significance for both sexes. In this population, stage 3 can be used to state that a male person is over 21 years-old; for females, another marker should be used. Conclusions: This technique can be useful for determining age over 21, particularly in males. Differences between studies are evident, suggesting that specific population standards should be used when applying this technique. Key words:Forensic sciences, forensic odontology, age estimation, third molar, periodontal ligament. PMID:25674324

  10. Dynamic Mechanical and Nanofibrous Topological Combinatory Cues Designed for Periodontal Ligament Engineering

    PubMed Central

    Kim, Joong-Hyun; Kang, Min Sil; Eltohamy, Mohamed; Kim, Tae-Hyun; Kim, Hae-Won

    2016-01-01

    Complete reconstruction of damaged periodontal pockets, particularly regeneration of periodontal ligament (PDL) has been a significant challenge in dentistry. Tissue engineering approach utilizing PDL stem cells and scaffolding matrices offers great opportunity to this, and applying physical and mechanical cues mimicking native tissue conditions are of special importance. Here we approach to regenerate periodontal tissues by engineering PDL cells supported on a nanofibrous scaffold under a mechanical-stressed condition. PDL stem cells isolated from rats were seeded on an electrospun polycaprolactone/gelatin directionally-oriented nanofiber membrane and dynamic mechanical stress was applied to the cell/nanofiber construct, providing nanotopological and mechanical combined cues. Cells recognized the nanofiber orientation, aligning in parallel, and the mechanical stress increased the cell alignment. Importantly, the cells cultured on the oriented nanofiber combined with the mechanical stress produced significantly stimulated PDL specific markers, including periostin and tenascin with simultaneous down-regulation of osteogenesis, demonstrating the roles of topological and mechanical cues in altering phenotypic change in PDL cells. Tissue compatibility of the tissue-engineered constructs was confirmed in rat subcutaneous sites. Furthermore, in vivo regeneration of PDL and alveolar bone tissues was examined under the rat premaxillary periodontal defect models. The cell/nanofiber constructs engineered under mechanical stress showed sound integration into tissue defects and the regenerated bone volume and area were significantly improved. This study provides an effective tissue engineering approach for periodontal regeneration—culturing PDL stem cells with combinatory cues of oriented nanotopology and dynamic mechanical stretch. PMID:26989897

  11. Mesenchymal stem cell characteristics of dental pulp and periodontal ligament stem cells after in vivo transplantation.

    PubMed

    Lei, Ming; Li, Kun; Li, Bei; Gao, Li-Na; Chen, Fa-Ming; Jin, Yan

    2014-08-01

    Mesenchymal stem cells (MSCs) isolated from human postnatal dental pulp and periodontal ligament (PDL) tissues can give rise to multilineage differentiation in vitro and generate related dental tissues in vivo. However, the cell properties of human dental pulp stem cells (DPSCs) and PDL stem cells (PDLSCs) after in vivo implantation remain largely unidentified. In this study, cells were re-isolated from in vivo-generated dental pulp-like and PDL-like tissues (termed re-DPCs and re-PDLCs, respectively) as a result of ectopic transplantation of human DPSC and PDLSC sheets. The cell characteristics in terms of colony-forming ability, cell surface antigens and multi-differentiation potentials were all evaluated before and after implantation. It was found that re-DPCs and re-PDLCs were of human and mesenchymal origin and positive for MSC markers such as STRO-1, CD146, CD29, CD90 and CD105; and, to some extent, re-DPCs could maintain their colony forming abilities. Moreover, both cell types were able to form mineral deposits and differentiate into adipocytes and chondrocytes; however, quantitative analysis and related gene expression determination showed that the osteo-/chondro-differentiation capabilities of re-DPCs and re-PDLCs were significantly reduced compared to those of DPSCs and PDLSCs, respectively (P < 0.05); re-PDLCs showed a greater reduction potential than re-DPCs. We conclude that DPSCs and PDLSCs may maintain their MSC characteristics after in vivo implantation and, compared to PDLSCs, DPSCs appear much more stable under in vivo conditions. These findings provide additional cellular and molecular evidence that supports expanding the use of dental tissue-derived stem cells in cell therapy and tissue engineering. PMID:24824581

  12. Periodontal ligament, cementum, and alveolar bone in the oldest herbivorous tetrapods, and their evolutionary significance.

    PubMed

    LeBlanc, Aaron R H; Reisz, Robert R

    2013-01-01

    Tooth implantation provides important phylogenetic and functional information about the dentitions of amniotes. Traditionally, only mammals and crocodilians have been considered truly thecodont, because their tooth roots are coated in layers of cementum for anchorage of the periodontal ligament, which is in turn attached to the bone lining the alveolus, the alveolar bone. The histological properties and developmental origins of these three periodontal tissues have been studied extensively in mammals and crocodilians, but the identities of the periodontal tissues in other amniotes remain poorly studied. Early work on dental histology of basal amniotes concluded that most possess a simplified tooth attachment in which the tooth root is ankylosed to a pedestal composed of "bone of attachment", which is in turn fused to the jaw. More recent studies have concluded that stereotypically thecodont tissues are also present in non-mammalian, non-crocodilian amniotes, but these studies were limited to crown groups or secondarily aquatic reptiles. As the sister group to Amniota, and the first tetrapods to exhibit dental occlusion, diadectids are the ideal candidates for studies of dental evolution among terrestrial vertebrates because they can be used to test hypotheses of development and homology in deep time. Our study of Permo-Carboniferous diadectid tetrapod teeth and dental tissues reveal the presence of two types of cementum, periodontal ligament, and alveolar bone, and therefore the earliest record of true thecodonty in a tetrapod. These discoveries in a stem amniote allow us to hypothesize that the ability to produce the tissues that characterize thecodonty in mammals and crocodilians is very ancient and plesiomorphic for Amniota. Consequently, all other forms of tooth implantation in crown amniotes are derived arrangements of one or more of these periodontal tissues and not simply ankylosis of teeth to the jaw by plesiomorphically retaining "bone of attachment", as

  13. Periodontal Ligament, Cementum, and Alveolar Bone in the Oldest Herbivorous Tetrapods, and Their Evolutionary Significance

    PubMed Central

    LeBlanc, Aaron R. H.; Reisz, Robert R.

    2013-01-01

    Tooth implantation provides important phylogenetic and functional information about the dentitions of amniotes. Traditionally, only mammals and crocodilians have been considered truly thecodont, because their tooth roots are coated in layers of cementum for anchorage of the periodontal ligament, which is in turn attached to the bone lining the alveolus, the alveolar bone. The histological properties and developmental origins of these three periodontal tissues have been studied extensively in mammals and crocodilians, but the identities of the periodontal tissues in other amniotes remain poorly studied. Early work on dental histology of basal amniotes concluded that most possess a simplified tooth attachment in which the tooth root is ankylosed to a pedestal composed of “bone of attachment”, which is in turn fused to the jaw. More recent studies have concluded that stereotypically thecodont tissues are also present in non-mammalian, non-crocodilian amniotes, but these studies were limited to crown groups or secondarily aquatic reptiles. As the sister group to Amniota, and the first tetrapods to exhibit dental occlusion, diadectids are the ideal candidates for studies of dental evolution among terrestrial vertebrates because they can be used to test hypotheses of development and homology in deep time. Our study of Permo-Carboniferous diadectid tetrapod teeth and dental tissues reveal the presence of two types of cementum, periodontal ligament, and alveolar bone, and therefore the earliest record of true thecodonty in a tetrapod. These discoveries in a stem amniote allow us to hypothesize that the ability to produce the tissues that characterize thecodonty in mammals and crocodilians is very ancient and plesiomorphic for Amniota. Consequently, all other forms of tooth implantation in crown amniotes are derived arrangements of one or more of these periodontal tissues and not simply ankylosis of teeth to the jaw by plesiomorphically retaining “bone of attachment

  14. [Effect of fibronectin on the synthesis of extracellular matrix proteins in periodontal ligament cells].

    PubMed

    Wan, L; Wu, Z; Zhou, Y

    1996-11-01

    Immunofluorescence staining method and fluorescence spectrophotometry were used to study the synthesis of extracellular matrix proteins in periodontal ligament cells (PDL cells) when exogenous fibronectin (FN) existed. The results showed that the right amount of exogenous FN (0.044 mumol/l) could increase the amount of type I collagen and type III collagen in PDL cells (P < 0.01), inhibit the synthesis of FN itself (P < 0.01). It suggested that exogenous FN can effect the synthesis of extracellular matrix proteins so as to promote a new connective tissue attachment formation. PMID:9592289

  15. Impact of Nanotopography and/or Functional Groups on Periodontal Ligament Cell Growth

    NASA Astrophysics Data System (ADS)

    Şaşmazel, Hilal Türkoğlu; Manolache, S.; Gümüşderelİoğlu, M.

    The main purpose of this contribution was to obtain COOH functionalities and/or nanotopographic changes on the surface of 3D, non-woven polyester fabric (NWPF) discs (12.5 mm in diameter) by using low pressure water/O2 plasma assisted treatments. The prepared discs were characterized by various methods after the plasma treatment. Periodontal ligament (PDL) fibroblasts were used in cell culture studies. The cell culture results showed that plasma treated 3D NWPF discs are favorable for PDL cell spreading, growth and viability due to the presence of functional groups and/or the nanotopography of their surfaces.

  16. Leptin Effects on the Regenerative Capacity of Human Periodontal Cells

    PubMed Central

    Nokhbehsaim, Marjan; Keser, Sema; Jäger, Andreas; Jepsen, Søren; Bourauel, Christoph

    2014-01-01

    Obesity is increasing throughout the globe and characterized by excess adipose tissue, which represents a complex endocrine organ. Adipose tissue secrets bioactive molecules called adipokines, which act at endocrine, paracrine, and autocrine levels. Obesity has recently been shown to be associated with periodontitis, a disease characterized by the irreversible destruction of the tooth-supporting tissues, that is, periodontium, and also with compromised periodontal healing. Although the underlying mechanisms for these associations are not clear yet, increased levels of proinflammatory adipokines, such as leptin, as found in obese individuals, might be a critical pathomechanistic link. The objective of this study was to examine the impact of leptin on the regenerative capacity of human periodontal ligament (PDL) cells and also to study the local leptin production by these cells. Leptin caused a significant downregulation of growth (TGFβ1, and VEGFA) and transcription (RUNX2) factors as well as matrix molecules (collagen, and periostin) and inhibited SMAD signaling under regenerative conditions. Moreover, the local expression of leptin and its full-length receptor was significantly downregulated by inflammatory, microbial, and biomechanical signals. This study demonstrates that the hormone leptin negatively interferes with the regenerative capacity of PDL cells, suggesting leptin as a pathomechanistic link between obesity and compromised periodontal healing. PMID:25136363

  17. Policaprolactone/polyvinylpyrrolidone/siloxane hybrid materials: Synthesis and in vitro delivery of diclofenac and biocompatibility with periodontal ligament fibroblasts.

    PubMed

    Peña, José A; Gutiérrez, Sandra J; Villamil, Jean C; Agudelo, Natalia A; Pérez, León D

    2016-01-01

    In this paper, we report the synthesis of polycaprolactone (PCL) based hybrid materials containing hydrophilic domains composed of N-vinylpyrrolidone (VP), and γ-methacryloxypropyltrimethoxysilane (MPS). The hybrid materials were obtained by RAFT copolymerization of N-vinylpyrrolidone and MPS using a pre-formed dixanthate-end-functionalized PCL as macro-chain transfer agent, followed by a post-reaction crosslinking step. The composition of the samples was determined by elemental and thermogravimetric analyses. Differential scanning calorimetry and X-ray diffraction indicated that the crystallinity of PCL decreases in the presence of the hydrophilic domains. Scanning electron microscopy images revealed that the samples present an interconnected porous structure on the swelling. Compared to PCL, the hybrid materials presented low water contact angle values and higher elastic modulus. These materials showed controlled release of diclofenac, and biocompatibility with human periodontal ligament fibroblasts. PMID:26478287

  18. Autoregulation of Periodontal Ligament Cell Phenotype and Functions by Transforming Growth Factor-β1

    PubMed Central

    Brady, T.A.; Piesco, N.P.; Buckley, M.J.; Langkamp, H.H.; Bowen, L.L.

    2016-01-01

    During orthodontic tooth movement, mechanical forces acting on periodontal ligament (PDL) cells induce the synthesis of mediators which alter the growth, differentiation, and secretory functions of cells of the PDL. Since the cells of the PDL represent a heterogeneous population, we examined mechanically stress-induced cytokine profiles in three separate clones of human osteoblast-like PDL cells. Of the four pro-inflammatory cytokines investigated, only IL-6 and TGF-β1 were up-regulated in response to mechanical stress. However, the expression of other pro-inflammatory cytokines such as IL-1β, TNF-α, or IL-8 was not observed. To understand the consequences of the increase in TGF-β1 expression following mechanical stress, we examined the effect of TGF-β1 on PDL cell phenotype and functions. TGF-β1 was mitogenic to PDL cells at concentrations between 0.4 and 10 ng/mL. Furthermore, TGF-β1 down-regulated the osteoblast-like phenotype of PDL cells, i.e., alkaline phosphatase activity, calcium phosphate nodule formation, expression of osteocalcin, and TGF-β1, in a dose-dependent manner. Although initially TGF-β1 induced expression of type I collagen mRNA, prolonged exposure to TGF-β1 down-regulated the ability of PDL cells to express type I collagen mRNA. Our results further show that, within 4 hrs, exogenously applied TGF-β1 down-regulated IL-6 expression in a dose-dependent manner, and this inhibition was sustained over a six-day period. In summary, the data suggest that mechanically stress-induced TGF-β1 expression may be a physiological mechanism to induce mitogenesis in PDL cells while down-regulating its osteoblast-like features and simultaneously reducing the IL-6-induced bone resorption. PMID:9786634

  19. Surface Chemistry of Nanoscale Mineralized Collagen Regulates Periodontal Ligament Stem Cell Fate.

    PubMed

    Fu, Yu; Liu, Shuai; Cui, Sheng-Jie; Kou, Xiao-Xing; Wang, Xue-Dong; Liu, Xiao-Mo; Sun, Yue; Wang, Gao-Nan; Liu, Yan; Zhou, Yan-Heng

    2016-06-29

    The interplay between stem cells and their extracellular microenvironment is of critical importance to the stem cell-based therapeutics in regenerative medicine. Mineralized collagen is the main component of bone extracellular matrix, but the effect of interfacial properties of mineralized collagen on subsequent cellular behaviors is unclear. This study examined the role of surface chemistry of nanoscale mineralized collagen on human periodontal ligament stem cell (hPDLSC) fate decisions. The intrafibrillarly mineralized collagen (IMC), fabricated by a biomimetic bottom-up approach, showed a bonelike hierarchy with nanohydroxyapatites (HAs) periodically embedded within fibrils. The infrared spectrum of the IMC showed the presence of phosphate, carbonate, amide I and II bands; and infrared mapping displayed uniform and higher spatial distribution of mineralization in the IMC. However, the distribution of the phosphate group differed far from that of the amide I group in the extrafibrillarly mineralized collagen (EMC), in which flowerlike HA clusters randomly depositing around the surface of the fibrils. Moreover, a large quantity of extrafibrillar HAs covered up the C═O stretch and N-H in-plane bend, resulting in substantial reduction of amide I and II bands. Cell experiments demonstrated that the hPDLSCs seeded on the IMC exhibited a highly branched, osteoblast-like polygonal shape with extended pseudopodia and thick stress fiber formation; while cells on the EMC displayed a spindle shape with less branch points and thin actin fibril formation. Furthermore, the biocompatibility of EMC was much lower than that of IMC. Interestingly, even without osteogenic induction, mRNA levels of major osteogenic differentiation genes were highly expressed in the IMC during cultivation time. These data suggest that the IMC with a similar nanotopography and surface chemistry to natural mineralized collagen directs hPDLSCs toward osteoblast differentiation, providing a promising

  20. Modeling stress-relaxation behavior of the periodontal ligament during the initial phase of orthodontic treatment.

    PubMed

    Romanyk, Dan L; Melenka, Garrett W; Carey, Jason P

    2013-09-01

    The periodontal ligament is the tissue that provides early tooth motion as a result of applied forces during orthodontic treatment: a force-displacement behavior characterized by an instantaneous displacement followed by a creep phase and a stress relaxation phase. Stress relaxation behavior is that which provides the long-term loading to and causes remodelling of the alveolar bone, which is responsible for the long-term permanent displacement of the tooth. In this study, the objective was to assess six viscoelastic models to predict stress relaxation behavior of rabbit periodontal ligament (PDL). Using rabbit stress relaxation data found in the literature, it was found that the modified superposition theory (MST) model best predicts the rabbit PDL behavior as compared to nonstrain-dependent and strain-dependent versions of the Burgers four-parameter and the five-parameter viscoelastic models, as well as predictions by Schapery's viscoelastic model. Furthermore, it is established that using a quadratic form for MST strain dependency provides more stable solutions than the cubic form seen in previous studies. PMID:23722595

  1. Effect of cyclical forces on the periodontal ligament and alveolar bone remodeling during orthodontic tooth movement

    PubMed Central

    Kalajzic, Zana; Peluso, Elizabeth Blake; Utreja, Achint; Dyment, Nathaniel; Nihara, Jun; Xu, Manshan; Chen, Jing; Uribe, Flavio; Wadhwa, Sunil

    2014-01-01

    Objective To investigate the effect of externally applied cyclical (vibratory) forces on the rate of tooth movement, the structural integrity of the periodontal ligament, and alveolar bone remodeling. Methods Twenty-six female Sprague-Dawley rats (7 weeks old) were divided into four groups: CTRL (unloaded), VBO (molars receiving a vibratory stimulus only), TMO (molars receiving an orthodontic spring only), and TMO+VB (molars receiving an orthodontic spring and the additional vibratory stimulus). In TMO and TMO+VB groups, the rat first molars were moved mesially for 2 weeks using Nickel-Titanium coil spring delivering 25 g of force. In VBO and TMO+VB groups, cyclical forces at 0.4 N and 30 Hz were applied occlusally twice a week for 10 minutes. Microfocus X-ray computed tomography analysis and tooth movement measurements were performed on the dissected rat maxillae. Tartrate-resistant acid phosphatase staining and collagen fiber assessment were performed on histological sections. Results Cyclical forces significantly inhibited the amount of tooth movement. Histological analysis showed marked disorganization of the collagen fibril structure of the periodontal ligament during tooth movement. Tooth movement caused a significant increase in osteoclast parameters on the compression side of alveolar bone and a significant decrease in bone volume fraction in the molar region compared to controls. Conclusions Tooth movement was significantly inhibited by application of cyclical forces. PMID:23937517

  2. Biomaterials for promoting periodontal regeneration in human intrabony defects: a systematic review.

    PubMed

    Sculean, Anton; Nikolidakis, Dimitris; Nikou, George; Ivanovic, Aleksandar; Chapple, Iain L C; Stavropoulos, Andreas

    2015-06-01

    Intrabony periodontal defects are a frequent complication of periodontitis and, if left untreated, may negatively affect long-term tooth prognosis. The optimal outcome of treatment in intrabony defects is considered to be the absence of bleeding on probing, the presence of shallow pockets associated with periodontal regeneration (i.e. formation of new root cementum with functionally orientated inserting periodontal ligament fibers connected to new alveolar bone) and no soft-tissue recession. A plethora of different surgical techniques, often including implantation of various types of bone graft and/or bone substitutes, root surface demineralization, guided tissue regeneration, growth and differentiation factors, enamel matrix proteins or various combinations thereof, have been employed to achieve periodontal regeneration. Despite positive observations in animal models and successful outcomes reported for many of the available regenerative techniques and materials in patients, including histologic reports, robust information on the degree to which reported clinical improvements reflect true periodontal regeneration does not exist. Thus, the aim of this review was to summarize, in a systematic manner, the available histologic evidence on the effect of reconstructive periodontal surgery using various types of biomaterials to enhance periodontal wound healing/regeneration in human intrabony defects. In addition, the inherent problems associated with performing human histologic studies and in interpreting the results, as well as certain ethical considerations, are discussed. The results of the present systematic review indicate that periodontal regeneration in human intrabony defects can be achieved to a variable extent using a range of methods and materials. Periodontal regeneration has been observed following the use of a variety of bone grafts and substitutes, guided tissue regeneration, biological factors and combinations thereof. Combination approaches appear to

  3. Allogeneic Transplantation of Periodontal Ligament-Derived Multipotent Mesenchymal Stromal Cell Sheets in Canine Critical-Size Supra-Alveolar Periodontal Defect Model

    PubMed Central

    Tsumanuma, Yuka; Iwata, Takanori; Kinoshita, Atsuhiro; Washio, Kaoru; Yoshida, Toshiyuki; Yamada, Azusa; Takagi, Ryo; Yamato, Masayuki; Okano, Teruo; Izumi, Yuichi

    2016-01-01

    Abstract Periodontitis is a chronic inflammatory disease that induces the destruction of tooth-supporting tissues, followed by tooth loss. Although several approaches have been applied to periodontal regeneration, complete periodontal regeneration has not been accomplished. Tissue engineering using a combination of cells and scaffolds is considered to be a viable alternative strategy. We have shown that autologous transplantation of periodontal ligament-derived multipotent mesenchymal stromal cell (PDL-MSC) sheets regenerates periodontal tissue in canine models. However, the indications for autologous cell transplantation in clinical situations are limited. Therefore, this study evaluated the safety and efficacy of allogeneic transplantation of PDL-MSC sheets using a canine horizontal periodontal defect model. Canine PDL-MSCs were labeled with enhanced green fluorescent protein (EGFP) and were cultured on temperature-responsive dishes. Three-layered cell sheets were transplanted around denuded root surfaces either autologously or allogeneically. A mixture of β-tricalcium phosphate and collagen gel was placed on the bone defects. Eight weeks after transplantation, dogs were euthanized and subjected to microcomputed tomography and histological analyses. RNA and DNA were extracted from the paraffin sections to verify the presence of EGFP at the transplantation site. Inflammatory markers from peripheral blood sera were quantified using an enzyme-linked immunosorbent assay. Periodontal regeneration was observed in both the autologous and the allogeneic transplantation groups. The allogeneic transplantation group showed particularly significant regeneration of newly formed cementum, which is critical for the periodontal regeneration. Serum levels of inflammatory markers from peripheral blood sera showed little difference between the autologous and allogeneic groups. EGFP amplicons were detectable in the paraffin sections of the allogeneic group. These results suggest

  4. Allogeneic Transplantation of Periodontal Ligament-Derived Multipotent Mesenchymal Stromal Cell Sheets in Canine Critical-Size Supra-Alveolar Periodontal Defect Model.

    PubMed

    Tsumanuma, Yuka; Iwata, Takanori; Kinoshita, Atsuhiro; Washio, Kaoru; Yoshida, Toshiyuki; Yamada, Azusa; Takagi, Ryo; Yamato, Masayuki; Okano, Teruo; Izumi, Yuichi

    2016-01-01

    Periodontitis is a chronic inflammatory disease that induces the destruction of tooth-supporting tissues, followed by tooth loss. Although several approaches have been applied to periodontal regeneration, complete periodontal regeneration has not been accomplished. Tissue engineering using a combination of cells and scaffolds is considered to be a viable alternative strategy. We have shown that autologous transplantation of periodontal ligament-derived multipotent mesenchymal stromal cell (PDL-MSC) sheets regenerates periodontal tissue in canine models. However, the indications for autologous cell transplantation in clinical situations are limited. Therefore, this study evaluated the safety and efficacy of allogeneic transplantation of PDL-MSC sheets using a canine horizontal periodontal defect model. Canine PDL-MSCs were labeled with enhanced green fluorescent protein (EGFP) and were cultured on temperature-responsive dishes. Three-layered cell sheets were transplanted around denuded root surfaces either autologously or allogeneically. A mixture of β-tricalcium phosphate and collagen gel was placed on the bone defects. Eight weeks after transplantation, dogs were euthanized and subjected to microcomputed tomography and histological analyses. RNA and DNA were extracted from the paraffin sections to verify the presence of EGFP at the transplantation site. Inflammatory markers from peripheral blood sera were quantified using an enzyme-linked immunosorbent assay. Periodontal regeneration was observed in both the autologous and the allogeneic transplantation groups. The allogeneic transplantation group showed particularly significant regeneration of newly formed cementum, which is critical for the periodontal regeneration. Serum levels of inflammatory markers from peripheral blood sera showed little difference between the autologous and allogeneic groups. EGFP amplicons were detectable in the paraffin sections of the allogeneic group. These results suggest that

  5. A Biofilm Pocket Model to Evaluate Different Non-Surgical Periodontal Treatment Modalities in Terms of Biofilm Removal and Reformation, Surface Alterations and Attachment of Periodontal Ligament Fibroblasts

    PubMed Central

    Hägi, Tobias T.; Klemensberger, Sabrina; Bereiter, Riccarda; Nietzsche, Sandor; Cosgarea, Raluca; Flury, Simon; Lussi, Adrian; Sculean, Anton; Eick, Sigrun

    2015-01-01

    Background and Aim There is a lack of suitable in vitro models to evaluate various treatment modalities intending to remove subgingival bacterial biofilm. Consequently, the aims of this in vitro-study were: a) to establish a pocket model enabling mechanical removal of biofilm and b) to evaluate repeated non-surgical periodontal treatment with respect to biofilm removal and reformation, surface alterations, tooth hard-substance-loss, and attachment of periodontal ligament (PDL) fibroblasts. Material and Methods Standardized human dentin specimens were colonized by multi-species biofilms for 3.5 days and subsequently placed into artificially created pockets. Non-surgical periodontal treatment was performed as follows: a) hand-instrumentation with curettes (CUR), b) ultrasonication (US), c) subgingival air-polishing using erythritol (EAP) and d) subgingival air-polishing using erythritol combined with chlorhexidine digluconate (EAP-CHX). The reduction and recolonization of bacterial counts, surface roughness (Ra and Rz), the caused tooth substance-loss (thickness) as well as the attachment of PDL fibroblasts were evaluated and statistically analyzed by means of ANOVA with Post-Hoc LSD. Results After 5 treatments, bacterial reduction in biofilms was highest when applying EAP-CHX (4 log10). The lowest reduction was found after CUR (2 log10). Additionally, substance-loss was the highest when using CUR (128±40 µm) in comparison with US (14±12 µm), EAP (6±7 µm) and EAP-CHX (11±10) µm). Surface was roughened when using CUR and US. Surfaces exposed to US and to EAP attracted the highest numbers of PDL fibroblasts. Conclusion The established biofilm model simulating a periodontal pocket combined with interchangeable placements of test specimens with multi-species biofilms enables the evaluation of different non-surgical treatment modalities on biofilm removal and surface alterations. Compared to hand instrumentation the application of ultrasonication and of air

  6. Healing of sites within the dog periodontal ligament after application of cold to the periodontal attachment apparatus.

    PubMed

    Tal, H; Kozlovsky, A; Pitaru, S

    1991-08-01

    The potential of periodontal ligament-derived tissues to regenerate periodontal attachment after cryosurgical trauma to the PDL in dogs was evaluated. The buccal alveolar plate of each canine tooth was exposed by a semi-lunar excision. A 3 mm thick cryoprobe, cooled to -81 degrees C, was placed on the bone 5 mm apical to the crest for 10 s. This induced cellular devitalization in the bone directly in contact with the probe and the PDL under it. The freezing-thawing cycle was repeated 3 times. Control sites were sham-operated at room temperature. Histologic sections from the center of the lesions were obtained from 1 h, 48 h and 30 d specimens. 1-h control and experimental histologic sections were similar. At 48 h post-surgery, the cellular component of the frozen PDL could not be identified and inflammatory response was minimal. The collagenous framework, however, appeared to form a continuum between the alveolar bone and cementum. Lacunae in the bone at the frozen segment were empty. The injured PDL was surrounded by normal PDL. Control specimens appeared normal. At 30 d, the PDL space in the frozen segments was populated by PDL-like tissue which did not differ significantly from the PDL coronal or apical to it. Collagen fibers appeared to be attached to the cementum on one side and to the alveolar bone on the other. Bone resorption or ankylosis was not observed in the experimental sites. It is suggested that the extracellular matrix in the devitalized area was preserved, supporting regeneration of the cryolesion. PMID:1894749

  7. Osteoblast histogenesis in periodontal ligament and tibial metaphysis during simulated weightlessness

    NASA Technical Reports Server (NTRS)

    Fielder, Paul J.; Morey, Emily R.; Roberts, W. Eugene

    1986-01-01

    Utilizing the nuclear morphometric assay for osteoblast histogenesis, the effect of simulated weightlessness (SW) on the relative numbers of the periodontal ligament (PDL) osteoblast progenitors and on the total number of osteogenic cells was determined in rats. Weightlessness was simulated by subjecting rats to continuous 30-deg head-down posture using a modified back-harness device of Morey (1979). The response of a partially unloaded, weight-bearing bone, tibial primary spongiosa (PS), was compared to a normally loaded, nonweight-bearing PDL bone. Data indicated a similar differentiation sequence in PS and PDL, which suggests that these bones might be sensitive to the same systemic factors. Preosteoblast numbers were seen to decrease in both nonweight-bearing and weight-bearing bones during SW (compared with rats not exposed to SW), indicating the importance of systemic mediators, such as cephalad fluid shift, physiological stress, and/or growth retardation.

  8. Cell attachment of periodontal ligament cells on commercially pure titanium at the early stage.

    PubMed

    Zhou, Bin; Cao, Yingguang; Wu, Lijuan; Yuan, Yanxiang; Zeng, Yinping

    2004-01-01

    In order to study the character of periodontal ligament cells (PDLCs) attaching on commercially pure titanium (cpTi) by morphology and metrology on the early stage (24 h), 1 x 10(5)/ml PDLCs in 2 ml culture medium were seeded on cpTi discs fixed in 24-well culture plates. Morphology of cell attachment was observed by contrast phase microscope, scanning electron microscope (SEM) and fluroscence microscopy. Cell adhesion was analyzed by MTT at 0.5, 1, 2, 4 h respectively. PDLCs could attach and spread on cpTi discs. SEM showed that PDLCs had pseudopod-like protuberance. PDLCs showed different attaching phases and reached saturation in cell number at 2 h. It was concluded that PDLCs had good biocompatibility with cpTi, and showed a regular and dynamic pattern in the process of attaching to cpTi. PMID:15315359

  9. Experimentally Determined Mechanical Properties of, and Models for, the Periodontal Ligament: Critical Review of Current Literature

    PubMed Central

    Fill, Ted S.; Carey, Jason P.; Toogood, Roger W.; Major, Paul W.

    2011-01-01

    Introduction. This review is intended to highlight and discuss discrepancies in the literature of the periodontal ligament's (PDL) mechanical properties and the various experimental approaches used to measure them. Methods. Searches were performed on biomechanical and orthodontic publications (in databases: Compendex, EMBASE, MEDLINE, PubMed, ScienceDirect, and Scopus). Results. The review revealed that significant variations exist, some on the order of six orders of magnitude, in the PDL's elastic constants and mechanical properties. Possible explanations may be attributable to different experimental approaches and assumptions. Conclusions. The discrepancies highlight the need for further research into PDL properties under various clinical and experimental loading conditions. Better understanding of the PDL's biomechanical behavior under physiologic and traumatic loading conditions might enhance the understanding of the PDL's biologic reaction in health and disease. Providing a greater insight into the response of the PDL would be instrumental to orthodontists and engineers for designing more predictable, and therefore more efficacious, orthodontic appliances. PMID:21772924

  10. Biomechanical behavior of bovine periodontal ligament: Experimental tests and constitutive model.

    PubMed

    Oskui, Iman Z; Hashemi, Ata; Jafarzadeh, Hamid

    2016-09-01

    A viscohyperelastic constitutive model with the use of the internal variables approach was formulated to evaluate the nonlinear elastic and time dependent anisotropic mechanical behavior of the periodontal ligament (PDL). Since the relaxation response was found to depend on the applied stretch, the adoption of the nonlinear viscous behavior in the present model was necessary. In this paper, Helmholtz free energy function was assigned to the material as the sum of hyperelastic and viscous terms which is based on the physical concept of internal variables. The constitutive model parameters were evaluated from the comparison of the proposed model and experimental data. For this purpose, tensile response of the bovine PDL samples under different stretch rates was obtained. The good correspondence between the proposed model and the experimental results confirmed the capability of the model to interpret the stretch rate behavior of the PDL. Moreover, the validity of structural model parameters was checked according to the results of the stress relaxation tests. PMID:27315371

  11. Transdifferentiation of periodontal ligament-derived stem cells into retinal ganglion-like cells and its microRNA signature

    PubMed Central

    Ng, Tsz Kin; Yung, Jasmine S. Y.; Choy, Kwong Wai; Cao, Di; Leung, Christopher K. S.; Cheung, Herman S.; Pang, Chi Pui

    2015-01-01

    Retinal diseases are the leading causes of irreversible visual impairment and blindness in the developed countries. Human retina has limited regenerative power to replace cell loss. Stem cell replacement therapy has been proposed as a viable option. Previously, we have induced human adult periodontal ligament stem cells (PDLSCs) to the retinal lineage. In this study, we modified our induction protocol to direct human adult PDLSCs into retinal ganglion-like cells and determined the microRNA (miRNA) signature of this transdifferentiation process. The differentiated PDLSCs demonstrated the characteristics of functional neurons as they expressed neuronal and retinal ganglion cell markers (ATOH7, POU4F2, β-III tubulin, MAP2, TAU, NEUROD1 and SIX3), formed synapses and showed glutamate-induced calcium responses as well as spontaneous electrical activities. The global miRNA expression profiling identified 44 upregulated and 27 downregulated human miRNAs after retinal induction. Gene ontology analysis of the predicted miRNA target genes confirmed the transdifferentiation is closely related to neuronal differentiation processes. Furthermore, the expressions of 2 miRNA-targeted candidates, VEGF and PTEN, were significantly upregulated during the induction process. This study identified the transdifferentiation process of human adult stem cells into retinal ganglion-like cells and revealed the involvement of both genetic and miRNA regulatory mechanisms. PMID:26549845

  12. PERK-eIF2α-ATF4 pathway mediated by endoplasmic reticulum stress response is involved in osteodifferentiation of human periodontal ligament cells under cyclic mechanical force.

    PubMed

    Yang, Shuang-Yan; Wei, Fu-Lan; Hu, Li-Hua; Wang, Chun-Ling

    2016-08-01

    To prevent excess accumulation of unfolded proteins in endoplasmic reticulum (ER), eukaryotic cells have signaling pathways from the ER to the cytosol or nucleus. These processes are known as the endoplasmic reticulum stress (ERS) response. Protein kinase R like endoplasmic reticulum kinase (PERK) is a major transducer of the ERS response and it directly phosphorylate α-subunit of eukaryotic initiation factor 2 (eIF2α), resulting in translational attenuation. Phosphorylated eIF2α specifically promoted the translation of the activating transcription factor 4 (ATF4). ATF4 is a known important transcription factor which plays a pivotal role in osteoblast differentiation and bone formation. Furthermore, ATF4 is a downstream target of PERK. Studies have shown that PERK-eIF2α-ATF4 signal pathway mediated by ERS was involved in osteoblastic differentiation of osteoblasts. We have known that orthodontic tooth movement is a process of periodontal ligament cells (PDLCs) osteodifferentiation and alveolar bone remodeling under mechanical force. However, the involvement of PERK-eIF2α-ATF4 signal pathway mediated by ERS in osteogenic differentiation of PDLCs under mechanical force has not been unclear. In our study, we applied the cyclic mechanical force at 10% elongation with 0.5Hz to mimic occlusal force, and explored whether PERK-eIF2α-ATF4 signaling pathway mediated by ERS involved in osteogenic differentiation of PDLCs under mechanical force. Firstly, cyclic mechanical force will induce ERS and intensify several osteoblast marker genes (ATF4, OCN, and BSP). Next, we found that PERK overexpression increased eIF2α phosphorylation and expression of ATF4, furthermore induced BSP, OCN expression, thus it will promote osteodifferentiation of hPDLCs; mechanical force could promote this effect. However, PERK(-/-) cells showed the opposite changes, which will inhibit osteodifferentiation of hPDLCs. Taken together, our study proved that PERK-eIF2α-ATF4 signaling pathway

  13. In vitro Osteogenic impulse effect of Dexamethasone on periodontal ligament stem cells

    PubMed Central

    Roozegar, Mohamad Ali; Mohammadi, Tayebeh Malek; Havasian, Mohamad Reza; Panahi, Jafar; Hashemian, Amirreza; Amraei, Mansur; Hoshmand, Behzad

    2015-01-01

    Periodontium is a complex organ composed of mineralized epithelial and connective tissue. Dexamethasone could stimulate proliferation of osteoblast and fibroblasts. This study aimed to assess the osteogenic effect of dexamethasone on periodental ligament (PDL) stem cells. PDL stem cells were collected from periodontal ligament tissue of root of extracted premolar of young and healthy people. The stem cells were cultured in α-MEM Medium in three groups, one group with basic medium contains (α- MEM and FBS 10 % and 50 mmol of β_ gelisrophosphat and L_ ascorbic acid µg/ml), the second group: basic medium with dexamethasone and the third one: basic medium without any osteogenic stimulant. Mineralization of cellular layer was analyzed with Alizarin red stain method. Osteogenic analysis was done by Alkaline phosphates and calcium test. These analysis indicated that the amount of intra-cellular calcium and alkaline phosphates in the Dexamethasone group was far more than the control and basic group (P<0.05). The results of Alizarin red stain indicated more mineralization of cultured cells in Dexamethasone group (P<0.05). The study results showed that Dexamethasone has significant osteogenic effect on PDL stem cells and further studies are recommended to evaluate its effect on treatment of bone disorders. PMID:25848170

  14. Evaluation of the resolving potency of a novel reconstruction filter on periodontal ligament space with dental cone-beam CT: a quantitative phantom study

    NASA Astrophysics Data System (ADS)

    Houno, Yuuki; Hishikawa, Toshimitsu; Gotoh, Ken-ichi; Naitoh, Munetaka; Ariji, Eiichiro; Kodera, Yoshie

    2014-03-01

    Diagnosis of the alveolar bone condition is important for the treatment planning of periodontal disease. Especially the determination of periodontal ligament space is the most important remark because it represents the periodontal tissue support for tooth retention. However, owing to the image blur of the current cone-beam CT (CBCT) imaging technique, the periodontal ligament space is difficult to visualize. In this study, we developed an original periodontal ligament phantom (PLP) and evaluated the image quality of simulated periodontal ligament space using a novel reconstruction filter for CBCT that emphasized high frequency component. PLP was composed from two resin blocks of different materials, the bone equivalent block and the dentine equivalent block. They were assembled to make continuously changing space from 0.0 to 1.0 millimeter that mimics periodontal ligament space. PLP was placed in water and the image was obtained by using Alphard-3030 dental cone-beam CT (Asahi Roentgen Industry Co., Ltd.). Then we reconstructed the projection data with a novel reconstruction filter. The axial images were compared with conventional reconstructed images. In novel filter reconstruction images, 0.4 millimeter of the space width was steadily detected by calculation of pixel value, on the other hand 0.6 millimeter was in conventional images. With our method, the resolving potency of conebeam CT images was improved.

  15. Functional Local Renin-Angiotensin System in Human and Rat Periodontal Tissue

    PubMed Central

    Santos, Carlos F.; Morandini, Ana C.; Dionísio, Thiago J.; Faria, Flávio A.; Lima, Marta C.; Figueiredo, Caio M.; Colombini-Ishikiriama, Bella L.; Sipert, Carla R.; Maciel, Rubens P.; Akashi, Ana P.; Souza, Gabriela P.; Garlet, Gustavo P.; Rodini, Camila O.; Amaral, Sandra L.; Becari, Christiane; Salgado, Maria C.; Oliveira, Eduardo B.; Matus, Isaac; Didier, Daniela N.; Greene, Andrew S.

    2015-01-01

    The initiation or progression of periodontitis might involve a local renin-angiotensin system (RAS) in periodontal tissue. The aim of this study was to further characterize the local RAS in human and rat periodontal tissues between healthy and periodontally-affected tissue. Components of the RAS were investigated using in vitro, ex vivo and in vivo experiments involving both human and Wistar rat periodontium. Although not upregulated when challenged with P. gingivalis-lipopolysaccharide, human gingival and periodontal ligament fibroblasts expressed RAS components. Likewise, healthy and inflamed human gingiva expressed RAS components, some of which were shown to be functional, yet no differences in expression were found between healthy and diseased gingiva. However, in inflamed tissue the immunoreactivity was greater for the AT1R compared to AT2R in fibroblasts. When compared to healthy tissue, ACE activity was increased in human gingiva from volunteers with gingivitis. Human-gingiva homogenates generated Ang II, Ang 1-9 and Ang 1-7 when incubated with precursors. In gingiva homogenates, Ang II formation from Ang I was nearly abolished only when captopril and chymostatin were combined. Ang 1-7 formation was significantly greater when human gingiva homogenates were incubated with chymostatin alone compared to incubation without any inhibitor, only captopril, or captopril and chymostatin. In rat gingiva, RAS components were also found; their expression was not different between healthy and experimentally induced periodontitis (EP) groups. However, renin inhibition (aliskiren) and an AT1R antagonist (losartan) significantly blocked EP-alveolar-bone loss in rats. Collectively, these data are consistent with the hypothesis that a local RAS system is not only present but is also functional in both human and rat periodontal tissue. Furthermore, blocking AT1R and renin can significantly prevent periodontal bone loss induced by EP in rats. PMID:26244896

  16. A micromechanically-based, three-dimensional interface finite element for the modelling of the periodontal ligament.

    PubMed

    Genna, Francesco

    2006-08-01

    Some ideas are presented for the implementation of an interface finite element capable to model in 3-dimensions several mechanical features of the periodontal ligament. Such an element is based on a simple 2-cable micromechanical model, able to reproduce the periodontal ligament stiffness and strength under any loading condition, including the pure torsion of a tooth. A single cable represents a sufficiently populated sample of collagen fibres, each with an initially crimped geometry; a single collagen fibre can provide a mechanical response, in tension, only when it is completely uncoiled. The macroscopic interface behaviour is obtained by statistical integrations over the uncoiled length of each collagen fibre, up to the fibre failure. Such a model can reproduce the periodontal ligament anisotropy due to the variable fibre orientation along the tooth root, its different behaviour in tension/compression/shear, its different behaviour for extrusive/intrusive loading, and so forth. Some numerical examples illustrate the potentialities of this interface element, quite simple in essence but rather complete from an engineering viewpoint. PMID:17144047

  17. An electron microscopic radioautographic study of collagen secretion in periodontal ligament fibroblasts of the mouse: I. Normal fibroblasts

    SciTech Connect

    Cho, M.I.; Garant, P.R.

    1981-12-01

    Analysis of electron microscopic radioautographs revealed a maximum labeling with /sup 3/H-proline of rough endoplasmic reticulum (RER) at 3 minutes, Golgi saccules 1 and 2 at 10 minutes, Golgi saccules type 3 at 20 minutes, and presecretory and secretory granules at 30 minutes. Labeling of the extra-cellular collagen matrix occurred at 30 minutes and increased with time. These observations suggest that pro-a-chains of collagen in periodontal ligament fibroblasts are synthesized in the RER and transported to the Golgi apparatus within 10 minutes. These chains then undergo parallel alignment in Golgi saccules type 2 and form segment-long-spacing-like crystallites in Golgi saccules type 3 between 10 and 20 minutes. The peak labeling of presecretory granules and mature secretory granules in small amounts at 30 minutes and the rapid increase in labeling of extracellular collagen matrix which begins at 30 minutes, indicates that the formation of secretory granules requires approximately 30 minutes and that a rapid system of secretory granule translocation exists in periodontal ligament fibroblasts. This evidence further supports the previously published morphologic evidence for a microtubule-dependent system of collagen secretion in periodontal ligament fibroblasts (Cho and Garant, 1981b).

  18. α11β1 Integrin-Dependent Regulation of Periodontal Ligament Function in the Erupting Mouse Incisor

    PubMed Central

    Popova, Svetlana N.; Barczyk, Malgorzata; Tiger, Carl-Fredrik; Beertsen, Wouter; Zigrino, Paola; Aszodi, Attila; Miosge, Nicolai; Forsberg, Erik; Gullberg, Donald

    2007-01-01

    The fibroblast integrin α11β1 is a key receptor for fibrillar collagens. To study the potential function of α11 in vivo, we generated a null allele of the α11 gene. Integrin α11−/− mice are viable and fertile but display dwarfism with increased mortality, most probably due to severely defective incisors. Mutant incisors are characterized by disorganized periodontal ligaments, whereas molar ligaments appear normal. The primary defect in the incisor ligament leads to halted tooth eruption. α11β1-defective embryonic fibroblasts displayed severe defects in vitro, characterized by (i) greatly reduced cell adhesion and spreading on collagen I, (ii) reduced ability to retract collagen lattices, and (iii) reduced cell proliferation. Analysis of matrix metalloproteinase in vitro and in vivo revealed disturbed MMP13 and MMP14 synthesis in α11−/− cells. We show that α11β1 is the major receptor for collagen I on mouse embryonic fibroblasts and suggest that α11β1 integrin is specifically required on periodontal ligament fibroblasts for cell migration and collagen reorganization to help generate the forces needed for axial tooth movement. Our data show a unique role for α11β1 integrin during tooth eruption. PMID:17420280

  19. Immunolocalization of lubricin in the rat periodontal ligament during experimental tooth movement.

    PubMed

    Leonardi, Rosalia; Loreto, Carla; Talic, Nabeel; Caltabiano, Rosario; Musumeci, Giuseppe

    2012-11-01

    Lubricin is a protein which contributes to the boundary lubrication, facilitating low friction levels at the interfacing surfaces of joints. In tendons and ligaments it facilitates the relative movement of collagen bundles. Its expression is affected by mechanical signals and cytokines. During application of orthodontic forces to teeth, there is a transduction of mechanical forces to the cells of the periodontal ligament (PDL), which triggers several biological reactions causing the synthesis of prostaglandins, cytokines and growth factors. The aim of the present study was to examine the immunolocalization of lubricin and to evaluate if it is time-dependently and differentially detected within the PDL following the application of orthodontic forces to create areas of compression and tension. This was achieved by placing elastic bands between the maxillary first and second molars of 16 male Sprague-Dawley rats (each weighing 120-200g) for 12 and 24h. The molar-bearing segments were dissected and processed for histological and immunohistochemical examination. Binding of a monoclonal antibody was used to evaluate lubricin localization using an indirect streptavidin/biotin immunperoxidase technique. Lubricin, was constitutively expressed in the PDL of rat molars. After the experimental force was applied to the tooth, lubricin was down-regulated, on both sides (compression and tension) of the PDL, in a time-dependent fashion, although to a different extent, being at any time more expressed on the tension side. Furthermore, in every sample, almost all PDL cells in the adjacent tooth cementum and alveolar bone, were more heavily immunolabeled by lubricin antibody, contrary to those located in the central portion of the PDL. Lubricin expression therefore seems related to PDL remodeling and tooth displacement following the application of an orthodontic force, and it appears that lubricin may play an important role during tooth movement. PMID:22209395

  20. Effect of the simulated periodontal ligament on cast post-and-core removal using an ultrasonic device

    PubMed Central

    BRITO-JUNIOR, Manoel; BRAGA, Neilor Mateus Antunes; RODRIGUES, Danilo Costa; CAMILO, Carla Cristina; FARIA-E-SILVA, André Luis

    2010-01-01

    Objective The aim of this study was to evaluate the effect of simulated periodontal ligament (SPDL) on custom cast dowel and core removal by ultrasonic vibration. Material and Methods Thirty-two human maxillary canines were included in resin cylinders with or without SPDL made from polyether impression material. In order to allow tensile testing, the roots included in resin cylinders with SPDL were fixed to cylinders with two stainless steel wires. Post-holes were prepared by standardizing the length at 8 mm and root canal impressions were made with self-cured resin acrylic. Cast dowel and core sets were fabricated and luted with Panavia F resin cement. Half of the samples were submitted to ultrasonic vibration before the tensile test. Data were analyzed statistically by two-way ANOVA and Tukey's post-hoc tests (p<0.05). Results The ultrasonic vibration reduced the tensile strength of the samples directly included in resin cylinders. There was no difference between the values, whether or not ultrasonic vibration was used, when the PDL was simulated. However, the presence of SPDL affected the tensile strength values even when no ultrasonic vibration was applied. Conclusion Simulation of PDL has an effect on both ultrasonic vibration and tensile testing. PMID:21085812

  1. In vitro phagocytosis of exogenous collagen by fibroblasts from the periodontal ligament: an electron microscopic study.

    PubMed Central

    Svoboda, E L; Brunette, D M; Melcher, A H

    1979-01-01

    There have been numerous electron microscopic reports of apparent phagocytosis of collagen by fibroblasts and other cells in vivo. We have developed an in vitro system which, to the best of our knowledge, will permit for the first time the study of regulatory mechanisms governing phagocytosis and digestion of collagen fibres. Cells were cultured from explants of monkey periodontal ligament, subcultured, and grown to confluence in alpha-MEM plus 15% fetal calf serum plus antibiotics. The confluent cells were then cultured together with minced rat tail tendon collagen in alpha-MEM lacking proline, lysine, glycine and fetal calf serum for up to 7 days, after which they were processed for electron microscopy. Intracellular collagen profiles could be seen in cultured cells that were associated with exogenous collagen fibrils as early as 24 hours after addition of the collagen. Through electron microscopic examination of serial sections of the culture, we have demonstrated: (1) that fibroblasts can phagocytose collagen; (2) that the observed intracellular collagen is not the result of aggregation of endogenous synthesized collagen; (3) that it is not possible to base a decision as to whether a collagen fibril has been phagocytosed in whole or in part by the type of vesicle with which it is associated; (4) that cleavage of collagen into small pieces may not be a necessary prelude to its phagocytosis. Images Fig. 1 Fig. 2 Fig. 4 (cont.) Fig. 4 Fig. 6 (cont.) Fig. 6 Fig. 7 Fig. 8 Fig. 9 PMID:108237

  2. The role of the fluid phase in the viscous response of bovine periodontal ligament.

    PubMed

    Bergomi, Marzio; Cugnoni, Joël; Botsis, John; Belser, Urs C; Anselm Wiskott, H W

    2010-04-19

    The mechanical response of the periodontal ligament (PDL) is complex. This tissue responds as a hyperelastic solid when pulled in tension while demonstrating a viscous behavior under compression. This intricacy is reflected in the tissue's morphology, which comprises fibers, glycosaminoglycans, a jagged interface with the surrounding porous bone and an extensive vascular network. In the present study we offer an analysis of the viscous behavior and the interplay between the fibrous matrix and its fluid phase. Cylindrical specimens comprising layers of dentine, PDL and bone were extracted from bovine first molars and affixed to a tensile-compressive loading machine. The viscous properties of the tissue were analyzed (1) by subjecting the specimens to sinusoidal displacements at various frequencies and (2) by cycling the specimens in 'fully saturated' and in 'partially dry' conditions. Both modes assisted in determining the contribution of the fluid phase to the mechanical response. It was concluded that: (1) PDL showed pseudo-plastic viscous features for cyclic compressive loading, (2) these viscous features essentially resulted from interactions between the porous matrix and unbound fluid content of the tissue. Removing the liquid from the PDL largely eliminates its damping effect in compression. PMID:20185135

  3. Nuclear morphometric analysis of osteoblast precursor cells in periodontal ligament, SL-3 rats

    NASA Technical Reports Server (NTRS)

    Roberts, W. E.; Fielder, P. J.; Rosenoer, L. M.; Maese, A. C.; Gonsalves, M. R.; Morey, E. R.; Morey-Holton, E. R. (Principal Investigator)

    1987-01-01

    Five small (55 days old, 196 +/- 5 g) (mean +/- SE) and five large (83 days old, 382 +/- 4 g) Sprague-Dawley strain, specific pathogen-free rats were exposed to a 7-day spaceflight and 12-h postflight recovery period. As measured in 3-micron sections, periodontal ligament (PDL) fibroblastlike cells were classified according to nuclear size: A + A' (40-79), B (80-119), C (120-169), and D (greater than or equal to 170 microns 3). Since the histogenesis sequence is A----A'----C----D----osteoblast, the relative incidence of A + A' to C + D is an osteogenic index. No difference in A + A' or C + D cells in small rats may reflect partial recovery of preosteoblast formation (A----C) during the 12-h postflight period. Large flight rats demonstrated increased numbers of A + A', indicating an inhibition of preosteoblast formation (A----C). At least in the older group, a 7-day flight is adequate to reduce PDL osteogenic potential (inhibition in PDL osteoblast differentiation and/or specific attrition of C + D cells) that does not recover by 12-h postflight.

  4. The Biomechanical Function of Periodontal Ligament Fibres in Orthodontic Tooth Movement

    PubMed Central

    McCormack, Steven W.; Witzel, Ulrich; Watson, Peter J.; Fagan, Michael J.; Gröning, Flora

    2014-01-01

    Orthodontic tooth movement occurs as a result of resorption and formation of the alveolar bone due to an applied load, but the stimulus responsible for triggering orthodontic tooth movement remains the subject of debate. It has been suggested that the periodontal ligament (PDL) plays a key role. However, the mechanical function of the PDL in orthodontic tooth movement is not well understood as most mechanical models of the PDL to date have ignored the fibrous structure of the PDL. In this study we use finite element (FE) analysis to investigate the strains in the alveolar bone due to occlusal and orthodontic loads when PDL is modelled as a fibrous structure as compared to modelling PDL as a layer of solid material. The results show that the tension-only nature of the fibres essentially suspends the tooth in the tooth socket and their inclusion in FE models makes a significant difference to both the magnitude and distribution of strains produced in the surrounding bone. The results indicate that the PDL fibres have a very important role in load transfer between the teeth and alveolar bone and should be considered in FE studies investigating the biomechanics of orthodontic tooth movement. PMID:25036099

  5. A histopathological study of the role of periodontal ligament tissue in root resorption in the rat.

    PubMed

    Shiraishi, C; Hara, Y; Abe, Y; Ukai, T; Kato, I

    2001-02-01

    Whether periodontal ligament (PDL) tissue is capable of inducing root resorption was examined. The distal root of the rat molar was sectioned at the furcation and the PDL tissue removed from the root (non-PDL group, n=40). The distal root with the PDL intact was also prepared (PDL-intact group, n=40). The roots were transplanted into the dorsal skin of the rat. On the 1st, 3rd, 5th, 7th, 10th, 14th, 21st or 28th day after transplantation, the roots were removed together with surrounding dorsal subcutaneous tissue and were fixed, demineralized and embedded in paraffin. Serial sections from each block were stained with haematoxylin and eosin or by the tartrate-resistant acid phosphatase (TRAP) method to observe root-resorbing cell formation. Cyclo-oxygenase-2 (COX2) was also detected immunohistologically to examine prostaglandin E(2) production. On the 7th day after transplantation, multinucleated root-resorbing cells with TRAP were observed in the PDL-intact group. The number of TRAP-positive cells peaked on the 10th day after transplantation. COX2-positive cells were observed in PDL during the early experimental stages. No root resorption was seen in the non-PDL group. These results suggest that PDL tissue is involved in the formation of root-resorbing cells and root resorption. PMID:11163317

  6. The biomechanical function of periodontal ligament fibres in orthodontic tooth movement.

    PubMed

    McCormack, Steven W; Witzel, Ulrich; Watson, Peter J; Fagan, Michael J; Gröning, Flora

    2014-01-01

    Orthodontic tooth movement occurs as a result of resorption and formation of the alveolar bone due to an applied load, but the stimulus responsible for triggering orthodontic tooth movement remains the subject of debate. It has been suggested that the periodontal ligament (PDL) plays a key role. However, the mechanical function of the PDL in orthodontic tooth movement is not well understood as most mechanical models of the PDL to date have ignored the fibrous structure of the PDL. In this study we use finite element (FE) analysis to investigate the strains in the alveolar bone due to occlusal and orthodontic loads when PDL is modelled as a fibrous structure as compared to modelling PDL as a layer of solid material. The results show that the tension-only nature of the fibres essentially suspends the tooth in the tooth socket and their inclusion in FE models makes a significant difference to both the magnitude and distribution of strains produced in the surrounding bone. The results indicate that the PDL fibres have a very important role in load transfer between the teeth and alveolar bone and should be considered in FE studies investigating the biomechanics of orthodontic tooth movement. PMID:25036099

  7. Evaluation of Periodontal Ligament Cell Viability in Three Different Storage Media: An in Vitro Study

    PubMed Central

    Sharma, Sanjay; Reddy, Y. G.; Mittal, Rakesh; Agarwal, Vishal; Singh, Chanchal; Singh, Amandeep

    2015-01-01

    Objectives: This study was undertaken to evaluate the viability of periodontal ligament (PDL) cells of avulsed teeth in three different storage media. Materials and Methods: Forty-five premolars extracted for orthodontic therapeutic purposes were randomly and equally divided into three groups based on storage media used [Group I: milk (control); Group II: aloe vera (experimental); Group III: egg white (experimental)]. Following extractions, the teeth were placed in one of the three different storage media for 30 minutes, following which the scrapings of the PDL from these teeth were collected in Falcon tubes containing collagenase enzyme in 2.5 mL of phosphate buffered saline. The tubes were subsequently incubated for 30 minutes and centrifuged for five minutes at 800 rpm. The obtained PDL cells were stained with Trypan Blue and were observed under optical microscope. The percentage of viable cells was calculated. Results: Aloe vera showed the highest percentage of viable cells (114.3±8.0), followed by egg white (100.9±6.3) and milk (101.1±7.3). Conclusion: Within the limitations of this study, it appears that aloe vera maintains PDL cell viability better than egg white or milk. PMID:26877742

  8. Periodontal ligament injection in the dog primary dentition: spread of local anaesthetic solution.

    PubMed

    Tagger, E; Tagger, M; Sarnat, H; Mass, E

    1994-09-01

    The spread of local anaesthetic solution administered with a pressure syringe has not been studied as extensively in young animals having primary or mixed dentitions as in adult animals. The purpose of this investigation was to study the distribution of local anaesthetic solution injected into the periodontal ligament of young dogs. India ink was added to carpules containing 2% lidocaine and 1:100,000 epinephrine, and the spread of solution was examined macroscopically and microscopically. Injections were made with a pressure syringe (Ligmaject) at 58 sites mesial and distal to primary teeth in five dogs aged 3-9 months. Three dogs were killed within 12 hours, the other two after 5 days. Spread of the ink was studied in non-decalcified slabs, in three-dimensional cleared specimens, and in histological sections. The solution usually reached the alveolar bone crest, seeped under the periosteum and alongside vascular channels into bone marrow, reaching natural cavities such as the crypts of tooth buds and the mandibular canal. The ink did not penetrate into the enamel organ or contact the permanent tooth buds. The solution appeared to spread along the path of least resistance, governed by the intricacies of anatomical structures and fascial planes. Therefore the risk of mechanical damage to permanent tooth germs appears to be minimal. PMID:7811670

  9. Neurogenesis of neural crest-derived periodontal ligament stem cells by EGF and bFGF.

    PubMed

    Fortino, Veronica R; Chen, Ren-Shiang; Pelaez, Daniel; Cheung, Herman S

    2014-04-01

    Neuroregenerative medicine is an ever-growing field in which regeneration of lost cells/tissues due to a neurodegenerative disease is the ultimate goal. With the scarcity of available replacement alternatives, stem cells provide an attractive source for regenerating neural tissue. While many stem cell sources exist, including: mesenchymal stem cells, embryonic stem cells, and induced pluripotent stem cells, the limited cellular potency, technical difficulties, and ethical considerations associated with these make finding alternate sources a desirable goal. Periodontal ligament stem cells (PDLSCs) derived from the neural crest were induced into neural-like cells using a combination of epidermal growth factor, and basic fibroblast growth factor. Morphological changes were evident in our treated group, seen under both light microscopy and scanning electron microscopy. A statistically significant increase in the expression of neuron-specific β-tubulin III and the neural stem/progenitor cell marker nestin, along with positive immunohistochemical staining for glial fibrillary acidic protein, demonstrated the success of our treatment in inducing both neuronal and glial phenotypes. Positive staining for synaptophysin demonstrated neural connections and electrophysiological recordings indicated that when subjected to whole-cell patch clamping, our treated cells displayed inward currents conducted through voltage-gated sodium (Na(+) ) channels. Taken together, our results indicate the success of our treatment in inducing PDLSCs to neural-like cells. The ease of sourcing and expansion, their embryologic neural crest origin, and the lack of ethical implications in their use make PDLSCs an attractive source for use in neuroregenerative medicine. PMID:24105823

  10. GCN5 modulates osteogenic differentiation of periodontal ligament stem cells through DKK1 acetylation in inflammatory microenvironment

    PubMed Central

    Li, Bei; Sun, Jin; Dong, Zhiwei; Xue, Peng; He, Xiaoning; Liao, Li; Yuan, Lin; Jin, Yan

    2016-01-01

    Periodontal ligament stem cells (PDLSCs) from periodontitis patients showed defective osteogenic differentiation. However, the mechanism of impaired osteogenic differentiation of PDLSCs in inflammatory microenvironments is still unclear. In this study, we found that inflammation in the microenvironment resulted in downregulation of histone acetyltransferase GCN5 expression and lack of GCN5 caused decreased osteogenic differentiation of PDLSCs. Previous study showed activated Wnt/β-cateinin pathway of PDLSCs resulted in defective osteogenic differentiation. Here we found knockdown of GCN5 decreased the expression of DKK1, an inhibitor of Wnt/β-cateinin pathway, thus activated Wnt/β-catenin pathway of PDLSCs. Mechanistically, GCN5 regulated DKK1 expression by acetylation of Histone H3 lysine 9 (H3K9) and Histone H3 lysine 14 (H3K14) at its promoter region. Interestingly, we found that in vivo injection of aspirin rescued the periodontitis of rats through inhibiting inflammation and upregulating GCN5 expression. Furthermore, aspirin treatment of PDLSCs upregulated GCN5 expression and increased osteogenic differentiation of PDLSCs. In conclusion, GCN5 plays a protective role in periodontitis through acetylation of DKK1 and applying drugs targeting GCN5, such as aspirin, could be a new approach for periodontitis treatment. PMID:27216891

  11. GCN5 modulates osteogenic differentiation of periodontal ligament stem cells through DKK1 acetylation in inflammatory microenvironment.

    PubMed

    Li, Bei; Sun, Jin; Dong, Zhiwei; Xue, Peng; He, Xiaoning; Liao, Li; Yuan, Lin; Jin, Yan

    2016-01-01

    Periodontal ligament stem cells (PDLSCs) from periodontitis patients showed defective osteogenic differentiation. However, the mechanism of impaired osteogenic differentiation of PDLSCs in inflammatory microenvironments is still unclear. In this study, we found that inflammation in the microenvironment resulted in downregulation of histone acetyltransferase GCN5 expression and lack of GCN5 caused decreased osteogenic differentiation of PDLSCs. Previous study showed activated Wnt/β-cateinin pathway of PDLSCs resulted in defective osteogenic differentiation. Here we found knockdown of GCN5 decreased the expression of DKK1, an inhibitor of Wnt/β-cateinin pathway, thus activated Wnt/β-catenin pathway of PDLSCs. Mechanistically, GCN5 regulated DKK1 expression by acetylation of Histone H3 lysine 9 (H3K9) and Histone H3 lysine 14 (H3K14) at its promoter region. Interestingly, we found that in vivo injection of aspirin rescued the periodontitis of rats through inhibiting inflammation and upregulating GCN5 expression. Furthermore, aspirin treatment of PDLSCs upregulated GCN5 expression and increased osteogenic differentiation of PDLSCs. In conclusion, GCN5 plays a protective role in periodontitis through acetylation of DKK1 and applying drugs targeting GCN5, such as aspirin, could be a new approach for periodontitis treatment. PMID:27216891

  12. In vitro models of periodontal cells: a comparative study of long-term gingival, periodontal ligament and alveolar bone cell cultures in the presence of beta-glycerophosphate and dexamethasone.

    PubMed

    Cabral, Maria Cristina Trigo; Costa, Maria Adelina; Fernandes, Maria Helena

    2007-06-01

    Human gingival (HG), periodontal ligament (HPL) and alveolar bone (HAB) cells (first subculture) were cultured (10(4) cells/cm2) for 35 days in alpha-Minimal Essential Medium supplemented with 10% fetal bovine serum in the presence of (i) ascorbic acid (AA, 50 microg/mL), (ii) AA + beta-glycerophosphate (betaGP, 10 mM) and (iii) AA + betaGP + dexamethasone (Dex, 10 nM). Cultures were assessed for cell attachment and spreading, cell proliferation, alkaline phosphatase (ALP) and acid phosphatase (ACP) activities and matrix mineralization. HG cell cultures presented a high proliferation rate, a low ability to synthesize ALP and ACP and the formation of a non-mineralized extracellular matrix, regardless the experimental situation. HPL cell cultures were very sensitive to the culture conditions and showed a high proliferation rate, synthesis of moderate levels of ALP and ACP and a modest matrix mineralization in the presence of AA + betaGP + Dex. HAB cell cultures presented a growth rate lower than that of HG and HPL cells, a high ALP activity and comparatively low levels of ACP, and the ready formation of a heavy mineralized matrix in the presence of betaGP. In the three periodontal cell cultures, Dex enhanced cell proliferation and expression of osteoblastic markers. Results showed that betaGP and Dex allowed the modulation of the cell proliferation/differentiation behavior within the proposed physiological and regenerative capabilities of these periodontal cells. PMID:17268872

  13. The effect of calcitriol on high mobility group box 1 expression in periodontal ligament cells during orthodontic tooth movement in rats.

    PubMed

    Cui, Jian; Li, Juan; Wang, Wei; Han, Xiuchun; Du, Juan; Sun, Jing; Feng, Wei; Liu, Bo; Liu, Hongrui; Amizuka, Norio; Li, Minqi

    2016-04-01

    High mobility group box 1 (HMGB1) is a late inflammatory cytokine that plays an important role in periodontal tissue remodeling during orthodontic tooth movement. Calcitriol (1,25-dihydroxyvitamin D3 [1α,25 (OH)2D3]) is a systemic calcium-regulating hormone shown to downregulate expression of multiple proinflammatory cytokines in human periodontal ligament cells in response to orthodontic force. The purpose of this study was to investigate the effect of 1α,25(OH)2D3 on the expression of HMGB1 in periodontal ligament (PDL) cells during orthodontic tooth movement. Seven-week-old male Wistar rats were used for experimentation. Tooth movement was assessed using a nickel-titanium coil spring to apply mechanical loading to the tooth for 5 days. This was followed by administration of either 1α,25(OH)2D3 or normal saline by gavage every other day for up to 28 days. Immunohistochemistry was used to analyze the expression of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6 and HMGB1. After discontinuation of orthodontic force, expression of the early inflammatory cytokines IL-6 and TNF-α were time-dependently reduced in the 1α,25(OH)2D3 group compared with the control group at each time point. Similarly, expression of HMGB1 was decreased over time in both the 1α,25(OH)2D3 and normal saline groups, and 1α,25(OH)2D3 administration enhanced this decline. These findings indicate that administration of 1α,25(OH)2D3 might provide a favorable microenvironment for orthodontic tooth movement by downregulating expression of HMGB1 in PDL cells. PMID:26956363

  14. Neurogenesis of Neural Crest Derived Periodontal Ligament Stem Cells by EGF and bFGF

    PubMed Central

    Fortino, Veronica R.; Chen, Ren-Shiang; Pelaez, Daniel; Cheung, Herman S.

    2013-01-01

    Neuroregenerative medicine is an ever-growing field in which regeneration of lost cells/tissues due to a neurodegenerative disease is the ultimate goal. With the scarcity of available replacement alternatives, stem cells provide an attractive source for regenerating neural tissue. While many stem cell sources exist, including: mesenchymal stem cells (MSCs), embryonic stem cells (ESCs), and induced pluripotent stem cells (iPSCs), the limited cellular potency, technical difficulties, and ethical considerations associated with these make finding alternate sources a desirable goal. Periodontal ligament stem cells (PDLSCs) derived from the neural crest were induced into neural-like cells using a combination of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF). Morphological changes were evident in our treated group, seen under both light microscopy and scanning electron microscopy (SEM). A statistically significant increase in the expression of neuron-specific β-tubulin III and the neural stem/progenitor cell marker nestin, along with positive immunohistochemical staining for glial fibrillary acidic protein (GFAP), demonstrated the success of our treatment in inducing both neuronal and glial phenotypes. Positive staining for synaptophysin demonstrated neural connections and electrophysiological recordings indicated that when subjected to whole cell patch clamping, our treated cells displayed inward currents conducted through voltage-gated sodium (Na+) channels. Taken together, our results indicate the success of our treatment in inducing PDLSCs to neural-like cells. The ease of sourcing and expansion, their embryologic neural crest origin, and the lack of ethical implications in their use make PDLSCs an attractive source for use in neuroregenerative medicine. PMID:24105823

  15. Strain rate dependent properties of human craniovertebral ligaments.

    PubMed

    Mattucci, Stephen F E; Moulton, Jeffrey A; Chandrashekar, Naveen; Cronin, Duane S

    2013-07-01

    Craniovertebral ligaments were tested to failure under tensile loading. Ligaments tested included: transverse ligament, anterior atlanto occipital membrane, posterior atlanto occipital membrane, capsular ligaments between Skull-C1 and C1-C2, anterior atlantoaxial membrane, posterior atlantoaxial membrane and the tectorial membrane/vertical cruciate/apical/alar ligament complex. The objective of this study was to obtain mechanical properties of craniovertebral ligaments of a younger population, at varying strain rates representative of automotive crash scenarios, and investigate rate and gender effects for use in numerical models of the cervical spine. There have been few studies conducted on the mechanical properties of human craniovertebral ligaments. Only one study has tested all of the ligaments, and previous studies use older age specimens (mean age 67, from most complete study). Further, tests were often not performed at elongation rates representative of car crash scenarios. Previous studies did not perform tests in an environment resembling in vivo conditions, which has been shown to have a significant effect on ligament tensile behaviour. Fifty-four craniovertebral ligaments were isolated from twenty-one spines, and tested to failure in tension under simulated in vivo temperature and hydration levels, at quasi-static (0.5 s(-1)) and high strain rates (150 s(-1)). Values for failure force, failure elongation, stiffness, and toe region elongation were obtained from force-displacement curves. Values were analyzed for strain rate and gender effects. Increased strain rate produced several significant effects including: higher failure forces for the transverse ligament and capsular ligament (Skull-C1), lower failure elongation for the tectorial membrane complex, higher stiffness for the tectorial membrane complex and capsular ligament (Skull-C1), and lower toe region elongation for capsular ligament (Skull-C1). Gender effects were limited. Ligament tests

  16. Effects of cryopreservation with a newly-developed magnetic field programmed freezer on periodontal ligament cells and pulp tissues.

    PubMed

    Abedini, S; Kaku, M; Kawata, T; Koseki, H; Kojima, S; Sumi, H; Motokawa, M; Fujita, T; Ohtani, J; Ohwada, N; Tanne, K

    2011-06-01

    The purpose of this study was to evaluate the effects of long-term cryopreservation on the isolated human periodontal ligament cells (PDL) and pulp tissues. In the first part of study, 10 freshly extracted teeth were selected and divided into two groups. In the cryopreserved group, the teeth were frozen for 5 years using a programmed freezer combined with a magnetic field, known as Cells Alive System "CAS". As for the control group, freshly extracted teeth were used. In each group, extracted PDL tissues were cultured and gene expression and protein concentration of collagen type I, alkaline-phosphatase (ALP) and vascular endothelial growth factor (VEGF) was compared between the two groups. In the second part, pulp tissues were obtained from 10 mature and immature third molars which were freshly extracted or cryopreserved for three months. Expression of VEGF and nerve growth factor (NGF) mRNAs and the protein concentration in the supernatant were investigated. Results indicated that long-term cryopreservation with the use of CAS freezer cannot affect the growth rate and characteristics of PDL cells. There was no significant difference in VEGF expression and VEGF and NGF protein concentration of pulp cells derived from cryopreserved teeth with immature apex and control group with mature root formation. Finally, proper PDL regeneration and appropriate apexogenesis after transplanting magnetically cryopreserved immature tooth was clinically confirmed. These findings demonstrate that teeth banking with the use of magnetic field programmed freezer can be available for future autotransplantation as a treatment modality for replacing missing teeth. PMID:21397593

  17. Association between Human Body Composition and Periodontal Disease.

    PubMed

    Salekzamani, Yagoub; Shirmohammadi, Adileh; Rahbar, Mohammad; Shakouri, Seyed-Kazem; Nayebi, Farough

    2011-01-01

    Obesity in humans might increase the risk of periodontitis. The aim of the present study was to examine the relationship between body composition of males and their periodontal status. AS total of 150 males (aged 30-60) were selected: 31 were periodontally healthy, 45 had gingivitis, 39 had initial periodontitis, and 35 suffered from established periodontitis. BMI (body mass index), WC (waist circumference), and body composition parameters (consisting of body water, body fat, and skeletal muscle and bone mass) were measured. After adjusting for age, history of diabetes, smoking, physical activity status, and socioeconomic status, statistically significant correlations were found between periodontitis and BMI, WC, and body composition. There was only a statistically significant difference between the periodontal health and established periodontitis; that is, periodontal disease in mild forms (gingivitis) and initial periodontitis do not influence these variables (BMI, WC, and body composition parameters) and only the severe form of the disease influences the variables. These data suggest that there is a considerable association between severe forms of periodontal disease in males and their body composition, but this preliminary finding needs to be confirmed in more extensive studies. PMID:22111011

  18. Comparative in vitro study of the effectiveness of Green tea extract and common storage media on periodontal ligament fibroblast viability

    PubMed Central

    Adeli, Fahimeh; Zabihi, Ebrahim; Abedian, Zeinab; Gharekhani, Samane; Pouramir, Mahdi; Khafri, Soraya; Ghasempour, Maryam

    2016-01-01

    Objective: Green tea extract (GTE) was shown to be effective in preserving periodontal ligament fibroblasts (PDLFs) of avulsed teeth. This study aimed at determining the potential of GTE in preserving the viability of PDLFs comparing with different storage media. Materials and Methods: Periodontal ligament cells were obtained from freshly extracted healthy impacted third molars and cultured in Dulbecco's Modified Eagle Medium (DMEM). Cell viability was determined by storing the cells in seven media; DMEM, tap water, Hank's balanced salt solution (HBSS), whole milk, hypotonic sucrose solution, GTE, and GTE + sucrose for 1, 2, 4, and 24 h at 37°C using tetrazolium salt-based colorimetric (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide) assay. Statistical analysis was performed by one-way analysis of variance and post hoc tests. Results: GTE showed significantly higher protective effect than HBSS at 2, 4, and 24 h (P = 0.009, P = 0.02, P = 0.016), DMED at 2 h (P = 0.003), and milk at 4 h (P = 0.039). Conclusion: Although with undesirable osmolality and pH, GTE had a good ability in preserving the PDLFs comparing with other studied media. PMID:27403063

  19. Dynamic Mechanical Properties of Intact Human Cervical Spine Ligaments

    PubMed Central

    Ivancic, Paul C.; Coe, Marcus P.; Ndu, Anthony B.; Tominaga, Yasuhiro; Carlson, Erik J.; Rubin, Wolfgang; (FH), Dipl-Ing; Panjabi, Manohar M.

    2009-01-01

    BACKGROUND CONTEXT Most previous studies have investigated ligaments mechanical properties at slow elongation rates of less than 25 mm/s. PURPOSE To determine the tensile mechanical properties, at a fast elongation rate, of intact human cervical anterior and posterior longitudinal, capsular, and interspinous and supraspinous ligaments, middle-third disc, and ligamentum flavum. STUDY DESIGN/SETTING In vitro biomechanical study. METHODS A total of 97 intact bone-ligament-bone specimens (C2–C3 to C7-T1) were prepared from six cervical spines (average age: 80.6 years, range, 71 to 92 years) and were elongated to complete rupture at an average (SD) peak rate of 723 (106) mm/s using a custom-built apparatus. Non-linear force vs. elongation curves were plotted and peak force, peak elongation, peak energy, and stiffness were statistically compared (P<0.05) among ligament. A mathematical model was developed to determine the quasi-static physiological ligament elongation. RESULTS Highest average peak force, up to 244.4 and 220.0 N in the ligamentum flavum and capsular ligament, respectively, were significantly greater than in the anterior longitudinal ligament and middle-third disc. Highest peak elongation reached 5.9 mm in the intraspinous and supraspinous ligaments, significantly greater than in the middle-third disc. Highest peak energy of 0.57 J was attained in the capsular ligament, significantly greater than in the anterior longitudinal ligament and middle-third disc. Average stiffness was generally greatest in the ligamentum flavum and least in the intraspinous and supraspinous ligaments. For all ligaments, peak elongation was greater than average physiological elongation computed using the mathematical model. CONCLUSIONS Comparison of the present results with previously reported data indicated that high speed elongation may cause cervical ligaments to fail at a higher peak force and smaller peak elongation and may be stiffer and absorb less energy, as compared to a

  20. Skeletal ligament healing using the recombinant human amelogenin protein.

    PubMed

    Hanhan, Salem; Ejzenberg, Ayala; Goren, Koby; Saba, Faris; Suki, Yarden; Sharon, Shay; Shilo, Dekel; Waxman, Jacob; Spitzer, Elad; Shahar, Ron; Atkins, Ayelet; Liebergall, Meir; Blumenfeld, Anat; Deutsch, Dan; Haze, Amir

    2016-05-01

    Injuries to ligaments are common, painful and debilitating, causing joint instability and impaired protective proprioception sensation around the joint. Healing of torn ligaments usually fails to take place, and surgical replacement or reconstruction is required. Previously, we showed that in vivo application of the recombinant human amelogenin protein (rHAM(+)) resulted in enhanced healing of the tooth-supporting tissues. The aim of this study was to evaluate whether amelogenin might also enhance repair of skeletal ligaments. The rat knee medial collateral ligament (MCL) was chosen to prove the concept. Full thickness tear was created and various concentrations of rHAM(+), dissolved in propylene glycol alginate (PGA) carrier, were applied to the transected MCL. 12 weeks after transection, the mechanical properties, structure and composition of transected ligaments treated with 0.5 μg/μl rHAM(+) were similar to the normal un-transected ligaments, and were much stronger, stiffer and organized than control ligaments, treated with PGA only. Furthermore, the proprioceptive free nerve endings, in the 0.5 μg/μl rHAM(+) treated group, were parallel to the collagen fibres similar to their arrangement in normal ligament, while in the control ligaments the free nerve endings were entrapped in the scar tissue at different directions, not parallel to the axis of the force. Four days after transection, treatment with 0.5 μg/μl rHAM(+) increased the amount of cells expressing mesenchymal stem cell markers at the injured site. In conclusion application of rHAM(+) dose dependently induced mechanical, structural and sensory healing of torn skeletal ligament. Initially the process involved recruitment and proliferation of cells expressing mesenchymal stem cell markers. PMID:26917487

  1. Regeneration of periodontal tissues in non-human primates with rhGDF-5 and beta-tricalcium phosphate.

    PubMed

    Emerton, K B; Drapeau, S J; Prasad, H; Rohrer, M; Roffe, P; Hopper, K; Schoolfield, J; Jones, A; Cochran, D L

    2011-12-01

    The application of growth factors has been advocated in support of periodontal regeneration. Recombinant human growth and differentiation factor-5 (rhGDF-5), a member of the bone morphogenetic protein family, has been used to encourage periodontal tissue regeneration. This study evaluated the dose response of rhGDF-5 lyophilized onto beta-tricalcium phosphate (bTCP) granules for periodontal tissue regeneration in a baboon model. Periodontal defects were created bilaterally in 12 baboons by a split-mouth design. Plaque was allowed to accumulate around wire ligatures to create chronic disease. After 2 mos, the ligatures were removed, and a notch was placed at the base of the defect. Two teeth on each side of the mouth were randomly treated with bTCP only, 0.5, 1.0, or 2.0 mg rhGDF-5/g bTCP. Animals were sacrificed 5 mos post-treatment, with micro-CT and histomorphometric analysis performed. After 5 mos, analysis showed alveolar bone, cementum, and periodontal ligament formation in all treatment groups, with a dose-dependent increase in rhGDF-5-treated groups. Height of periodontal tissues also increased with the addition of rhGDF-5, and the amount of residual graft material decreased with rhGDF-5 treatment. Therefore, rhGDF-5 delivered on bTCP demonstrated effective regeneration of all 3 tissues critical for periodontal repair. PMID:21940517

  2. Biomechanics of a Bone-Periodontal Ligament-Tooth Fibrous Joint

    PubMed Central

    Lin, Jeremy D.; Özcoban, Hüseyin; Greene, Janelle; Jang, Andrew T.; Djomehri, Sabra; Fahey, Kevin; Hunter, Luke; Schneider, Gerold A; Ho, Sunita P.

    2013-01-01

    This study investigates bone-tooth association under compression to identify strain amplified sites within the bone-periodontal ligament (PDL)-tooth fibrous joint. Our results indicate that the biomechanical response of the joint is due to a combinatorial response of constitutive properties of organic, inorganic, and fluid components. Second maxillary molars within intact maxillae (N=8) of 5-month-old rats were loaded with a μ-XCT-compatible in situ loading device at various permutations of displacement rates (0.2, 0.5, 1.0, 1.5, 2.0 mm/min) and peak reactionary load responses (5, 10, 15, 20 N). Results indicated a nonlinear biomechanical response of the joint, in which the observed reactionary load rates were directly proportional to displacement rates (velocities). No significant differences in peak reactionary load rates at a displacement rate of 0.2 mm/min were observed. However, for displacement rates greater than 0.2 mm/min, an increasing trend in reactionary rate was observed for every peak reactionary load with significant increases at 2.0 mm/min. Regardless of displacement rates, two distinct behaviors were identified with stiffness (S) and reactionary load rate (LR) values at a peak load of 5 N (S5 N=290–523 N/mm) being significantly lower than those at 10 N (LR5 N=1–10 N/s) and higher (S10N–20 N=380–684 N/mm; LR10N–20 N=1–19 N/s). Digital image correlation revealed the possibility of a screw-like motion of the tooth into the PDL-space, i.e., predominant vertical displacement of 35 μm at 5 N, followed by a slight increase to 40 μm at 10 N and 50 μm at 20 N of the tooth and potential tooth rotation at loads above 10 N. Narrowed and widened PDL spaces as a result of tooth displacement indicated areas of increased apparent strain within the complex. We propose that such highly strained regions are “hot spots” that can potentiate local tissue adaptation under physiological loading and adverse tissue adaptation under pathological loading

  3. Histologic studies on the extension of the inflammatory infiltrate in human periodontitis.

    PubMed

    Moskow, B S; Polson, A M

    1991-08-01

    This study was undertaken to re-examine early and recent morphologic descriptions of gingival and periodontal inflammation based on a study of gingival biopsies and block sections of human jaws. A collection of 350 autopsy and surgically retrieved jaw sections containing multiple teeth and displaying various stages of periodontal inflammation were subjected to routine histologic preparation and analyzed with step serial sections. 105 gingival biopsies, serially sectioned, including 15 clinically normal specimens, were also studied. The results of these investigations suggest that the inflammatory lesion extends into the alveolar process and elicits a response, often before evidence of crestal resorption or connective tissue attachment loss has occurred. Similarly, deep penetrations of inflammatory cells into the alveolar bone, periodontal ligament and periapical tissues, along with fibrosis and enlargement of the marrow spaces, were common findings with advancing disease. More widespread distributions of inflammatory cells than previously described were found in clinically normal gingiva, while in more inflamed gingiva, the inflammatory cell types found and their pattern of distribution varied greatly from individual to individual. These observations cast doubt on the perception of human periodontitis as a localized and marginal disease and suggest that its effects may be much more pervasive than previously thought. PMID:1894748

  4. Mechanical responses of the periodontal ligament based on an exponential hyperelastic model: a combined experimental and finite element method.

    PubMed

    Huang, Huixiang; Tang, Wencheng; Yan, Bin; Wu, Bin; Cao, Dan

    2016-01-01

    The V-W exponential hyperelastic model is adopted to describe the instantaneous elastic response of the periodontal ligament (PDL). The general theoretical framework of constitutive modeling is described based on nonlinear continuum mechanics, and the elasticity tensor used to develop UMAT subroutine is formulated. Nanoindentation experiment is performed to characterize mechanical properties of an adult pig PDL specimen. Then the experiment is simulated by using the finite element (FE) analysis. Meanwhile, the optimized material parameters are identified by the inverse FE method. The good agreement between the simulated results and experimental data demonstrates that the V-W model is capable of describing the mechanical behavior of the PDL. Therefore, the model and its implementation into FE code are validated. By using the model, we simulate the tooth movement under orthodontic loading to predict the mechanical responses of the PDL. The results show that local concentrations of stress and strain in the PDL are found. PMID:25648914

  5. Predicting the holistic force-displacement relation of the periodontal ligament: in-vitro experiments and finite element analysis

    PubMed Central

    2014-01-01

    Background The biomechanical property of the periodontal ligament (PDL) is important in orthodontics and prosthodontics. The objective of this study was to evaluate the feasibility of measuring the biomechanical behavior of the periodontal ligament using micro-computed tomography (micro-CT). Methods A custom-made apparatus measured the force and displacement of a porcine PDL specimen within the micro-CT environment. Synchronized computed tomography (CT) images were used to obtain the deformation and displacement of the entire specimen and to reconstruct the three-dimensional mesh model. To match the experimental results, finite element analysis was then applied to simulate the biomechanical response of the PDL. The mechanical model of the PDL was assumed as the hyperelastic material in this study. Results The volume variations of the tooth and the alveolar bone were less than 1%, which implies that tooth displacement was caused mostly by displacement of the PDL. Only translational displacement was observed with each load step because the transformation matrix acquired from the CT image registration was identical. The force-displacement curve revealed the nonlinear behavior of the PDL. There was a high correlation between the experimental displacement results and the simulation displacement results. The numerical results (based on the assumption that the PDL is the hyperelastic material) showed good agreement with the experimental results. Conclusions Nondestructive measurements by micro-CT obtained the biomechanical behavior of the PDL. Using the hyperelastic characteristic as the constitutive model can properly predict the force-displacement relation of the PDL after loading. This study provided a feasible approach for measuring the biomechanical behavior of the PDL for further dental application. PMID:25077405

  6. Morphological changes in the rat periodontal ligament and its vascularity after experimental tooth movement using superelastic forces.

    PubMed

    Noda, Koji; Nakamura, Yoshiki; Kogure, Kyotaro; Nomura, Yoshiaki

    2009-02-01

    The aim of this study was to statistically assess the morphological changes of the rat periodontal ligament (PDL) and its vascularity in relation to varied magnitudes of superelastic force in experimental tooth movement using nickel-titanium (NiTi) alloy wire. Forces of 0.8, 1.6, 4, 8, and 18 g were applied to the upper first molars of five groups of 10-week-old male Wistar rats (300-320 g) for 1, 7, 14, 21, and 28 days. A control group with no orthodontic appliance application was assessed in accordance with the five experimental periods. The specimens were observed under light microscopy, processed by computer imaging, and analysed statistically with Tukey's HSD non-parametric test. One day after the start of the experiment, a few blood vessels could be seen in the compressed PDL with forces of 0.8 and 1.6 g. The cross-sectional areas of blood vessels (CAV) and periodontal ligament (CAPL) in the experimental groups where a force of over 4 g was applied were significantly smaller than those where 0.8 and 1.6 g forces were used, and in the control group. On day 7, large CAV were seen in the 1.6, 4, and 8 g groups. On day 28, the 8 and 18 g groups showed significantly larger CAPL than the 0.8, 4 g, or control groups. The findings suggest that a light continuous force, under 1.6 g, maintains the vascular structure during experimental tooth movement. In contrast, a heavy continuous force over 4 g causes the vascular structure to be absent in the early stages of tooth movement, but a dynamic regeneration of the PDL with vascularity and expansion follows. PMID:19073960

  7. Comparison of Periodontal Ligament Injection and Inferior Alveolar Nerve Block in Mandibular Primary Molars Pulpotomy: A Randomized Control Trial

    PubMed Central

    Haghgoo, Roza; Taleghani, Ferial

    2015-01-01

    Background: Inferior alveolar nerve block is a common technique for anesthesia of the primary mandibular molars. A number of disadvantages have been shown to be associated with this technique. Periodontal ligament (PDL) injection could be considered as an alternative to inferior alveolar nerve block. The aim of this study was to evaluate the effectiveness of PDL injection in the anesthesia of primary molar pulpotomy with mandibular block. Methods: This study was performed using a sequential double-blind randomized trial design. 80 children aged 3-7 years old who required pulpotomy in symmetrical mandibular primary molars were selected. The teeth of these children were anesthetized with periodontal injection on one side of the mandible and block on the other. Pulpotomy was performed on each patient during the same appointment. Signs of discomfort, including hand and body tension and eye movement, the verbal complaint and crying (SEM scale), were evaluated by a dental assistant who was blinded to the treatment allocation of the patients. Finally, the data were analyzed using the exact Fisher test and Pearson Chi-squared exact test. Results: Success rate was 88/75 and 91/25 in the PDL injection and nerve block groups, respectively. There was no statistically significant difference between the two techniques (P = 0.250). Conclusion: Results showed that PDL injection can be used as an alternative to nerve block in pulpotomy of the mandibular primary molars. PMID:26028895

  8. Quasi-linear viscoelastic characterization of human hip ligaments.

    PubMed

    Kemper, Andrew R; McNally, Craig; Smith, Byron; Duma, Stefan M

    2007-01-01

    The object of this study was to develop a quasi-linear viscoelastic model for the iliofemoral and ischiofemoral hip ligaments. In order to accomplish this, a total of 56 axial tension tests were performed on 8 bone-ligament-bone specimens prepared from 4 fresh frozen male cadavers. Each specimen went through a battery of 7 tests including a series of step-and-hold tests and load-and-unload ramp tests. The bone-ligament-bone specimens were situated so that the load from a servo-hydraulic Material Testing System would be applied on the long axis of each ligament. The reduced relaxation data was fit to a two exponential damping function while the instantaneous elastic response was fit to a power-law function. These two constituents were then combined to create a single constitutive equation for each ligament. The quasi-linear viscoelastic model presented in this study can be used to improve the biofidelity of computational models of the human hip. PMID:17487102

  9. Nuclear factor-κB modulates osteogenesis of periodontal ligament stem cells through competition with β-catenin signaling in inflammatory microenvironments.

    PubMed

    Chen, X; Hu, C; Wang, G; Li, L; Kong, X; Ding, Y; Jin, Y

    2013-01-01

    Inflammation can influence multipotency and self-renewal of mesenchymal stem cells (MSCs), resulting in their awakened bone-regeneration ability. Human periodontal ligament tissue-derived MSCs (PDLSCs) have been isolated, and their differentiation potential was found to be defective due to β-catenin signaling indirectly regulated by inflammatory microenvironments. Nuclear factor-κB (NF-κB) is well studied in inflammation by many different groups. The role of NF-κB needs to be studied in PDLSCs, although genetic evidences have recently shown that NF-κB inhibits osteoblastic bone formation in mice. However, the mechanism as to how inflammation leads to the modulation of β-catenin and NF-κB signaling remains unclear. In this study, we investigated β-catenin and NF-κB signaling through regulation of glycogen synthase kinase 3β activity (GSK-3β, which modulates β-catenin and NF-κB signaling) using a specific inhibitor LiCl and a phosphatidylinositol 3-kinase (PI3K) inhibitor LY 294002. We identified that NF-κB signaling might be more important for the regulation of osteogenesis in PDLSCs from periodontitis compared with β-catenin. BAY 11-7082 (an inhibitor of NF-κB) could inhibit phosphorylation of p65 and partly rescue the differentiation potential of PDLSCs in inflammation. Our data indicate that NF-κB has a central role in regulating osteogenic differentiation of PDLSCs in inflammatory microenvironments. Given the molecular mechanisms of NF-κB in osteogenic differentiation governed by inflammation, it can be said that NF-κB helps in improving stem cell-mediated inflammatory bone disease therapy. PMID:23449446

  10. Nuclear factor-κB modulates osteogenesis of periodontal ligament stem cells through competition with β-catenin signaling in inflammatory microenvironments

    PubMed Central

    Chen, X; Hu, C; Wang, G; Li, L; Kong, X; Ding, Y; Jin, Y

    2013-01-01

    Inflammation can influence multipotency and self-renewal of mesenchymal stem cells (MSCs), resulting in their awakened bone-regeneration ability. Human periodontal ligament tissue-derived MSCs (PDLSCs) have been isolated, and their differentiation potential was found to be defective due to β-catenin signaling indirectly regulated by inflammatory microenvironments. Nuclear factor-κB (NF-κB) is well studied in inflammation by many different groups. The role of NF-κB needs to be studied in PDLSCs, although genetic evidences have recently shown that NF-κB inhibits osteoblastic bone formation in mice. However, the mechanism as to how inflammation leads to the modulation of β-catenin and NF-κB signaling remains unclear. In this study, we investigated β-catenin and NF-κB signaling through regulation of glycogen synthase kinase 3β activity (GSK-3β, which modulates β-catenin and NF-κB signaling) using a specific inhibitor LiCl and a phosphatidylinositol 3-kinase (PI3K) inhibitor LY 294002. We identified that NF-κB signaling might be more important for the regulation of osteogenesis in PDLSCs from periodontitis compared with β-catenin. BAY 11-7082 (an inhibitor of NF-κB) could inhibit phosphorylation of p65 and partly rescue the differentiation potential of PDLSCs in inflammation. Our data indicate that NF-κB has a central role in regulating osteogenic differentiation of PDLSCs in inflammatory microenvironments. Given the molecular mechanisms of NF-κB in osteogenic differentiation governed by inflammation, it can be said that NF-κB helps in improving stem cell-mediated inflammatory bone disease therapy. PMID:23449446

  11. Evaluation of Qualitative Changes in Simulated Periodontal Ligament and Alveolar Bone Using a Noncontact Electromagnetic Vibration Device with a Laser Displacement Sensor

    PubMed Central

    Kobayashi, Hiroshi; Hayashi, Makoto; Yamaoka, Masaru; Yasukawa, Takuya; Ibi, Haruna; Ogiso, Bunnai

    2016-01-01

    Evaluating periodontal tissue condition is an important diagnostic parameter in periodontal disease. Noncontact electromagnetic vibration device (NEVD) was previously developed to monitor this condition using mechanical parameters. However, this system requires accelerometer on the target tooth. This study assessed application of laser displacement sensor (LDS) to NEVD without accelerometer using experimental tooth models. Tooth models consisted of cylindrical rod, a tissue conditioner, and polyurethane or polyurethane foam to simulate tooth, periodontal ligament, and alveolar bone, respectively. Tissue conditioner was prepared by mixing various volumes of liquid with powder. Mechanical parameters (resonant frequency, elastic modulus, and coefficient of viscosity) were assessed using NEVD with the following methods: Group A, measurement with accelerometer; Group B, measurement with LDS in the presence of accelerometer; and Group C, measurement with LDS in the absence of accelerometer. Mechanical parameters significantly decreased with increasing liquid volume. Significant differences were also observed between the polyurethane and polyurethane foam models. Meanwhile, no statistically significant differences were observed between Groups A and B; however, most mechanical parameters in Group C were significantly larger and more distinguishable than those of Groups A and B. LDS could measure mechanical parameters more accurately and clearly distinguished the different periodontal ligament and alveolar bone conditions. PMID:27274995

  12. Evaluation of Qualitative Changes in Simulated Periodontal Ligament and Alveolar Bone Using a Noncontact Electromagnetic Vibration Device with a Laser Displacement Sensor.

    PubMed

    Kobayashi, Hiroshi; Hayashi, Makoto; Yamaoka, Masaru; Yasukawa, Takuya; Ibi, Haruna; Ogiso, Bunnai

    2016-01-01

    Evaluating periodontal tissue condition is an important diagnostic parameter in periodontal disease. Noncontact electromagnetic vibration device (NEVD) was previously developed to monitor this condition using mechanical parameters. However, this system requires accelerometer on the target tooth. This study assessed application of laser displacement sensor (LDS) to NEVD without accelerometer using experimental tooth models. Tooth models consisted of cylindrical rod, a tissue conditioner, and polyurethane or polyurethane foam to simulate tooth, periodontal ligament, and alveolar bone, respectively. Tissue conditioner was prepared by mixing various volumes of liquid with powder. Mechanical parameters (resonant frequency, elastic modulus, and coefficient of viscosity) were assessed using NEVD with the following methods: Group A, measurement with accelerometer; Group B, measurement with LDS in the presence of accelerometer; and Group C, measurement with LDS in the absence of accelerometer. Mechanical parameters significantly decreased with increasing liquid volume. Significant differences were also observed between the polyurethane and polyurethane foam models. Meanwhile, no statistically significant differences were observed between Groups A and B; however, most mechanical parameters in Group C were significantly larger and more distinguishable than those of Groups A and B. LDS could measure mechanical parameters more accurately and clearly distinguished the different periodontal ligament and alveolar bone conditions. PMID:27274995

  13. Human Memory B Cells in Healthy Gingiva, Gingivitis, and Periodontitis.

    PubMed

    Mahanonda, Rangsini; Champaiboon, Chantrakorn; Subbalekha, Keskanya; Sa-Ard-Iam, Noppadol; Rattanathammatada, Warattaya; Thawanaphong, Saranya; Rerkyen, Pimprapa; Yoshimura, Fuminobu; Nagano, Keiji; Lang, Niklaus P; Pichyangkul, Sathit

    2016-08-01

    The presence of inflammatory infiltrates with B cells, specifically plasma cells, is the hallmark of periodontitis lesions. The composition of these infiltrates in various stages of homeostasis and disease development is not well documented. Human tissue biopsies from sites with gingival health (n = 29), gingivitis (n = 8), and periodontitis (n = 21) as well as gingival tissue after treated periodontitis (n = 6) were obtained and analyzed for their composition of B cell subsets. Ag specificity, Ig secretion, and expression of receptor activator of NF-κB ligand and granzyme B were performed. Although most of the B cell subsets in healthy gingiva and gingivitis tissues were CD19(+)CD27(+)CD38(-) memory B cells, the major B cell component in periodontitis was CD19(+)CD27(+)CD38(+)CD138(+)HLA-DR(low) plasma cells, not plasmablasts. Plasma cell aggregates were observed at the base of the periodontal pocket and scattered throughout the gingiva, especially apically toward the advancing front of the lesion. High expression of CXCL12, a proliferation-inducing ligand, B cell-activating factor, IL-10, IL-6, and IL-21 molecules involved in local B cell responses was detected in both gingivitis and periodontitis tissues. Periodontitis tissue plasma cells mainly secreted IgG specific to periodontal pathogens and also expressed receptor activator of NF-κB ligand, a bone resorption cytokine. Memory B cells resided in the connective tissue subjacent to the junctional epithelium in healthy gingiva. This suggested a role of memory B cells in maintaining periodontal homeostasis. PMID:27335500

  14. Periodontitis

    MedlinePlus

    ... fall out. Periodontitis is the primary cause of tooth loss in adults. This disorder is uncommon in ... damage of the tissues and bone surrounding the tooth. Because plaque contains bacteria, infection is likely, and ...

  15. Fabrication of Core-Shell PEI/pBMP2-PLGA Electrospun Scaffold for Gene Delivery to Periodontal Ligament Stem Cells.

    PubMed

    Xie, Qiao; Jia, Lie-Ni; Xu, Hong-Yu; Hu, Xiang-Gang; Wang, Wei; Jia, Jun

    2016-01-01

    Bone tissue engineering is the most promising technology for enhancing bone regeneration. Scaffolds loaded with osteogenic factors improve the therapeutic effect. In this study, the bioactive PEI (polyethylenimine)/pBMP2- (bone morphogenetic protein-2 plasmid-) PLGA (poly(D, L-lactic-co-glycolic acid)) core-shell scaffolds were prepared using coaxial electrospinning for a controlled gene delivery to hPDLSCs (human periodontal ligament stem cells). The pBMP2 was encapsulated in the PEI phase as a core and PLGA was employed to control pBMP2 release as a shell. First, the scaffold characterization and mechanical properties were evaluated. Then the gene release behavior was analyzed. Our results showed that pBMP2 was released at high levels in the first few days, with a continuous release behavior in the next 28 days. At the same time, PEI/pBMP2 showed high transfection efficiency. Moreover, the core-shell electrospun scaffold showed BMP2 expression for a much longer time (more than 28 days) compared with the single axial electrospun scaffold, as evaluated by qRT-PCR and western blot after culturing with hPDLSCs. These results suggested that the core-shell PEI/pBMP2-PLGA scaffold fabricated by coaxial electrospinning had a good gene release behavior and showed a prolonged expression time with a high transfection efficiency. PMID:27313626

  16. Fabrication of Core-Shell PEI/pBMP2-PLGA Electrospun Scaffold for Gene Delivery to Periodontal Ligament Stem Cells

    PubMed Central

    Xie, Qiao; Jia, Lie-ni; Xu, Hong-yu; Hu, Xiang-gang; Wang, Wei; Jia, Jun

    2016-01-01

    Bone tissue engineering is the most promising technology for enhancing bone regeneration. Scaffolds loaded with osteogenic factors improve the therapeutic effect. In this study, the bioactive PEI (polyethylenimine)/pBMP2- (bone morphogenetic protein-2 plasmid-) PLGA (poly(D, L-lactic-co-glycolic acid)) core-shell scaffolds were prepared using coaxial electrospinning for a controlled gene delivery to hPDLSCs (human periodontal ligament stem cells). The pBMP2 was encapsulated in the PEI phase as a core and PLGA was employed to control pBMP2 release as a shell. First, the scaffold characterization and mechanical properties were evaluated. Then the gene release behavior was analyzed. Our results showed that pBMP2 was released at high levels in the first few days, with a continuous release behavior in the next 28 days. At the same time, PEI/pBMP2 showed high transfection efficiency. Moreover, the core-shell electrospun scaffold showed BMP2 expression for a much longer time (more than 28 days) compared with the single axial electrospun scaffold, as evaluated by qRT-PCR and western blot after culturing with hPDLSCs. These results suggested that the core-shell PEI/pBMP2-PLGA scaffold fabricated by coaxial electrospinning had a good gene release behavior and showed a prolonged expression time with a high transfection efficiency. PMID:27313626

  17. Human gingiva-derived mesenchymal stromal cells contribute to periodontal regeneration in beagle dogs.

    PubMed

    Yu, Xinbo; Ge, Shaohua; Chen, Shulan; Xu, Quanchen; Zhang, Jin; Guo, Hongmei; Yang, Pishan

    2013-01-01

    Gingiva-derived mesenchymal stromal cells (GMSCs) have been considered as a promising alternative strategy for periodontal regeneration based on their potential for multilineage differentiation in vitro and the ability to form new bone in vivo. In order to investigate the capacity of GMSCs for periodontal regeneration and the fate of GMSCs during periodontal tissue repair, enhanced green fluorescent protein-labeled GMSCs were transplanted into class III furcation defects created in beagle dogs. The results showed that the transplanted GMSCs significantly enhanced the regeneration of the damaged periodontal tissue, including the alveolar bone, cementum and functional periodontal ligament (PDL). Moreover, GMSCs were able to differentiate into osteoblasts, cementoblasts and PDL fibroblasts in vivo. These findings indicate that GMSCs represent a novel cell source for periodontal tissue reconstruction. PMID:24777155

  18. Characteristics of the three ligaments of human spring ligament complex from a viewpoint of elements.

    PubMed

    Tohno, Yoshiyuki; Tohno, Setsuko; Taniguchi, Akira; Azuma, Cho; Minami, Takeshi; Mahakkanukrauh, Pasuk

    2012-06-01

    To elucidate characteristics of the three ligaments constituting the spring ligament complex from a viewpoint of elements, the authors investigated age-related changes of elements, relationships among their elements, relationships among ligaments in the elements, and gender differences in the three ligaments of the spring ligament complex, the superomedial calcaneonavicular (SMCN), inferoplantar longitudinal calcaneonavicular (ICN), and third or medioplantar oblique calcaneonavicular (TCN) ligaments. After ordinary dissection at Nara Medical University was finished, the SMCN, ICN, and TCN ligaments of the spring ligament complex were removed from the subjects. The subjects consisted of 10 men and 12 women, ranging in age from 62 to 99 years (average age = 80.5 ± 9.7 years). After incineration with nitric acid and perchloric acid, the element contents were determined by inductively coupled plasma-atomic emission spectrometry. It was found that although the Ca and P content hardly changed in the SMCN ligament with aging, the Ca and P content in the ICN ligament increased to about three and five times higher in the 80s in comparison with the 60s, respectively, whereas in the TCN ligament, it increased about 40% and 90% higher in the 80s compared with the 60s, respectively. Regarding the relationships among elements, significant direct correlations were found among the contents of Ca, P, and Mg in all the three ligaments of the spring ligament complex. This finding was in agreement with the previous finding obtained with the three ligaments of the anterior cruciate ligament, posterior longitudinal ligament, and ligamentum capitis femoris. Whether there were significant correlations among the three ligaments of the spring ligament complex with regard to the Ca, P, S, Mg, Zn, and Fe contents was examined using Pearson's correlation. It was found that there were significant direct correlations between the SMCN and TCN ligaments in all the Ca, P, Mg, and Zn contents and

  19. Three-dimensional stress In vitro promotes the proliferation and differentiation of periodontal ligament stem cells implanted by bioactive glass.

    PubMed

    Wang, T; Li, G; Chen, J; Lin, Z; Qin, H; Ji, J

    2016-01-01

    To analyze the biological and mechanical microenvironment on the directional differentiation of periodontal ligament stem cells (PDLSCs) In vitro. PDLSCs were cultured in three-dimensional stress system In vitro for 1, 2 and 3 weeks. Methods like immunohistochemistry and flow cytometry were adopted and the proliferation and differentiation situation of PDLSCs were determined. Bioactive glass (BAG) of 0%, 10%, 20%, 30% and 40% was implanted into PDLSCs with or without three-dimensional stress for 3 weeks, respectively. The proliferation and differentiation situation of PDLSCs were determined. The mRNA levels of Alkaline phosphatase (ALP), Type I Collagen (COL I), Type II Collagen (COL II), Bone sialoprotein (BSP), Osteocalcin (OCN) and Osteopontin (OPN) were determined by semi-quantitative RT-PCR. 30% BAG and three-dimensional stress for 3 weeks promoted the proliferation and differentiation of PDLSCs mostly. PDLSCs induced by BAG and 3D force and the control all expressed the mRNA of ALP, COLⅠand COL Ⅱ. The BAG and three-dimensional stress induced PDLSCs also expressed the mRNA of BSP, OCN and OPN. BAG and three-dimensional stress indicated microenvironment In vitro can promote the proliferation and differentiation of PDLSCs. PMID:27609476

  20. Stress Induced in the Periodontal Ligament under Orthodontic Loading (Part I): A Finite Element Method Study Using Linear Analysis

    PubMed Central

    Hemanth, M; deoli, Shilpi; Raghuveer, H P; Rani, M S; Hegde, Chatura; Vedavathi, B

    2015-01-01

    Background: Orthodontic tooth movement is a complex procedure that occurs due to various biomechanical changes in the periodontium. Optimal orthodontic forces yield maximum tooth movement whereas if the forces fall beyond the optimal threshold it can cause deleterious effects. Among various types of tooth movements intrusion and lingual root torque are associated with causing root resoprtion, especially with the incisors. Therefore in this study, the stress patterns in the periodontal ligament (PDL) were evaluated with intrusion and lingual root torque using finite element method (FEM). Materials and Methods: A three-dimensional (3D) FEM model of the maxillary incisors was generated using SOLIDWORKS modeling software. Stresses in the PDL were evaluated with intrusive and lingual root torque movements by a 3D FEM using ANSYS software using linear stress analysis. Results: It was observed that with the application of intrusive load compressive stresses were distributed at the apex whereas tensile stress was seen at the cervical margin. With the application of lingual root torque maximum compressive stress was distributed at the apex and tensile stress was distributed throughout the PDL. Conclusion: For intrusive and lingual root torque movements stress values over the PDL was within the range of optimal stress value as proposed by Lee, with a given force system by Proffit as optimum forces for orthodontic tooth movement using linear properties. PMID:26464555

  1. In situ Compressive Loading and Correlative Noninvasive Imaging of the Bone-periodontal Ligament-tooth Fibrous Joint

    PubMed Central

    Jang, Andrew T.; Lin, Jeremy D.; Seo, Youngho; Etchin, Sergey; Merkle, Arno; Fahey, Kevin; Ho, Sunita P.

    2014-01-01

    This study demonstrates a novel biomechanics testing protocol. The advantage of this protocol includes the use of an in situ loading device coupled to a high resolution X-ray microscope, thus enabling visualization of internal structural elements under simulated physiological loads and wet conditions. Experimental specimens will include intact bone-periodontal ligament (PDL)-tooth fibrous joints. Results will illustrate three important features of the protocol as they can be applied to organ level biomechanics: 1) reactionary force vs. displacement: tooth displacement within the alveolar socket and its reactionary response to loading, 2) three-dimensional (3D) spatial configuration and morphometrics: geometric relationship of the tooth with the alveolar socket, and 3) changes in readouts 1 and 2 due to a change in loading axis, i.e. from concentric to eccentric loads. Efficacy of the proposed protocol will be evaluated by coupling mechanical testing readouts to 3D morphometrics and overall biomechanics of the joint. In addition, this technique will emphasize on the need to equilibrate experimental conditions, specifically reactionary loads prior to acquiring tomograms of fibrous joints. It should be noted that the proposed protocol is limited to testing specimens under ex vivo conditions, and that use of contrast agents to visualize soft tissue mechanical response could lead to erroneous conclusions about tissue and organ-level biomechanics. PMID:24638035

  2. An electron microscopic radioautographic study of collagen secretion in periodontal ligament fibroblasts of the mouse: II. Colchicine-treated fibroblasts

    SciTech Connect

    Cho, M.I.; Garant, P.R.

    1981-12-01

    Colchicine administered intravenously depolymerized microtubules and disrupted the normal organization of the Golgi apparatus in periodontal ligament fibroblasts. Radioautography with /sup 3/H-proline indicated that collagen secretion was completely inhibited during a period of approximately 4 hours following the onset of the colchicine effect. During this period of secretory inhibition, labeled collagen precursors were present within a variety of dense bodies, primarily located in a juxtanuclear location replacing the normal Golgi complex. The time course of /sup 3/H-proline labeling from 2 to 8 hours suggested that small, newly formed dense bodies fused to form larger dense bodies and pleomorphic structures (zebra bodies), within which collagen precursors appeared to undergo partial polymerization. Autophagosomes, many labeled with /sup 3/H-proline, also increased in number after colchicine administration. A gradual decline in /sup 3/H-proline label occurred from 4 to 24 hours, presumably due to exocytosis of dense bodies or by the digestion of labeled collagen precursors within autophagosomes. These results support the concept that an intact microtubular network is essential for the organized transport of collagen precursors, from the rough endoplasmic reticulum to the Golgi apparatus, and the eventual transport and exocytosis of collagen secretory granules.

  3. Neural Structures within Human Meniscofemoral Ligaments: A Cadaveric Study

    PubMed Central

    Gupte, Chinmay M.; Shaerf, Daniel A.; Sandison, Ann; Bull, Anthony M. J.; Amis, Andrew A.

    2014-01-01

    Aim. To investigate the existence of neural structures within the meniscofemoral ligaments (MFLs) of the human knee. Methods. The MFLs from 8 human cadaveric knees were harvested. 5 μm sections were H&E-stained and examined under light microscopy. The harvested ligaments were then stained using an S100 monoclonal antibody utilising the ABC technique to detect neural components. Further examination was performed on 60–80 nm sections under electron microscopy. Results. Of the 8 knees, 6 were suitable for examination. From these both MFLs existed in 3, only anterior MFLs were present in 2, and an isolated posterior MFL existed in 1. Out of the 9 MFLs, 4 demonstrated neural structures on light and electron microscopy and this was confirmed with S100 staining. The ultrastructure of these neural components was morphologically similar to mechanoreceptors. Conclusion. Neural structures are present in MFLs near to their meniscal attachments. It is likely that the meniscofemoral ligaments contribute not only as passive secondary restraints to posterior draw but more importantly to proprioception and may therefore play an active role in providing a neurosensory feedback loop. This may be particularly important when the primary restraint has reduced function as in the posterior cruciate ligament—deficient human knee. PMID:25938111

  4. Composition of Human Peri-implantitis and Periodontitis Lesions

    PubMed Central

    Carcuac, O.; Berglundh, T.

    2014-01-01

    The aim of the present study was to examine differences in cellular characteristics of human peri-implantitis and periodontitis lesions. Two groups of patients were included: 40 patients with generalized severe chronic periodontitis and 40 patients presenting with severe peri-implantitis. Soft tissue biopsies were obtained from diseased sites (probing pocket depth ≥ 7 mm with bleeding on probing) and prepared for histologic and immunohistochemical analysis. In contrast to periodontitis samples, peri-implantitis lesions were more than twice as large and contained significantly larger area proportions, numbers, and densities of CD138-, CD68-, and MPO-positive cells than periodontitis lesions. Peri-implantitis lesions also extended to a position that was apical of the pocket epithelium and not surrounded by noninfiltrated connective tissue. They further presented with significantly larger densities of vascular structures in the connective tissue area lateral to the infiltrated connective tissue than within the infiltrate. This study suggests that peri-implantitis and periodontitis lesions exhibit critical histopathologic differences, which contribute to the understanding of dissimilarities in onset and progression between the 2 diseases. PMID:25261052

  5. Generation and periodontal differentiation of human gingival fibroblasts-derived integration-free induced pluripotent stem cells.

    PubMed

    Yin, Xiaohui; Li, Yang; Li, Jingwen; Li, Peng; Liu, Yinan; Wen, Jinhua; Luan, Qingxian

    2016-05-01

    Induced pluripotent stem cells (iPSCs) have been recognized as a promising cell source for periodontal tissue regeneration. However, the conventional virus-based reprogramming approach is associated with a high risk of genetic mutation and limits their therapeutic utility. Here, we successfully generated iPSCs from readily accessible human gingival fibroblasts (hGFs) through an integration-free and feeder-free approach via delivery of reprogramming factors of Oct4, Sox2, Klf4, L-myc, Lin28 and TP53 shRNA with episomal plasmid vectors. The iPSCs presented similar morphology and proliferation characteristics as embryonic stem cells (ESCs), and expressed pluripotent markers including Oct4, Tra181, Nanog and SSEA-4. Additionally, these cells maintained a normal karyotype and showed decreased CpG methylation ratio in the promoter regions of Oct4 and Nanog. In vivo teratoma formation assay revealed the development of tissues representative of three germ layers, confirming the acquisition of pluripotency. Furthermore, treatment of the iPSCs in vitro with enamel matrix derivative (EMD) or growth/differentiation factor-5 (GDF-5) significantly up-regulated the expression of periodontal tissue markers associated with bone, periodontal ligament and cementum respectively. Taken together, our data demonstrate that hGFs are a valuable cell source for generating integration-free iPSCs, which could be sequentially induced toward periodontal cells under the treatment of EMD and GDF-5. PMID:26456649

  6. The blood vessel system in the periodontal ligament of the equine cheek teeth--part I: The spatial arrangement in layers.

    PubMed

    Masset, Alexandra; Staszyk, Carsten; Gasse, Hagen

    2006-11-01

    Corrosion casts of blood vessels in the periodontium of cheek teeth from eight horses were observed three-dimensionally with a dissection microscope. Selected specimens were examined in a scanning electron microscope. Periodontal blood vessels communicated with those from the gingiva, the alveolar bone, and the apical region. In the upper jaw, there were anastomoses with the blood vessels of the mucosa of the maxillary sinus. The periodontal vascular system was organized in two or three layers. The peripheral layer was mainly composed of large venules, the inner one consisted of capillaries. In the intermediate layer, blood vessels were post-capillary venules. This layer was developed only in horses under 10 years of age. In all layers the vascular orientation was mainly occluso-apical, this was defined as the standard pattern. There were many variations displayed in different courses of certain blood vessels. The vascular organization is discussed with regard to the specialized functions of the periodontal ligament (PDL). The wide vessels of the outer layer are thought to play a mechanical role as part of a shock absorbing system. The capillaries of the inner layer meet nutritional requirements. The disappearance of the intermediate layer in horses older than 10 years is taken as an adaptation to the remodelling of the PDL. Modifications in the standard pattern of vascular arrangements are also interpreted as adaptations to life-long changes in the periodontal space. Anastomoses between the periodontal vasculature and the blood vessels of the maxillary sinus indicate that periodontal disease may be transferred into the sinus. PMID:17140145

  7. Evaluating Stress Distribution Pattern in Periodontal Ligament of Maxillary Incisors during Intrusion Assessed by the Finite Element Method

    PubMed Central

    Salehi, Parisa; Gerami, Alayar; Najafi, Amirhosein; Torkan, Sepideh

    2015-01-01

    Statement of the Problem The use of miniscrews has expedited the true maxillary incisor intrusion and has minimized untoward side effects such as labial tipping. Purpose The aim of this study was to assess the stress distribution in the periodontal ligament of maxillary incisors when addressed to different models of intrusion mechanics using miniscrews by employing finite element methods. The degree of relative and absolute intrusion of maxillary incisors in different conditions was also evaluated. Materials and Method Finite element model of maxillary central incisor to first premolar was generated by assembling images obtained from a three-dimensional model of maxillary dentition. Four different conditions of intrusion mechanics were simulated with different placement sites of miniscrews as well as different points of force application. In each model, 25-g force was applied to maxillary incisors via miniscrews. Results In all four models, increased stress values were identified in the apical region of lateral incisor. Proclination of maxillary incisors was also reported in all the four models. The minimum absolute intrusion was observed when the miniscrew was placed between the lateral incisor and canine and the force was applied at right angles to the archwire, which is very common in clinical practice. Conclusion From the results yield by this study, it seems that the apical region of lateral incisor is the most susceptible region to root resorption during anterior intrusion. When the minimum flaring of maxillary incisors is required in clinical situations, it is suggested to place the miniscrew halfway between the roots of lateral incisor and canine with the force applied to the archwire between central and lateral incisor. In order to achieve maximum absolute intrusion, it is advised to place miniscrew between the roots of central and lateral incisors with the force applied at a right angle to the archwire between these two teeth. PMID:26636119

  8. The mechanical function of the periodontal ligament in the macaque mandible: a validation and sensitivity study using finite element analysis

    PubMed Central

    Panagiotopoulou, Olga; Kupczik, Kornelius; Cobb, Samuel N

    2011-01-01

    Whilst the periodontal ligament (PDL) acts as an attachment tissue between bone and tooth, hypotheses regarding the role of the PDL as a hydrodynamic damping mechanism during intraoral food processing have highlighted its potential importance in finite element (FE) analysis. Although experimental and constitutive models have correlated the mechanical function of the PDL tissue with its anisotropic, heterogeneous, viscoelastic and non-linear elastic nature, in many FE simulations the PDL is either present or absent, and when present is variably modelled. In addition, the small space the PDL occupies and the inability to visualize the PDL tissue using μCT scans poses issues during FE model construction and so protocols for the PDL thickness also vary. In this paper we initially test and validate the sensitivity of an FE model of a macaque mandible to variations in the Young's modulus and the thickness of the PDL tissue. We then tested the validity of the FE models by carrying out experimental strain measurements on the same mandible in the laboratory using laser speckle interferometry. These strain measurements matched the FE predictions very closely, providing confidence that material properties and PDL thickness were suitably defined. The FE strain results across the mandible are generally insensitive to the absence and variably modelled PDL tissue. Differences are only found in the alveolar region adjacent to the socket of the loaded tooth. The results indicate that the effect of the PDL on strain distribution and/or absorption is restricted locally to the alveolar bone surrounding the teeth and does not affect other regions of the mandible. PMID:20584094

  9. Secretome Profiling of Periodontal Ligament from Deciduous and Permanent Teeth Reveals a Distinct Expression Pattern of Laminin Chains

    PubMed Central

    Giovani, Priscila A.; Salmon, Cristiane R.; Martins, Luciane; Paes Leme, Adriana F.; Rebouças, Pedro; Puppin Rontani, Regina M.; Mofatto, Luciana S.; Sallum, Enilson A.; Nociti, Francisco H.; Kantovitz, Kamila R.

    2016-01-01

    It has been suggested that there are histological and functional distinctions between the periodontal ligament (PDL) of deciduous (DecPDL) and permanent (PermPDL) teeth. Thus, we hypothesized that DecPDL and PermPDL display differences in the constitutive expression of genes/proteins involved with PDL homeostasis. Primary PDL cell cultures were obtained for DecPDL (n = 3) and PermPDL (n = 3) to allow us to perform label-free quantitative secretome analysis. Although a highly similar profile was found between DecPDL and PermPDL cells, comparative secretome analysis evidenced that one of the most stickling differences involved cell adhesion molecules, including laminin subunit gamma 1 (LAMC1) and beta 2 (LAMB2). Next, total RNA and protein extracts were obtained from fresh PDL tissues of deciduous (n = 6) and permanent (n = 6) teeth, and Western blotting and qPCR analysis were used to validate our in vitro findings. Western blot analysis confirmed that LAMC1 was increased in DecPDL fresh tissues (p<0.05). Furthermore, qPCR data analysis revealed that mRNA levels for laminin subunit beta 1 (LAMB1), beta 3 (LAMB3), LAMC1, and gamma 2 (LAMC2) were higher in DecPDL fresh tissues, whereas transcripts for LAMB2 were increased in PermPDL (p<0.05). In conclusion, the differential expression of laminin chains in DecPDL and PermPDL suggests an involvement of laminin-dependent pathways in the control of physiological differences between them. PMID:27149379

  10. Engineering the periodontal ligament in hyaluronan-gelatin-type I collagen constructs: upregulation of apoptosis and alterations in gene expression by cyclic compressive strain.

    PubMed

    Saminathan, Aarthi; Sriram, Gopu; Vinoth, Jayasaleen Kumar; Cao, Tong; Meikle, Murray C

    2015-02-01

    To engineer constructs of the periodontal ligament (PDL), human PDL cells were incorporated into a matrix of hyaluronan, gelatin, and type I collagen (COLI) in sample holders (13×1 mm) of six-well Biopress culture plates. The loading dynamics of the PDL were mimicked by applying a cyclic compressive strain of 33.4 kPa (340.6 gm/cm(2)) to the constructs for 1.0 s every 60 s, for 6, 12, and 24 h in a Flexercell FX-4000C Strain Unit. Compression significantly increased the number of nonviable cells and increased the expression of several apoptosis-related genes, including initiator and executioner caspases. Of the 15 extracellular matrix genes screened, most were upregulated at some point after 6-12 h deformation, but all were downregulated at 24 h, except for MMPs1-3 and CTGF. In culture supernatants, matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinases-1 (TIMP-1) protein levels were upregulated at 24 h; receptor activator of nuclear kappa factor B (RANKL), osteoprotegerin (OPG) and fibroblast growth factor-2 (FGF-2) were unchanged; and connective tissue growth factor (CTGF) not detected. The low modulus of elasticity of the constructs was a disadvantage-future mechanobiology studies and tissue engineering applications will require constructs with much higher stiffness. Since the major structural protein of the PDL is COLI, a more rational approach would be to permeabilize preformed COLI scaffolds with PDL-populated matrices. PMID:25181942

  11. Ibandronate promotes osteogenic differentiation of periodontal ligament stem cells by regulating the expression of microRNAs

    SciTech Connect

    Zhou, Qiang; Zhao, Zhi-Ning; Cheng, Jing-Tao; Zhang, Bin; Xu, Jie; Huang, Fei; Zhao, Rui-Ni; Chen, Yong-Jin

    2011-01-07

    Research highlights: {yields} Ibandronate significantly promote the proliferation of PDLSC cells. {yields} Ibandronate enhanced the expression of ALP, COL-1, OPG, OCN, Runx2. {yields} The expression of a class of miRNAs, e.g., miR-18a, miR-133a, miR-141 and miR-19a, was significantly modified in PDLSC cells cultured with ibandronate. {yields} Ibandronate regulates the expression of diverse bone formation-related genes via miRNAs in PDLSCs. {yields} Ibandronate can suppress the activity of osteoclast while promoting the proliferation of osteoblast by regulating the expression of microRNAs. -- Abstract: Bisphosphonates (BPs) have a profound effect on bone resorption and are widely used to treat osteoclast-mediated bone diseases. They suppress bone resorption by inhibiting the activity of mature osteoclasts and/or the formation of new osteoclasts. Osteoblasts may be an alternative target for BPs. Periodontal ligament stem cells (PDLSCs) exhibit osteoblast-like features and are capable of differentiating into osteoblasts or cementoblasts. This study aimed to determine the effects of ibandronate, a nitrogen-containing BP, on the proliferation and the differentiation of PDLSCs and to identify the microRNAs (miRNAs) that mediate these effects. The PDLSCs were treated with ibandronate, and cell proliferation was measured using the MTT (3-dimethylthiazol-2,5-diphenyltetrazolium bromide) assay. The expression of genes and miRNAs involved in osteoblastic differentiation was assayed using quantitative real-time reverse-transcription polymerase chain reaction (qRT-PCR). Ibandronate promoted the proliferation of PDLSCs and enhanced the expression of alkaline phosphatase (ALP), type I collagen (COL-1), osteoprotegerin (OPG), osteocalcin (OCN), and Runx2. The expression of miRNAs, including miR-18a, miR-133a, miR-141 and miR-19a, was significantly altered in the PDLSCs cultured with ibandronate. In PDLSCs, ibandronate regulates the expression of diverse bone formation

  12. Synchrotron radiation analysis of possible correlations between metal status in human cementum and periodontal disease.

    PubMed

    Martin, R R; Naftel, S J; Nelson, A J; Edwards, M; Mithoowani, H; Stakiw, J

    2010-03-01

    Periodontitis is a serious disease that affects up to 50% of an adult population. It is a chronic condition involving inflammation of the periodontal ligament and associated tissues leading to eventual tooth loss. Some evidence suggests that trace metals, especially zinc and copper, may be involved in the onset and severity of periodontitis. Thus we have used synchrotron X-ray fluorescence imaging on cross sections of diseased and healthy teeth using a microbeam to explore the distribution of trace metals in cementum and adhering plaque. The comparison between diseased and healthy teeth indicates that there are elevated levels of zinc, copper and nickel in diseased teeth as opposed to healthy teeth. This preliminary correlation between elevated levels of trace metals in the cementum and plaque of diseased teeth suggests that metals may play a role in the progress of periodontitis. PMID:20157281

  13. Synchrotron radiation analysis of possible correlations between metal status in human cementum and periodontal disease

    SciTech Connect

    Martin, R.R.; Naftel, S.J.; Nelson, A.J.; Edwards, M.; Mithoowani, H.; Stakiw, J.

    2010-03-16

    Periodontitis is a serious disease that affects up to 50% of an adult population. It is a chronic condition involving inflammation of the periodontal ligament and associated tissues leading to eventual tooth loss. Some evidence suggests that trace metals, especially zinc and copper, may be involved in the onset and severity of periodontitis. Thus we have used synchrotron X-ray fluorescence imaging on cross sections of diseased and healthy teeth using a microbeam to explore the distribution of trace metals in cementum and adhering plaque. The comparison between diseased and healthy teeth indicates that there are elevated levels of zinc, copper and nickel in diseased teeth as opposed to healthy teeth. This preliminary correlation between elevated levels of trace metals in the cementum and plaque of diseased teeth suggests that metals may play a role in the progress of periodontitis.

  14. Human Periodontal Stem Cells Release Specialized Proresolving Mediators and Carry Immunomodulatory and Prohealing Properties Regulated by Lipoxins

    PubMed Central

    Cianci, Eleonora; Recchiuti, Antonio; Trubiani, Oriana; Diomede, Francesca; Marchisio, Marco; Miscia, Sebastiano; Colas, Romain A.; Dalli, Jesmond; Serhan, Charles N.

    2016-01-01

    Unresolved inflammation and tissue destruction are underlying mechanisms of periodontitis, which is linked to dysregulated polymorphonuclear neutrophil (PMN) functions. Lipoxin A4 (LXA4) is a specialized proresolving lipid mediator (SPM) that dampens excessive inflammation, promotes resolution, and protects from leukocyte-mediated tissue damage. Human periodontal ligament stem cells (hPDLSCs) represent key players during tissue regeneration and may contribute to resolution of inflammation; thus, they may represent a promising tool in regenerative dentistry. In the present study, we investigated the actions of hPDLSCs on PMN apoptosis and antimicrobial functions, and determined the impact of LXA4 on hPDLSCs. hPDLSCs significantly reduced apoptosis and stimulated microbicidal activity of human PMNs, via both cell-cell interactions and paracrine mechanisms. Lipid mediator metabololipidomics analysis demonstrated that hPDLSCs biosynthesize SPMs, including resolvin D1, D2, D5, and D6; protectin D1; maresins; and LXB4; as well as prostaglandins D2, E2, and F2α. LXA4 significantly enhanced proliferation, migration, and wound healing capacity of hPDLSCs through the activation of its cognate receptor ALX/FPR2, expressed on hPDLSCs. Together, these results demonstrate that hPDLSCs modulate PMN functions, and provide the first evidence that stem cells generate SPM and that the LXA4-ALX/FPR2 axis regulates regenerative functions of hPDLSCs by a novel receptor-mediated mechanism. Significance These findings uncovered unappreciated features of stem cells from the periodontal ligament, supporting the notion that these cells may act as master regulators of pathophysiological events through the release of mediators that promote the resolution of inflammation and bacterial killing. The study also demonstrated that it is possible to modulate important functions of periodontal stem cells using lipoxin A4, a potent endogenous stop signal of inflammation. Thus, this study revealed an

  15. Ligament fibre recruitment at the human ankle joint complex in passive flexion.

    PubMed

    Stagni, Rita; Leardini, Alberto; Ensini, Andrea

    2004-12-01

    Knowledge of ligament fibre recruitment at the human ankle joint complex is a fundamental prerequisite for analysing mobility and stability. Previous experimental and modelling studies have shown that ankle motion must be guided by fibres within the calcaneofibular and tibiocalcaneal ligaments, which remain approximately isometric during passive flexion. The purpose of this study was to identify these fibres. Three below-knee amputated specimens were analysed during passive flexion with combined radiostereometry for bone pose estimation and 3D digitisation for ligament attachment area identification. A procedure based on singular value decomposition enabled matching bone pose with digitised data and therefore reconstructing position in space of ligament attachment areas in each joint position. Eleven ordered fibres, connecting corresponding points on origin and insertion curves, were modelled for each of the following ligaments: posterior talofibular, calcaneofibular, anterior talofibular, posterior tibiotalar, tibiocalcaneal, and anterior tibiotalar. The measured changes in length for the ligament fibres revealed patterns of tightening and slackening. The most anterior fibre of the calcaneofibular and the medio-anterior fibre of the tibiocalcaneal ligament exhibited the most isometric behaviour, as well as the most posterior fibre of the anterior talofibular ligament. Fibres within the calcaneofibular ligament remain parallel in the transverse plane, while those within the tibiocalcaneal ligament become almost parallel in joint neutral position. For both these ligaments, fibres maintain their relative inclination in the sagittal plane throughout the passive flexion range. The observed significant change in both shape and orientation of the ankle ligaments suggest that this knowledge is fundamental for future mechanical analysis of their response to external forces. PMID:15519590

  16. Effect of Coconut Water Concentration on Survival of Bench-Dried Periodontal Ligament Cells

    PubMed Central

    Al-Haj Ali, Sanaa; Mhaidat, Nizar; Awawdeh, Lama; Naffa, Randa

    2011-01-01

    ABSTRACT Background : Coconut water is a biological and sterile liquid. It contains a variety of electrolytes, sugars and amino acids. The purpose of this study is to evaluate the effect of concentration and maturity of coconut water on its ability to preserve human PDL cell viability after exposure to dry time of up to 120 minutes using an in vitro cell culture model. Methods : PDL cells were obtained from sound permanent first molars which were cultured in Dulbecco’s Modified Eagle’s Medium (DMEM). Cultures were subjected to 0, 30, 60, 90 and 120 minutes dry periods then incubated with 100 and 50% young and mature coconut water for 45 minutes at room temperature (18-26°C). Untreated cells at 0 and 120 minutes, and cells incubated in DMEM served as controls. PDL cell viability was assessed by MTT assay. Statistical analysis of data was accomplished by using one-way analysis of variance complemented by Tukey test, and the level of significance was 5% (p < 0.05). Results : 100% mature coconut water (MCW) was better than 50% dilutions obtained from mature or young coconuts. However, no significant benefit to the cells was noticed from the addition of the soaking step prior to 30 minutes dry time. Conclusion : Avulsed teeth which are left dry for > 30 minutes may be benefited from soaking in 100% mature coconut water; further studies on simulated avulsion in animal models are needed to verify the above results.

  17. Identification of Master Regulator Genes in Human Periodontitis.

    PubMed

    Sawle, A D; Kebschull, M; Demmer, R T; Papapanou, P N

    2016-08-01

    Analytic approaches confined to fold-change comparisons of gene expression patterns between states of health and disease are unable to distinguish between primary causal disease drivers and secondary noncausal events. Genome-wide reverse engineering approaches can facilitate the identification of candidate genes that may distinguish between causal and associative interactions and may account for the emergence or maintenance of pathologic phenotypes. In this work, we used the algorithm for the reconstruction of accurate cellular networks (ARACNE) to analyze a large gene expression profile data set (313 gingival tissue samples from a cross-sectional study of 120 periodontitis patients) obtained from clinically healthy (n = 70) or periodontitis-affected (n = 243) gingival sites. The generated transcriptional regulatory network of the gingival interactome was subsequently interrogated with the master regulator inference algorithm (MARINA) and gene expression signature data from healthy and periodontitis-affected gingiva. Our analyses identified 41 consensus master regulator genes (MRs), the regulons of which comprised between 25 and 833 genes. Regulons of 7 MRs (HCLS1, ZNF823, XBP1, ZNF750, RORA, TFAP2C, and ZNF57) included >500 genes each. Gene set enrichment analysis indicated differential expression of these regulons in gingival health versus disease with a type 1 error between 2% and 0.5% and with >80% of the regulon genes in the leading edge. Ingenuity pathway analysis showed significant enrichment of 36 regulons for several pathways, while 6 regulons (those of MRs HCLS1, IKZF3, ETS1, NHLH2, POU2F2, and VAV1) were enriched for >10 pathways. Pathways related to immune system signaling and development were the ones most frequently enriched across all regulons. The unbiased analysis of genome-wide regulatory networks can enhance our understanding of the pathobiology of human periodontitis and, after appropriate validation, ultimately identify target molecules of

  18. Comparison of Coconut Water and Jordanian Propolis on Survival of Bench-dried Periodontal Ligament Cells: An in vitro Cell Culture Study

    PubMed Central

    Al-Jundi, Suhad; Mhaidat, Nizar

    2013-01-01

    ABSTRACT Aim: The aim of this study is to assess and compare the efficacy of Jordanian propolis and full concentration mature coconut water in their ability to preserve periodontal ligament (PDL) cell viability after exposure of PDL cells to up to 120 minutes dry storage. Materials and methods: PDL cells were obtained from sound permanent first molars which were cultured in Dulbecco's Modified Eagles Medium (DMEM). Cultures were subjected to 0, 30, 45, 60, 90 and 120 minutes dry storage times then incubated with 100% mature coconut water, Jordanian propolis and DMEM for 45 minutes at room temperature (18-26°C). Untreated cells served as controls at each dry storage time tested. PDL cell viability was assessed by MTT assay. Statistical analysis of data was accomplished by using one-way analysis of variance complemented by Tukey test and the level of significance was 5% ( p < 0.05). Results: Up to 60 minutes dry storage, no significant improvement on the percentage of viable cells was found from soaking in all tested media. On the other hand, soaking in mature coconut water only resulted in higher percentages of viable cells at >60 minutes dry storage. However, this improvement was not significant (p > 0.05). Conclusion: Avulsed teeth which have been left dry for <45 minutes should be replanted immediately, whereas avulsed teeth which have been left dry for >45 minutes may benefit from soaking for 45 minutes in mature coconut water. How to cite this article: Al-Haj Ali SN, Al-Jundi S, Mhaidat N. Comparison of Coconut Water and Jordanian Propolis on Survival of Bench-dried Periodontal Ligament Cells: An in vitro Cell Culture Study. Int J Clin Pediatr Dent 2013;6(3):161-165. PMID:25206215

  19. The application of bone morphogenetic proteins to periodontal and peri-implant tissue regeneration: A literature review

    PubMed Central

    Sasikumar, Karuppanan P.; Elavarasu, Sugumari; Gadagi, Jayaprakash S.

    2012-01-01

    Progress in understanding the role of bone morphogenetic proteins (BMPs) in craniofacial and tooth development and the demonstration of stem cells in periodontal ligament have set the stage for periodontal regenerative therapy and tissue engineering. Furthermore, recent approval by the Food and Drug Administration of recombinant human BMPs for accelerating bone fusion in slow-healing fractures indicates that this protein family may prove useful in designing regenerative treatments in periodontics. In the near term, these advances are likely to be applied to periodontal surgery; ultimately, they may facilitate approaches to regenerating whole lost periodontal structures. PMID:23066304

  20. Overexpression of X chromosome-linked inhibitor of apoptosis by inhibiting microRNA-24 protects periodontal ligament cells against hydrogen peroxide-induced cell apoptosis.

    PubMed

    Liu, C; Chen, Z; Wang, J; Hu, H

    2016-01-01

    Hydrogen peroxide (H2O2), a common oral clinical drug for the tooth bleaching, induces severe cell apoptosis of periodontal ligament cells (PDLCs). The excessive cell apoptosis of PDLCs impairs periodontal tissue damage and repair. However, the underlying mechanism is incompletely understood. Here, we showed that microRNA-24 (miR-24) played an important role in regulating H2O2-induced cell apoptosis of PDLCs. We found that miR-24 expression was increased in PDLCs in response to H2O2 treatment. Down-regulation of miR-24 obviously rescued H2O2-induced cell apoptosis in PDLCs. By bioinformatic analysis, X chromosome-linked inhibitor of apoptosis (XIAP) was identified as a candidate target gene of miR-24, which was further verified by the dual-luciferase reporter assay. Furthermore, the protein expression level of phosphatase and tensin homolog deleted on chromosome ten was significantly decreased by miR-24 silencing, whereas the phosphorylation of Akt was remarkably increased by miR-24 silencing. In addition, the gene silencing of XIAP significantly reduced Akt activity and blocked the protective effect of the miR-24 inhibitor against H2O2-induced cell apoptosis. Overall, our findings suggest that miR-24 plays an important role in regulating the cell survival of PDLCs through targeting XIAP. PMID:27188727

  1. Influence of developing ligaments on the muscles in contact with them: a study of the annular ligament of the radius and the sacrospinous ligament in mid-term human fetuses

    PubMed Central

    Kim, Ji Hyun; Rodriguez-Vazquez, Jose Francisco; Murakami, Gen; Fukuzawa, Yoshitaka; Asamoto, Ken; Nakano, Takashi

    2013-01-01

    The supinator muscle originates from the annular ligament of the radius, and the muscle fibers and ligament take a similar winding course. Likewise, the coccygeus muscle and the sacrospinous ligament are attached together, and show a similar fiber orientation. During dissection of adult cadavers for our educational curriculum, we had the impression that these ligaments grow in combination with degeneration of parts of the muscles. In histological sections of 25 human fetuses at 10-32 weeks of gestation, we found that the proximal parts of the supinator muscle were embedded in collagenous tissue when the developing annular ligament of the radius joined the thick intermuscular connecting band extending between the extensor carpi radialis and anconeus muscles at 18-22 weeks of gestation, and the anterior parts of the coccygeus muscle were surrounded by collagenous tissue when the intramuscular tendon became the sacrospinous ligament at 28-32 weeks. Parts of these two muscles each seemed to provide a mold for the ligament, and finally became involved with it. This may be the first report to indicate that a growing ligament has potential to injure parts of the "mother muscle," and that this process may be involved in the initial development of the ligament. PMID:23869262

  2. Elastic properties of Thiel-embalmed human ankle tendon and ligament.

    PubMed

    Liao, Xiaochun; Kemp, Sandy; Corner, George; Eisma, Roos; Huang, Zhihong

    2015-10-01

    Thiel embalming is recommended as an alternative to formalin-based embalming because it preserves tissue elasticity, color, and flexibility in the long term, with low infection and toxicity risk. The degree to which Thiel embalming preserves elasticity has so far been assessed mainly by subjective scoring, with little quantitative verification. The aim of this study is to quantify the effect of Thiel embalming on the elastic properties of human ankle tendons and ligament. Biomechanical tensile tests were carried out on six Thiel-embalmed samples each of the peroneus longus, peroneus brevis, and calcaneal tendons, and the calcaneofibular ligament, with strain rates of 0.25%s(-1), 2%s(-1), and 8%s(-1). The stress-strain relationship was calculated from the force-extension response with cross-sectional area and gauge length. Young's modulus was determined from the stress-strain curve. The results showed that the tendon and ligament elasticity were lower after Thiel embalming than the literature values for fresh nonembalmed tendons and ligament. The biomechanical tensile test showed that the measured elasticity of Thiel-embalmed tendons and ligaments increased with the strain rate. The Thiel embalming method is useful for preserving human ankle tendons and ligaments for anatomy and surgery teaching and research, but users need to be aware of its softening effects. The method retains the mechanical strain rate effect on tendons and ligament. PMID:25707906

  3. Periodontal pocket as a potential reservoir of high risk human papilloma virus: A pilot study

    PubMed Central

    Dayakar, Manjunath Mundoor; Shipilova, Anna; Gupta, Dinesh

    2016-01-01

    Aim: Human papilloma viruses (HPVs) are small DNA viruses that have been identified in periodontal pocket as well as gingival sulcus. High risk HPVs are also associated with a subset of head and neck carcinomas. HPV detection in periodontium has previously involved DNA detection. This study attempts to: (a) Detect the presence or absence of high risk HPV in marginal periodontiun by identifying E6/E7 messenger RNA (mRNA) in cells from samples obtained by periodontal pocket scraping. (b) Detect the percentage of HPV E6/E7 mRNA in cells of pocket scrapings, which is responsible for producing oncoproteins E6 and E7. Materials and Methods: Pocket scrapings from the periodontal pockets of eight subjects with generalized chronic periodontitis were taken the detection of presence or absence of E6, E7 mRNA was performed using in situ hybridization and flow cytometry. Results: HPV E6/E7 mRNA was detected in four of the eight samples. Conclusion: Presence of high risk human papillomaviruses in periodontal pockets patients of diagnosed with chronic periodontitis, not suffering from head and neck squamous cell carcinoma in the present day could link periodontitis to HPV related squamous cell carcinoma. Prevalence studies are needed detecting the presence of HPV in marginal periodontium as well as prospective studies of HPV positive periodontitis patients are required to explore this possible link. PMID:27143823

  4. Assessment of cellular materials generated by co-cultured 'inflamed' and healthy periodontal ligament stem cells from patient-matched groups.

    PubMed

    Tang, Hao-Ning; Xia, Yu; Xu, Jie; Tian, Bei-Min; Zhang, Xi-Yu; Chen, Fa-Ming

    2016-08-01

    Recently, stem cells derived from the'inflamed' periodontal ligament (PDL) tissue of periodontally diseased teeth (I-PDLSCs) have been increasingly suggested as a more readily accessible source of cells for regenerative therapies than those derived from healthy PDL tissue (H-PDLSCs). However, substantial evidence indicates that I-PDLSCs exhibit impaired functionalities compared with H-PDLSCs. In this study, patient-matched I-PDLSCs and H-PDLSCs were co-cultured at various ratios. Cellular materials derived from these cultures were investigated regarding their osteogenic potential in vitro and capacity to form new bone following in vivo transplantation. While patient-matched I-PDLSCs and H-PDLSCs could co-exist in co-culture systems, the proportion of I-PDLSCs tended to increase during in vitro incubation. Compared with H-PDLSC monoculture, the presence of I-PDLSCs in the co-cultures appeared to enhance the overall cell proliferation. Although not completely rescued, the osteogenic and regenerative potentials of the cellular materials generated by co-cultured I-PDLSCs and H-PDLSCs were significantly improved compared with those derived from I-PDLSC monocultures. Notably, cells in co-cultures containing either 50% I-PDLSCs plus 50% H-PDLSCs or 25% I-PDLSCs plus 75% H-PDLSCs expressed osteogenesis-related proteins and genes at levels similar to those expressed in H-PDLSC monocultures (P>0.05). Irrespective of the percentage of I-PDLSCs, robust cellular materials were obtained from co-cultures with 50% or more H-PDLSCs, which exhibited equivalent potential to form new bone in vivo compared with sheets generated by H-PDLSC monocultures. These data suggest that the co-culture of I-PDLSCs with patient-matched H-PDLSCs is a practical and effective method for increasing the overall osteogenic and regenerative potentials of resultant cellular materials. PMID:27237095

  5. The Effect of Propolis As A Biological Storage Media on Periodontal Ligament Cell Survival in An Avulsed Tooth: An In Vitro Study

    PubMed Central

    Ahangari, Zohreh; Alborzi, Samiye; Yadegari, Zahra; Dehghani, Fatemeh; Ahangari, Leila; Naseri, Mandana

    2013-01-01

    Objective: Both the length of extra-alveolar time and type of storage media are significant factors that can affect the long-term prognosis of replanted teeth. This study aims to compare propolis 50%, propolis 10%, Hank’s balanced salt solution (HBSS), milk and egg white on periodontal ligament (PDL) cell survival for different time points. Materials and Methods: : In this in vitro experimental study, we divided 60 extracted teeth without any periodontal diseases into five experimental and two control groups that consisted each experimental group with 10 and each control group with 5 teeth. The storage times were one and three hours for each media. The controls corresponded to 0-minute (positive) and 12-hour (negative) dry time. Rinsing in the experimental media, the teeth were treated with dispase and collagenase for one hour. Cell viability was determined by using trypan blue exclusion. Statistical analysis of the data was accomplished by using two-way analysis of variance (ANOVA) complemented by the Tukey’s HSD post-hoc. Results: Within one hour, there was no significant difference between the two propolis groups, however these two groups had significantly more viable PDL cells compared to the other experimental media (p<0.05). The results of the three-hour group showed that propolis 10% was significantly better than egg white, whereas both propolis 10% and 50% were significantly better than milk (p<0.05). Conclusion: Based on PDL cell viability, propolis could be recommended as a suitable biological storage media for avulsed teeth. PMID:24027666

  6. Correlation of mast cells in different stages of human periodontal diseases: Pilot study

    PubMed Central

    Agrawal, Raina; Gupta, Jagriti; Gupta, Krishna Kumar; Kumar, Vinod

    2016-01-01

    Aims and Objectives: The aim of this study was to evaluate and correlate the relationship between mast cells counts and different stages of human periodontal diseases. Materials and Methods: The study sample comprised 50 patients, which were divided into three groups, consisting of 10 cases of clinically healthy gingival tissues (control group) 20 cases of dental plaque-induced gingivitis with no attachment loss and 20 cases of localized chronic periodontitis (LCP) characterized by the loss of periodontal support. The samples for control group were obtained during tooth extractions for orthodontic reasons. The specimens were immediately fixed in 10% neutral buffered formalin. Conclusion: In this study, LCP cases had higher mast cell counts compared to gingivitis sites or healthy tissues. Increased mast cell counts in the progressing sites of periodontal diseases may indicate the importance of these cells in the progression of chronic periodontitis. PMID:27194868

  7. Evaluation of Osteogenic and Cementogenic Potential of Periodontal Ligament Fibroblast Spheroids Using a Three-Dimensional In Vitro Model of Periodontium

    PubMed Central

    Berahim, Zurairah; Moharamzadeh, Keyvan; Jowett, Adrian K.; Rawlinson, Andrew

    2015-01-01

    The aim of this study was to develop a three-dimensional in vitro model of periodontium to investigate the osteogenic and cementogenic differentiation potential of the periodontal ligament fibroblast (PDLF) spheroids within a dentin-membrane complex. PDLFs were cultured in both spheroid forms and monolayers and were seeded onto two biological collagen-based and synthetic membranes. Cell-membrane composites were then transferred onto dentin slices with fibroblasts facing the dentin surface and further cultured for 20 days. The composites were then processed for histology and immunohistochemical analyses for osteocalcin, Runx2, periostin, and cementum attachment protein (CAP). Both membranes seeded with PDLF-derived cells adhered to dentin and fibroblasts were present at the dentin interface and spread within both membranes. All membrane-cell-dentine composites showed positive staining for osteocalcin, Runx2, and periostin. However, CAP was not expressed by any of the tissue composites. It can be concluded that PDLFs exhibited some osteogenic potential when cultured in a 3D matrix in the presence of dentin as shown by the expression of osteocalcin. However the interaction of cells and dentin in this study was unable to stimulate cementum formation. The type of membrane did not have a significant effect upon differentiation, but fibroblast seeded-PGA membrane demonstrated better attachment to dentin than the collagen membrane. PMID:26633971

  8. Evaluation and comparison of efficacy of three different storage media, coconut water, propolis, and oral rehydration solution, in maintaining the viability of periodontal ligament cells

    PubMed Central

    Sanghavi, Tulsi; Shah, Nimisha; Parekh, Vaishali; Singbal, Kiran

    2013-01-01

    Background: Two of the most critical factors affecting the prognosis of an avulsed tooth after replantation are extra oral dry time and the storage medium in which the tooth is placed before treatment is rendered. However, the ability of a storage/transport medium to support cell viability can be more important than the extra oral time to prevent ankylosis and replacement resorption. Aim: Purpose of this study was evaluation and comparison of efficacy of a new storage medium, oral rehydration solution (ORS) with coconut water, and propolis in maintaining the viability of periodontal ligament (PDL) cells by using a collagenase-dispase assay. Materials and Methods: 40 teeth were selected with intact crown which were advised for Orthodontic extraction having healthy PDL. Teeth were then randomly divided into three experimental storage solution groups. Other 10 were divided into positive and negative control groups (5 each). Statistical Analysis and Result: The results were statistically analyzed with analysis of variance and multiple range by using post hoc tests. The results of the prevailing study indicated that coconut water group demonstrated a significantly higher number of viable PDL cells than propolis 50%, and ORS. There was no significant difference between coconut water and propolis 50% groups. PMID:23349581

  9. Tooth periodontal ligament: Direct 3D microCT visualization of the collagen network and how the network changes when the tooth is loaded.

    PubMed

    Naveh, Gili R S; Brumfeld, Vlad; Shahar, Ron; Weiner, Steve

    2013-02-01

    The periodontal ligament (PDL), a soft tissue connecting the tooth and the bone, is essential for tooth movement, bone remodeling and force dissipation. A collagenous network that connects the tooth root surface to the alveolar jaw bone is one of the major components of the PDL. The organization of the collagenous component and how it changes under load is still poorly understood. Here using a state-of-the-art custom-made loading apparatus and a humidified environment inside a microCT, we visualize the PDL collagenous network of a fresh rat molar in 3D at 1 μm voxel size without any fixation or contrasting agents. We demonstrate that the PDL collagen network is organized in sheets. The spaces between sheets vary thus creating dense and sparse networks. Upon vertical loading, the sheets in both networks are stretched into well aligned arrays. The sparse network is located mainly in areas which undergo compressive loading as the tooth moves towards the bone, whereas the dense network functions mostly in tension as the tooth moves further from the bone. This new visualization method can be used to study other non-mineralized or partially mineralized tissues, and in particular those that are subjected to mechanical loads. The method will also be valuable for characterizing diseased tissues, as well as better understanding the phenotypic expressions of genetic mutants. PMID:23110851

  10. Functional human T-cell immunity and osteoprotegerin ligand control alveolar bone destruction in periodontal infection

    PubMed Central

    Teng, Yen-Tung A.; Nguyen, Hai; Gao, Xuijuan; Kong, Young-Yun; Gorczynski, Reginald M.; Singh, Bhagirath; Ellen, Richard P.; Penninger, Josef M.

    2000-01-01

    Periodontitis, a prime cause of tooth loss in humans, is implicated in the increased risk of systemic diseases such as heart failure, stroke, and bacterial pneumonia. The mechanisms by which periodontitis and antibacterial immunity lead to alveolar bone and tooth loss are poorly understood. To study the human immune response to specific periodontal infections, we transplanted human peripheral blood lymphocytes (HuPBLs) from periodontitis patients into NOD/SCID mice. Oral challenge of HuPBL-NOD/SCID mice with Actinobacillus actinomycetemcomitans, a well-known Gram-negative anaerobic microorganism that causes human periodontitis, activates human CD4+ T cells in the periodontium and triggers local alveolar bone destruction. Human CD4+ T cells, but not CD8+ T cells or B cells, are identified as essential mediators of alveolar bone destruction. Stimulation of CD4+ T cells by A. actinomycetemcomitans induces production of osteoprotegerin ligand (OPG-L), a key modulator of osteoclastogenesis and osteoclast activation. In vivo inhibition of OPG-L function with the decoy receptor OPG diminishes alveolar bone destruction and reduces the number of periodontal osteoclasts after microbial challenge. These data imply that the molecular explanation for alveolar bone destruction observed in periodontal infections is mediated by microorganism-triggered induction of OPG-L expression on CD4+ T cells and the consequent activation of osteoclasts. Inhibition of OPG-L may thus have therapeutic value to prevent alveolar bone and/or tooth loss in human periodontitis. This article may have been published online in advance of the print edition. The date of publication is available from the JCI website, http://www.jci.org. J. Clin. Invest. 106:R59–R67 (2000). PMID:10995794

  11. Rare Periodontal Ligament Drainage for Periapical Inflammation of an Adjacent Tooth: A Case Report and Review of the Literature

    PubMed Central

    Guo, Hongmei; Lu, Wei; Han, Qianqian; Li, Shubo; Yang, Pishan

    2014-01-01

    Aim. To report a case with an unusual drainage route of periapical inflammation exiting through the gingival sulcus of an adjacent vital tooth and review probable factors determining the diversity of the discharge routes of periapical inflammation. Summary. An 18-year-old male patient presented with periodontal abscess of tooth 46, which was found to be caused by a periapical cyst with an acute abscess of tooth 45. During endodontic surgery, a rarely reported drainage route for periapical inflammation via the gingival sulcus of an adjacent vital tooth was observed for the first time. Complete periodontal healing of the deep pocket of tooth 46 and hiding of the periapical cyst of tooth 45 followed after root canal treatment and periapical surgery with Bio-Oss Collagen implantation on tooth 45. The drainage routes of periapical inflammation are multivariate and the diversity of drainage pathways of periapical inflammation is mainly related to factors such as gravity, barriers against inflammation, and the causative tooth itself. PMID:25587462

  12. Arterial Supply to the Human Anterior Cruciate Ligament

    PubMed Central

    Toy, Brian J.; Yeasting, Richard A.; Morse, Dennis E.; McCann, Patricia

    1995-01-01

    The arterial supply to the anterior cruciate ligament (ACL) was prepared for study by injecting a fresh cadaver knee with an epoxy lead-oxide solution and subsequently immersing it in 10% formalin for a 2-week period. The vasculature of the ACL was exposed through dissection for examination. A second specimen was prepared similarly and was evaluated by a CAT scan. ACL vascularization arises from the middle genicular artery and vessels of the infrapatella fat pad and adjacent synovium. The artery gives rise to periligamentous vessels which form a web-like network within the synovial membrane. These periligamentous vessels give rise to penetrating branches which transversely cross the ACL and anastomose with a network of longitudinally oriented endoligamentous vessels. Terminal branches of the inferior medial and lateral genicular arteries supply the distal portion of the ACL directly. The extremities of the ACL seem to be better vascularized than the middle part, and the proximal portion seems to have a greater vascular density than the distal portion. The arteries at the ligamentous-osseous junctions of the ACL do not significantly contribute to the ligament's vascularity. Ramifications concerning the ACL's blood supply as it relates to athletic training is also discussed. ImagesFig 1.Fig 2.Fig 3.Fig 4. PMID:16558326

  13. [Comparison of gene expression profile of cementoblasts with periodontal ligament cells in mouse mandible with laser capture microdissection].

    PubMed

    Yokoyama, Yoshiko

    2008-03-01

    Cementum is an essential tissue to maintain tooth function and should be closely correlated to tooth root development and periodontal tissue regeneration. However, detailed features of the periodontium including cementum and specific markers for cementoblasts are unknown. Moreover, the molecular mechanism of periodontal tissue development, homeostasis and regeneration remains unknown. Previous studies have usually examined cementum or periodontalligament (PDL) tissue obtained by manual curettage, resulting in difficulties in isolating pure cementum or PDL. We employed laser capture microdissection (LCM) to isolate cementoblasts and PDL cells from undecalcified frozen sections of murine mandible and to obtain RNA of good quality for subsequent genetic analysis. Over 500 cementoblasts and PDL cells were separately laser captured under microscopy. A bioanalyzer detected peaks of 18S and 28S rRNA both in the laser-dissected cementoblasts and in PDL cells, suggesting that the RNA was of sufficient quality. The RNA samples were amplified due to their small amount and a comparative analysis of mRNA expression by GeneChip showed that about 2,000 genes were differentially expressed between cementoblasts and PDL cells. Both cementoblast-positive and PDL cell-negative genes were serially analyzed by quantitative RT-PCR using RNA samples obtained from mandibles and femurs. Several genes were expressed at higher levels in the mandible than in the femur, suggesting that some might be cementoblast-specific markers. We established a novel experimental system with which to isolate target tissues from single cells in undecalcified frozen sections and to obtain intact RNA. These methodologies could be useful for further investigation of mineralized tissues and to explore tissue-specific factors. PMID:18421948

  14. Immunolocalization of a human cementoblastoma-conditioned medium-derived protein.

    PubMed

    Arzate, H; Jiménez-García, L F; Alvarez-Pérez, M A; Landa, A; Bar-Kana, I; Pitaru, S

    2002-08-01

    Little is known about the molecular mechanisms that regulate the cementogenesis process, because specific cementum markers are not yet available. To investigate whether a cementoblastoma-conditioned medium-derived protein (CP) could be useful as a cementum biological marker, we studied its expression and distribution in human periodontal tissues, human periodontal ligament, alveolar bone, and cementoblastoma-derived cells. In human periodontal tissues, immunoreactivity to anti-CP was observed throughout the cementoid phase of acellular and cellular cementum, cementoblasts, cementocytes, cells located in the endosteal spaces of human alveolar bone, and in cells in the periodontal ligament located near the blood vessels. Immunopurified CP promoted cell attachment on human periodontal ligament, alveolar bone-derived cells, and gingival fibroblasts. A monoclonal antibody against bovine cementum attachment protein (CAP) cross-reacted with CP. These findings indicate that CP identifies potential cementoblast progenitor cells, is immunologically related to CAP species, and serves as a biological marker for cementum. PMID:12147744

  15. Bone Regeneration Potential of Stem Cells Derived from Periodontal Ligament or Gingival Tissue Sources Encapsulated in RGD-Modified Alginate Scaffold

    PubMed Central

    Chen, Chider; Xu, Xingtian; Akiyama, Kentaro; Ansari, Sahar; Zadeh, Homayoun H.; Shi, Songtao

    2014-01-01

    Mesenchymal stem cells (MSCs) provide an advantageous alternative therapeutic option for bone regeneration in comparison to current treatment modalities. However, delivering MSCs to the defect site while maintaining a high MSC survival rate is still a critical challenge in MSC-mediated bone regeneration. Here, we tested the bone regeneration capacity of periodontal ligament stem cells (PDLSCs) and gingival mesenchymal stem cells (GMSCs) encapsulated in a novel RGD- (arginine-glycine-aspartic acid tripeptide) coupled alginate microencapsulation system in vitro and in vivo. Five-millimeter-diameter critical-size calvarial defects were created in immunocompromised mice and PDLSCs and GMSCs encapsulated in RGD-modified alginate microspheres were transplanted into the defect sites. New bone formation was assessed using microcomputed tomography and histological analyses 8 weeks after transplantation. Results confirmed that our microencapsulation system significantly enhanced MSC viability and osteogenic differentiation in vitro compared with non-RGD-containing alginate hydrogel microspheres with larger diameters. Results confirmed that PDLSCs were able to repair the calvarial defects by promoting the formation of mineralized tissue, while GMSCs showed significantly lower osteogenic differentiation capability. Further, results revealed that RGD-coupled alginate scaffold facilitated the differentiation of oral MSCs toward an osteoblast lineage in vitro and in vivo, as assessed by expression of osteogenic markers Runx2, ALP, and osteocalcin. In conclusion, these results for the first time demonstrated that MSCs derived from orofacial tissue encapsulated in RGD-modified alginate scaffold show promise for craniofacial bone regeneration. This treatment modality has many potential dental and orthopedic applications. PMID:24070211

  16. Bone regeneration potential of stem cells derived from periodontal ligament or gingival tissue sources encapsulated in RGD-modified alginate scaffold.

    PubMed

    Moshaverinia, Alireza; Chen, Chider; Xu, Xingtian; Akiyama, Kentaro; Ansari, Sahar; Zadeh, Homayoun H; Shi, Songtao

    2014-02-01

    Mesenchymal stem cells (MSCs) provide an advantageous alternative therapeutic option for bone regeneration in comparison to current treatment modalities. However, delivering MSCs to the defect site while maintaining a high MSC survival rate is still a critical challenge in MSC-mediated bone regeneration. Here, we tested the bone regeneration capacity of periodontal ligament stem cells (PDLSCs) and gingival mesenchymal stem cells (GMSCs) encapsulated in a novel RGD- (arginine-glycine-aspartic acid tripeptide) coupled alginate microencapsulation system in vitro and in vivo. Five-millimeter-diameter critical-size calvarial defects were created in immunocompromised mice and PDLSCs and GMSCs encapsulated in RGD-modified alginate microspheres were transplanted into the defect sites. New bone formation was assessed using microcomputed tomography and histological analyses 8 weeks after transplantation. Results confirmed that our microencapsulation system significantly enhanced MSC viability and osteogenic differentiation in vitro compared with non-RGD-containing alginate hydrogel microspheres with larger diameters. Results confirmed that PDLSCs were able to repair the calvarial defects by promoting the formation of mineralized tissue, while GMSCs showed significantly lower osteogenic differentiation capability. Further, results revealed that RGD-coupled alginate scaffold facilitated the differentiation of oral MSCs toward an osteoblast lineage in vitro and in vivo, as assessed by expression of osteogenic markers Runx2, ALP, and osteocalcin. In conclusion, these results for the first time demonstrated that MSCs derived from orofacial tissue encapsulated in RGD-modified alginate scaffold show promise for craniofacial bone regeneration. This treatment modality has many potential dental and orthopedic applications. PMID:24070211

  17. Quantitative comparison of ligament formulation and pre-strain in finite element analysis of the human lumbar spine.

    PubMed

    Hortin, Mitchell S; Bowden, Anton E

    2016-11-01

    Data has been published that quantifies the nonlinear, anisotropic material behaviour and pre-strain behaviour of the anterior longitudinal, supraspinous (SSL), and interspinous ligaments of the human lumbar spine. Additionally, data has been published on localized material properties of the SSL. These results have been incrementally incorporated into a previously validated finite element model of the human lumbar spine. Results suggest that the effects of increased ligament model fidelity on bone strain energy were moderate and the effects on disc pressure were slight, and do not justify a change in modelling strategy for most clinical applications. There were significant effects on the ligament stresses of the ligaments that were directly modified, suggesting that these phenomena should be included in FE models where ligament stresses are the desired metric. PMID:27007776

  18. Bacteriology of severe periodontitis in young adult humans.

    PubMed Central

    Moore, W E; Holdeman, L V; Smibert, R M; Hash, D E; Burmeister, J A; Ranney, R R

    1982-01-01

    A total of 78 bacteriological samples were taken from the supragingival tooth surface after superficial cleaning with toothpicks or from the periodontal sulci of 42 affected sites in 21 adolescents or young adults with severe generalized periodontitis. Of 190 bacterial species, subspecies, or serotypes detected among 2,723 isolates, 11 species exceeded 1% of the subgingival flora and were most closely associated with the diseased sulci. Eleven others were also sufficiently frequent to be suspect agents of tissue destruction. Many of these species are known pathogens of other body sites. In addition, 10 species of Treponema were isolated. One of these and the "large treponeme" were also more closely associated with severe periodontitis than they were with healthy sites or gingivitis. There were highly significant differences between the composition of the flora of the affected sulci and the flora of (i) the adjacent supragingival tooth surface, (ii) the gingival crevice of periodontally healthy people, and (iii) sites with a gingival index score of 0 or 2 in experimental gingivitis studies. The floras of different individuals were also significantly different. There was no statistically detectable effect of sampling per se upon the composition of the flora of subsequent samples from the same sites. The composition of the supragingival flora of the patients with severe generalized periodontitis that had serum antibody to Actinobacillus actinomycetemcomitans was significantly different from the supragingival flora of patients without this serum antibody. However, there was no statistically significant difference in the composition of their subgingival floras. PMID:7152665

  19. Biomechanical adaptation of the bone-periodontal ligament (PDL)-tooth fibrous joint as a consequence of disease.

    PubMed

    Lin, Jeremy D; Lee, Jihyun; Ozcoban, Hüseyin; Schneider, Gerold A; Ho, Sunita P

    2014-06-27

    In this study, an in vivo ligature-induced periodontitis rat model was used to investigate temporal changes to the solid and fluid phases of the joint by correlating shifts in joint biomechanics to adaptive changes in soft and hard tissue morphology and functional space. After 6 and 12 weeks of ligation, coronal regions showed a significant decrease in alveolar crest height, increased expression of TNF-α, and degradation of attachment fibers as indicated by decreased collagen birefringence. Cyclical compression to peak loads of 5-15N at speeds of 0.2-2.0mm/min followed by load relaxation tests showed decreased stiffness and reactionary load rate values, load relaxation, and load recoverability, of ligated joints. Shifts in joint stiffness and reactionary load rate increased with time while shifts in joint relaxation and recoverability decreased between control and ligated groups, complementing measurements of increased tooth displacement as evaluated through digital image correlation. Shifts in functional space between control and ligated joints were significantly increased at the interradicular (Δ10-25μm) and distal coronal (Δ20-45μm) regions. Histology revealed time-dependent increases in nuclei elongation within PDL cells and collagen fiber alignment, uncrimping, and directionality, in 12-week ligated joints compared to random orientation in 6-week ligated joints and to controls. We propose that altered strains from tooth hypermobility could cause varying degrees of solid-to-fluid compaction, alter dampening characteristics of the joint, and potentiate increased adaptation at the risk of joint failure. PMID:24332618

  20. Smoking and Periodontal Disease

    PubMed Central

    Borojevic, Tea

    2012-01-01

    Periodontitis is a group of inflammatory diseases affecting the supporting tissues of the tooth (periodontium). The periodontium consists of four tissues : gingiva, alveolar bone and periodontal ligaments. Tobbaco use is one of the modifiable risk factors and has enormous influance on the development, progres and tretmen results of periodontal disease. The relationship between smoking and periodontal health was investigated as early as the miiddle of last century. Smoking is an independent risk factor for the initiation, extent and severity of periodontal disease. Additionally, smoking can lower the chances for successful tretment. Tretmans in patients with periodontal disease must be focused on understanding the relationship between genetic and environmental factors. Only with individual approach we can identify our pacients risks and achieve better results. PMID:23678331

  1. Smoking and periodontal disease.

    PubMed

    Borojevic, Tea

    2012-01-01

    Periodontitis is a group of inflammatory diseases affecting the supporting tissues of the tooth (periodontium). The periodontium consists of four tissues : gingiva, alveolar bone and periodontal ligaments. Tobbaco use is one of the modifiable risk factors and has enormous influance on the development, progres and tretmen results of periodontal disease. The relationship between smoking and periodontal health was investigated as early as the miiddle of last century. Smoking is an independent risk factor for the initiation, extent and severity of periodontal disease. Additionally, smoking can lower the chances for successful tretment. Tretmans in patients with periodontal disease must be focused on understanding the relationship between genetic and environmental factors. Only with individual approach we can identify our pacients risks and achieve better results. PMID:23678331

  2. Multiphasic Scaffolds for Periodontal Tissue Engineering

    PubMed Central

    Ivanovski, S.; Vaquette, C.; Gronthos, S.; Hutmacher, D.W.; Bartold, P.M.

    2014-01-01

    For a successful clinical outcome, periodontal regeneration requires the coordinated response of multiple soft and hard tissues (periodontal ligament, gingiva, cementum, and bone) during the wound-healing process. Tissue-engineered constructs for regeneration of the periodontium must be of a complex 3-dimensional shape and adequate size and demonstrate biomechanical stability over time. A critical requirement is the ability to promote the formation of functional periodontal attachment between regenerated alveolar bone, and newly formed cementum on the root surface. This review outlines the current advances in multiphasic scaffold fabrication and how these scaffolds can be combined with cell- and growth factor–based approaches to form tissue-engineered constructs capable of recapitulating the complex temporal and spatial wound-healing events that will lead to predictable periodontal regeneration. This can be achieved through a variety of approaches, with promising strategies characterized by the use of scaffolds that can deliver and stabilize cells capable of cementogenesis onto the root surface, provide biomechanical cues that encourage perpendicular alignment of periodontal fibers to the root surface, and provide osteogenic cues and appropriate space to facilitate bone regeneration. Progress on the development of multiphasic constructs for periodontal tissue engineering is in the early stages of development, and these constructs need to be tested in large animal models and, ultimately, human clinical trials. PMID:25139362

  3. Three-dimensional micro-computed tomographic evaluation of periodontal regeneration: a human report of intrabony defects treated with Bio-Oss collagen.

    PubMed

    Nevins, Marc L; Camelo, Marcelo; Rebaudi, Alberto; Lynch, Samuel E; Nevins, Myron

    2005-08-01

    This study utilized three-dimensional micro-computed tomography (micro-CT) to evaluate the regenerative response to Bio-Oss Collagen when used alone or in combination with a Bio-Gide bilayer collagen membrane for the treatment of four intrabony defects (5 to 7 mm) around single-rooted teeth. The micro-CT observations are compared to the clinical, radiographic, and histologic results, which have been previously reported. After reflecting a full-thickness flap, thorough degranulation and root planing were accomplished. Bio-Oss Collagen was then used to fill the defects, and in two cases a Bio-Gide membrane was placed over the filled defect. Radiographs, clinical probing depths, and attachment levels were obtained before treatment and immediately preceding en bloc resection of teeth and surrounding tissues 9 months later. A mean pocket depth reduction of 5.75 mm and mean clinical attachment level gain of 5.25 mm were recorded. The histologic evaluation demonstrated the formation of a complete new attachment apparatus with new cementum, periodontal ligament, and alveolar bone at the level of and coronal to the calculus reference notch. Micro-CT evaluation confirmed the histologic results and demonstrated the absence of ankylosis or root resorption for all specimens. This human histologic study demonstrated that Bio-Oss Collagen has the capacity to facilitate regeneration of the periodontal attachment apparatus when placed in intrabony defects. Micro-CT observations confirmed the histologic results and enhanced the three-dimensional understanding of periodontal wound healing. The results indicate that micro-CT may be useful for three-dimensional evaluation of periodontal regenerative procedures. PMID:16089044

  4. A biomechanical assessment of the coupling of torsion and tension in the human scapholunate ligament.

    PubMed

    Zdero, R; Olsen, M; Elfatori, S; Skrinskas, T; Schemitsch, E; Whyne, C; von Schroeder, H

    2008-08-01

    The mechanical behaviour of human scapholunate ligaments is not well described in the literature with regard to torsion. In this study, intact scapholunate specimens were mechanically tested in torsion to determine whether a simultaneous tensile load was generated. Human intact scapholunate specimens (n = 19) were harvested. The scaphoid and lunate bones were potted in square chambers using epoxy cement, while the interposing ligament remained exposed. Each specimen was mounted rigidly in a specially designed test jig and remained at a fixed axial length during all tests. Specimens were subjected to a torsional load regime that included cyclic preconditioning, ramp-up, stress relaxation, ramp-down, rest, and torsion to failure. Torque and axial tension were monitored simultaneously. The relationship between torsion and tension was determined. Graphs of torque versus tension were generated, from which outcome measures were extracted. Tests demonstrated a clear relationship between applied torsion and the resulting generation of tension for the ligament during ramp-up (torsion-to-tension ratio, 38.86 +/- 29.00 mm; linearity coefficient R2 = 0.89 +/- 0.15; n = 19), stress relaxation (torsion-to-tension ratio, 23.43 +/- 15.84 mm; R2 = 0.90 +/- 0.09; n = 16), and failure tests (torsion-to-tension ratio, 38.81 +/- 26.39mm; R2 = 0.77 +/- 0.20; n = 16). No statistically significant differences were detected between the torsion-to-tension ratios (p = 0.13) or between the linearity (R2) of the best-fit lines (p > 0.085). A strongly coupled linear relationship between torsion and tension for the scapholunate ligament was exhibited in all test phases. This may suggest interplay between these two parameters in the stabilization of the ligament during normal motion and for injury cascades. PMID:18935807

  5. Effect of diode low-level lasers on fibroblasts derived from human periodontal tissue: a systematic review of in vitro studies.

    PubMed

    Ren, Chong; McGrath, Colman; Jin, Lijian; Zhang, Chengfei; Yang, Yanqi

    2016-09-01

    This study aimed to systematically assess the parameter-specific effects of the diode low-level laser on human gingival fibroblasts (HGFs) and human periodontal ligament fibroblasts (HPDLFs). An extensive search was performed in major electronic databases including PubMed (1997), EMBASE (1947) and Web of Science (1956) and supplemented by hand search of reference lists and relevant laser journals for cell culture studies investigating the effect of diode low-level lasers on HGFs and HPDLFs published from January 1995 to December 2015. A total of 21 studies were included after screening 324 independent records, amongst which eight targeted HPDLFs and 13 focussed on HGFs. The diode low-level laser showed positive effects on promoting fibroblast proliferation and osteogenic differentiation and modulating cellular inflammation via changes in gene expression and the release of growth factors, bone-remodelling markers or inflammatory mediators in a parameter-dependent manner. Repeated irradiations with wavelengths in the red and near-infrared range and at an energy density below 16 J/cm(2) elicited favourable responses. However, considerable variations and weaknesses in the study designs and laser protocols limited the interstudy comparison and clinical transition. Current evidence showed that diode low-level lasers with adequate parameters stimulated the proliferation and modulated the inflammation of fibroblasts derived from human periodontal tissue. However, further in vitro studies with better designs and more appropriate study models and laser parameters are anticipated to provide sound evidence for clinical studies and practice. PMID:27422104

  6. Quercitrin for periodontal regeneration: effects on human gingival fibroblasts and mesenchymal stem cells

    PubMed Central

    Gómez-Florit, Manuel; Monjo, Marta; Ramis, Joana M.

    2015-01-01

    Periodontal disease (PD) is the result of an infection and chronic inflammation of the gingiva that may lead to its destruction and, in severe cases, alveolar bone and tooth loss. The ultimate goal of periodontal treatment is to achieve periodontal soft and hard tissues regeneration. We previously selected quercitrin, a catechol-containing flavonoid, as a potential agent for periodontal applications. In this study, we tested the ability of quercitrin to alter biomarker production involved in periodontal regeneration on primary human gingival fibroblasts (hGF) and primary human mesenchymal stem cells (hMSC) cultured under basal and inflammatory conditions. To mimic PD inflammatory status, interleukin-1 beta (IL-1β) was used. The expression of different genes related to inflammation and extracellular matrix were evaluated and prostaglandin E2 (PGE2) production was quantified in hGFs; alkaline phosphatase (ALP) activity and calcium content were analysed in hMSCs. Quercitrin decreased the release of the inflammatory mediator PGE2 and partially re-established the impaired collagen metabolism induced by IL-1β treatment in hGFs. Quercitrin also increased ALP activity and mineralization in hMSCs, thus, it increased hMSCs differentiation towards the osteoblastic lineage. These findings suggest quercitrin as a novel bioactive molecule with application to enhance both soft and hard tissue regeneration of the periodontium. PMID:26558438

  7. Estrogen enhances the bone regeneration potential of periodontal ligament stem cells derived from osteoporotic rats and seeded on nano-hydroxyapatite/collagen/poly(L-lactide)

    PubMed Central

    E, LING-LING; XU, WEN-HUAN; FENG, LIN; LIU, YI; CAI, DONG-QING; WEN, NING; ZHENG, WEN-JIE

    2016-01-01

    This study investigated the effects of estrogen on the bone regeneration potential of periodontal ligament stem cells (PDLSCs) derived from osteoporotic rats and seeded on a collagen-based composite scaffold [nano-hydroxyapatite/collagen/poly(L-lactide) (nHAC/PLA)]. For this purpose, 48 healthy 3-month-old Sprague-Dawley female rats were divided into 2 groups as follows: the bilaterally ovariectomized (OVX) rats and sham-operated rats. The PDLSCs were isolated at 3 months after surgery (by which time postmenopausal osteoporosis had developed). The effects of estrogen on the characteristics of these cells seeded in a culture plate and of the cells seeded on nHAC/PLA were then investigated. The PDLSC + nHAC/PLA constructs were implanted subcutaneously into the backs of severe combined immunodeficient (SCID) mice for 12 weeks in order to examine the role of estrogen in the bone formation ability of PDLSCs derived from osteoporotic rats. The results from methyl thiazolyl tetrazolium (MTT) assay revealed that the proliferation of the cells derived from the rats in the OVX group was significantly higher than that of the cells derived from the rats in the sham-operated group at the stage of logarithmic growth. The staining intensity of alkaline phosphatase (ALP) and the mineralization of the cells derived from the rats in the OVX group was significantly weaker than that of the cells from the rats in the sham-operated group. When the PDLSCs were seeded on nHAC/PLA, ALP activity, osteocalcin (OCN) secretion, mineral formation and the mRNA expression levels of ALP, OCN, estrogen receptor (ER)α and ERβ in the cells derived from the rats in the OVX group were markedly decreased. Treatment with 17β-estradiol (E2) significantly weakened the proliferative ability of the cells derived from the OVX group rats, and enhanced their osteogenic differentiation ability and the mRNA expression levels of ALP, OCN, ERα and ERβ. When the constructs were implanted into the backs of SCID

  8. Estrogen enhances the bone regeneration potential of periodontal ligament stem cells derived from osteoporotic rats and seeded on nano-hydroxyapatite/collagen/poly(L-lactide).

    PubMed

    E, Ling-Ling; Xu, Wen-Huan; Feng, Lin; Liu, Yi; Cai, Dong-Qing; Wen, Ning; Zheng, Wen-Jie

    2016-06-01

    This study investigated the effects of estrogen on the bone regeneration potential of periodontal ligament stem cells (PDLSCs) derived from osteoporotic rats and seeded on a collagen-based composite scaffold [nano-hydroxyapatite/collagen/poly(L-lactide) (nHAC/PLA)]. For this purpose, 48 healthy 3‑month-old Sprague-Dawley female rats were divided into 2 groups as follows: the bilaterally ovariectomized (OVX) rats and sham‑operated rats. The PDLSCs were isolated at 3 months after surgery (by which time postmenopausal osteoporosis had developed). The effects of estrogen on the characteristics of these cells seeded in a culture plate and of the cells seeded on nHAC/PLA were then investigated. The PDLSC + nHAC/PLA constructs were implanted subcutaneously into the backs of severe combined immunodeficient (SCID) mice for 12 weeks in order to examine the role of estrogen in the bone formation ability of PDLSCs derived from osteoporotic rats. The results from methyl thiazolyl tetrazolium (MTT) assay revealed that the proliferation of the cells derived from the rats in the OVX group was significantly higher than that of the cells derived from the rats in the sham-operated group at the stage of logarithmic growth. The staining intensity of alkaline phosphatase (ALP) and the mineralization of the cells derived from the rats in the OVX group was significantly weaker than that of the cells from the rats in the sham-operated group. When the PDLSCs were seeded on nHAC/PLA, ALP activity, osteocalcin (OCN) secretion, mineral formation and the mRNA expression levels of ALP, OCN, estrogen receptor (ER)α and ERβ in the cells derived from the rats in the OVX group were markedly decreased. Treatment with 17β-estradiol (E2) significantly weakened the proliferative ability of the cells derived from the OVX group rats, and enhanced their osteogenic differentiation ability and the mRNA expression levels of ALP, OCN, ERα and ERβ. When the constructs were implanted

  9. Double-edged-sword effect of IL-1β on the osteogenesis of periodontal ligament stem cells via crosstalk between the NF-κB, MAPK and BMP/Smad signaling pathways

    PubMed Central

    Mao, C-y; Wang, Y-g; Zhang, X; Zheng, X-y; Tang, T-t; Lu, E-y

    2016-01-01

    Microenvironmental conditions can interfere with the functional role and differentiation of mesenchymal stem cells (MSCs). Recent studies suggest that an inflammatory microenvironment can significantly impact the osteogenic potential of periodontal ligament stem cells (PDLSCs), but the precise effects and mechanisms involved remain unclear. Here, we show for the first time that interleukin-1β (IL-1β) has dual roles in the osteogenesis of PDLSCs at concentrations ranging from physiologically healthy levels to those found in chronic periodontitis. Low doses of IL-1β activate the BMP/Smad signaling pathway to promote the osteogenesis of PDLSCs, but higher doses of IL-1β inhibit BMP/Smad signaling through the activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling, inhibiting osteogenesis. These results demonstrate that crosstalk between NF-κB, MAPK and BMP/Smad signaling mediates this dual effect of IL-1β on PDLSCs. We also show that the impaired osteogenesis of PDLSCs results in more inflammatory cytokines and chemokines being released, inducing the chemotaxis of macrophages, which further clarifies the role of PDLSCs in the pathogenesis of periodontitis. PMID:27415426

  10. Double-edged-sword effect of IL-1β on the osteogenesis of periodontal ligament stem cells via crosstalk between the NF-κB, MAPK and BMP/Smad signaling pathways.

    PubMed

    Mao, C-Y; Wang, Y-G; Zhang, X; Zheng, X-Y; Tang, T-T; Lu, E-Y

    2016-01-01

    Microenvironmental conditions can interfere with the functional role and differentiation of mesenchymal stem cells (MSCs). Recent studies suggest that an inflammatory microenvironment can significantly impact the osteogenic potential of periodontal ligament stem cells (PDLSCs), but the precise effects and mechanisms involved remain unclear. Here, we show for the first time that interleukin-1β (IL-1β) has dual roles in the osteogenesis of PDLSCs at concentrations ranging from physiologically healthy levels to those found in chronic periodontitis. Low doses of IL-1β activate the BMP/Smad signaling pathway to promote the osteogenesis of PDLSCs, but higher doses of IL-1β inhibit BMP/Smad signaling through the activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling, inhibiting osteogenesis. These results demonstrate that crosstalk between NF-κB, MAPK and BMP/Smad signaling mediates this dual effect of IL-1β on PDLSCs. We also show that the impaired osteogenesis of PDLSCs results in more inflammatory cytokines and chemokines being released, inducing the chemotaxis of macrophages, which further clarifies the role of PDLSCs in the pathogenesis of periodontitis. PMID:27415426

  11. A model of human knee ligaments in the sagittal plane. Part 2: Fibre recruitment under load.

    PubMed

    Zavatsky, A B; O'Connor, J J

    1992-01-01

    A mathematical model of the knee ligaments in the sagittal plane is used to study the forces in the cruciate and collateral ligaments produced by anterior/posterior tibial translation. The model is based on ligament fibre functional architecture. Geometric analysis of the deformed configurations of the model ligaments provides the additional compatibility conditions necessary for calculation of the statically indeterminate distributions of strain and stress within the ligaments and the sharing of load between ligaments. The investigation quantifies the process of ligament fibre recruitment, which occurs when fibres made slack by passive flexion/extension of the knee stretch and change their spatial positions in order to resist applied loads. The calculated ligament forces are in reasonable agreement with experimental results reported in the literature. The model explains some subtleties of ligament function not incorporated in models that represent the ligaments by a small number of lines. PMID:1482509

  12. The influence of cellular source on periodontal regeneration using calcium phosphate coated polycaprolactone scaffold supported cell sheets.

    PubMed

    Dan, Hongxia; Vaquette, Cédryck; Fisher, Anthony G; Hamlet, Stephen M; Xiao, Yin; Hutmacher, Dietmar W; Ivanovski, Saso

    2014-01-01

    Cell-based therapy is considered a promising approach to achieving predictable periodontal regeneration. In this study, the regenerative potential of cell sheets derived from different parts of the periodontium (gingival connective tissue, alveolar bone and periodontal ligament) were investigated in an athymic rat periodontal defect model. Periodontal ligament (PDLC), alveolar bone (ABC) and gingival margin-derived cells (GMC) were obtained from human donors. The osteogenic potential of the primary cultures was demonstrated in vitro. Cell sheets supported by a calcium phosphate coated melt electrospun polycaprolactone (CaP-PCL) scaffold were transplanted to denuded root surfaces in surgically created periodontal defects, and allowed to heal for 1 and 4 weeks. The CaP-PCL scaffold alone was able to promote alveolar bone formation within the defect after 4 weeks. The addition of ABC and PDLC sheets resulted in significant periodontal attachment formation. The GMC sheets did not promote periodontal regeneration on the root surface and inhibited bone formation within the CaP-PCL scaffold. In conclusion, the combination of either PDLC or ABC sheets with a CaP-PCL scaffold could promote periodontal regeneration, but ABC sheets were not as effective as PDLC sheets in promoting new attachment formation. PMID:24120045

  13. Quasi-linear viscoelastic properties of the human medial patello-femoral ligament.

    PubMed

    Criscenti, G; De Maria, C; Sebastiani, E; Tei, M; Placella, G; Speziali, A; Vozzi, G; Cerulli, G

    2015-12-16

    The evaluation of viscoelastic properties of human medial patello-femoral ligament is fundamental to understand its physiological function and contribution as stabilizer for the selection of the methods of repair and reconstruction and for the development of scaffolds with adequate mechanical properties. In this work, 12 human specimens were tested to evaluate the time- and history-dependent non linear viscoelastic properties of human medial patello-femoral ligament using the quasi-linear viscoelastic (QLV) theory formulated by Fung et al. (1972) and modified by Abramowitch and Woo (2004). The five constant of the QLV theory, used to describe the instantaneous elastic response and the reduced relaxation function on stress relaxation experiments, were successfully evaluated. It was found that the constant A was 1.21±0.96MPa and the dimensionless constant B was 26.03±4.16. The magnitude of viscous response, the constant C, was 0.11±0.02 and the initial and late relaxation time constants τ1 and τ2 were 6.32±1.76s and 903.47±504.73s respectively. The total stress relaxation was 32.7±4.7%. To validate our results, the obtained constants were used to evaluate peak stresses from a cyclic stress relaxation test on three different specimens. The theoretically predicted values fit the experimental ones demonstrating that the QLV theory could be used to evaluate the viscoelastic properties of the human medial patello-femoral ligament. PMID:26573904

  14. Single-molecule imaging of BMP4 dimerization on human periodontal ligament cells.

    PubMed

    Mi, H-W; Lee, M-C; Chiang, Y-C; Chow, L-P; Lin, C-P

    2011-11-01

    We expressed bone morphogenetic protein 4 (BMP4) fused with enhanced green fluorescent protein (BMP4-EGFP) in the secretory pathways of producer cells. Fluorescent EGFP was acquired only after we interrupted the transport of BMP4-EGFP by culturing cells at a lower temperature (20°C), and the dynamics of BMP4-EGFP could be monitored by single-molecule microscopy. Western blotting analysis confirmed that exposure to low temperature helped the integrated formation of BMP4-EGFP fusion proteins. In this study, for the first time, we could image the fluorescently labeled BMP4 molecules localized on the plasma membrane of living hPDL cells. The one-step photobleaching with EGFP and the "blinking" behavior of quantum dots suggest that the fluorescent spots represent the events of single BMP4 molecules. Single-molecule tracking showed that the BMP receptors (BMPR) dimerize after BMP4 stimulation, or that a complex of one BMP4 molecule and a pre-formed BMPR dimer develops first, followed by the binding of the second BMP4 molecule. Furthermore, BMP4-EGFP enhanced the osteogenic differentiation of hPDL cells via signal transduction involving BMP receptors. This single-molecule imaging technique might be a valuable tool for the future development of BMP4 gene therapy and regenerative medicine mediated by hPDLs. PMID:21841042

  15. Mesenchymal Stem Cell Characteristics of Human Anterior Cruciate Ligament Outgrowth Cells

    PubMed Central

    Kunz, Manuela; Prager, Patrick; Barthel, Thomas; Jakob, Franz; Nöth, Ulrich; Murray, Martha M.; Evans, Christopher H.; Porter, Ryan M.

    2011-01-01

    When ruptured, the anterior cruciate ligament (ACL) of the human knee has limited regenerative potential. However, the goal of this report was to show that the cells that migrate out of the human ACL constitute a rich population of progenitor cells and we hypothesize that they display mesenchymal stem cell (MSC) characteristics when compared with adherent cells derived from bone marrow or collagenase digests from ACL. We show that ACL outgrowth cells are adherent, fibroblastic cells with a surface immunophenotype strongly positive for cluster of differentiation (CD)29, CD44, CD49c, CD73, CD90, CD97, CD105, CD146, and CD166, weakly positive for CD106 and CD14, but negative for CD11c, CD31, CD34, CD40, CD45, CD53, CD74, CD133, CD144, and CD163. Staining for STRO-1 was seen by immunohistochemistry but not flow cytometry. Under suitable culture conditions, the ACL outgrowth-derived MSCs differentiated into chondrocytes, osteoblasts, and adipocytes and showed capacity to self-renew in an in vitro assay of ligamentogenesis. MSCs derived from collagenase digests of ACL tissue and human bone marrow were analyzed in parallel and displayed similar, but not identical, properties. In situ staining of the ACL suggests that the MSCs reside both aligned with the collagenous matrix of the ligament and adjacent to small blood vessels. We conclude that the cells that emigrate from damaged ACLs are MSCs and that they have the potential to provide the basis for a superior, biological repair of this ligament. PMID:21247268

  16. Evaluation of the Stress Induced in Tooth, Periodontal Ligament & Alveolar Bone with Varying Degrees of Bone Loss During Various Types of Orthodontic Tooth Movements

    PubMed Central

    Mahajan, Shalu; Verma, Santosh; Bhardwaj, Preeti; Sharma, Geeta

    2016-01-01

    Introduction The force applied on to a tooth with periodontal bone loss may generate different magnitude and pattern of stresses in the periodontium when compared to a tooth with no bone loss & under the same force system. The intensity of the forces and moment to force ratios needed to be applied during an Orthodontic treatment must be adapted to obtain the same movement as in a tooth with a healthy periodontal support. Aim Evaluation and assessment of the stress distribution during various types of Orthodontic tooth movement on application of Orthodontic force, at various levels of alveolar bone loss; & determination of the most ideal force system producing the Optimum Stress (i.e., stress within optimum range), uniformly (conducive to bodily movement of maxillary canine with varying degrees of bone loss). Materials and Methods A human maxillary canine tooth of right side was simulated by means of Finite Element Method (FEM). Five different models were constructed with bone loss ranging from 0mm in model 1, to 8mm in model 5 (progressing at 2mm per model). Ten different loading conditions were applied on these models and the stress generated was charted at various occluso-gingival levels and surfaces around the tooth. The evaluation and assessment of the stress distribution during various types of Orthodontic tooth movement on application of Orthodontic force, at various levels of alveolar bone loss was done. Results The results showed that there was a high positive correlation between the increase in bone loss & the stress generated, suggesting an elevation in the stress with advancing bone loss. Additionally, the type of tooth movement was found to be changed with bone loss. During the determination of ideal force system it was found that the centre of resistance of the canine migrated apically with bone loss and an increase in the moment to force ratio (Mc:F) was required to control the root position in these cases. Conclusion A high positive correlation

  17. Global Metabolomic Analysis of Human Saliva and Plasma from Healthy and Diabetic Subjects, with and without Periodontal Disease

    PubMed Central

    Barnes, Virginia M.; Kennedy, Adam D.; Panagakos, Fotinos; Devizio, William; Trivedi, Harsh M.; Jönsson, Thomas; Guo, Lining; Cervi, Shannon; Scannapieco, Frank A.

    2014-01-01

    Recent studies suggest that periodontal disease and type 2 diabetes mellitus are bi-directionally associated. Identification of a molecular signature for periodontitis using unbiased metabolic profiling could allow identification of biomarkers to assist in the diagnosis and monitoring of both diabetes and periodontal disease. This cross-sectional study identified plasma and salivary metabolic products associated with periodontitis and/or diabetes in order to discover biomarkers that may differentiate or demonstrate an interaction of these diseases. Saliva and plasma samples were analyzed from 161 diabetic and non-diabetic human subjects with a healthy periodontium, gingivitis and periodontitis. Metabolite profiling was performed using Metabolon's platform technology. A total of 772 metabolites were found in plasma and 475 in saliva. Diabetics had significantly higher levels of glucose and α-hydroxybutyrate, the established markers of diabetes, for all periodontal groups of subjects. Comparison of healthy, gingivitis and periodontitis saliva samples within the non-diabetic group confirmed findings from previous studies that included increased levels of markers of cellular energetic stress, increased purine degradation and glutathione metabolism through increased levels of oxidized glutathione and cysteine-glutathione disulfide, markers of oxidative stress, including increased purine degradation metabolites (e.g. guanosine and inosine), increased amino acid levels suggesting protein degradation, and increased ω-3 (docosapentaenoate) and ω-6 fatty acid (linoleate and arachidonate) signatures. Differences in saliva between diabetic and non-diabetic cohorts showed altered signatures of carbohydrate, lipid and oxidative stress exist in the diabetic samples. Global untargeted metabolic profiling of human saliva in diabetics replicated the metabolite signature of periodontal disease progression in non-diabetic patients and revealed unique metabolic signatures associated

  18. Global metabolomic analysis of human saliva and plasma from healthy and diabetic subjects, with and without periodontal disease.

    PubMed

    Barnes, Virginia M; Kennedy, Adam D; Panagakos, Fotinos; Devizio, William; Trivedi, Harsh M; Jönsson, Thomas; Guo, Lining; Cervi, Shannon; Scannapieco, Frank A

    2014-01-01

    Recent studies suggest that periodontal disease and type 2 diabetes mellitus are bi-directionally associated. Identification of a molecular signature for periodontitis using unbiased metabolic profiling could allow identification of biomarkers to assist in the diagnosis and monitoring of both diabetes and periodontal disease. This cross-sectional study identified plasma and salivary metabolic products associated with periodontitis and/or diabetes in order to discover biomarkers that may differentiate or demonstrate an interaction of these diseases. Saliva and plasma samples were analyzed from 161 diabetic and non-diabetic human subjects with a healthy periodontium, gingivitis and periodontitis. Metabolite profiling was performed using Metabolon's platform technology. A total of 772 metabolites were found in plasma and 475 in saliva. Diabetics had significantly higher levels of glucose and α-hydroxybutyrate, the established markers of diabetes, for all periodontal groups of subjects. Comparison of healthy, gingivitis and periodontitis saliva samples within the non-diabetic group confirmed findings from previous studies that included increased levels of markers of cellular energetic stress, increased purine degradation and glutathione metabolism through increased levels of oxidized glutathione and cysteine-glutathione disulfide, markers of oxidative stress, including increased purine degradation metabolites (e.g. guanosine and inosine), increased amino acid levels suggesting protein degradation, and increased ω-3 (docosapentaenoate) and ω-6 fatty acid (linoleate and arachidonate) signatures. Differences in saliva between diabetic and non-diabetic cohorts showed altered signatures of carbohydrate, lipid and oxidative stress exist in the diabetic samples. Global untargeted metabolic profiling of human saliva in diabetics replicated the metabolite signature of periodontal disease progression in non-diabetic patients and revealed unique metabolic signatures associated

  19. Tissue specific characteristics of cells isolated from human and rat tendons and ligaments

    PubMed Central

    Scutt, N; Rolf, CG; Scutt, A

    2008-01-01

    Background Tendon and ligament injuries are common and costly in terms of surgery and rehabilitation. This might be improved by using tissue engineered constructs to accelerate the repair process; a method used successfully for skin wound healing and cartilage repair. Progress in this field has however been limited; possibly due to an over-simplistic choice of donor cell. For tissue engineering purposes it is often assumed that all tendon and ligament cells are similar despite their differing roles and biomechanics. To clarify this, we have characterised cells from various tendons and ligaments of human and rat origin in terms of proliferation, response to dexamethasone and cell surface marker expression. Methods Cells isolated from tendons by collagenase digestion were plated out in DMEM containing 10% fetal calf serum, penicillin/streptomycin and ultraglutamine. Cell number and collagen accumulation were by determined methylene blue and Sirius red staining respectively. Expression of cell surface markers was established by flow cytometry. Results In the CFU-f assay, human PT-derived cells produced more and bigger colonies suggesting the presence of more progenitor cells with a higher proliferative capacity. Dexamethasone had no effect on colony number in ACL or PT cells but 10 nM dexamethasone increased colony size in ACL cultures whereas higher concentrations decreased colony size in both ACL and PT cultures. In secondary subcultures, dexamethasone had no significant effect on PT cultures whereas a stimulation was seen at low concentrations in the ACL cultures and an inhibition at higher concentrations. Collagen accumulation was inhibited with increasing doses in both ACL and PT cultures. This differential response was also seen in rat-derived cells with similar differences being seen between Achilles, Patellar and tail tendon cells. Cell surface marker expression was also source dependent; CD90 was expressed at higher levels by PT cells and in both humans and

  20. Impact of Periodontal Therapy on the Subgingival Microbiota of Severe Periodontitis: Comparison between Good Responders and “Refractory” Subjects by the Human Oral Microbe Identification Microarray (HOMIM)

    PubMed Central

    Colombo, Ana Paula V.; Bennet, Susan; Cotton, Sean L.; Goodson, J. Max; Kent, Ralph; Haffajee, Anne D.; Socransky, Sigmund S.; Hasturk, Hatice; Van Dyke, Thomas E.; Dewhirst, Floyd E.; Paster, Bruce J.

    2014-01-01

    Aim This study compared the changes on the subgingival microbiota of subjects with “refractory” periodontitis (RP) or treatable periodontitis (GR) before and after periodontal therapy by using the Human Oral Microbe Identification Microarray (HOMIM). Methods Individuals with chronic periodontitis were classified as RP (n=17) based on mean attachment loss (AL) and/or >3 sites with AL ≥2.5 mm after scaling and root planing, surgery and systemically administered amoxicillin and metronidazole or as GR (n=30) based on mean attachment gain and no sites with AL ≥2.5 mm after treatment. Subgingival plaque samples were taken at baseline and 15 months after treatment and analyzed for the presence of 300 species by HOMIM analysis. Significant differences in taxa before and after therapy were sought using the Wilcoxon test. Results The majority of species evaluated decreased in prevalence in both groups after treatment; however, only a small subset of organisms was significantly affected. Species that increased or persisted in high frequency in RP but were significantly reduced in GR included Bacteroidetes sp., Porphyromonas endodontalis, Porphyromonas gingivalis, Prevotella spp., Tannerella forsythia, Dialister spp., Selenomonas spp., Catonella morbi, Eubacterium spp., Filifactor alocis, Parvimonas micra, Peptostreptococcus sp. OT113, Fusobacterium sp. OT203, Pseudoramibacter alactolyticus, Streptococcus intermedius or Streptococcus constellatus and Shuttlesworthia satelles. In contrast, Capnocytophaga sputigena, Cardiobacterium hominis, Gemella haemolysans, Haemophilus parainfluenzae, Kingella oralis, Lautropia mirabilis, Neisseria elongata, Rothia dentocariosa, Streptococcus australis and Veillonella spp. were more associated with therapeutic success. Conclusion Persistence of putative and novel periodontal pathogens, as well as low prevalence of beneficial species was associated with chronic “refractory” periodontitis. PMID:22324467

  1. Comparative anatomy of the meniscofemoral ligament in humans and some domestic mammals.

    PubMed

    Gupte, C M; Bull, A M J; Murray, R; Amis, A A

    2007-02-01

    The purpose of this study was to investigate the presence, position and relative sizes of the meniscofemoral ligaments (MFL) in three quadrupeds and humans and relate these to the caudal slope of the lateral tibial plateau. Canine, ovine and equine stifles and human knees were dissected to identify the presence of MFLs, their obliquity in relation to the caudal cruciate ligaments (CCL), the relative size and shape of the MFLs compared with the CCL, the points of femoral attachment of the MFLs and CCL, and the distance between the MFLs and CCL at their midpoints. The lateral tibial condyle was divided sagittally with a handsaw and the caudal slope was measured. An MFL was present in all quadrupeds. It was caudal to the CCL, being analogous to the human posterior MFL. There was no structure analogous to the human anterior MFL, a structure that has a different femoral attachment from the human posterior MFL and MFLs in other species examined. The meniscotibial attachments were of varying sizes. The size ratio between the MFL and CCL was greater in all three quadrupeds than it was in the human knee. The MFL lies more obliquely than the CCL in all species examined. The caudal tibial slope was steeper in the quadrupeds. In the stifle joints of quadrupeds, the MFL is a substantial structure and appears to be related to the caudal tibial slope. It is known to resist caudal translation of the tibia in conjunction with the lateral meniscus. This must be borne in mind when considering its function in the human knee. PMID:17266668

  2. Chronic stress accelerates ligature-induced periodontitis by suppressing glucocorticoid receptor-α signaling.

    PubMed

    Lu, Huaixiu; Xu, Minguang; Wang, Feng; Liu, Shisen; Gu, Jing; Lin, Songshan; Zhao, Lisheng

    2016-01-01

    Periodontitis is a common chronic inflammatory disease. Recent studies have shown that chronic stress (CS) might modulate periodontal disease, but there are few models of CS-induced periodontitis, and the underlying mechanisms are unclear. The present study established a rat model of periodontitis associated with CS induced by nylon thread ligatures. The severity of periodontitis was evaluated in this model by radiographic and pathological examination. The inflammatory reaction indicated by the elevated serum levels of interleukin (IL)-1β, IL-6 and IL-8 was assessed by enzyme-linked immunosorbent assay. Toll-like receptor-4 (TLR4) and glucocorticoid receptor-α (GR-α) expressions were detected by reverse transcriptase-PCR and western blotting. Open-field tests and serum corticosterone were used to evaluate CS. The results showed that CS induced behavioral changes and increased corticosterone levels of the animals with periodontitis. CS stimulation markedly increased alveolar bone loss, periodontal pocket depth and the number of plaques. It also enhanced the inflammatory reaction. These results suggest that CS accelerated the ligature-induced pathological changes associated with periodontitis. Further analysis of the mechanisms involved showed that GR-α expression was significantly downregulated in periodontal tissues of the animals undergoing CS. Blocking GR-α signaling in lipopolysaccharide and corticosteroid-treated human periodontal ligament fibroblast cells in vitro significantly upregulated the expression of p-Akt (protein kinase B) and TLR4, promoted nuclear factor-κB activity and increased levels of IL-1β, IL-6 and IL-8. This research suggests that CS might accelerate the pathological progression of periodontitis by a GR-α signaling-mediated inflammatory response and that this may be a potential therapeutic target for the treatment of periodontal disease, particularly in patients with CS. PMID:27012709

  3. Chronic stress accelerates ligature-induced periodontitis by suppressing glucocorticoid receptor-α signaling

    PubMed Central

    Lu, Huaixiu; Xu, Minguang; Wang, Feng; Liu, Shisen; Gu, Jing; Lin, Songshan; Zhao, Lisheng

    2016-01-01

    Periodontitis is a common chronic inflammatory disease. Recent studies have shown that chronic stress (CS) might modulate periodontal disease, but there are few models of CS-induced periodontitis, and the underlying mechanisms are unclear. The present study established a rat model of periodontitis associated with CS induced by nylon thread ligatures. The severity of periodontitis was evaluated in this model by radiographic and pathological examination. The inflammatory reaction indicated by the elevated serum levels of interleukin (IL)-1β, IL-6 and IL-8 was assessed by enzyme-linked immunosorbent assay. Toll-like receptor-4 (TLR4) and glucocorticoid receptor-α (GR-α) expressions were detected by reverse transcriptase-PCR and western blotting. Open-field tests and serum corticosterone were used to evaluate CS. The results showed that CS induced behavioral changes and increased corticosterone levels of the animals with periodontitis. CS stimulation markedly increased alveolar bone loss, periodontal pocket depth and the number of plaques. It also enhanced the inflammatory reaction. These results suggest that CS accelerated the ligature-induced pathological changes associated with periodontitis. Further analysis of the mechanisms involved showed that GR-α expression was significantly downregulated in periodontal tissues of the animals undergoing CS. Blocking GR-α signaling in lipopolysaccharide and corticosteroid-treated human periodontal ligament fibroblast cells in vitro significantly upregulated the expression of p-Akt (protein kinase B) and TLR4, promoted nuclear factor-κB activity and increased levels of IL-1β, IL-6 and IL-8. This research suggests that CS might accelerate the pathological progression of periodontitis by a GR-α signaling-mediated inflammatory response and that this may be a potential therapeutic target for the treatment of periodontal disease, particularly in patients with CS. PMID:27012709

  4. Strain distribution in the ligament using photoelasticity. A direct application to the human ACL.

    PubMed

    Yamamoto, K; Hirokawa, S; Kawada, T

    1998-04-01

    Large and highly variable deformations of the anterior cruciate ligament (ACL) in the human knee cannot be adequately quantified by one-dimensional and/or localized measurements. In order to measure strains in the entire area of the ACL, we employed the photoelastic coating method to analyze stress on the basis of the strains. A specific kind of polyurethane possessing optically high fringe-sensitivity was found to be most suitable for the measurement purposes. Although the photoelastic method has been successfully applied in various fields for stress analyses, its use in studying large deformations of biological tissues has not been reported. Therefore, before proceeding with our main study, we first examined the effects of polyurethane film on the mechanical properties of the ligament. We found that the film had a negligible effect on the tissues' properties, and closely reflected the strain behavior of the tissues. We then applied the method to measure strains on an actual ACL during free flexion-extension of the knee. A specially designed apparatus was used to allow a natural motion of the knee. A portion of the femoral bone was removed to expose the ACL to view. Measurement and analysis gave continuous information about strain distribution, including the variations of strain along the principal strain directions in the ACL. PMID:9690485

  5. Material and structural tensile properties of the human medial patello-femoral ligament.

    PubMed

    Criscenti, G; De Maria, C; Sebastiani, E; Tei, M; Placella, G; Speziali, A; Vozzi, G; Cerulli, G

    2016-02-01

    The medial patellofemoral ligament (MPFL) is considered the most important passive patellar stabilizer and acts 50-60% of the force of the medial soft-tissue which restrains the lateralization of the patella between 0° and 30°. In this work, 24 human knees have been tested to evaluate the material properties of MPFL and to determine the structural behavior of femur-MPFL-Patella complex (FMPC). Particular attention was given to maintain the anatomical orientation between the patella and MPFL and to the evaluation of the elongation during the mechanical tests. The ultimate stress of the isolated ligament was 16±11MPa, the ultimate strain was 24.3±6.8%, the Young׳s Modulus was 116±95MPa and the strain energy density was 2.97±1.69MPa. The ultimate load of the whole structure, FMPC, was 145±68N, the ultimate elongation was 9.5±2.9mm, the linear stiffness was 42.5±10.2N/mm and the absorbed energy was 818.8±440.7Nmm. The evaluation of material and structural properties of MPFL is fundamental to understand its contribution as stabilizer and for the selection of repair and reconstruction methods. PMID:26454357

  6. Ultrastructural observations on bacterial invasion in cementum and radicular dentin of periodontally diseased human teeth.

    PubMed

    Adriaens, P A; Edwards, C A; De Boever, J A; Loesche, W J

    1988-08-01

    In this study the bacterial invasion in root cementum and radicular dentin of periodontally diseased, caries-free human teeth was examined. In addition, structural changes in these tissues, which could be related to the bacterial invasion, were reported. Twenty-one caries-free human teeth with extensive periodontal attachment loss were studied by light and scanning electron microscopy. At the base of the gingival pocket, bacteria were found in the spaces between remnants of Sharpey's fibers and their point of insertion in the cementum. In teeth that had been scaled and root planed, most of the root cementum had been removed. Bacterial invasion was found in the remaining root cementum. The invasion seemed to start as a localized process, often involving only one bacterium. In other areas bacteria were present in lacunar defects in the cementum. These lacunae extended into the radicular dentin. In 11 teeth bacteria had invaded the dentinal tubules. Most bacteria were located in the outer 300 microns of the dentinal tubules, although occasionally they were found in deeper parts. In two of the nontreated teeth, bacteria were detected on the pulpal wall. No correlation was found between the presence of bacterial invasion and the absence of radicular cementum. No bacteria were found in the portion of the root located apically to the epithelial attachment. These data are in agreement with our results from cultural studies of the bacterial flora in these structures. It was also demonstrated that in spite of meticulous scaling and root planning and personal oral hygiene, bacterial plaque remained present on radicular surfaces. Both the invaded dentinal tubules and the lacunae could act as bacterial reservoirs from which recolonization of treated root surfaces occurs. From these reservoirs bacteria could also induce pulpal pathoses. Since these bacterial reservoirs are not eliminated by conventional mechanical periodontal treatment, it seems appropriate to combine mechanical

  7. Surface modification of nano-silica on the ligament advanced reinforcement system for accelerated bone formation: primary human osteoblasts testing in vitro and animal testing in vivo

    NASA Astrophysics Data System (ADS)

    Li, Mengmeng; Wang, Shiwen; Jiang, Jia; Sun, Jiashu; Li, Yuzhuo; Huang, Deyong; Long, Yun-Ze; Zheng, Wenfu; Chen, Shiyi; Jiang, Xingyu

    2015-04-01

    The Ligament Advanced Reinforcement System (LARS) has been considered as a promising graft for ligament reconstruction. To improve its biocompatibility and effectiveness on new bone formation, we modified the surface of a polyethylene terephthalate (PET) ligament with nanoscale silica using atom transfer radical polymerization (ATRP) and silica polymerization. The modified ligament is tested by both in vitro and in vivo experiments. Human osteoblast testing in vitro exhibits an ~21% higher value in cell viability for silica-modified grafts compared with original grafts. Animal testing in vivo shows that there is new formed bone in the case of a nanoscale silica-coated ligament. These results demonstrate that our approach for nanoscale silica surface modification on LARS could be potentially applied for ligament reconstruction.The Ligament Advanced Reinforcement System (LARS) has been considered as a promising graft for ligament reconstruction. To improve its biocompatibility and effectiveness on new bone formation, we modified the surface of a polyethylene terephthalate (PET) ligament with nanoscale silica using atom transfer radical polymerization (ATRP) and silica polymerization. The modified ligament is tested by both in vitro and in vivo experiments. Human osteoblast testing in vitro exhibits an ~21% higher value in cell viability for silica-modified grafts compared with original grafts. Animal testing in vivo shows that there is new formed bone in the case of a nanoscale silica-coated ligament. These results demonstrate that our approach for nanoscale silica surface modification on LARS could be potentially applied for ligament reconstruction. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr01439e

  8. Modulation of proliferation and differentiation of human anterior cruciate ligament-derived stem cells by different growth factors.

    PubMed

    Cheng, Ming-Te; Yang, Hui-Wen; Chen, Tain-Hsiung; Lee, Oscar Kuang-Sheng

    2009-12-01

    We have previously isolated and identified stem cells from human cruciate ligaments. The goal of this study was to evaluate the proliferation and differentiation abilities of ligament-derived stem cells (LSCs) cultured with growth factors, including fibroblast growth factor 2 (FGF-2), epidermal growth factor, and transforming growth factor-beta 1 (TGF-b1). The ligament tissues were obtained from patients with anterior cruciate ligament injuries receiving arthroscopic surgeries. LSCs were obtained by collagenase digestion and plating as previously reported. Surface immunophenotype and the potential for trilineage differentiation into osteoblasts, chondrocytes, and adipocytes were confirmed. It was found that proliferation of the cells was enhanced with the addition of FGF-2 and TGF-b1. Upon TGF-b1 treatment, expression of collagen type I and type III, tenascin-c, fibronectin, and a-smooth muscle actin were significantly upregulated. Additionally, LSCs treated with TGF-b1 and FGF-2 increased the production of collagenous and noncollagenous extracellular matrix protein. Together, these results demonstrate that LSCs respond differently to various cytokines, and the results further validate the potential of using cruciate ligament tissue as a stem cell source for tissue engineering purposes. PMID:19586317

  9. Future dentistry: cell therapy meets tooth and periodontal repair and regeneration

    PubMed Central

    Catón, Javier; Bostanci, Nagihan; Remboutsika, Eumorphia; De Bari, Cosimo; Mitsiadis, Thimios A

    2011-01-01

    Abstract Cell-based tissue repair of the tooth and – tooth-supporting – periodontal ligament (PDL) is a new attractive approach that complements traditional restorative or surgical techniques for replacement of injured or pathologically damaged tissues. In such therapeutic approaches, stem cells and/or progenitor cells are manipulated in vitro and administered to patients as living and dynamic biological agents. In this review, we discuss the clonogenic potential of human dental and periodontal tissues such as the dental pulp and the PDL and their potential for tooth and periodontal repair and/or regeneration. We propose novel therapeutic approaches using stem cells or progenitor cells, which are targeted to regenerate the lost dental or periodontal tissue. PMID:21199329

  10. Periodontal Specific Differentiation of Dental Follicle Stem Cells into Osteoblast, Fibroblast, and Cementoblast.

    PubMed

    Sowmya, S; Chennazhi, K P; Arzate, Higinio; Jayachandran, P; Nair, Shantikumar V; Jayakumar, R

    2015-10-01

    The dental follicle is a source of dental follicle stem cells (DFCs), which have the potential to differentiate into the periodontal lineage. DFCs therefore are of value in dental tissue engineering. The purpose of this study was to evaluate the effect of growth factor type and concentration on DFC differentiation into periodontal specific lineages. DFCs were isolated from the human dental follicle and characterized for the expression of mesenchymal markers. The cells were positive for CD-73, CD-44, and CD-90; and negative for CD-33, CD-34, and CD-45. The expression of CD-29 and CD-31 was almost negligible. The cells also expressed periodontal ligament and cementum markers such as periodontal ligament-associated protein-1 (PLAP-1), fibroblast growth factor-2 (FGF-2), and cementum protein-1 (CEMP-1), however, the expression of osteoblast markers was absent. Further, the DFCs were cultured in three different induction medium to analyze the osteoblastic, fibroblastic, and cementoblastic differentiation. Runt-related transcription factor 2 (RUNX-2), alkaline phosphatase (ALP) activity, alizarin staining, calcium quantification, collagen type-1 (Col-1), and osteopontin (OPN) expression confirmed the osteoblastic differentiation of DFCs. DFCs cultured in recombinant human FGF-2 (rhFGF-2) containing medium showed enhanced PLAP-1, FGF-2, and COL-1 expression with increasing concentration of rhFGF-2 which thereby confirmed periodontal ligament fibroblastic differentiation. Similarly, DFCs cultured in recombinant human cementum protein-1 (rhCEMP-1) containing medium showed enhanced bone sialoprotein-2 (BSP-2), CEMP-1, and COL-1 expression with respect to rhCEMP-1 which confirmed cementoblastic differentiation. The expression of osteoblast, fibroblast, and cementoblast-related genes of DFCs cultured in induction medium was enhanced in comparison to DFCs cultured in noninduction medium. Thus, growth factor-dependent differentiation of DFCs into periodontal specific lineages

  11. Mouthrinses as adjuncts in periodontal therapy.

    PubMed

    Walsh, T F

    1996-05-01

    Periodontal diseases are a group of related inflammatory disorders, initiated by dental plaque and causing destruction of the supporting structures of the teeth. Although the inflammatory response is a fundamental defence mechanism against bacterial infection, its persistence over a long period of time may extensively damage the periodontal tissues: cementum, alveolar bone, periodontal ligament and dentogingival tissues. These disorders, despite recent improvements in oral health are still a major cause of tooth loss in patients over 35 years of age. PMID:8948174

  12. Diabetes and periodontitis

    PubMed Central

    Deshpande, Kalyani; Jain, Ashish; Sharma, RaviKant; Prashar, Savita; Jain, Rajni

    2010-01-01

    The main aim of this review is to update the reader with practical knowledge concerning the relationship between diabetes mellitus and periodontal diseases. Exclusive data is available on the association between these two chronic diseases till date. Articles published on this relationship often provide the knowledge of definitions of diabetes mellitus and periodontal diseases, prevalence, extent, severity of periodontal disease, complications of diabetes along with the possible underlying mechanisms. The authors reviewed human epidemiological studies, cross-sectional observations and longitudinal cohort, case control that evaluated variables exclusively over the past 30 years and the predominant findings from the “certain” articles are summarized in this review. This review clarifies certain queries such as 1) Do periodontal diseases have an effect on the metabolic control of diabetes? 2) Does diabetes act as a risk factor of periodontitis? 3) What are the possible underlying mechanisms relating the connection between these two chronic diseases? 4) What is the effect of periodontal intervention on metabolic control of diabetes? After a thorough survey of literature, it was observed that diabetes acts as a risk factor in development of periodontitis as periodontitis is significantly aggravated in patients suffering from diabetes having long term hyperglycemia. Different mechanisms underlying the association between the accelerated periodontal disease and diabetes are emerging but still more work is required. Major efforts are required to elucidate the impact of periodontal diseases on diabetes. At the same time, patients are needed to be made aware of regular periodontal maintenance schedule and oral hygiene. PMID:21731243

  13. Expression of extracellular matrix molecules typical of articular cartilage in the human scapholunate interosseous ligament

    PubMed Central

    Milz, S; Aktas, T; Putz, R; Benjamin, M

    2006-01-01

    The scapholunate interosseous ligament (SLIL) connects the scaphoid and lunate bones and plays a crucial role in carpal kinematics. Its rupture leads to carpal instability and impairment of radiocarpal joint function. As the ligament is one of the first structures affected in rheumatoid arthritis, we conducted an immunohistochemical study of cadaveric tissue to determine whether it contains known autoantigens for rheumatoid arthritis. We immunolabelled the ligament from one hand in 12 cadavers with monoclonal antibodies directed against a wide range of extracellular matrix (ECM) molecules associated with both fibrous and cartilaginous tissues. The labelling profile has also enabled us to comment on how the molecular composition of the ligament relates to its mechanical function. All regions of the ligament labelled for types I, III and VI collagens, chondroitin 4 and 6 sulphates, keratan sulphate, dermatan sulphate, versican, tenascin and cartilage oligomeric matrix protein (COMP). However, both entheses labelled strongly for type II collagen, aggrecan and link protein and were distinctly fibrocartilaginous. In some regions, the ligament attached to bone via a region of hyaline cartilage that was continuous with articular cartilage. Labelling for cartilage molecules in the midsubstance was most evident dorsally. We conclude that the SLIL has an ECM which is typical of other highly fibrocartilaginous ligaments that experience both tensile load and shear. The presence of aggrecan, link protein, COMP and type II collagen could explain why the ligament may be a target for autoantigenic destruction in some forms of rheumatoid arthritis. PMID:16761970

  14. Biomaterials for periodontal regeneration

    PubMed Central

    Shue, Li; Yufeng, Zhang; Mony, Ullas

    2012-01-01

    Periodontal disease is characterized by the destruction of periodontal tissues. Various methods of regenerative periodontal therapy, including the use of barrier membranes, bone replacement grafts, growth factors and the combination of these procedures have been investigated. The development of biomaterials for tissue engineering has considerably improved the available treatment options above. They fall into two broad classes: ceramics and polymers. The available ceramic-based materials include calcium phosphate (eg, tricalcium phosphate and hydroxyapatite), calcium sulfate and bioactive glass. The bioactive glass bonds to the bone with the formation of a layer of carbonated hydroxyapatite in situ. The natural polymers include modified polysaccharides (eg, chitosan,) and polypeptides (collagen and gelatin). Synthetic polymers [eg, poly(glycolic acid), poly(L-lactic acid)] provide a platform for exhibiting the biomechanical properties of scaffolds in tissue engineering. The materials usually work as osteogenic, osteoconductive and osteoinductive scaffolds. Polymers are more widely used as a barrier material in guided tissue regeneration (GTR). They are shown to exclude epithelial downgrowth and allow periodontal ligament and alveolar bone cells to repopulate the defect. An attempt to overcome the problems related to a collapse of the barrier membrane in GTR or epithelial downgrowth is the use of a combination of barrier membranes and grafting materials. This article reviews various biomaterials including scaffolds and membranes used for periodontal treatment and their impacts on the experimental or clinical management of periodontal defect. PMID:23507891

  15. A model of human knee ligaments in the sagittal plane. Part 1: Response to passive flexion.

    PubMed

    Zavatsky, A B; O'Connor, J J

    1992-01-01

    The development of a mathematical model of the knee ligaments in the sagittal plane is presented. Essential features of the model are (a) the representation of selected cruciate ligament fibres as isometric links in a kinematic mechanism that controls passive knee flexion and (b) the mapping of all other ligament fibres between attachments on the tibia and femur. Fibres slacken and tighten as the ligament attachment areas on the bones move relative to each other. The model is used to study the shape and fibre length changes of the cruciate and collateral ligaments in response to passive flexion/extension of the knee. The model ligament shape and fibre length changes compare well qualitatively with experimental results reported in the literature. The results suggest that when designing and implanting a ligament replacement with the aim of reproducing the natural fibre strain patterns, the surgeon must not only implant through the natural attachment areas but must also maintain the natural fibre mapping and render all fibres just tight at the appropriate flexion angle. PMID:1482508

  16. Pro-inflammatory cytokine levels in human apical periodontitis: Correlation with clinical and histological findings.

    PubMed

    Jakovljevic, Aleksandar; Knezevic, Aleksandra; Karalic, Danijela; Soldatovic, Ivan; Popovic, Branka; Milasin, Jelena; Andric, Miroslav

    2015-08-01

    This study aimed to compare the levels of tumour necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) between apical periodontitis lesions with different clinical and histological features. Based on clinical data and history of disease, 100 human apical periodontitis lesions were categorised as either asymptomatic or symptomatic lesions. According to histological examination, lesions were divided into periapical granulomas and radicular cysts. Pulp tissues of 25 impacted wisdom teeth were used as controls. Homogenised tissue samples were centrifuged and supernatants were used for the determination of cytokine levels by enzyme-linked immunosorbent assay. Significantly higher levels of IL-1β and IL-6 were found in symptomatic lesions compared with asymptomatic lesions and control tissues (P < 0.001, P < 0.001, respectively). The concentration of IL-1β was significantly higher in radicular cysts compared with periapical granulomas (P = 0.003). Symptomatic lesions, as judged by high local production of IL-1β and IL-6, represent an immunologically active stage of the disease. PMID:25163634

  17. Scanning electron microscopic analysis of the effect of Carisolv gel on periodontally compromised human root surfaces.

    PubMed

    Grisi, Daniela Corrêa; Theodoro, Letícia Helena; Sampaio, José Eduardo César; Grisi, Márcio Fernando de Moraes; Salvador, Sérgio Luiz de Souza

    2006-01-01

    The aim of this study was to analyze, under scanning electron microscopy (SEM), the morphologic characteristics of root surfaces after application of Carisolv gel in association with scaling and root planing (SRP). Sixty periodontally compromised extracted human teeth were randomly assigned to 6 groups: 1) SRP alone; 2) passive topical application of Carisolv + SRP; 3) active topical application of Carisolv + SRP; 4) multiple applications of Carisolv + SRP; 5) SRP + 24% EDTA; 6) topical application of Carisolv + SRP + 24% EDTA. Carisolv gel was applied to root surfaces for 30 s, followed by scaling and root planing, consisting of 50 strokes with Gracey curettes in an apical-coronal direction, parallel to the long axis of the tooth. The only exception was group 4, in which the roots were instrumented until a smooth, hard and glass-like surface was achieved. All specimens were further analyzed by SEM. The results showed that the treatment with Carisolv caused significant changes in root surface morphology of periodontally compromised teeth only when the chemical agent was actively applied (burnishing technique). Carisolv failed to remove the smear layer completely, especially with a single application, independently of the method of application. Multiple applications of Carisolv were necessary to achieve a smear layer reduction comparable to that obtained with 24% EDTA conditioning. PMID:16924336

  18. Effect of tetracycline HCl on periodontally-affected human root surfaces.

    PubMed

    Trombelli, L; Scabbia, A; Zangari, F; Griselli, A; Wikesjö, U M; Calura, G

    1995-08-01

    Scanning electron microscopy was used to evaluate surface characteristics of periodontitis-exposed instrumented human cementum and dentin surfaces following topical application of tetracycline HCl (TTC). Specimens were randomly assigned to application of sterile saline for 1 minute (control); TTC (10 mg/ml) for 1 minute and 4 minutes, respectively; and TTC (100 mg/ml) for 1 minute and 4 minutes, respectively. Solutions were applied with a cotton pellet using a burnishing technique. Control specimens exhibited an amorphous irregular surface smear layer. TTC treatment of cementum for 1 minute resulted in a relatively debris-free, nonhomogeneous surface. The 4-minute application resulted in a surface exhibiting a densely fibrillar, mat-like texture. Dentin specimens conditioned for 1 minute showed a smooth surface with many tubule openings partially occluded by debris. The 4-minute treatment exposed a 3-dimensional network of intertubular and peritubular collagen fibrils. No consistent morphologic differences were observed between cementum or dentin specimens treated with TTC at concentrations of 10 and 100 mg/ml, respectively. The results suggest that topical application of TTC produces morphologic alterations of periodontitis-exposed cementum and dentin that appear related to application interval rather than concentration of the drug. PMID:7473011

  19. In vivo identification of periodontal progenitor cells.

    PubMed

    Roguljic, H; Matthews, B G; Yang, W; Cvija, H; Mina, M; Kalajzic, I

    2013-08-01

    The periodontal ligament contains progenitor cells; however, their identity and differentiation potential in vivo remain poorly characterized. Previous results have suggested that periodontal tissue progenitors reside in perivascular areas. Therefore, we utilized a lineage-tracing approach to identify and track periodontal progenitor cells from the perivascular region in vivo. We used an alpha-smooth muscle actin (αSMA) promoter-driven and tamoxifen-inducible Cre system (αSMACreERT2) that, in combination with a reporter mouse line (Ai9), permanently labels a cell population, termed 'SMA9'. To trace the differentiation of SMA9-labeled cells into osteoblasts/cementoblasts, we utilized a Col2.3GFP transgene, while expression of Scleraxis-GFP was used to follow differentiation into periodontal ligament fibroblasts during normal tissue formation and remodeling following injury. In uninjured three-week-old SMA9 mice, tamoxifen labeled a small population of cells in the periodontal ligament that expanded over time, particularly in the apical region of the root. By 17 days and 7 weeks after labeling, some SMA9-labeled cells expressed markers indicating differentiation into mature lineages, including cementocytes. Following injury, SMA9 cells expanded, and differentiated into cementoblasts, osteoblasts, and periodontal ligament fibroblasts. SMA9-labeled cells represent a source of progenitors that can give rise to mature osteoblasts, cementoblasts, and fibroblasts within the periodontium. PMID:23735585

  20. Periodontal disease: modulation of the inflammatory cascade by dietary n-3 polyunsaturated fatty acids.

    PubMed

    Sculley, D V

    2014-06-01

    Periodontal disease, including gingivitis and periodontitis, is caused by the interaction between pathogenic bacteria and the host immune system. The ensuing oxidative stress and inflammatory cascade result in the destruction of gingival tissue, alveolar bone and periodontal ligament. This article reviews the underlying mechanisms and host-bacteria interactions responsible for periodontal disease and evidence that nutritional supplementation with fish oil may provide a protective effect. Historical investigations of diet and disease have highlighted an inverse relationship between ingestion of fish oil, which is high in n-3 polyunsaturated fatty acids, and the incidence of typical inflammatory diseases such as arthritis and coronary heart disease. Ingestion of n-3 polyunsaturated fatty acids, such as docosahexaenoic acid and eicosapentaenoic acid, results in their incorporation into membrane phospholipids, which can alter eicosanoid production after stimulation during the immune response. These eicosanoids promote a reduction in chronic inflammation, which has led to the proposal that fish oil is a possible modulator of inflammation and may reduce the severity of periodontal diseases. Tentative animal and human studies have provided an indication of this effect. Further human investigation is needed to establish the protective effects of fish oil in relation to periodontal disease. PMID:23889472

  1. The effects of extracts of chewing sticks (Salvadora persica) on healthy and periodontally involved human dentine: a SEM study.

    PubMed

    Almas, K

    2001-01-01

    The popularity and availability of chewing sticks (Salvadora persica) in the Asia, Middle East and Africa make them a commonly used oral hygiene tool in those societies. Salvador persica chewing stick called miswak is frequently used in Saudi Arabia. The antimicrobial effects of miswak has been well documented. The aim of this study is to find our the effect of aqueous extracts of miswak on healthy and periodontally involved human dentine with Scanning Electron Microscopy (SEM) in vitro. 25% aqueous extract of freshly prepared miswak solution was used for the study. Twelve human premolars teeth (6 healthy and 6 with periodontal disease) recently extracted for orthodontic and periodontal reasons were used. 24 SEM specimens were prepared and treated with miswak extract with different conditions e.g. soaking and burnishing with miswak extract. Soaking the healthy and periodontally diseased root dentine in miswak extract resulted in partial removal of smear layer and occlusion of dentinal tubules was observed in dentine specimens burnished with miswak solution. Further research is needed to evaluate the effect of aqueous extract of miswak on etched human dentine at higher concentrations. PMID:11808063

  2. Periodontal disease and diabetes.

    PubMed

    Bascones-Martínez, Antonio; Arias-Herrera, Santiago; Criado-Cámara, Elena; Bascones-Ilundáin, Jaime; Bascones-Ilundáin, Cristina

    2012-01-01

    Diabetes is considered to be a genetically and environmentally based chronic metabolic and vascular syndrome caused by a partial or total insulin deficiency with alteration in the metabolism of lipids, carbohydrates and proteins culminating with different manifestations in different organisms. In humans hyperglycemia is the main consequence of defects in the secretion and/or action of insulin, and its deregulation can produce secondary lesions in various organs, especially kidneys, eyes, nerves, blood vessels and immune systems. Periodontal disease is an entity of localized infection that involves tooth-supporting tissues. The first clinical manifestation of periodontal disease is the appearance of periodontal pockets, which offer a favorable niche for bacterial colonization. The etiology of periodontal disease is multifactorial, being caused by interactions between multiple micro-organisms (necessary but not sufficient primary etiologic factors), a host with some degree of susceptibility and environmental factors. According to current scientific evidence, there is a symbiotic relationship between diabetes and periodontitis, such that diabetes is associated with an increased incidence and progression of periodontitis, and periodontal infection is associated with poor glycaemic control in diabetes due to poor immune systems. Hence, for a good periodontal control it is necessary to treat both periodontal disease and glycaemic control. PMID:23393673

  3. Freeze gelated porous membranes for periodontal tissue regeneration.

    PubMed

    Qasim, Saad B; Delaine-Smith, Robin M; Fey, Tobias; Rawlinson, Andrew; Rehman, Ihtesham Ur

    2015-09-01

    Guided tissue regeneration (GTR) membranes have been used for the management of destructive forms of periodontal disease as a means of aiding regeneration of lost supporting tissues, including the alveolar bone, cementum, gingiva and periodontal ligaments (PDL). Currently available GTR membranes are either non-biodegradable, requiring a second surgery for removal, or biodegradable. The mechanical and biofunctional limitations of currently available membranes result in a limited and unpredictable treatment outcome in terms of periodontal tissue regeneration. In this study, porous membranes of chitosan (CH) were fabricated with or without hydroxyapatite (HA) using the simple technique of freeze gelation (FG) via two different solvents systems, acetic acid (ACa) or ascorbic acid (ASa). The aim was to prepare porous membranes to be used for GTR to improve periodontal regeneration. FG membranes were characterized for ultra-structural morphology, physiochemical properties, water uptake, degradation, mechanical properties, and biocompatibility with mature and progenitor osteogenic cells. Fourier transform infrared (FTIR) spectroscopy confirmed the presence of hydroxyapatite and its interaction with chitosan. μCT analysis showed membranes had 85-77% porosity. Mechanical properties and degradation rate were affected by solvent type and the presence of hydroxyapatite. Culture of human osteosarcoma cells (MG63) and human embryonic stem cell-derived mesenchymal progenitors (hES-MPs) showed that all membranes supported cell proliferation and long term matrix deposition was supported by HA incorporated membranes. These CH and HA composite membranes show their potential use for GTR applications in periodontal lesions and in addition FG membranes could be further tuned to achieve characteristics desirable of a GTR membrane for periodontal regeneration. PMID:25968357

  4. Increased Eotaxin and MCP-1 Levels in Serum from Individuals with Periodontitis and in Human Gingival Fibroblasts Exposed to Pro-Inflammatory Cytokines.

    PubMed

    Boström, Elisabeth A; Kindstedt, Elin; Sulniute, Rima; Palmqvist, Py; Majster, Mirjam; Holm, Cecilia Koskinen; Zwicker, Stephanie; Clark, Reuben; Önell, Sebastian; Johansson, Ingegerd; Lerner, Ulf H; Lundberg, Pernilla

    2015-01-01

    Periodontitis is a chronic inflammatory disease of tooth supporting tissues resulting in periodontal tissue destruction, which may ultimately lead to tooth loss. The disease is characterized by continuous leukocyte infiltration, likely mediated by local chemokine production but the pathogenic mechanisms are not fully elucidated. There are no reliable serologic biomarkers for the diagnosis of periodontitis, which is today based solely on the degree of local tissue destruction, and there is no available biological treatment tool. Prompted by the increasing interest in periodontitis and systemic inflammatory mediators we mapped serum cytokine and chemokine levels from periodontitis subjects and healthy controls. We used multivariate partial least squares (PLS) modeling and identified monocyte chemoattractant protein-1 (MCP-1) and eotaxin as clearly associated with periodontitis along with C-reactive protein (CRP), years of smoking and age, whereas the number of remaining teeth was associated with being healthy. Moreover, body mass index correlated significantly with serum MCP-1 and CRP, but not with eotaxin. We detected higher MCP-1 protein levels in inflamed gingival connective tissue compared to healthy but the eotaxin levels were undetectable. Primary human gingival fibroblasts displayed strongly increased expression of MCP-1 and eotaxin mRNA and protein when challenged with tumor necrosis factor-α (TNF-α and interleukin-1β (IL-1β), key mediators of periodontal inflammation. We also demonstrated that the upregulated chemokine expression was dependent on the NF-κΒ pathway. In summary, we identify higher levels of CRP, eotaxin and MCP-1 in serum of periodontitis patients. This, together with our finding that both CRP and MCP-1 correlates with BMI points towards an increased systemic inflammatory load in patients with periodontitis and high BMI. Targeting eotaxin and MCP-1 in periodontitis may result in reduced leukocyte infiltration and inflammation in

  5. Increased Eotaxin and MCP-1 Levels in Serum from Individuals with Periodontitis and in Human Gingival Fibroblasts Exposed to Pro-Inflammatory Cytokines

    PubMed Central

    Sulniute, Rima; Palmqvist, Py; Majster, Mirjam; Holm, Cecilia Koskinen; Zwicker, Stephanie; Clark, Reuben; Önell, Sebastian; Johansson, Ingegerd; Lerner, Ulf H.; Lundberg, Pernilla

    2015-01-01

    Periodontitis is a chronic inflammatory disease of tooth supporting tissues resulting in periodontal tissue destruction, which may ultimately lead to tooth loss. The disease is characterized by continuous leukocyte infiltration, likely mediated by local chemokine production but the pathogenic mechanisms are not fully elucidated. There are no reliable serologic biomarkers for the diagnosis of periodontitis, which is today based solely on the degree of local tissue destruction, and there is no available biological treatment tool. Prompted by the increasing interest in periodontitis and systemic inflammatory mediators we mapped serum cytokine and chemokine levels from periodontitis subjects and healthy controls. We used multivariate partial least squares (PLS) modeling and identified monocyte chemoattractant protein-1 (MCP-1) and eotaxin as clearly associated with periodontitis along with C-reactive protein (CRP), years of smoking and age, whereas the number of remaining teeth was associated with being healthy. Moreover, body mass index correlated significantly with serum MCP-1 and CRP, but not with eotaxin. We detected higher MCP-1 protein levels in inflamed gingival connective tissue compared to healthy but the eotaxin levels were undetectable. Primary human gingival fibroblasts displayed strongly increased expression of MCP-1 and eotaxin mRNA and protein when challenged with tumor necrosis factor-α (TNF-α and interleukin-1β (IL-1β), key mediators of periodontal inflammation. We also demonstrated that the upregulated chemokine expression was dependent on the NF-κΒ pathway. In summary, we identify higher levels of CRP, eotaxin and MCP-1 in serum of periodontitis patients. This, together with our finding that both CRP and MCP-1 correlates with BMI points towards an increased systemic inflammatory load in patients with periodontitis and high BMI. Targeting eotaxin and MCP-1 in periodontitis may result in reduced leukocyte infiltration and inflammation in

  6. Tissue engineered periodontal products.

    PubMed

    Bartold, P M; Gronthos, S; Ivanovski, S; Fisher, A; Hutmacher, D W

    2016-02-01

    Attainment of periodontal regeneration is a significant clinical goal in the management of advanced periodontal defects arising from periodontitis. Over the past 30 years numerous techniques and materials have been introduced and evaluated clinically and have included guided tissue regeneration, bone grafting materials, growth and other biological factors and gene therapy. With the exception of gene therapy, all have undergone evaluation in humans. All of the products have shown efficacy in promoting periodontal regeneration in animal models but the results in humans remain variable and equivocal concerning attaining complete biological regeneration of damaged periodontal structures. In the early 2000s, the concept of tissue engineering was proposed as a new paradigm for periodontal regeneration based on molecular and cell biology. At this time, tissue engineering was a new and emerging field. Now, 14 years later we revisit the concept of tissue engineering for the periodontium and assess how far we have come, where we are currently situated and what needs to be done in the future to make this concept a reality. In this review, we cover some of the precursor products, which led to our current position in periodontal tissue engineering. The basic concepts of tissue engineering with special emphasis on periodontal tissue engineering products is discussed including the use of mesenchymal stem cells in bioscaffolds and the emerging field of cell sheet technology. Finally, we look into the future to consider what CAD/CAM technology and nanotechnology will have to offer. PMID:25900048

  7. Porphyromonas gulae Has Virulence and Immunological Characteristics Similar to Those of the Human Periodontal Pathogen Porphyromonas gingivalis.

    PubMed

    Lenzo, Jason C; O'Brien-Simpson, Neil M; Orth, Rebecca K; Mitchell, Helen L; Dashper, Stuart G; Reynolds, Eric C

    2016-09-01

    Periodontitis is a significant problem in companion animals, and yet little is known about the disease-associated microbiota. A major virulence factor for the human periodontal pathogen Porphyromonas gingivalis is the lysyl- and arginyl-specific proteolytic activity of the gingipains. We screened several Porphyromonas species isolated from companion animals-P. asaccharolytica, P. circumdentaria, P. endodontalis, P. levii, P. gulae, P. macacae, P. catoniae, and P. salivosa-for Lys- and Arg-specific proteolytic activity and compared the epithelial and macrophage responses and induction of alveolar bone resorption of the protease active species to that of Porphyromonas gingivalis Only P. gulae exhibited Lys-and Arg-specific proteolytic activity. The genes encoding the gingipains (RgpA/B and Kgp) were identified in the P. gulae strain ATCC 51700 and all publicly available 12 draft genomes of P. gulae strains. P. gulae ATCC 51700 induced levels of alveolar bone resorption in an animal model of periodontitis similar to those in P. gingivalis W50 and exhibited a higher capacity for autoaggregation and binding to oral epithelial cells with induction of apoptosis. Macrophages (RAW 264.7) were found to phagocytose P. gulae ATCC 51700 and the fimbriated P. gingivalis ATCC 33277 at similar levels. In response to P. gulae ATCC 51700, macrophages secreted higher levels of cytokines than those induced by P. gingivalis ATCC 33277 but lower than those induced by P. gingivalis W50, except for the interleukin-6 response. Our results indicate that P. gulae exhibits virulence characteristics similar to those of the human periodontal pathogen P. gingivalis and therefore may play a key role in the development of periodontitis in companion animals. PMID:27354442

  8. Periodontal Cell Implantation Contributes to the Regeneration of the Periodontium in an Indirect Way

    PubMed Central

    Yu, Na; Bronckers, Antonius L.J.J.; Oortgiesen, Daniel A.W.; Yan, Xiangzhen; Yang, Fang; Walboomers, X. Frank

    2015-01-01

    Periodontitis is the most common human infectious disease. Regeneration of bone and soft tissue defects after periodontitis remains challenging, although the transplantation of periodontal ligament (PDL) cells seems a liable strategy. However, little is known about the function of PDL cells after transplantation. In the current study, a combination of in vitro coculture systems and in vivo immunohistochemistry (IHC) was used to investigate the role of PDL cells in the regenerative process. First, a coculture method was used, in which mesenchymal cells (representing the host tissue) were brought into direct contact with PDL cells (representing the transplanted cell population). It was found that PDL cells significantly increased mineralized matrix formation and osteocalcin expression, whereas control cells did not. Similar results were obtained when a noncontact coculture system was applied separating PDL and mesenchymal cells. In an in vivo rat model, regeneration of alveolar bone and ligament was seen after PDL cell transplantation. Implanted PDL cells were found clustered along the newly formed tissues. IHC showed enhanced osteopontin expression and gap junction staining in areas neighboring implanted PDL cells. In conclusion, PDL cells enhance periodontal regeneration through a trophic factor stimulating the osteogenic activity of the surrounding host cells. PMID:25077766

  9. Spatiotemporally controlled microchannels of periodontal mimic scaffolds.

    PubMed

    Park, C H; Kim, K H; Rios, H F; Lee, Y M; Giannobile, W V; Seol, Y J

    2014-12-01

    Physiologic bioengineering of the oral, dental, and craniofacial complex requires optimized geometric organizations of fibrous connective tissues. A computer-designed, fiber-guiding scaffold has been developed to promote tooth-supporting periodontal tissue regeneration and functional restoration despite limited printing resolution for the manufacture of submicron-scaled features. Here, we demonstrate the use of directional freeze-casting techniques to control pore directional angulations and create mimicked topographies to alveolar crest, horizontal, oblique, and apical fibers of natural periodontal ligaments. For the differing anatomic positions, the gelatin displayed varying patterns of ice growth, determined via internal pore architectures. Regardless of the freezing coordinates, the longitudinal pore arrangements resulted in submicron-scaled diameters (~50 µm), along with corresponding high biomaterial porosity (~90%). Furthermore, the horizontal + coronal ([Formula: see text]) freezing orientation facilitated the creation of similar structures to major fibers in the periodontal ligament interface. This periodontal tissue-mimicking microenvironment is a potential tissue platform for the generation of naturally oriented ligamentous tissues consistent with periodontal ligament neogenesis. PMID:25216511

  10. Quantitative detection of Staphylococcus aureus, Enterococcus faecalis and Pseudomonas aeruginosa in human oral epithelial cells from subjects with periodontitis and periodontal health.

    PubMed

    Colombo, Andrea V; Barbosa, Graziela M; Higashi, Daniela; di Micheli, Giorgio; Rodrigues, Paulo H; Simionato, Maria Regina L

    2013-10-01

    Epithelial cells in oral cavities can be considered reservoirs for a variety of bacterial species. A polymicrobial intracellular flora associated with periodontal disease has been demonstrated in buccal cells. Important aetiological agents of systemic and nosocomial infections have been detected in the microbiota of subgingival biofilm, especially in individuals with periodontal disease. However, non-oral pathogens internalized in oral epithelial cells and their relationship with periodontal status are poorly understood. The purpose of this study was to detect opportunistic species within buccal and gingival crevice epithelial cells collected from subjects with periodontitis or individuals with good periodontal health, and to associate their prevalence with periodontal clinical status. Quantitative detection of total bacteria and Staphylococcus aureus, Pseudomonas aeruginosa and Enterococcus faecalis in oral epithelial cells was determined by quantitative real-time PCR using universal and species-specific primer sets. Intracellular bacteria were visualized by confocal microscopy and fluorescence in situ hybridization. Overall, 33% of cell samples from patients with periodontitis contained at least one opportunistic species, compared with 15% of samples from healthy individuals. E. faecalis was the most prevalent species found in oral epithelial cells (detected in 20.6% of patients with periodontitis, P = 0.03 versus healthy individuals) and was detected only in cells from patients with periodontitis. Quantitative real-time PCR showed that high levels of P. aeruginosa and S. aureus were present in both the periodontitis and healthy groups. However, the proportion of these species was significantly higher in epithelial cells of subjects with periodontitis compared with healthy individuals (P = 0.016 for P. aeruginosa and P = 0.047 for S. aureus). Although E. faecalis and P. aeruginosa were detected in 57% and 50% of patients, respectively, with probing depth and

  11. Periodontal Treatment Downregulates Protease-Activated Receptor 2 in Human Gingival Crevicular Fluid Cells

    PubMed Central

    Euzebio Alves, Vanessa Tubero; Bueno da Silva, Henrique Aparecido; de França, Bruno Nunes; Eichler, Rosangela Santos; Saraiva, Luciana; de Carvalho, Maria Helena Catelli

    2013-01-01

    Protease-activated receptor 2 (PAR2) is implicated in the pathogenesis of chronic inflammatory diseases, including periodontitis; it can be activated by gingipain and produced by Porphyromonas gingivalis and by neutrophil protease 3 (P3). PAR2 activation plays a relevant role in inflammatory processes by inducing the release of important inflammatory mediators associated with periodontal breakdown. The effects of periodontal treatment on PAR2 expression and its association with levels of proinflammatory mediators and activating proteases were investigated in chronic periodontitis patients. Positive staining for PAR2 was observed in gingival crevicular fluid cells and was reflective of tissue destruction. Overexpression of PAR2 was positively associated with inflammatory clinical parameters and with the levels of interleukin-6 (IL-6), IL-8, tumor necrosis factor alpha, matrix metalloprotease 2 (MMP-2), MMP-8, hepatocyte growth factor, and vascular endothelial growth factor. Elevated levels of gingipain and P3 and decreased levels of dentilisin and the protease inhibitors secretory leukocyte protease inhibitor and elafin were also associated with PAR2 overexpression. Healthy periodontal sites from individuals with chronic periodontitis showed diminished expression of PAR2 mRNA and the PAR2 protein (P < 0.05). Furthermore, periodontal treatment resulted in decreased PAR2 expression and correlated with decreased expression of inflammatory mediators and activating proteases. We concluded that periodontal treatment resulted in decreased levels of proteases and that proinflammatory mediators are associated with decreased PAR2 expression, suggesting that PAR2 expression is influenced by the presence of periodontal infection and is not a constitutive characteristic favoring periodontal inflammation. PMID:24042113

  12. The uncertainty of predicting intact anterior cruciate ligament degeneration in terms of structural properties using T(2)(*) relaxometry in a human cadaveric model.

    PubMed

    Biercevicz, A M; Akelman, M R; Rubin, L E; Walsh, E G; Merck, D; Fleming, B C

    2015-04-13

    The combination of healing anterior cruciate ligament (ACL) volume and the distributions of T2(*) relaxation times within it have been shown to predict the biomechanical failure properties in a porcine model. This MR-based prediction model has not yet been used to assess ligament degeneration in the aging human knee. Using a set of 15 human cadaveric knees of varying ages, we obtained in situ MR measures of volume and T2(*) of the intact ACL and then related these MR variables to biomechanical outcomes (maximum and yield loads, linear stiffness) obtained via ex vivo failure testing. Using volume in conjunction with the median T2(*) value, the multiple linear regression model did not predict maximum failure load for the intact human ACL; R(2)=0.23, p=0.200. Similar insignificant results were found for yield load and linear stiffness. Naturally restricted distributions of the intact ligament volume and T2(*) (demonstrated by the respective Z-scores) in an older cadaveric population were the likely reason for the insignificant results. These restricted distributions may negatively affect the ability to detect a correlation when one exists. Further research is necessary to understand the relationship of MRI variables and ligament degeneration. While this study failed to find a significant prediction of human biomechanical outcome using these MR variables, with further research, an MR-based approach may offer a tool to longitudinally assess changes in cruciate ligament degradation. PMID:25746575

  13. The relationship between periodontal disease (pd) and cardiovascular disease (cvd).

    PubMed

    Trevisan, Maurizio; Dorn, Joan

    2010-01-01

    The recent focus on the potential link between periodontal and cardiovascular disease (PD and CVD) is part of the larger renewed interest on the role of infection and inflammation in the etiology of atherosclerosis and its clinical manifestations. Periodontal Disease is an inflammatory process affecting the periodontium, the tissue that surrounds and supports the teeth. The process usually starts with an inflammatory process of the gum (gingivitis) but it may progress with an extensive involvement of the gum, as well as the periodontal ligament and the bone surrounding the teeth resulting in substantial bone loss. Periodontal disease is a common oral pathological condition in the adult age and represents the leading cause of tooth loss. PD prevalence increases with age and there are estimates that up to 49,000,000 Americans may suffer from some form of gum disease. The gingival plaque associated with PD is colonized by a number of gram-positive and gram-negative bacteria that have been shown to affect the initiation and development of PD and have been associated with the potential etiological role of PD in CVD and other chronic conditions. A potential etiological link between PD and CVD may have important public health implications as both the exposure (PD) and the outcomes (CVD) are highly prevalent in industrialized societies. In situations in which both the exposure and the outcome are highly prevalent even modest associations, like those observed in the studies reporting on the link between PD and CVD outcomes, may have relevance. There are not definite data on the effect of periodontal treatment on CVD clinical outcomes (either in primary or secondary prevention) however it should be pointed out that the limited (both in terms of numbers and study design) experimental evidence in humans suggests a possible beneficial effect of periodontal treatment of indices of functional and structural vascular health. PMID:21415980

  14. Directional sensitivity of human periodontal mechanoreceptive afferents to forces applied to the teeth.

    PubMed Central

    Trulsson, M; Johansson, R S; Olsson, K A

    1992-01-01

    1. Single-unit impulse activity from thirty-eight mechanoreceptive afferent fibres was recorded in the human inferior alveolar nerve using tungsten microelectrodes. All afferents responded to mechanical stimulation of the teeth and most likely supplied periodontal mechanoreceptors. 2. All afferents showed their highest sensitivity to forces applied to a particular tooth (the lower incisors, the canine or the first premolar). Forces with 'ramp-and-hold' shaped profiles of similar magnitudes were applied to that tooth in the following six directions: lingual, labial, mesial and distal in the horizontal plane, and up and down in the axial direction of the tooth. Both static and dynamic response components were analysed. 3. All afferents were 'slowly adapting' since they discharged continuously in response to static forces in at least one stimulation direction. Twenty-five afferents (66%) were spontaneously active in the sense that they showed an on-going discharge in the absence of external stimulation. 4. Diverse receptive fields were observed. Most afferents (74%) responded to static forces in two or three of the four horizontal directions. Likewise, all units showed excitatory responses to axial loading with a majority (74%) responding in one of the two axial directions and the remainder in both axial directions. Spontaneously active afferents generally decreased their discharge rate when stimulated in directions opposite to the directions exciting the afferent. With regard to population responses, approximately half of the afferents showed excitatory responses to each stimulus direction except for downwards, in which 86% responded. 5. Twenty-three afferents (61%) exhibited the strongest response to forces in one of the horizontal directions. Of those, a majority were most responsive to the lingual direction (52%) and some to the labial direction (30%). Accordingly, the discharge rates during force application averaged over the whole afferent sample were highest in

  15. Constitutive modeling of the human Anterior Cruciate Ligament (ACL) under uniaxial loading using viscoelastic prony series and hyperelastic five parameter Mooney-Rivlin model

    NASA Astrophysics Data System (ADS)

    Chakraborty, Souvik; Mondal, Debabrata; Motalab, Mohammad

    2016-07-01

    In this present study, the stress-strain behavior of the Human Anterior Cruciate Ligament (ACL) is studied under uniaxial loads applied with various strain rates. Tensile testing of the human ACL samples requires state of the art test facilities. Furthermore, difficulty in finding human ligament for testing purpose results in very limited archival data. Nominal Stress vs. deformation gradient plots for different strain rates, as found in literature, is used to model the material behavior either as a hyperelastic or as a viscoelastic material. The well-known five parameter Mooney-Rivlin constitutivemodel for hyperelastic material and the Prony Series model for viscoelastic material are used and the objective of the analyses comprises of determining the model constants and their variation-trend with strain rates for the Human Anterior Cruciate Ligament (ACL) material using the non-linear curve fitting tool. The relationship between the model constants and strain rate, using the Hyperelastic Mooney-Rivlin model, has been obtained. The variation of the values of each coefficient with strain rates, obtained using Hyperelastic Mooney-Rivlin model are then plotted and variation of the values with strain rates are obtained for all the model constants. These plots are again fitted using the software package MATLAB and a power law relationship between the model constants and strain rates is obtained for each constant. The obtained material model for Human Anterior Cruciate Ligament (ACL) material can be implemented in any commercial finite element software package for stress analysis.

  16. Interactions between Periodontal Bacteria and Human Oral Epithelial Cells: Fusobacterium nucleatum Adheres to and Invades Epithelial Cells

    PubMed Central

    Han, Yiping W.; Shi, Wenyuan; Huang, George T.-J.; Kinder Haake, Susan; Park, No-Hee; Kuramitsu, Howard; Genco, Robert J.

    2000-01-01

    Bacteria are causative agents of periodontal diseases. Interactions between oral bacteria and gingival epithelial cells are essential aspects of periodontal infections. Using an in vitro tissue culture model, a selected group of gram-negative anaerobic bacteria frequently associated with periodontal diseases, including Bacteroides forsythus, Campylobacter curvus, Eikenella corrodens, Fusobacterium nucleatum, Porphyromonas gingivalis, and Prevotella intermedia, were examined for their ability to adhere to and invade primary cultures of human gingival epithelial cells (HGEC). The effects of these bacteria on the production of interleukin-8 (IL-8), a proinflammatory chemokine, were also measured. These studies provided an initial demonstration that F. nucleatum adhered to and invaded HGEC and that this was accompanied by high levels of IL-8 secretion from the epithelial cells. The attachment and invasion characteristics of F. nucleatum were also tested using KB cells, an oral epithelial cell line. The invasion was verified by transmission electron microscopy and with metabolic inhibitors. Invasion appeared to occur via a “zipping” mechanism and required the involvement of actins, microtubules, signal transduction, protein synthesis, and energy metabolism of the epithelial cell, as well as protein synthesis by F. nucleatum. A spontaneous mutant, lam, of F. nucleatum, isolated as defective in autoagglutination, was unable to attach to or invade HGEC or KB cells, further indicating the requirement of bacterial components in these processes. Sugar inhibition assays indicated that lectin-like interactions were involved in the attachment of F. nucleatum to KB cells. Investigation of these new virulence phenotypes should improve our understanding of the role of F. nucleatum in periodontal infections. PMID:10816455

  17. Periodontal manifestations of hyperoxaluria and oxalosis.

    PubMed

    Moskow, B S

    1989-05-01

    Dental and periodontal findings associated with primary hyperoxaluria in a 29-year old male patient are described. This is a rare, inherited, metabolic disease which results in excessive calcium oxalate synthesis. The predominant and early manifestation of hyperoxaluria is nephrocalcinosis which results in chronic renal failure. Widespread extrarenal deposits of calcium oxalate crystals, however, is a consistent finding. Extensive infiltration of crystals was noted in the pulps of the teeth, in the marrow spaces of the alveolar bone, in the gingival corium, and in the periodontal ligament. Crystalline calcium oxalate deposits in the periodontal ligament provoked a granulomatous foreign-body reaction. This resulted in aggressive external root resorption leading to pulp exposure and tooth mobility. PMID:2738833

  18. Intraplaque hemorrhage, a potential consequence of periodontal bacteria gathering in human carotid atherothrombosis.

    PubMed

    Brun, Adrian; Rangé, Hélène; Prouvost, Bastien; Meilhac, Olivier; Mazighi, Mikael; Amarenco, Pierre; Lesèche, Guy; Bouchard, Philippe; Michel, Jean-Baptiste

    2016-01-01

    Periodontal diseases are multifactorial inflammatory diseases, caused by a bacterial biofilm involving both innate and adaptative immunity, characterized by the destruction of tooth-supporting tissues. In the context of periodontitis, the spread of weak pathogenic bacteria into the bloodstream has been described. These bacteria will preferentially localize to existing clot within the circulation. Atherothrombosis of the carotid arteries is a local pathology and a common cause of cerebral infarction. Intraplaque hemorrhages render the lesion more prone to clinical complications such as stroke. The main objective of this study is to explore the biological relationship between carotid intraplaque hemorrhage and periodontal diseases. This study included consecutive patients with symptomatic or asymptomatic carotid stenosis, admitted for endarterectomy surgical procedure (n=41). In conditioned media of the carotid samples collected, markers of neutrophil activation (myeloperoxidase or MPO, DNA-MPO complexes) and hemoglobin were quantified. To investigate the presence of DNA from periodontal bacteria in atherosclerotic plaque, PCR analysis using specific primers was performed. Our preliminary results indicate an association between neutrophil activation and intraplaque hemorrhages, reflected by the release of MPO (p<0,01) and MPO-DNA complexes (p<0,05). Presence of DNA from periodontitis-associated bacteria was found in 32/41 (78%) atheromatous plaque samples. More specifically, DNA from Pg, Tf, Pi, Aa was found in 46%, 24%, 34% and 68% of the samples, respectively. Hemoglobin levels were higher in conditioned media in carotid samples where the bacteria were found, but this was not statistically significant. Our data confirm the relationship between intraplaque hemorrhage and neutrophil activation. In addition, the presence of periodontal bacteria DNA in carotid atheromatous plaque, may contribute to this activation. Further analysis is needed to fully explore the raw

  19. Localized expression of mRNA for phagocyte-specific chemotactic cytokines in human periodontal infections.

    PubMed Central

    Tonetti, M S; Imboden, M A; Gerber, L; Lang, N P; Laissue, J; Mueller, C

    1994-01-01

    In bacterial infections, mononuclear and polymorphonuclear phagocytes are key components of host defenses. Recent investigations have indicated that chemokines are able to recruit and activate phagocytes. In particular, interleukin-8 (IL-8) attracts polymorphonuclear leukocytes (PMNs), while monocyte chemoattractant protein-1 (MCP-1) is selective for cells of the monocyte/macrophage lineage. In this investigation, we analyzed the in situ expression of IL-8 and MCP-1 mRNAs in human periodontal infections. Specific mRNA was detected by in situ hybridization using 35S-labeled riboprobes in frozen tissue sections. Phagocytes (PMNs and macrophages) were specifically detected as elastase-positive or CD68+ cells by a three-stage immunoperoxidase technique. Results indicated that expression of phagocyte-specific cytokines was confined to selected tissue locations and, in general, paralleled phagocyte infiltration. In particular, IL-8 expression was maximal in the junctional epithelium adjacent to the infecting microorganisms; PMN infiltration was more prominent in the same area. MCP-1 was expressed in the chronic inflammatory infiltrate and along the basal layer of the oral epithelium. Cells of the monocyte/macrophage lineage were demonstrated to be present in the same areas. The observed expression pattern may be the most economic way to establish a cell-type-selective chemotactic gradient within the tissue that is able to effectively direct polymorphonuclear phagocyte migration toward the infecting microorganisms and modulate mononuclear phagocyte infiltration in the surrounding tissues. This process may optimize host defenses and contribute to containing leukocyte infiltration to the infected and inflamed area, thus limiting tissue damage. Images PMID:8063420

  20. A Putative Association of a Single Nucleotide Polymorphism in GPR126 with Aggressive Periodontitis in a Japanese Population

    PubMed Central

    Asano, Yoshihiro; Imai, Atsuko; Kawai, Shinji; Michikami, Ikumi; Yamashita, Motozo; Yamada, Satoru; Kitamura, Masahiro; Murakami, Shinya

    2016-01-01

    Periodontitis is an inflammatory disease causing loss of tooth-supporting periodontal tissue. Disease susceptibility to the rapidly progressive form of periodontitis, aggressive periodontitis (AgP), appears to be influenced by genetic risk factors. To identify these in a Japanese population, we performed whole exome sequencing of 41 unrelated generalized or localized AgP patients. We found that AgP is putatively associated with single nucleotide polymorphism (SNP) rs536714306 in the G-protein coupled receptor 126 gene, GPR126 [c.3086 G>A (p.Arg1029Gln)]. Since GPR126 activates the cAMP/PKA signaling pathway, we performed cAMP ELISA analysis of cAMP concentrations, and found that rs536714306 impaired the signal transactivation of GPR126. Moreover, transfection of human periodontal ligament (HPDL) cells with wild-type or mutant GPR126 containing rs536714306 showed that wild-type GPR126 significantly increased the mRNA expression of bone sialoprotein, osteopontin, and Runx2 genes, while mutant GPR126 had no effect on the expression of these calcification-related genes. The increase in expression of these genes was through the GPR126-induced increase of bone morphogenic protein-2, inhibitor of DNA binding (ID) 2, and ID4 expression. These data indicate that GPR126 might be important in maintaining the homeostasis of periodontal ligament tissues through regulating the cytodifferentiation of HPDL cells. The GPR126 SNP rs536714306 negatively influences this homeostasis, leading to the development of AgP, suggesting that it is a candidate genetic risk factor for AgP in the Japanese population. PMID:27509131

  1. Uncovering the molecular networks in periodontitis

    PubMed Central

    Trindade, Fábio; Oppenheim, Frank G.; Helmerhorst, Eva J.; Amado, Francisco; Gomes, Pedro S.; Vitorino, Rui

    2015-01-01

    Periodontitis is a complex immune-inflammatory disease that results from a preestablished infection in gingiva, mainly due to Gram-negative bacteria that colonize deeper in gingival sulcus and latter periodontal pocket. Host inflammatory and immune responses have both protective and destructive roles. Although cytokines, prostaglandins, and proteases struggle against microbial burden, these molecules promote connective tissue loss and alveolar bone resorption, leading to several histopathological changes, namely destruction of periodontal ligament, deepening of periodontal pocket, and bone loss, which can converge to attain tooth loss. Despite the efforts of genomics, transcriptomics, proteomics/peptidomics, and metabolomics, there is no available biomarker for periodontitis diagnosis, prognosis, and treatment evaluation, which could assist on the established clinical evaluation. Nevertheless, some genes, transcripts, proteins and metabolites have already shown a different expression in healthy subjects and in patients. Though, so far, ‘omics approaches only disclosed the host inflammatory response as a consequence of microbial invasion in periodontitis and the diagnosis in periodontitis still relies on clinical parameters, thus a molecular tool for assessing periodontitis lacks in current dental medicine paradigm. Saliva and gingival crevicular fluid have been attracting researchers due to their diagnostic potential, ease, and noninvasive nature of collection. Each one of these fluids has some advantages and disadvantages that are discussed in this review. PMID:24828325

  2. Periodontal maintenance.

    PubMed

    Tan, A E S

    2009-09-01

    The main goal of periodontal therapy is to establish an oral environment compatible with periodontal health by the physical disruption of the plaque biofilm and adjunctive chemical means if required. Implicit in this objective is the ongoing requirement of detection and interception of new and recurrent disease, which continues at selected intervals for the life of the dentition after the initial ("active") phase of periodontal treatment. This concept of ongoing periodontal maintenance therapy has been embraced as the mandatory requirement for favourable periodontal outcomes based on institutional clinical trials and in practice-based studies in various parts of the world. This review examines the ramifications of periodontal maintenance therapy based upon a multi-level assessment of logistic issues and risk factors at three levels: (1) The patient level - treatment time; patient attendance compliance; and homecare measures, antiseptics/antibiotics and smoking. (2) The level of the individual tooth - tooth loss; and evaluation of success versus survival. (3) The level of each tooth surface ("site") - probing depth, loss of attachment and bleeding on probing; and changes in clinical attachment levels. In spite of the diversity of studies conducted, there is agreement on the efficacy of periodontal maintenance therapy when compared with studies on untreated populations and in treated cases that were not maintained. PMID:19737263

  3. A forward dynamics simulation of human lumbar spine flexion predicting the load sharing of intervertebral discs, ligaments, and muscles.

    PubMed

    Rupp, T K; Ehlers, W; Karajan, N; Günther, M; Schmitt, S

    2015-10-01

    Determining the internal dynamics of the human spine's biological structure is one essential step that allows enhanced understanding of spinal degeneration processes. The unavailability of internal load figures in other methods highlights the importance of the forward dynamics approach as the most powerful approach to examine the internal degeneration of spinal structures. Consequently, a forward dynamics full-body model of the human body with a detailed lumbar spine is introduced. The aim was to determine the internal dynamics and the contribution of different spinal structures to loading. The multi-body model consists of the lower extremities, two feet, shanks and thighs, the pelvis, five lumbar vertebrae, and a lumped upper body including the head and both arms. All segments are modelled as rigid bodies. 202 muscles (legs, back, abdomen) are included as Hill-type elements. 58 nonlinear force elements are included to represent all spinal ligaments. The lumbar intervertebral discs were modelled nonlinearly. As results, internal kinematics, muscle forces, and internal loads for each biological structure are presented. A comparison between the nonlinear (new, enhanced modelling approach) and linear (standard modelling approach, bushing) modelling approaches of the intervertebral disc is presented. The model is available to all researchers as ready-to-use C/C++ code within our in-house multi-body simulation code demoa with all relevant binaries included. PMID:25653134

  4. Lessons learned and unlearned in periodontal microbiology

    PubMed Central

    Teles, Ricardo; Teles, Flavia; Frias-Lopez, Jorge; Paster, Bruce; Haffajee, Anne

    2013-01-01

    Periodontal diseases are initiated by bacterial species living in polymicrobial biofilms at or below the gingival margin and progress largely as a result of the inflammation initiated by specific subgingival species. In the past few decades, efforts to understand the microbiota of periodontal diseases have led to an exponential increase in information about biofilms associated with periodontal health and disease. In fact, the oral microbiota is one of the best characterized microbiomes that colonize the human body. Despite this increased knowledge, one has to ask if our fundamental concepts of the etiology and pathogenesis of periodontal diseases have really changed. In this chapter we will review how our comprehension of the structure and function of the subgingival microbiota evolved over the years in search of lessons learned and unlearned in periodontal microbiology. More specifically, this review focuses on: 1) how the data obtained through molecular techniques has impacted our knowledge of the etiology of periodontal infections; 2) the potential role of viruses in the etiopathogenesis of periodontal diseases; 3) how concepts of microbial ecology have expanded our understanding of host microbial interactions that might lead to periodontal diseases; 4) the role of inflammation in the pathogenesis of periodontal diseases; and 5) the impact of these evolving concepts on treatment and preventive approaches to periodontal infections. We will conclude by reviewing how novel systems biology approaches promise to unravel new details of the pathogenesis of periodontal diseases and, hopefully, lead to a better understanding of periodontal disease mechanisms. PMID:23574465

  5. Ultrasonic device for measuring periodontal attachment levels

    NASA Astrophysics Data System (ADS)

    Lynch, J. E.; Hinders, M. K.

    2002-07-01

    Periodontal disease is manifested clinically by a degradation of the ligament that attaches the tooth to the bone. The most widely used diagnostic tool for assessment of periodontal diseases, measurement of periodontal attachment loss with a manual probe, may overestimate attachment loss by as much as 2 mm in untreated sites, while underestimating attachment loss by an even greater margin following treatment. Manual probing is also invasive, which causes patient discomfort. This work describes the development and testing of an ultrasonographic periodontal probe designed to replace manual probing. It uses a thin stream of water to project an ultrasonic beam into the periodontal pocket, and then measures echoes off features within the pocket. To do so, the ultrasonic beam must be narrowed from 2 (the diameter of the transducer) to 0.5 mm (the approximate width of the periodontal pocket at the gingival margin). The proper choice of transducer frequency, the proper method for controlling water flow from the probe, and a model for interpreting these echoes are also addressed. Initial results indicate that the device measures echoes from the hard tissue of the tooth surface, and that the periodontal attachment level can be inferred from these echoes.

  6. Bi-linear mechanical property determination of acellular human patellar tendon grafts for use in anterior cruciate ligament replacement.

    PubMed

    Herbert, Anthony; Brown, Christopher; Rooney, Paul; Kearney, John; Ingham, Eileen; Fisher, John

    2016-06-14

    Anterior cruciate ligament rupture is rising in its prevalence amongst the young and those with physically active lifestyles. Acellular human patellar tendon (PT) grafts offer a promising restoration solution, returning knee joint stability and overcoming some of the current disadvantages of autologous or allogeneic grafts. However, it is necessary to ensure that the decellularisation bio-processes involved do not cause structural changes in the microstructure of the tendon tissue that may adversely affect the mechanical properties, particularly with respect to the physiological range of loading. Sixteen cadaveric human PT grafts were sourced and processed from eight donors, with full ethical approval and consent for use in research. Eight specimens were allocated for decellularisation, while the remaining eight contralateral specimens were used as native controls. Testing consisted of 12 preconditioning cycles followed by uniaxial extension until failure occurred. Stress-strain data was then fitted to a bi-linear model using least squares regression by a custom-written Matlab script. The elastic moduli for the toe region and linear region of each specimen were determined, in addition to the transition point co-ordinates and strain energy density for increasing strain. No significant differences were found between groups for all of the parameters investigated. Hence, the shape and magnitude of the stress-strain profile was found to be the same for both groups throughout loading. The results of this study indicated that decellularisation appeared to have no effect on the material properties of human PT grafts under quasistatic conditions. Therefore, acellular human PT grafts can offer a viable additional solution for ACL replacement compared to current autologous and allogeneic treatment options. PMID:27063250

  7. Periodontics in the next millennium.

    PubMed

    Vandersall, D C

    1998-07-01

    This article prognosticates where periodontology will be in the next millennium. The forecasting of such events is wrought with confusion because such predictions are shadowed by bias, dogmatism, prejudice, experiences, and opinions from either a closed or open mind. The results of the survey from 101 periodontists reflect opinions from varied backgrounds, years of clinical experience, and individual levels of success or failure. The responses cannot be tested for accuracy or duplicated by another survey except to wait out the test of time for the year 2025. Clinicians will be challenged to make decisions on accepting new techniques and concepts as these are brought into the therapeutic fold of periodontics. The clinician will be met with new possibilities as a paradigm shift is inevitable for periodontal practice in the next millennium. After all, who would have thought in the 1960s, the soft tissue augmentation era, that 22 years later in 1982, the regeneration of the lost attachment apparatus (alveolar bone, cementum, and periodontal ligament) would become a reality. This survey strongly suggests that by the end of the first quarter of the twenty-first century, local delivery of antimicrobials, growth and differentiation factors, and root biomodification agents will have a major impact on the practice of periodontics. One thing is certain, in the next millennium, considering the responses from this survey, a new era in periodontics will be here. By the year 2025, the research, development, and dissemination of new periodontal knowledge will be beyond the imagination from what was considered usual and customary for the twentieth century. PMID:9700454

  8. IPLA2 mRNA expression by human neutrophils in type 2 diabetes and chronic periodontitis.

    PubMed

    Ayilavarapu, Srinivas; Kantarci, Alpdogan; Hasturk, Hatice; Van Dyke, Thomas E

    2014-10-01

    Type 2 diabetes mellitus (T2D) is becoming increasingly prevalent worldwide and complications of T2D cause significant systemic and dental morbidity in the susceptible individual. Although T2D has been linked as a significant risk factor for chronic periodontitis (CP), molecular mechanisms explaining the pathogenesis and inflammatory impact of CP in T2D are lacking. iPLA2 is the calcium-independent form of phospholipase A2. In previous studies, we demonstrated that iPLA2 enzyme activity is altered in T2D. The purpose of this study was to elucidate the level of the iPLA2 abnormality in T2D by measuring messenger RNA levels in T2D-associated CP. A total of 53 healthy and T2D subjects with CP were recruited for this study. The clinical periodontal exam included probing pocket depth, clinical attachment levels and bleeding on probing. Peripheral venous blood was collected and neutrophils were isolated. Real time polymerase chain reaction was used to quantify iPLA2 mRNA in neutrophils from healthy controls and people with diabetes. Results revealed that the prevalence of moderate to severe CP was increased in people with T2D. The iPLA, mRNA levels in diabetics with different severity of CP were not significantly different compared to healthy controls; 1.07 vs 0.97 (mild CP), 1.07 vs 0.85 (moderate CP) and 1.07 vs 1.05 (severe CP). Collectively, the data suggest that levels of iPLA2 mRNA in T2D are not different than in health and are not directly influenced by periodontal disease status. The impact of inflammation on iPLA2 regulation is at the level of activation of the enzyme rather than expression at the mRNA level. PMID:25654966

  9. The effect of supragingival plaque control on the subgingival microflora in human periodontitis.

    PubMed

    Hellström, M K; Ramberg, P; Krok, L; Lindhe, J

    1996-10-01

    The aim of the present trial was to study if carefully practiced supragingival plaque control influenced the subgingival microbiota at periodontal sites with suprabony, infrabony, or furcation pockets. 12 subjects, 5 males and 7 females aged 44 to 69 years (mean age 55 years) participated in the study. None of the participants had during the last 12 months received periodontal therapy, and none of the subjects had used antibiotics during a 3-month period preceding the study. Following a screening examination, 6 to 8 sites per subject were selected which had a probing depth of > or = 5 mm. Among these sites, 1-3 sites had a suprabony location, 1-3 sites had an infrabony location, and 1-3 sites were associated with a furcation defect. The selected sites were exposed to a baseline examination at which the following parameters were recorded: plaque, gingivitis, probing pocket depth and probing attachment level. A bacterial sample was obtained from each of the selected sites: 2 sterile paper points were inserted into the pocket and kept in place for 30 seconds. The paper point samples were removed, placed in a vial containing an anaerobically prepared transport medium, and processed using routine procedures. Following the baseline examination, each subject was given a case presentation, received thorough supragingival scaling and was instructed to practice proper plaque control with the use of toothbrush and dentifrice. During the subsequent 30 weeks they were recalled 2-3xper week for professional tooth cleaning. Each session was handled by a dental hygienist and required about 15 min. Re-examinations were performed after 30 weeks. The findings indicated that professionally delivered and frequently repeated supragingival tooth cleaning, combined with careful self-performed plaque control had a marked effect on the subgingival microbiota of moderate to deep periodontal pockets. Thus, at sites with suprabony and infrabony pockets, as well as at furcation sites, the

  10. Anatomically Shaped Tooth and Periodontal Regeneration by Cell Homing

    PubMed Central

    Kim, K.; Lee, C.H.; Kim, B.K.; Mao, J.J.

    2010-01-01

    Tooth regeneration by cell delivery encounters translational hurdles. We hypothesized that anatomically correct teeth can regenerate in scaffolds without cell transplantation. Novel, anatomically shaped human molar scaffolds and rat incisor scaffolds were fabricated by 3D bioprinting from a hybrid of poly-ε-caprolactone and hydroxyapatite with 200-µm-diameter interconnecting microchannels. In each of 22 rats, an incisor scaffold was implanted orthotopically following mandibular incisor extraction, whereas a human molar scaffold was implanted ectopically into the dorsum. Stromal-derived factor-1 (SDF1) and bone morphogenetic protein-7 (BMP7) were delivered in scaffold microchannels. After 9 weeks, a putative periodontal ligament and new bone regenerated at the interface of rat incisor scaffold with native alveolar bone. SDF1 and BMP7 delivery not only recruited significantly more endogenous cells, but also elaborated greater angiogenesis than growth-factor-free control scaffolds. Regeneration of tooth-like structures and periodontal integration by cell homing provide an alternative to cell delivery, and may accelerate clinical applications. PMID:20448245

  11. Changes in the Distribution of Periodontal Nerve Fibers during Dentition Transition in the Cat

    PubMed Central

    Miki, Koji; Honma, Shiho; Ebara, Satomi; Kumamoto, Kenzo; Murakami, Shinya; Wakisaka, Satoshi

    2015-01-01

    The periodontal ligament has a rich sensory nerve supply which originates from the trigeminal ganglion and trigeminal mesencephalic nucleus. Although various types of mechanoreceptors have been reported in the periodontal ligament, the Ruffini ending is an essential one. It is unknown whether the distribution of periodontal nerve fibers in deciduous teeth is identical to that in permanent teeth or not. Moreover, morphological changes in the distribution of periodontal nerve fibers during resorption of deciduous teeth and eruption of successional permanent teeth in diphyodont animals have not been reported in detail. Therefore, in this study, we examined changes in the distribution of periodontal nerve fibers in the cat during changes in dentition (i.e., deciduous, mixed and permanent dentition) by immunohistochemistry of protein gene product 9.5. During deciduous dentition, periodontal nerve fibers were concentrated at the apical portion, and sparsely distributed in the periodontal ligament of deciduous molars. During mixed dentition, the periodontal nerve fibers of deciduous molars showed degenerative profiles during resorption. In permanent dentition, the periodontal nerve fibers of permanent premolars, the successors of deciduous molars, increased in number. Similar to permanent premolars, the periodontal nerve fibers of permanent molars, having no predecessors, increased in number, and were densely present in the apical portion. The present results indicate that the distribution of periodontal nerve fibers in deciduous dentition is almost identical to that in permanent dentition although the number of periodontal nerve fibers in deciduous dentition was low. The sparse distribution of periodontal nerve fibers in deciduous dentition agrees with clinical evidence that children are less sensitive to tooth stimulation than adults. PMID:26083023

  12. Advanced drug delivery approaches against periodontitis.

    PubMed

    Joshi, Deeksha; Garg, Tarun; Goyal, Amit K; Rath, Goutam

    2016-01-01

    Periodontitis is an inflammatory disease of gums involving the degeneration of periodontal ligaments, creation of periodontal pocket and resorption of alveolar bone, resulting in the disruption of the support structure of teeth. According to WHO, 10-15% of the global population suffers from severe periodontitis. The disease results from the growth of a diverse microflora (especially anaerobes) in the pockets and release of toxins, enzymes and stimulation of body's immune response. Various local or systemic approaches were used for an effective treatment of periodontitis. Currently, controlled local drug delivery approach is more favorable as compared to systemic approach because it mainly focuses on improving the therapeutic outcomes by achieving factors like site-specific delivery, low dose requirement, bypass of first-pass metabolism, reduction in gastrointestinal side effects and decrease in dosing frequency. Overall it provides a safe and effective mode of treatment, which enhances patient compliance. Complete eradication of the organisms from the sites was not achieved by using various surgical and mechanical treatments. So a number of polymer-based delivery systems like fibers, films, chips, strips, microparticles, nanoparticles and nanofibers made from a variety of natural and synthetic materials have been successfully tested to deliver a variety of drugs. These systems are biocompatible and biodegradable, completely fill the pockets, and have strong retention on the target site due to excellent mucoadhesion properties. The review summarizes various available and recently developing targeted delivery devices for the treatment of periodontitis. PMID:25005586

  13. Diagnostic Applications of Cone-Beam CT for Periodontal Diseases

    PubMed Central

    AlJehani, Yousef A.

    2014-01-01

    Objectives. This paper aims to review the diagnostic application of cone beam computed tomography (CBCT) in the field of periodontology. Data. Original articles that reported on the use of CBCT for periodontal disease diagnosis were included. Sources. MEDLINE (1990 to January 2014), PubMed (using medical subject headings), and Google Scholar were searched using the following terms in different combinations: “CBCT,” “volumetric CT,” “periodontal disease ,” and “periodontitis.” This was supplemented by hand-searching in peer-reviewed journals and cross-referenced with the articles accessed. Conclusions. Bony defects, caters, and furcation involvements seem to be better depicted on CBCT, whereas bone quality and periodontal ligament space scored better on conventional intraoral radiography. CBCT does not offer a significant advantage over conventional radiography for assessing the periodontal bone levels. PMID:24803932

  14. Periodontal Probe Improves Exams, Alleviates Pain

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Dentists, comedian Bill Cosby memorably mused, tell you not to pick your teeth with any sharp metal object. Then you sit in their chair, and the first thing they grab is an iron hook!" Conventional periodontal probing is indeed invasive, uncomfortable for the patient, and the results can vary greatly between dentists and even for repeated measurements by the same dentist. It is a necessary procedure, though, as periodontal disease is the most common dental disease, involving the loss of teeth by the gradual destruction of ligaments that hold teeth in their sockets in the jawbone. The disease usually results from an increased concentration of bacteria in the pocket, or sulcus, between the gums and teeth. These bacteria produce acids and other byproducts, which enlarge the sulcus by eroding the gums and the periodontal ligaments. The sulcus normally has a depth of 1 to 2 millimeters, but in patients with early stages of periodontal disease, it has a depth of 3 to 5 millimeters. By measuring the depth of the sulcus, periodontists can have a good assessment of the disease s progress. Presently, there are no reliable clinical indicators of periodontal disease activity, and the best available diagnostic aid, periodontal probing, can only measure what has already been lost. A method for detecting small increments of periodontal ligament breakdown would permit earlier diagnosis and intervention with less costly and time-consuming therapy, while overcoming the problems associated with conventional probing. The painful, conventional method for probing may be destined for the archives of dental history, thanks to the development of ultrasound probing technologies. The roots of ultrasound probes are in an ultrasound-based time-of-flight technique routinely used to measure material thickness and length in the Nondestructive Evaluation Sciences Laboratory at Langley Research Center. The primary applications of that technology have been for corrosion detection and bolt tension

  15. Mathematical modeling of ligaments and tendons.

    PubMed

    Woo, S L; Johnson, G A; Smith, B A

    1993-11-01

    Ligaments and tendons serve a variety of important functions in maintaining the structure of the human body. Although abundant literature exists describing experimental investigations of these tissues, mathematical modeling of ligaments and tendons also contributes significantly to understanding their behavior. This paper presents a survey of developments in mathematical modeling of ligaments and tendons over the past 20 years. Mathematical descriptions of ligaments and tendons are identified as either elastic or viscoelastic, and are discussed in chronological order. Elastic models assume that ligaments and tendons do not display time dependent behavior and thus, they focus on describing the nonlinear aspects of their mechanical response. On the other hand, viscoelastic models incorporate time dependent effects into their mathematical description. In particular, two viscoelastic models are discussed in detail; quasi-linear viscoelasticity (QLV), which has been widely used in the past 20 years, and the recently proposed single integral finite strain (SIFS) model. PMID:8302027

  16. The Effect of Brain-Derived Neurotrophic Factor on Periodontal Furcation Defects

    PubMed Central

    Jimbo, Ryo; Tovar, Nick; Janal, Malvin N.; Mousa, Ramy; Marin, Charles; Yoo, Daniel; Teixeira, Hellen S.; Anchieta, Rodolfo B.; Bonfante, Estevam A.; Konishi, Akihiro; Takeda, Katsuhiro; Kurihara, Hidemi; Coelho, Paulo G.

    2014-01-01

    This study aimed to observe the regenerative effect of brain-derived neurotrophic factor (BDNF) in a non-human primate furcation defect model. Class II furcation defects were created in the first and second molars of 8 non-human primates to simulate a clinical situation. The defect was filled with either, Group A: BDNF (500 µg/ml) in high-molecular weight-hyaluronic acid (HMW-HA), Group B: BDNF (50 µg/ml) in HMW-HA, Group C: HMW-HA acid only, Group D: empty defect, or Group E: BDNF (500 µg/ml) in saline. The healing status for all groups was observed at different time-points with micro computed tomography. The animals were euthanized after 11 weeks, and the tooth-bone specimens were subjected to histologic processing. The results showed that all groups seemed to successfully regenerate the alveolar buccal bone, however, only Group A regenerated the entire periodontal tissue, i.e., alveolar bone, cementum and periodontal ligament. It is suggested that the use of BDNF in combination with a scaffold such as the hyaluronic acid in periodontal furcation defects may be an effective treatment option. PMID:24454754

  17. An evaluation of tricalcium phosphate implants in human periodontal osseous defects of two patients.

    PubMed

    Baldock, W T; Hutchens, L H; McFall, W T; Simpson, D M

    1985-01-01

    This study evaluated the use of tricalcium phosphate (TCP) ceramic implant material in periodontal osseous defects. Thirteen defects in two patients were treated with mucoperiosteal flaps and placement of TCP. The defects were evaluated clinically and radiographically utilizing standardized probe placement and radiographic technique. Clinically, there was a mean probing pocket reduction of 4.5 mm as a result of a mean gain of clinical probing attachment level of 2.0 mm and a mean gingival recession of 2.5 mm. Radiographically, there was a mean "fill" of 1.8 mm. Six teeth were removed by block biopsy for histologic analysis, three at 3 months, one at 6 months and two a 9 months. The TCP particles were well tolerated and encapsulated by fibrous connective tissue, but the particles did not stimulate new bone growth. The junctional epithelium ended 1.62 mm coronal to the apical extent of a reference notch placed at the base of the defect. Although new cementum was observed, there was limited evidence of new attachment. PMID:3856005

  18. Periodontal Proteomics: Wonders Never Cease!

    PubMed Central

    Grover, Harpreet Singh; Kapoor, Shalini; Saksena, Neha

    2013-01-01

    Proteins are vital parts of living organisms, as they are integral components of the physiological metabolic pathways of cells. Periodontal tissues comprise multicompartmental groups of interacting cells and matrices that provide continuous support, attachment, proprioception, and physical protection for the teeth. The proteome map, that is, complete catalogue of the matrix and cellular proteins expressed in alveolar bone, cementum, periodontal ligament, and gingiva, is to be explored for more in-depth understanding of periodontium. The ongoing research to understand the signalling pathways that allow cells to divide, differentiate, and die in controlled manner has brought us to the era of proteomics. Proteomics is defined as the study of all proteins including their relative abundance, distribution, posttranslational modifications, functions, and interactions with other macromolecules, in a given cell or organism within a given environment and at a specific stage in the cell cycle. Its application to periodontal science can be used to monitor health status, disease onset, treatment response, and outcome. Proteomics can offer answers to critical, unresolved questions such as the biological basis for the heterogeneity in gingival, alveolar bone, and cemental cell populations. PMID:24490073

  19. Poor periodontal health: A cancer risk?

    PubMed Central

    Rajesh, K. S.; Thomas, Deepak; Hegde, Shashikanth; Kumar, M. S. Arun

    2013-01-01

    Evidence indicates that chronic infections and inflammation are associated with increased risk of cancer development. There has also been considerable evidence that proves the interrelationship between bacterial and viral infections and carcinogenesis. Periodontitis is a chronic oral infection thought to be caused by gram-negative anaerobic bacteria in the dental biofilm. Periodontal bacteria and viruses may act synergistically to cause periodontitis. Many studies have shown that periodontal pockets may act as reservoirs for human papilloma virus, cytomegalovirus, Epstein Barr virus, and suspected agents associated with oral cancer. Periodontitis, characterized by epithelial proliferation and migration, results in a chronic release of inflammatory cytokines, chemokines, growth factors, prostaglandins, and enzymes, all of which are associated with cancer development. This review article intends to shed light on the association between periodontal health and carcinogenesis. PMID:24554877

  20. Proteomics – The research frontier in periodontics

    PubMed Central

    Gupta, Abhaya; Govila, Vivek; Saini, Ashish

    2015-01-01

    Periodontitis is an inflammatory condition resulting from the interplay between the infectious agents and host factors. Various protein molecules play a vital role in the initiation, progression and severity of periodontal diseases. The study of proteins as biomarkers in periodontal diseases has been highlighted during the last few years. In periodontitis multiple bacteria derived (e.g. collagen degrading enzymes, elastase like enzymes etc) and host derived mediators (eg. PGE2, TNF, IL1, IL6, MMP's etc) expressed in the saliva and gingival crevicular fluid, can be utilized as diagnostic markers for the disease. Another significant development regarding human genes and proteins has been the discovery of potential new drugs for the treatment of periodontal diseases. Therefore the information of the proteins involved in the pathogenesis of periodontal diseases can be utilized for its diagnosis, prevention and treatment. PMID:25853048

  1. A Knee-Specific Finite Element Analysis of the Human Anterior Cruciate Ligament Impingement against the Femoral Intercondylar Notch

    PubMed Central

    Park, Hyung-Soon; Ahn, Chulhyun; Fung, David T.; Ren, Yupeng; Zhang, Li-Qun

    2010-01-01

    This work presents a finite element analysis of Anterior Cruciate Ligament (ACL) impingement against the intercondylar notch during tibial external rotation and abduction, as a mechanism of noncontact ACL injuries. Experimentally, ACL impingement was measured in a cadaveric knee in terms of impingement contact pressure and six degrees-of-freedom tibiofemoral kinematics. Three-dimensional geometries of the ACL, femur and tibia were incorporated into the finite element model of the individual knee specimen. A fiber-reinforced model was adopted, which accounts for the anisotropy, large deformation, nonlinearity and incompressibility of the ACL. With boundary conditions specified based on the experimental tibiofemoral kinematics, the finite element analysis showed that impingement between the ligament and the lateral wall of intercondylar notch could occur when the knee 45° was externally rotated at 29.1° and abducted at 10.0°. Strong contact pressure and tensile stress occurred at the impinging and nonimpinging sides of the ligament, respectively. The impingement force and contact area estimated from the model matched their counterparts from the corresponding cadaver experiment. The modeling and experimental approach provides a useful tool to characterize potential ACL impingement on a knee-specific basis, which may help elucidate the ACL injury mechanism and develop more effective treatments. PMID:20413123

  2. Treatment modalities and evaluation models for periodontitis

    PubMed Central

    Tariq, Mohammad; Iqbal, Zeenat; Ali, Javed; Baboota, Sanjula; Talegaonkar, Sushama; Ahmad, Zulfiqar; Sahni, Jasjeet K

    2012-01-01

    Periodontitis is the most common localized dental inflammatory disease related with several pathological conditions like inflammation of gums (gingivitis), degeneration of periodontal ligament, dental cementum and alveolar bone loss. In this perspective, the various preventive and treatment modalities, including oral hygiene, gingival irrigations, mechanical instrumentation, full mouth disinfection, host modulation and antimicrobial therapy, which are used either as adjunctive treatments or as stand-alone therapies in the non-surgical management of periodontal infections, have been discussed. Intra-pocket, sustained release systems have emerged as a novel paradigm for the future research. In this article, special consideration is given to different locally delivered anti-microbial and anti inflammatory medications which are either commercially available or are currently under consideration for Food and Drug Administration (FDA) approval. The various in vitro dissolution models and microbiological strain investigated to impersonate the infected and inflamed periodontal cavity and to predict the in vivo performance of treatment modalities have also been thrashed out. Animal models that have been employed to explore the pathology at the different stages of periodontitis and to evaluate its treatment modalities are enlightened in this proposed review. PMID:23373002

  3. Interaction between periodontitis and liver diseases

    PubMed Central

    Han, Pengyu; Sun, Dianxing; Yang, Jie

    2016-01-01

    Periodontitis is an oral disease that is highly prevalent worldwide, with a prevalence of 30–50% of the population in developed countries, but only ~10% present with severe forms. It is also estimated that periodontitis results in worldwide productivity losses amounting to ~54 billion USD yearly. In addition to the damage it causes to oral health, periodontitis also affects other types of disease. Numerous studies have confirmed the association between periodontitis and systemic diseases, such as diabetes, respiratory disease, osteoporosis and cardiovascular disease. Increasing evidence also indicated that periodontitis may participate in the progression of liver diseases, such as non-alcoholic fatty liver disease, cirrhosis and hepatocellular carcinoma, as well as affecting liver transplantation. However, to the best of our knowledge, there are currently no reviews elaborating upon the possible links between periodontitis and liver diseases. Therefore, the current review summarizes the human trials and animal experiments that have been conducted to investigate the correlation between periodontitis and liver diseases. Furthermore, in the present review, certain mechanisms that have been postulated to be responsible for the role of periodontitis in liver diseases (such as bacteria, pro-inflammatory mediators and oxidative stress) are considered. The aim of the review is to introduce the hypothesis that periodontitis may be important in the progression of liver disease, thus providing dentists and physicians with an improved understanding of this issue. PMID:27588170

  4. A unique localization of mechanoreceptors in the periodontal tissue of guinea pig teeth.

    PubMed

    Jayawardena, Chantha K; Takahashi, Nobuyuki; Takano, Yoshiro

    2002-08-01

    This study describes the unique distribution of Ruffini endings (RE) in the periodontal tissues of the guinea pig teeth with special references to their presence in the enamel-related aspects of the continuously growing incisors and molars. In guinea pig incisors, immunohistochemistry for PGP 9.5 and glia specific S-100 protein revealed a condensed distribution of well-developed RE in the bone-related part of the lingual periodontal ligament as has been reported in many other rodents. In most cases, some RE-like nerve elements characterized by dendritic ramification and rounded terminal Schwann cells were found to be located in the labial, enamel-related regions, where no periodontal ligament-like fiber arrangement was established. In the molar periodontal ligament, well-developed RE-like nerve elements were also distributed in the enamel-related part, but in intimate relation to thick periodontal fiber bundles inserted in the cementum pearls grown on the enamel surface. In some cases, few RE were located in the apical region of the alveolar socket, where no periodontal fiber bundles could be identified. Our data provide the first morphological evidence of the presence of RE-like nerve elements in the enamel-related, fibrous connective tissue of continuously erupting rodent incisors. These data indicate that RE in guinea pig periodontal tissues have variable spatial correlation to the surrounding fibers, implicating their diverse mechanoreceptive properties depending on the anatomical location. PMID:12389662

  5. Artificial Ligaments: Promise or Panacea?

    ERIC Educational Resources Information Center

    Lubell, Adele

    1987-01-01

    The Food and Drug Administration has approved a prosthetic ligament for limited use in persons with damaged anterior cruciate ligaments (ACL). This article addresses ligament repair, ACL tears, current treatment, development of the Gore-Tex artificial ligament, other artificial ligaments in process, and arguments for and against their use.…

  6. Periodontal tissue regeneration with PRP incorporated gelatin hydrogel sponges.

    PubMed

    Nakajima, Dai; Tabata, Yasuhiko; Sato, Soh

    2015-09-01

    Gelatin hydrogels have been designed and prepared for the controlled release of the transforming growth factor (TGF-b1) and the platelet-derived growth factor (PDGF-BB). PRP (Platelet rich plasma) contains many growth factors including the PDGF and TGF-b1. The objective of this study was to evaluate the regeneration of periodontal tissue following the controlled release of growth factors in PRP. For the periodontal ligament cells and osteoblast, PRP of different concentrations was added. The assessment of DNA, mitochondrial activity and ALP activity were measured. To evaluate the TGF-β1 release from PRP incorporated gelatin sponge, amounts of TGF-β1 in each supernatant sample were determined by the ELISA. Transplantation experiments to prepare a bone defect in a rat alveolar bone were an implanted gelatin sponge incorporated with different concentration PRP. In DNA assay and MTT assay, after the addition of PRP to the periodontal ligament cells and osteoblast, the cell count and mitochondrial activity had increased the most in the group with the addition of 5  ×  PRP. In the ALP assay, after the addition of PRP to the periodontal ligament cells, the cell activity had increased the most in the group with the addition of 3  ×  PRP. In the transplantation, the size of the bone regenerated in the defect with 3  ×  PRP incorporated gelatin sponge was larger than that of the other group. PMID:26481592

  7. Role of nitro-oxidative stress in the pathogenesis of experimental rat periodontitis

    PubMed Central

    BOŞCA, ADINA BIANCA; MICLĂUŞ, VIOREL; ILEA, ARANKA; CÂMPIAN, RADU SEPTIMIU; RUS, VASILE; RUXANDA, FLAVIA; RAŢIU, CRISTIAN; UIFĂLEAN, ANA; PÂRVU, ALINA ELENA

    2016-01-01

    Background and aims Periodontitis is a common chronic adult condition that implicates oxidative damage to gingival tissue, periodontal ligament and alveolar bone. This study aimed at assessing the association between the nitro-oxidative stress and the periodontal tissues destructions in experimental rat periodontitis. Methods Periodontitis was induced in 15 male albino rats by repetitive lesions to the gingiva adjacent to the inferior incisors, performed daily, for 16 days. On D1, D3, D6, D8, and D16 the onset and evolution of periodontitis were monitored by clinical and histopathological examinations; blood was collected and serum nitro-oxidative stress was evaluated through total nitrites and nitrates, total oxidative status, total antioxidant capacity, and oxidative stress index. Results The results demonstrated that there was a graded and continuous increase in serum levels of total nitrites and nitrates, total oxidative status and oxidative stress index, which was consistent with the severity of periodontal destructions during periodontitis progression. However, total antioxidant capacity was not significantly influenced by the disease progression. Conclusions In experimental rat periodontitis, the systemic nitro-oxidative stress was associated with the severity of periodontal destructions assessed clinically and histopathologically. Therefore, systemic nitro-oxidative stress parameters might be used as diagnostic tools in periodontitis. PMID:27004039

  8. [In vivo study of bacterial invasion in root planed and citric acid treated radicular surfaces of periodontally involved human teeth].

    PubMed

    Ito, K; Arai, N; Otogoto, J; Murai, S

    1989-06-01

    The purpose of this study was to investigate whether plaque bacteria invade the exposed radicular dentin after root planing or chemical root treatment in vivo. Eighteen caries-free human periodontally involved teeth with hopeless prognoses were studied. Fourteen teeth were scaled and root planed with hand curette type scalers. The proximal surface of each treated tooth was designated as the RP surface. The remaining half of the proximal surface was treated with citric acid (pH 1.0) for 3 minutes and was designated as the CA surface. Four untreated teeth served as controls. After 4 weeks, the teeth were extracted, and were processed for light microscopy and for scanning electron microscopy concerning bacterial invasion into the supragingival radicular dentin. The following results were obtained. 1. Radicular cementum was present on most untreated tooth surfaces. However, bacteria were never seen in the dentinal tubules. 2. Bacterial invasion into the dentinal tubules was observed in five of the 10 proximal surfaces (50% of the RP surfaces) and in nine of the 10 proximal surfaces (90% of the CA surfaces). 3. The depth (9.5 +/- 24.1 microns vs 84.6 +/- 136.3 microns) and percentage (0.8 +/- 2.1% vs 20.3 +/- 17.3%) of bacterial invasion in the dentinal tubules of the RP surfaces was lower than that of the CA surfaces. 4. Cocci and short rods were present in the supragingival dentinal tubules. 5. Since CA surfaces may accelerate bacterial invasion the citric acid treatment might be harmful in patients with inadequate plaque control. PMID:2700200

  9. Tendon and ligament imaging

    PubMed Central

    Hodgson, R J; O'Connor, P J; Grainger, A J

    2012-01-01

    MRI and ultrasound are now widely used for the assessment of tendon and ligament abnormalities. Healthy tendons and ligaments contain high levels of collagen with a structured orientation, which gives rise to their characteristic normal imaging appearances as well as causing particular imaging artefacts. Changes to ligaments and tendons as a result of disease and injury can be demonstrated using both ultrasound and MRI. These have been validated against surgical and histological findings. Novel imaging techniques are being developed that may improve the ability of MRI and ultrasound to assess tendon and ligament disease. PMID:22553301

  10. Novel chitosan/collagen scaffold containing transforming growth factor-{beta}1 DNA for periodontal tissue engineering

    SciTech Connect

    Zhang Yufeng; Cheng Xiangrong . E-mail: Xiangrongcheng@hotmail.com; Wang Jiawei; Wang Yining; Shi Bin; Huang Cui; Yang Xuechao; Liu Tongjun

    2006-05-26

    The current rapid progression in tissue engineering and local gene delivery system has enhanced our applications to periodontal tissue engineering. In this study, porous chitosan/collagen scaffolds were prepared through a freeze-drying process, and loaded with plasmid and adenoviral vector encoding human transforming growth factor-{beta}1 (TGF-{beta}1). These scaffolds were evaluated in vitro by analysis of microscopic structure, porosity, and cytocompatibility. Human periodontal ligament cells (HPLCs) were seeded in this scaffold, and gene transfection could be traced by green fluorescent protein (GFP). The expression of type I and type III collagen was detected with RT-PCR, and then these scaffolds were implanted subcutaneously into athymic mice. Results indicated that the pore diameter of the gene-combined scaffolds was lower than that of pure chitosan/collagen scaffold. The scaffold containing Ad-TGF-{beta}1 exhibited the highest proliferation rate, and the expression of type I and type III collagen up-regulated in Ad-TGF-{beta}1 scaffold. After implanted in vivo, EGFP-transfected HPLCs not only proliferated but also recruited surrounding tissue to grow in the scaffold. This study demonstrated the potential of chitosan/collagen scaffold combined Ad-TGF-{beta}1 as a good substrate candidate in periodontal tissue engineering.

  11. Periodontal regeneration of transplanted rat molars after cryopreservation.

    PubMed

    Kawasaki, Naoko; Hamamoto, Yoshioki; Nakajima, Tamio; Irie, Kazuharu; Ozawa, Hidehiro

    2004-01-01

    The effects of cryopreservation on periodontal regeneration of transplanted rat molars were investigated histologically and histochemically in rats. Bilateral first and second maxillary molars of 4-week-old Wistar rats were gently extracted and transplanted into the abdominal subcutaneous connective tissue immediately or after cryopreservation in liquid nitrogen overnight. Donor teeth were slowly frozen by a rate-controlling freezer (program freezer) using 5% dimethylsulfoxide (DMSO) and 6% hydroxyethyl starch (HES) as cryoprotectants. One-four weeks after transplantation, they were carefully excised with the surrounding tissues. Regeneration of acellular cementum, periodontal ligament, and alveolar bone were observed 2 weeks after immediate transplantation. The pulp was repaired by the ingrowth of granulation tissue from the root apex followed by the formation of calcified tissue. The regenerated periodontal ligament was positive for alkaline phosphatase (ALP). Small or mononuclear tartrate resistant acid phosphatase (TRAP) positive cells were scattered on the newly formed alveolar bone and on the hard tissue in the pulp, but there was no external or internal progressive root resorption at 4 weeks. Cryopreserved teeth had acellular cementum with a rough surface at 1 week, but with the increase of cementoblasts and the appearance of periodontal ligament and alveolar bone, the surface became smooth at 3 weeks. Epithelial rests of Malassez (ERM) also revived. After regeneration of the periodontal tissues at 4 weeks, there was no evidence of root resorption. Although the process proceeded slowly, the cryopreserved teeth showed the periodontal regeneration substantially similar to that of the immediately transplanted teeth without progressive root resorption, indicating that they could be applicable for clinical use. PMID:14693198

  12. Acceleration of purine degradation by periodontal diseases.

    PubMed

    Barnes, V M; Teles, R; Trivedi, H M; Devizio, W; Xu, T; Mitchell, M W; Milburn, M V; Guo, L

    2009-09-01

    Periodontal diseases, such as gingivitis and periodontitis, are characterized by bacterial plaque accumulation around the gingival crevice and the subsequent inflammation and destruction of host tissues. To test the hypothesis that cellular metabolism is altered as a result of host-bacteria interaction, we performed an unbiased metabolomic profiling of gingival crevicular fluid (GCF) collected from healthy, gingivitis, and periodontitis sites in humans, by liquid and gas chromatography mass spectrometry. The purine degradation pathway, a major biochemical source for reactive oxygen species (ROS) production, was significantly accelerated at the disease sites. This suggests that periodontal-disease-induced oxidative stress and inflammation are mediated through this pathway. The complex host-bacterial interaction was further highlighted by depletion of anti-oxidants, degradation of host cellular components, and accumulation of bacterial products in GCF. These findings provide new mechanistic insights and a panel of comprehensive biomarkers for periodontal disease progression. PMID:19767584

  13. Ligament-induced sacral fractures of the pelvis are possible.

    PubMed

    Steinke, Hanno; Hammer, Niels; Lingslebe, Uwe; Höch, Andreas; Klink, Thomas; Böhme, Jörg

    2014-07-01

    Pelvic ring stability is maintained passively by both the osseous and the ligamentous apparatus. Therapeutic approaches focus mainly on fracture patterns, so ligaments are often neglected. When they rupture along with the bone after pelvic ring fractures, disrupting stability, ligaments need to be considered during reconstruction and rehabilitation. Our aim was to determine the influence of ligaments on open-book injury using two experimental models with body donors. Mechanisms of bone avulsion related to open-book injury were investigated. Open-book injuries were induced in human pelves and subsequently investigated by anatomical dissection and endoscopy. The findings were compared to CT and MRI scans of open-book injuries. Relevant structures were further analyzed using plastinated cross-sections of the posterior pelvic ring. A fragment of the distal sacrum was observed, related to open-book injury. Two ligaments were found to be responsible for this avulsion phenomenon: the caudal portion of the anterior sacroiliac ligament and another ligament running along the ventral surface of the third sacral vertebra. The sacral fragment remained attached to the coxal bone by this second ligament after open-book injury. These results were validated using plastination and the structures were identified. Pelvic ligaments are probably involved in sacral avulsion caused by lateral traction. Therefore, ligaments should to be taken into account in diagnosis of open-book injury and subsequent therapy. PMID:24452928

  14. Role of Lipids in the Onset, Progression and Treatment of Periodontal Disease. A Systematic Review of Studies in Humans

    PubMed Central

    Varela-López, Alfonso; Giampieri, Francesca; Bullón, Pedro; Battino, Maurizio; Quiles, José L.

    2016-01-01

    The risk of different oral problems (root caries, tooth mobility, and tooth loss) can be increased by the presence of periodontal disease, which has also been associated with a growing list of systemic diseases. The presence of some bacteria is the primary etiology of this disease; a susceptible host is also necessary for disease initiation. In this respect, the progression of periodontal disease and healing of the periodontal tissues can be modulated by nutritional status. To clarify the role of lipids in the establishment, progression, and/or treatment of this pathology, a systematic review was conducted of English-written literature in PubMed until May 2016, which included research on the relationship of these dietary components with the onset and progression of periodontal disease. According to publication type, randomized-controlled trials, cohort, case-control and cross-sectional studies were included. Among all the analyzed components, those that have any effect on oxidative stress and/or inflammation seem to be the most interesting according to current evidence. On one hand, there is quite a lot of information in favor of a positive role of n-3 fatty acids, due to their antioxidant and immunomodulatory effects. On the other hand, saturated fat-rich diets increase oxidative stress as well the as intensity and duration of inflammatory processes, so they must be avoided. PMID:27463711

  15. Bioerodible injectable poly(ortho ester) for tetracycline controlled delivery to periodontal pockets: preliminary trial in humans.

    PubMed

    Schwach-Abdellaoui, K; Loup, P J; Vivien-Castioni, N; Mombelli, A; Baehni, P; Barr, J; Heller, J; Gurny, R

    2002-01-01

    The semisolid consistency of poly(ortho esters) (POEs) containing tetracycline free base allows direct injection in the periodontal pocket and shows sustained and almost constant in vitro release in phosphate buffer, pH 7.4 at 37 degrees C, for up to 14 days. Total polymer degradation concomitant with drug release was obtained. Formulations containing 10% or 20% (wt/wt) tetracycline were evaluated in a panel of 12 patients suffering from severe and recurrent periodontitis. In the first trial including 6 patients, single-rooted teeth and molar teeth with furcations were treated immediately after scaling and root planing. Patients tolerated both formulations well, experienced no pain during application, and showed no signs of irritation or discomfort during the observation period. However, retention of the formulation was minimal in this first study. An improved clinical protocol followed in the second study (stopping bleeding after scaling and root planning) prolonged the retention of the formulations in the inflamed periodontal pockets. For up to 11 days, tetracycline concentrations in the gingival crevicular fluid were higher than the minimum inhibitory concentration of tetracycline against most periodontal pathogens. PMID:12645992

  16. Role of Lipids in the Onset, Progression and Treatment of Periodontal Disease. A Systematic Review of Studies in Humans.

    PubMed

    Varela-López, Alfonso; Giampieri, Francesca; Bullón, Pedro; Battino, Maurizio; Quiles, José L

    2016-01-01

    The risk of different oral problems (root caries, tooth mobility, and tooth loss) can be increased by the presence of periodontal disease, which has also been associated with a growing list of systemic diseases. The presence of some bacteria is the primary etiology of this disease; a susceptible host is also necessary for disease initiation. In this respect, the progression of periodontal disease and healing of the periodontal tissues can be modulated by nutritional status. To clarify the role of lipids in the establishment, progression, and/or treatment of this pathology, a systematic review was conducted of English-written literature in PubMed until May 2016, which included research on the relationship of these dietary components with the onset and progression of periodontal disease. According to publication type, randomized-controlled trials, cohort, case-control and cross-sectional studies were included. Among all the analyzed components, those that have any effect on oxidative stress and/or inflammation seem to be the most interesting according to current evidence. On one hand, there is quite a lot of information in favor of a positive role of n-3 fatty acids, due to their antioxidant and immunomodulatory effects. On the other hand, saturated fat-rich diets increase oxidative stress as well the as intensity and duration of inflammatory processes, so they must be avoided. PMID:27463711

  17. Bacterial invasion in root cementum and radicular dentin of periodontally diseased teeth in humans. A reservoir of periodontopathic bacteria.

    PubMed

    Adriaens, P A; De Boever, J A; Loesche, W J

    1988-04-01

    In this study the viability and the distribution of bacteria within the radicular dentin and pulp of periodontally diseased caries-free teeth were studied. Healthy teeth served as controls. Samples were obtained from the pulp tissue and from the radicular dentin. Dentin samples were taken from the interdental surfaces in the subgingival area. Starting from the pulpal side, three to five successive dentin layers of approximately 1 mm thickness were sampled. The samples were processed and cultured using an anaerobic technique. Bacterial growth was detected in 87% of the periodontally diseased teeth. In 83% of the teeth, bacteria were present in at least one of the dentin layers. Fifty-nine percent of the diseased teeth, from which the pulp tissue was cultured, contained bacteria in the pulp samples. The mean bacterial concentrations in the pulp and dentin layers ranged from 1,399 to 16,537 colony-forming units (CFU) per mg of tissue. These concentrations were 259 to 7,190 times greater than concentrations found in healthy teeth. It is suggested that the roots of periodontally diseased teeth could act as bacterial reservoirs from which recolonization of mechanically treated root surfaces can occur, as well as infection of the dental pulp. These findings might change current concepts concerning root surface debridement in periodontal therapy. PMID:3164373

  18. Neck ligament strength is decreased following whiplash trauma

    PubMed Central

    Tominaga, Yasuhiro; Ndu, Anthony B; Coe, Marcus P; Valenson, Arnold J; Ivancic, Paul C; Ito, Shigeki; Rubin, Wolfgang; Panjabi, Manohar M

    2006-01-01

    Background Previous clinical studies have documented successful neck pain relief in whiplash patients using nerve block and radiofrequency ablation of facet joint afferents, including capsular ligament nerves. No previous study has documented injuries to the neck ligaments as determined by altered dynamic mechanical properties due to whiplash. The goal of the present study was to determine the dynamic mechanical properties of whiplash-exposed human cervical spine ligaments. Additionally, the present data were compared to previously reported control data. The ligaments included the anterior and posterior longitudinal, capsular, and interspinous and supraspinous ligaments, middle-third disc, and ligamentum flavum. Methods A total of 98 bone-ligament-bone specimens (C2–C3 to C7-T1) were prepared from six cervical spines following 3.5, 5, 6.5, and 8 g rear impacts and pre- and post-impact flexibility testing. The specimens were elongated to failure at a peak rate of 725 (SD 95) mm/s. Failure force, elongation, and energy absorbed, as well as stiffness were determined. The mechanical properties were statistically compared among ligaments, and to the control data (significance level: P < 0.05; trend: P < 0.1). The average physiological ligament elongation was determined using a mathematical model. Results For all whiplash-exposed ligaments, the average failure elongation exceeded the average physiological elongation. The highest average failure force of 204.6 N was observed in the ligamentum flavum, significantly greater than in middle-third disc and interspinous and supraspinous ligaments. The highest average failure elongation of 4.9 mm was observed in the interspinous and supraspinous ligaments, significantly greater than in the anterior longitudinal ligament, middle-third disc, and ligamentum flavum. The average energy absorbed ranged from 0.04 J by the middle-third disc to 0.44 J by the capsular ligament. The ligamentum flavum was the stiffest ligament, while the

  19. Expression of programmed death 1 ligand 1 on periodontal tissue cells as a possible protective feedback mechanism against periodontal tissue destruction

    PubMed Central

    ZHANG, JIEHUA; WANG, CHIEH-MEI; ZHANG, PING; WANG, XIAOQIAN; CHEN, JIAO; YANG, JUN; LU, WANLU; ZHOU, WENJIE; YUAN, WENWEN; FENG, YUN

    2016-01-01

    Programmed death 1 ligand 1 (PD-L1) is a negative co-stimulatory molecule in immune responses. Previous reports have indicated that inflammatory cytokines can upregulate the expression of PD-L1 in tumor cells, which in turn suppresses host immune responses. Periodontitis is characterized by persistent inflammation of the periodontium, which is initiated by infection with oral bacteria and results in damage to cells and the matrices of the periodontal connective tissues. In the present study, the expression and function of PD-L1 in periodontal tissue destruction were examined. Periodontal ligament cells (PDLCs) were stimulated by inflammatory cytokines and periodontal pathogens. The expression and function of PD-L1 on the surface of PDLCs was investigated using flow cytometry in vitro. Periodontal disease was induced by the injection of Porphyromonas gingivalis in mouse models. The expression levels of PD-L1 in the periodontal tissues of the mice were analyzed using flow cytometry and immunohistochemistry. PD-L1 was inducibly expressed on the PDLCs by the inflammatory cytokines and periodontal pathogens. The inflammation-induced expression of PD-L1 was shown to cause the apoptosis of activated T lymphocytes and improve the survival of PDLCs. Furthermore, in the mouse model of experimental periodontitis, the expression of PD-L1 in severe cases of periodontitis was significantly lower, compared with that in mild cases. By contrast, no significant differences were observed between the healthy control and severe periodontitis groups. The results of the present study showed that the expression of PD-L1 may inhibit the destruction of periodontal tissues, indicating the involvement of a possible protective feedback mechanism against periodontal infection. PMID:26847035

  20. Quantifying the Nonlinear, Anisotropic Material Response of Spinal Ligaments

    NASA Astrophysics Data System (ADS)

    Robertson, Daniel J.

    Spinal ligaments may be a significant source of chronic back pain, yet they are often disregarded by the clinical community due to a lack of information with regards to their material response, and innervation characteristics. The purpose of this dissertation was to characterize the material response of spinal ligaments and to review their innervation characteristics. Review of relevant literature revealed that all of the major spinal ligaments are innervated. They cause painful sensations when irritated and provide reflexive control of the deep spinal musculature. As such, including the neurologic implications of iatrogenic ligament damage in the evaluation of surgical procedures aimed at relieving back pain will likely result in more effective long-term solutions. The material response of spinal ligaments has not previously been fully quantified due to limitations associated with standard soft tissue testing techniques. The present work presents and validates a novel testing methodology capable of overcoming these limitations. In particular, the anisotropic, inhomogeneous material constitutive properties of the human supraspinous ligament are quantified and methods for determining the response of the other spinal ligaments are presented. In addition, a method for determining the anisotropic, inhomogeneous pre-strain distribution of the spinal ligaments is presented. The multi-axial pre-strain distributions of the human anterior longitudinal ligament, ligamentum flavum and supraspinous ligament were determined using this methodology. Results from this work clearly demonstrate that spinal ligaments are not uniaxial structures, and that finite element models which account for pre-strain and incorporate ligament's complex material properties may provide increased fidelity to the in vivo condition.

  1. Comparative in vitro SEM study of a novel root canal irrigant-MTAD and conventional root biomodifiers on periodontally involved human teeth

    PubMed Central

    Tandon, Charu; Govila, Vivek; Pant, Vandana Aditya; Meenawat, Ajita

    2015-01-01

    Background: Smear layer removal and collagen fiber exposure may improve regeneration which can be accomplished by use of root biomodifiers. These enhance the degree of connective tissue attachment to denuded roots. The objective of this in vitro study was to evaluate and compare novel root canal irrigant and other root biomodifiers for smear layer removal on periodontally involved human teeth. Materials and Methods: Forty human teeth were collected and stored in saline. After scaling and root planing, two samples were obtained from each tooth. Thus, a total of 80 dentin blocks were randomly divided into four groups: Mixture of tetracycline, acid and detergent (MTAD), tetracycline hydrochloride (TTC HCl), citric acid (CA), and ethylenediaminetetraacetic acid (EDTA). The agents were applied for 3 min by active burnishing. Immediately following treatment, the specimens were rinsed, dehydrated, fixed and prepared for scanning electron microscope and were examined at × 3500 magnification. Sampaio's index was evaluated by the previously trained blind examiner using photomicrographs. Groups were compared using analysis of variance followed by Tukey's post-hoc test. Results: Mixture of tetracycline, acid, and detergent is most efficacious in removing the smear layer and showed statistically significant dentinal tubules opening, followed by EDTA, TTC HCl, and CA. Conclusion: Mixture of tetracycline, acid and detergent and conventional root biomodifiers used in the study alters the dentin surface by smear layer removal and exposure of dentinal tubules. Hence, MTAD as a root biomodifier may have a significant role in periodontal regeneration. PMID:26229265

  2. Periodontal Plastic Surgery

    MedlinePlus

    ... Dental Implants Dentures Direct Bonding Implants versus Bridges Orthodontics and Aligners Periodontal Plastic Surgery Porcelain Crowns Porcelain ... Dental Implants Dentures Direct Bonding Implants versus Bridges Orthodontics and Aligners Periodontal Plastic Surgery Porcelain Crowns Porcelain ...

  3. Gum (Periodontal) Disease

    MedlinePlus

    ... forms of gum disease are gingivitis and periodontitis. Gingivitis and Periodontitis In gingivitis, the gums become red, swollen and can bleed easily. Gingivitis can usually be reversed with daily brushing and ...

  4. Epidemiology of periodontal disease: a review and clinical perspectives.

    PubMed

    Irfan, U M; Dawson, D V; Bissada, N F

    2001-01-01

    The purpose of this paper is to assimilate epidemiological evidence for the prevalence of periodontal disease in human populations, and for comprehensive understanding of the disease for health care providers. Periodontal disease is a pathological condition affecting the supporting structures of teeth. It is characterised by a bacterial challenge that can instigate a destructive host response leading to periodontal attachment loss, bone loss and ultimately, possible tooth loss. The specifics of the disease process are obscured by our incomplete understanding of the role of various risk factors. Periodontal epidemiology literature lacks consistency in methodology of research, which includes various definitions for periodontal disease and health; different approaches to measuring periodontal indices of pocket depth, and attachment loss; inconsistent study designs and lack of adjustments to known risk factors. These inconsistencies do not allow for effective comparison of epidemiological studies, which is essential to find strong associations of risk factors with periodontal disease, which in turn is necessary for the interpretation of risk and causality. This paper will address several areas within the topic of periodontal disease epidemiology, including definitions of periodontal disease instituted by researchers, approaches to epidemiological studies in periodontitis, and risk factors in periodontal disease. Consideration is given to aspects of design and analyses relevant to evaluation of reports in the literature. For the clinical practitioner this review provides a theoretical framework to approach patients with comprehensive knowledge of not only the disease presentation, but also the environmental factors that govern past history, present condition and future response to treatments and interventions. PMID:12666973

  5. Unusual periodontal findings in an AIDS patient with Burkitt's lymphoma. A case report.

    PubMed

    Hernández Vallejo, G; García, M D; López, A; Mendieta, C; Moskow, B S

    1989-12-01

    This report deals with a case of AIDS-related Burkitt's lymphoma in which some of the earliest findings were dental and periodontal in nature. The patient presented initially with painless and extremely loose teeth accompanied by progressive paresthesia of the lower jaw. Unique radiographic findings included extensive periodontal ligament space widening and bulbous, granuloma-like lesions about the apices of the teeth. These findings were associated with progressive tumor infiltration of the mandible and do not appear to be related to other reports of aggressive periodontitis associated with impaired immunologic functions in AIDS patients. PMID:2614637

  6. Relationship between Acute Phase of Chronic Periodontitis and Meteorological Factors in the Maintenance Phase of Periodontal Treatment: A Pilot Study

    PubMed Central

    Takeuchi, Noriko; Ekuni, Daisuke; Tomofuji, Takaaki; Morita, Manabu

    2015-01-01

    The acute phase of chronic periodontitis may occur even in patients during supportive periodontal therapy. However, the details are not fully understood. Since the natural environment, including meteorology affects human health, we hypothesized that weather conditions may affect occurrence of acute phase of chronic periodontitis. The aim of this study was to investigate the relationship between weather conditions and acute phase of chronic periodontitis in patients under supportive periodontal therapy. Patients who were diagnosed with acute phase of chronic periodontitis under supportive periodontal therapy during 2011–2013 were selected for this study. We performed oral examinations and collected questionnaires and meteorological data. Of 369 patients who experienced acute phase of chronic periodontitis, 153 had acute phase of chronic periodontitis without direct-triggered episodes. When using the autoregressive integrated moving average model of time-series analysis, the independent covariant of maximum hourly range of barometric pressure, maximum hourly range of temperature, and maximum daily wind speed were significantly associated with occurrence of acute phase of chronic periodontitis (p < 0.05), and 3.1% of the variations in these occurrence over the study period were explained by these factors. Meteorological variables may predict occurrence of acute phase of chronic periodontitis. PMID:26251916

  7. Relationship between Acute Phase of Chronic Periodontitis and Meteorological Factors in the Maintenance Phase of Periodontal Treatment: A Pilot Study.

    PubMed

    Takeuchi, Noriko; Ekuni, Daisuke; Tomofuji, Takaaki; Morita, Manabu

    2015-08-01

    The acute phase of chronic periodontitis may occur even in patients during supportive periodontal therapy. However, the details are not fully understood. Since the natural environment, including meteorology affects human health, we hypothesized that weather conditions may affect occurrence of acute phase of chronic periodontitis. The aim of this study was to investigate the relationship between weather conditions and acute phase of chronic periodontitis in patients under supportive periodontal therapy. Patients who were diagnosed with acute phase of chronic periodontitis under supportive periodontal therapy during 2011-2013 were selected for this study. We performed oral examinations and collected questionnaires and meteorological data. Of 369 patients who experienced acute phase of chronic periodontitis, 153 had acute phase of chronic periodontitis without direct-triggered episodes. When using the autoregressive integrated moving average model of time-series analysis, the independent covariant of maximum hourly range of barometric pressure, maximum hourly range of temperature, and maximum daily wind speed were significantly associated with occurrence of acute phase of chronic periodontitis (p < 0.05), and 3.1% of the variations in these occurrence over the study period were explained by these factors. Meteorological variables may predict occurrence of acute phase of chronic periodontitis. PMID:26251916

  8. Molecular Epidemiology of Oral Treponemes in Patients with Periodontitis and in Periodontitis-Resistant Subjects

    PubMed Central

    Moter, Annette; Riep, Birgit; Haban, Vesna; Heuner, Klaus; Siebert, Gerda; Berning, Moritz; Wyss, Chris; Ehmke, Benjamin; Flemmig, Thomas F.; Göbel, Ulf B.

    2006-01-01

    The etiologic role of oral treponemes in human periodontitis is still under debate. Although seen by dark-field microscopy in large numbers, their possible role is still unclear since they comprise some 60 different phylotypes, most of which are still uncultured. To determine their status as mere commensals or opportunistic pathogens, molecular epidemiological studies are required that include both cultured and as-yet-uncultured organisms. Here we present such data, comparing treponemal populations from chronic periodontitis (CP) or generalized aggressive periodontitis (GAP) patients. As a periodontitis-resistant (PR) control group, we included elderly volunteers with more than 20 natural teeth and no history of periodontal treatment and no or minimal clinical signs of periodontitis. Almost every treponemal phylotype was present in all three groups. For most treponemes, the proportion of subjects positive for a certain species or phylotype was higher in both periodontitis groups than in the PR group. This difference was pronounced for treponemes of the phylogenetic groups II and IV and for Treponema socranskii and Treponema lecithinolyticum. Between the periodontitis groups the only significant differences were seen for T. socranskii and T. lecithinolyticum, which were found more often in periodontal pockets of GAP patients than of CP patients. In contrast, no difference was found for Treponema denticola. Our findings, however, strengthen the hypothesis of treponemes being opportunistic pathogens. It appears that T. socranskii, T. lecithinolyticum and group II and IV treponemes may represent good indicators for periodontitis and suggest the value of the respective probes for microbiological diagnosis in periodontitis subjects. PMID:16954230

  9. Endoscopic Intermetatarsal Ligament Decompression.

    PubMed

    Lui, Tun Hing

    2015-12-01

    Morton neuroma is an entrapment of the intermetatarsal nerve by the deep intermetatarsal ligament. It is usually treated conservatively. Surgery is considered if there is recalcitrant pain that is resistant to conservative treatment. The surgical options include resection of the neuroma or decompression of the involved nerve. Decompression of the nerve by release of the intermetatarsal ligament can be performed by either an open or minimally invasive approach. We describe 2-portal endoscopic decompression of the intermetatarsal nerve. The ligament is released by a retrograde knife through the toe-web portal under arthroscopic guidance through the plantar portal. PMID:27284515

  10. The use of a synthetic skin substitute as a physical barrier to enhance healing in human periodontal furcation defects: a follow-up report.

    PubMed

    Flanary, D B; Twohey, S M; Gray, J L; Mellonig, J T; Gher, M E

    1991-11-01

    The purpose of this investigation is to compare the clinical response of guided tissue regeneration using a synthetic wound dressing with open flap debridement versus open flap debridement alone in the treatment of human furcation defects. The study group was composed of 19 patients with moderate to advanced adult periodontitis and at least one bilateral pair of Class II molar furcation defects. After the hygiene phase of therapy was completed, measurements were made with calibrated periodontal probes of the clinical attachment levels, probing depths, and soft tissue recession. Paired sites were randomly selected for treatment with either open flap debridement alone (control) or open flap debridement and placement of the synthetic wound dressing over the furcation (experimental). At the time of surgery, measurements of vertical and horizontal open probing attachment were recorded. The dressing was removed 5 to 6 weeks post-surgery. The sites were reentered at 6 months to evaluate healing and to repeat all measurements. Statistical comparisons using the Wilcoxon Sign Rank Test were made between the control and experimental sites. The results of 19 pairs of Class II molar furcation defects reveal statistically significant differences between the experimental and control sites in attachment levels, probing depths, and horizontal open probing attachment. These differences were of such small magnitude that they may not be clinically relevant. There were no other significant differences for any other clinical parameter, and none of the furcations in either group was completely closed.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1753321

  11. The use of platelet rich plasma with guided tissue regeneration in defects caused by periodontal diseases.

    PubMed

    Holly, D; Mracna, J

    2009-01-01

    The goal of periodontal treatment in not only the stabilization of disease but also the regeneration of the destructed tissue. In the past few years various procedures have been created to achieve this. The guided tissue regeneration is a surgical procedure developed on the basis of experimental studies. It enables the creation of periodontal tissues affected by periodontitis, the so called reattachment. It stands for formation of new attachment--meaning the regeneration of cementum, alveolar bone and periodontal ligament. This surgical procedure of the treatment of periodontitis is based on the principle of exclusion of the epithelium and also the gingival connective tissue from the root surface so the precursor cells (desmodontal cells) can occupy the defect and pursue their differentiation. Periodontal ligament containing cells with regenerative potential are the exclusive ones to have the ability to regenerate structures affected by periodontitis. The use of growth factors offer new aspects to the therapy (Fig. 7, Ref. 11). Full Text (Free, PDF) www.bmj.sk. PMID:20017463

  12. Periodontitis and diabetes interrelationships: role of inflammation.

    PubMed

    Iacopino, A M

    2001-12-01

    Diabetes mellitus is a systemic disease with several major complications affecting both the quality and length of life. One of these complications is periodontal disease (periodontitis). Periodontitis is much more than a localized oral infection. Recent data indicate that periodontitis may cause changes in systemic physiology. The interrelationships between periodontitis and diabetes provide an example of systemic disease predisposing to oral infection, and once that infection is established, the oral infection exacerbates systemic disease. In this case, it may also be possible for the oral infection to predispose to systemic disease. In order to understand the cellular/molecular mechanisms responsible for such a cyclical association, one must identify common physiological changes associated with diabetes and periodontitis that produce a synergy when the conditions coexist. A potential mechanistic link involves the broad axis of inflammation, specifically immune cell phenotype, serum lipid levels, and tissue homeostasis. Diabetes-induced changes in immune cell function produce an inflammatory immune cell phenotype (upregulation of proinflammatory cytokines from monocytes/polymorphonuclear leukocytes and downregulation of growth factors from macrophages). This predisposes to chronic inflammation, progressive tissue breakdown, and diminished tissue repair capacity. Periodontal tissues frequently manifest these changes because they are constantly wounded by substances emanating from bacterial biofilms. Diabetic patients are prone to elevated low density lipoprotein cholesterol and triglycerides (LDL/TRG) even when blood glucose levels are well controlled. This is significant, as recent studies demonstrate that hyperlipidemia may be one of the factors associated with diabetes-induced immune cell alterations. Recent human studies have established a relationship between high serum lipid levels and periodontitis. Some evidence now suggests that periodontitis itself may

  13. Cementogenesis and the induction of periodontal tissue regeneration by the osteogenic proteins of the transforming growth factor-beta superfamily.

    PubMed

    Ripamonti, U; Petit, J-C; Teare, J

    2009-04-01

    The antiquity and severity of periodontal diseases are demonstrated by the hard evidence of alveolar bone loss in gnathic remains of the Pliocene/Pleistocene deposits of the Bloubank Valley at Sterkfontein, Swartkrans and Kromdrai in South Africa. Extant Homo has characterized and cloned a superfamily of proteins which include the bone morphogenetic proteins that regulate tooth morphogenesis at different stages of development as temporally and spatially connected events. The induction of cementogenesis, periodontal ligament and alveolar bone regeneration are regulated by the co-ordinated expression of bone morphogenetic proteins. Naturally derived and recombinant human bone morphogenetic proteins induce periodontal tissue regeneration in mammals. Morphological analyses on undecalcified sections cut at 3-6 mum on a series of mandibular molar Class II and III furcation defects induced in the non-human primate Papio ursinus show the induction of cementogenesis. Sharpey's fibers nucleate as a series of composite collagen bundles within the cementoid matrix in close relation to embedded cementocytes. Osteogenic protein-1 and bone morphogenetic protein-2 possess a structure-activity profile, as shown by the morphology of tissue regeneration, preferentially cementogenic and osteogenic, respectively. In Papio ursinus, transforming growth factor-beta(3) also induces cementogenesis, with Sharpey's fibers inserting into newly formed alveolar bone. Capillary sprouting and invasion determine the sequential insertion and alignment of individual collagenic bundles. The addition of responding stem cells prepared by finely mincing fragments of autogenous rectus abdominis muscle significantly enhances the induction of periodontal tissue regeneration when combined with transforming growth factor-beta(3) implanted in Class II and III furcation defects of Papio ursinus. PMID:18842117

  14. High prevalence of anterolateral ligament abnormalities in magnetic resonance images of anterior cruciate ligament-injured knees.

    PubMed

    Claes, Steven; Bartholomeeusen, Stijn; Bellemans, Johan

    2014-03-01

    The purpose of this study was to identify the newly described anterolateral ligament of the human knee on magnetic resonance imaging and to describe its eventual radiological abnormalities in anterior cruciate ligament-injured subjects. A retrospective cohort study on a series of consecutive subjects undergoing anterior cruciate ligament reconstructive surgery was performed. The MR images of 206 included knees were studied and the status of the anterolateral ligament status was judged to be either "non-visualized", "normal" or "abnormal". Of all the visualized anterolateral ligaments, 44 (21.3%) were considered uninjured, while 162 (78.8%) knees demonstrated radiological ALL abnormalities. The majority of ALL abnormalities were situated in the distal part of the ligament (77.8%). In conclusion, the anterolateral ligament can be identified on classic knee magnetic resonance images. Although anterior cruciate ligament injured subjects often demonstrated associated anterolateral ligament lesions, further research is needed in order to establish the clinical relevance of these highly frequent radiological abnormalities. PMID:24873084

  15. Quorum Sensing Inhibition, Relevance to Periodontics

    PubMed Central

    Yada, Sudheer; Kamalesh, B; Sonwane, Siddharth; Guptha, Indra; Swetha, R K

    2015-01-01

    Quorum sensing helps bacteria to communicate with each other and in coordinating their behavior. Many diseases of human beings, plants, and animals are mediated by quorum sensing. Various approaches are being tried to inhibit this communication to control the diseases caused by bacteria. Periodontal pathogens also communicate through quorum sensing and new approaches to treat periodontal disease using quorum sensing inhibition need to explored. PMID:25709373

  16. Microflora and periodontal disease

    PubMed Central

    Scapoli, Luca; Girardi, Ambra; Palmieri, Annalisa; Testori, Tiziano; Zuffetti, Francesco; Monguzzi, Riccardo; Lauritano, Dorina; Carinci, Francesco

    2012-01-01

    Background: Periodontitis is a disease that affects and destroys the tissues that support teeth. Tissue damage results from a prolonged inflammatory response to an ecological shift in the composition of subgingival biofilms. Three bacterial species that constitute the red complex group, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola, are considered the main pathogens involved in periodontitis. Materials and Methods: In the present study, a real-time polymerase chain reaction bases assay was designed to detect and quantify red complex species, then used to investigate 307 periodontal pocket samples from 127 periodontitis patients and 180 controls. Results: Significant higher prevalence of red complex species and increased amount of P. gingivalis and T. denticola were detected in periodontal pocket of periodontitis patients. Conclusions: Results demonstrated that the test is a valuable tool to improve diagnosis of periodontal disease. PMID:23814584

  17. Gene expression in periodontal tissues following treatment

    PubMed Central

    Beikler, Thomas; Peters, Ulrike; Prior, Karola; Eisenacher, Martin; Flemmig, Thomas F

    2008-01-01

    Background In periodontitis, treatment aimed at controlling the periodontal biofilm infection results in a resolution of the clinical and histological signs of inflammation. Although the cell types found in periodontal tissues following treatment have been well described, information on gene expression is limited to few candidate genes. Therefore, the aim of the study was to determine the expression profiles of immune and inflammatory genes in periodontal tissues from sites with severe chronic periodontitis following periodontal therapy in order to identify genes involved in tissue homeostasis. Gingival biopsies from 12 patients with severe chronic periodontitis were taken six to eight weeks following non-surgical periodontal therapy, and from 11 healthy controls. As internal standard, RNA of an immortalized human keratinocyte line (HaCaT) was used. Total RNA was subjected to gene expression profiling using a commercially available microarray system focusing on inflammation-related genes. Post-hoc confirmation of selected genes was done by Realtime-PCR. Results Out of the 136 genes analyzed, the 5% most strongly expressed genes compared to healthy controls were Interleukin-12A (IL-12A), Versican (CSPG-2), Matrixmetalloproteinase-1 (MMP-1), Down syndrome critical region protein-1 (DSCR-1), Macrophage inflammatory protein-2β (Cxcl-3), Inhibitor of apoptosis protein-1 (BIRC-1), Cluster of differentiation antigen 38 (CD38), Regulator of G-protein signalling-1 (RGS-1), and Finkel-Biskis-Jinkins murine osteosarcoma virus oncogene (C-FOS); the 5% least strongly expressed genes were Receptor-interacting Serine/Threonine Kinase-2 (RIP-2), Complement component 3 (C3), Prostaglandin-endoperoxide synthase-2 (COX-2), Interleukin-8 (IL-8), Endothelin-1 (EDN-1), Plasminogen activator inhibitor type-2 (PAI-2), Matrix-metalloproteinase-14 (MMP-14), and Interferon regulating factor-7 (IRF-7). Conclusion Gene expression profiles found in periodontal tissues following therapy

  18. An update on periodontal aetiopathogenesis and clinical implications.

    PubMed

    Jin, Lijian

    2008-06-01

    Periodontal disease is the most commonly occurring yet unusual infection in humans. It is initiated by pathogenic plaque biofilm and characterized by bacteria-induced inflammatory destruction of tooth-supporting structures and alveolar bone. Periodontitis remains the most common cause of tooth loss in adults. Currently, periodontal diseases are also recognized as serious infections with profound effects on general health. In recent years, new concepts and discoveries have been made in further understanding of the nature of periodontal disease and its aetiopathogenesis. These can be well reflected in recognition of dental plaque as a biofilm; identification and characterization of periodontopathogens and their virulence factors; recognition of the importance of host-microbe symbiosis in periodontal health; identification of novel innate host defence molecules in periodontal tissues; further understanding of the molecular mechanisms involved in tissue destruction and alveolar bone resorption; appreciation of the crucial role of host susceptibility in periodontal pathogenesis; and identification of risk factors and incorporation of risk assessment in clinical practice. Committed oral health care professionals should therefore keep abreast of these changing concepts in periodontology and updated strategies for appropriate evidence-based practice. These views are fundamentally important for prevention, diagnosis and treatment of periodontal diseases and peri-implant infections, as well as for long-term maintenance of periodontal health and implant stability. This paper updates the advances in aetiopathogenesis of periodontal disease and highlights the relevant clinical implications and future perspectives. PMID:22073461

  19. Normalization of periodontal tissues in osteopetrotic mib mutant rats, treated with CSF-1

    NASA Technical Reports Server (NTRS)

    Wojtowicz, A.; Yamauchi, M.; Sotowski, R.; Ostrowski, K.

    1998-01-01

    The osteopetrotic mib mutation in rats causes defects in the skeletal bone tissue in young animals. These defects, i.e. slow bone remodelling, changes in both crystallinity and mineral content, are transient and undergo normalization, even without any treatment in 6-wk-old animals. Treatment with CSF-1 (colony stimulating factor-1) accelerates the normalization process in skeletal bones. The periodontal tissues around the apices of incisors show abnormalities caused by the slow remodelling process of the mandible bone tissue, the deficiency of osteoclasts and their abnormal morphology, as well as the disorganization of periodontal ligament fibres. In contrast to the skeletal tissues, these abnormalities would not undergo spontaneous normalization. Under treatment with colony stimulating factor 1 (CSF-1), the primitive bone trabeculae of mandible are resorbed and the normalization of the number of osteoclasts and their cytology occurs. The organization of the periodontal ligament fibres is partially restored, resembling the histological structure of the normal one.

  20. Relationship between invasion of the periodontium by periodontal pathogens and periodontal disease: a systematic review.

    PubMed

    Mendes, Luzia; Azevedo, Nuno Filipe; Felino, António; Pinto, Miguel Gonçalves

    2015-01-01

    Bacterial invasion of the periodontal tissues has been suggested as a relevant step in the etiopathogenesis of periodontal disease. However, its exact importance remains to be defined. The present systematic review assessed the scientific evidence concerning the relationship between the quality or quantity of periodontal microbiota in periodontal tissues and development of periodontal disease. The databases Medline-PubMed, Cochrane-CENTRAL, ISI Web of Knowledge and SCOPUS were searched, up to January 2014. Studies that reported evaluation of periodontal pathogens invasion on human tissues were selected. The screening of 440 title/abstracts elected 26 papers for full-text reading. Twenty three papers were subsequently excluded because of insufficient data or a study protocol not related to the objectives of this systematic review. All included studies were case-control studies that evaluated intracellular or adherent bacteria to epithelial cells from periodontal pockets versus healthy sulci. Study protocols presented heterogeneity regarding case and control definitions and methodological approaches for microbial identification. No consistent significant differences were found related to the presence/absence or proportion of specific periopathogens across the studies, as only one study found statistically significant differences regarding the presence of A. actinomycetemcomitans (p = 0.043), T. forsythia (P < 0.001), P. intermedia (P < 0.001), C. ochracea (P < 0.001) and C. rectus (P = 0.003) in epithelial cells from periodontal pockets vs. healthy sulci. All studies reported a larger unspecific bacterial load in or on the epithelial cells taken from a diseased site compared to a healthy sulcus. The current available data is of low to moderate quality and inconsistent mainly due to study design, poor reporting and methodological diversity. As so, there is insufficient evidence to support or exclude the invasion by periodontal pathogens as a key step in the

  1. Relationship between invasion of the periodontium by periodontal pathogens and periodontal disease: a systematic review

    PubMed Central

    Mendes, Luzia; Azevedo, Nuno Filipe; Felino, António; Pinto, Miguel Gonçalves

    2015-01-01

    Bacterial invasion of the periodontal tissues has been suggested as a relevant step in the etiopathogenesis of periodontal disease. However, its exact importance remains to be defined. The present systematic review assessed the scientific evidence concerning the relationship between the quality or quantity of periodontal microbiota in periodontal tissues and development of periodontal disease. The databases Medline-PubMed, Cochrane-CENTRAL, ISI Web of Knowledge and SCOPUS were searched, up to January 2014. Studies that reported evaluation of periodontal pathogens invasion on human tissues were selected. The screening of 440 title/abstracts elected 26 papers for full-text reading. Twenty three papers were subsequently excluded because of insufficient data or a study protocol not related to the objectives of this systematic review. All included studies were case-control studies that evaluated intracellular or adherent bacteria to epithelial cells from periodontal pockets versus healthy sulci. Study protocols presented heterogeneity regarding case and control definitions and methodological approaches for microbial identification. No consistent significant differences were found related to the presence/absence or proportion of specific periopathogens across the studies, as only one study found statistically significant differences regarding the presence of A. actinomycetemcomitans (p = 0.043), T. forsythia (P < 0.001), P. intermedia (P < 0.001), C. ochracea (P < 0.001) and C. rectus (P = 0.003) in epithelial cells from periodontal pockets vs. healthy sulci. All studies reported a larger unspecific bacterial load in or on the epithelial cells taken from a diseased site compared to a healthy sulcus. The current available data is of low to moderate quality and inconsistent mainly due to study design, poor reporting and methodological diversity. As so, there is insufficient evidence to support or exclude the invasion by periodontal pathogens as a key step in the

  2. Evaluation of anorganic bovine-derived hydroxyapatite matrix/cell binding peptide as a bone graft material in the treatment of human periodontal infrabony defects: A clinico-radiographic study

    PubMed Central

    Fatima, Ghousia; Shivamurthy, Ravindra; Thakur, Srinath; Baseer, Mohammad Abdul

    2015-01-01

    Background: Various bone graft materials have been used in the treatment of periodontal defects. A synthetic bone substitute material composed of P-15 with anorganic bone mineral has been scantly studied. Hence, the present study was aimed to evaluate and compare the efficacy of anorganic bovine-derived hydroxyapatite matrix (ABM)/cell binding peptide (P-15) in human periodontal infrabony defects with that of open flap debridement (OFD) alone. Materials and Methods: A split-mouth, randomized controlled clinical study was designed to investigate the efficacy of ABM/P-15. In this clinical trial, 10 patients having bilateral periodontal infrabony defects were treated either with ABM/P-15 or OFD and followed for a period of 9 months. At baseline and at 9 months probing pocket depth (PPD), relative attachment level (RAL), depth of a defect, and radiographic bone level were measured; and compared between test and control sites. Results: A statistically significant reduction (P < 0.001) in PPD was observed in test sites compared to control sites. Both sites showed a gain in RAL without any significant difference. Similarly, the radiographic evaluation revealed significantly higher radiographic defect fill in test sites as compared to control sites (P < 0.001). Conclusion: ABM/P-15 bone graft material appears to be useful and beneficial in the treatment of human periodontal infrabony defects. PMID:26941516

  3. Antimicrobials in periodontal maintenance.

    PubMed

    Jorgensen, M G; Slots, J

    2001-01-01

    Mechanical and chemical antimicrobial intervention is the mainstay of preventive periodontal therapy. Successful periodontal maintenance care depends upon the ability of oral health care professionals to combat periodontal infections, and patient compliance with prescribed follow-up care. Since tooth brushing, flossing, and oral rinsing do not reach pathogens present in furcations and at the depths of deep periodontal pockets, adequate oral hygiene should include subgingival treatment with home irrigators or other appropriate self-care remedies in patients with these conditions. Povidone-iodine for professional use and diluted bleach for self-care are inexpensive and valuable antimicrobial agents in periodontal maintenance. The present article outlines the prudent use of antimicrobial therapy in periodontal maintenance. PMID:11603305

  4. Ozone therapy in periodontics

    PubMed Central

    Gupta, G; Mansi, B

    2012-01-01

    Gingival and Periodontal diseases represent a major concern both in dentistry and medicine. The majority of the contributing factors and causes in the etiology of these diseases are reduced or treated with ozone in all its application forms (gas, water, oil). The beneficial biological effects of ozone, its anti-microbial activity, oxidation of bio-molecules precursors and microbial toxins implicated in periodontal diseases and its healing and tissue regeneration properties, make the use of ozone well indicated in all stages of gingival and periodontal diseases. The primary objective of this article is to provide a general review about the clinical applications of ozone in periodontics. The secondary objective is to summarize the available in vitro and in vivo studies in Periodontics in which ozone has been used. This objective would be of importance to future researchers in terms of what has been tried and what the potentials are for the clinical application of ozone in Periodontics. PMID:22574088

  5. Medial Collateral Ligament (MCL) Injuries

    MedlinePlus

    ... often occur among active teens, especially athletes. A torn medial collateral ligament (MCL) — a ligament that helps ... the more serious injuries. Teens who have a torn MCL tend to play contact sports, like football ...

  6. Novel application of stem cell-derived factors for periodontal regeneration

    SciTech Connect

    Inukai, Takeharu; Katagiri, Wataru; Yoshimi, Ryoko; Osugi, Masashi; Kawai, Takamasa; Hibi, Hideharu; Ueda, Minoru

    2013-01-11

    Highlights: Black-Right-Pointing-Pointer Mesenchymal stem cells (MSCs) secrete a variety of cytokines. Black-Right-Pointing-Pointer Cytokines were detected in conditioned medium from cultured MSCs (MSC-CM). Black-Right-Pointing-Pointer MSC-CM enhanced activation of dog MSCs and periodontal ligament cells. Black-Right-Pointing-Pointer MSC-CM significantly promoted alveolar bone and cementum regeneration. Black-Right-Pointing-Pointer Multiple cytokines contained in MSC-CM promote periodontal regeneration. -- Abstract: The effect of conditioned medium from cultured mesenchymal stem cells (MSC-CM) on periodontal regeneration was evaluated. In vitro, MSC-CM stimulated migration and proliferation of dog MSCs (dMSCs) and dog periodontal ligament cells (dPDLCs). Cytokines such as insulin-like growth factor, vascular endothelial growth factor, transforming growth factor-{beta}1, and hepatocyte growth factor were detected in MSC-CM. In vivo, one-wall critical-size, intrabony periodontal defects were surgically created in the mandible of dogs. Dogs with these defects were divided into three groups that received MSC-CM, PBS, or no implants. Absorbable atelo-collagen sponges (TERUPLUG Registered-Sign ) were used as a scaffold material. Based on radiographic and histological observation 4 weeks after transplantation, the defect sites in the MSC-CM group displayed significantly greater alveolar bone and cementum regeneration than the other groups. These findings suggest that MSC-CM enhanced periodontal regeneration due to multiple cytokines contained in MSC-CM.

  7. Cellular origins and differentiation control mechanisms during periodontal development and wound healing.

    PubMed

    Pitaru, S; McCulloch, C A; Narayanan, S A

    1994-03-01

    In the context of cellular origins, odontogenic epithelium and oral epithelium are the sources for junctional epithelium during development and during wound healing respectively. In contrast, both odontogenic and non-odontogenic mesenchyme contain the progenitors for gingival fibroblasts in developing tissues while in wounded tissues, gingival fibroblasts are derived from gingival connective tissues and comprise a heterogeneous population of cells with diverse properties and functions. Periodontal ligament, bone and cementum cell populations apparently originate from dental follicle progenitor cells during development, but during wound healing derive from ancestral cells in periodontal ligament and bone. Cellular differentiation in developing periodontium is governed in part by epithelial-mesenchymal interactions that generate specific signals which regulate selective cell populations in time and space. On the other hand, differentiation during wound healing and regeneration is regulated by a vast array of extracellular matrix informational molecules and by cytokines that induce both selective and non-selective responses in the different cell lineages and their precursors. Further, several important signalling systems are irretrievably lost after development is complete. Thus, in the context of cellular origins and differentiation, developing and wounded periodontal tissues exhibit fundamental differences. Future prospects for improved healing and regeneration of periodontal tissues may derive from identification and isolation of informational molecules that are stored in connective tissue matrices. These molecules and elucidation of their functions may open new perspectives in our understanding of the biology of periodontal wound healing and may provide novel approaches to periodontal regeneration. PMID:8158503

  8. Gingipains from the Periodontal Pathogen Porphyromonas gingivalis Play a Significant Role in Regulation of Angiopoietin 1 and Angiopoietin 2 in Human Aortic Smooth Muscle Cells

    PubMed Central

    Khalaf, Hazem; Sirsjö, Allan; Bengtsson, Torbjörn

    2015-01-01

    Angiopoietin 1 (Angpt1) and angiopoietin 2 (Angpt2) are the ligands of tyrosine kinase (Tie) receptors, and they play important roles in vessel formation and the development of inflammatory diseases, such as atherosclerosis. Porphyromonas gingivalis is a Gram-negative periodontal bacterium that is thought to contribute to the progression of cardiovascular disease. The aim of this study was to investigate the role of P. gingivalis infection in the modulation of Angpt1 and Angpt2 in human aortic smooth muscle cells (AoSMCs). We exposed AoSMCs to wild-type (W50 and 381), gingipain mutant (E8 and K1A), and fimbrial mutant (DPG-3 and KRX-178) P. gingivalis strains and to different concentrations of tumor necrosis factor (TNF). The atherosclerosis risk factor TNF was used as a positive control in this study. We found that P. gingivalis (wild type, K1A, DPG3, and KRX178) and TNF upregulated the expression of Angpt2 and its transcription factor ETS1, respectively, in AoSMCs. In contrast, Angpt1 was inhibited by P. gingivalis and TNF. However, the RgpAB mutant E8 had no effect on the expression of Angpt1, Angpt2, or ETS1 in AoSMCs. The results also showed that ETS1 is critical for P. gingivalis induction of Angpt2. Exposure to Angpt2 protein enhanced the migration of AoSMCs but had no effect on proliferation. This study demonstrates that gingipains are crucial to the ability of P. gingivalis to markedly increase the expressed Angpt2/Angpt1 ratio in AoSMCs, which determines the regulatory role of angiopoietins in angiogenesis and their involvement in the development of atherosclerosis. These findings further support the association between periodontitis and cardiovascular disease. PMID:26283334

  9. Gingipains from the Periodontal Pathogen Porphyromonas gingivalis Play a Significant Role in Regulation of Angiopoietin 1 and Angiopoietin 2 in Human Aortic Smooth Muscle Cells.

    PubMed

    Zhang, Boxi; Khalaf, Hazem; Sirsjö, Allan; Bengtsson, Torbjörn

    2015-11-01

    Angiopoietin 1 (Angpt1) and angiopoietin 2 (Angpt2) are the ligands of tyrosine kinase (Tie) receptors, and they play important roles in vessel formation and the development of inflammatory diseases, such as atherosclerosis. Porphyromonas gingivalis is a Gram-negative periodontal bacterium that is thought to contribute to the progression of cardiovascular disease. The aim of this study was to investigate the role of P. gingivalis infection in the modulation of Angpt1 and Angpt2 in human aortic smooth muscle cells (AoSMCs). We exposed AoSMCs to wild-type (W50 and 381), gingipain mutant (E8 and K1A), and fimbrial mutant (DPG-3 and KRX-178) P. gingivalis strains and to different concentrations of tumor necrosis factor (TNF). The atherosclerosis risk factor TNF was used as a positive control in this study. We found that P. gingivalis (wild type, K1A, DPG3, and KRX178) and TNF upregulated the expression of Angpt2 and its transcription factor ETS1, respectively, in AoSMCs. In contrast, Angpt1 was inhibited by P. gingivalis and TNF. However, the RgpAB mutant E8 had no effect on the expression of Angpt1, Angpt2, or ETS1 in AoSMCs. The results also showed that ETS1 is critical for P. gingivalis induction of Angpt2. Exposure to Angpt2 protein enhanced the migration of AoSMCs but had no effect on proliferation. This study demonstrates that gingipains are crucial to the ability of P. gingivalis to markedly increase the expressed Angpt2/Angpt1 ratio in AoSMCs, which determines the regulatory role of angiopoietins in angiogenesis and their involvement in the development of atherosclerosis. These findings further support the association between periodontitis and cardiovascular disease. PMID:26283334

  10. Regulator of Calcineurin 1 in Periodontal Disease

    PubMed Central

    Peters, Ulrike; Solominidou, Eleni; Korkmaz, Yüksel; Rüttermann, Stefan; Klocke, Astrid; Flemmig, Thomas Frank; Beikler, Thomas

    2016-01-01

    Nuclear factor of activated T-cells (NFAT) and NF-kB pathway associated processes are involved in the pathogenesis of various inflammatory disorders, for example, periodontal disease. The activation of these pathways is controlled by the regulator of calcineurin 1 (RCAN1). The aim of this study was to elucidate the role of RCAN1 in periodontal disease. Healthy and inflamed periodontal tissues were analyzed by immunohistochemistry and immunofluorescence using specific rabbit polyclonal anti-RCAN1 antibodies. For expression analysis human umbilical vein endothelial cells (HUVEC) were used. HUVEC were incubated for 2 h with Vascular Endothelial Growth Factor (VEGF) or with wild type and laboratory strains of Porphyromonas gingivalis (P. gingivalis). Expression analysis of rcan1 and cox2 was done by real time PCR using specific primers for rcan1.4 and cox2. The expression of rcan1 was found to be significantly suppressed in endothelial cells of chronically inflamed periodontal tissues compared to healthy controls. Rcan1 and cox2 were significantly induced by VEGF and wild type and laboratory P. gingivalis strains. Interestingly, the magnitude of the rcan1 and cox2 induction was strain dependent. The results of this study indicate that RCAN1 is suppressed in endothelial cells of chronically inflamed periodontal tissues. During an acute infection, however, rcan1 seems to be upregulated in endothelial cells, indicating a modulating role in immune homeostasis of periodontal tissues. PMID:27403036

  11. Microbiology of aggressive periodontitis.

    PubMed

    Könönen, Eija; Müller, Hans-Peter

    2014-06-01

    For decades, Aggregatibacter actinomycetemcomitans has been considered the most likely etiologic agent in aggressive periodontitis. Implementation of DNA-based microbiologic methodologies has considerably improved our understanding of the composition of subgingival biofilms, and advanced open-ended molecular techniques even allow for genome mapping of the whole bacterial spectrum in a sample and characterization of both the cultivable and not-yet-cultivable microbiota associated with periodontal health and disease. Currently, A. actinomycetemcomitans is regarded as a minor component of the resident oral microbiota and as an opportunistic pathogen in some individuals. Its specific JP2 clone, however, shows properties of a true exogenous pathogen and has an important role in the development of aggressive periodontitis in certain populations. Still, limited data exist on the impact of other microbes specifically in aggressive periodontitis. Despite a wide heterogeneity of bacteria, especially in subgingival samples collected from patients, bacteria of the red complex in particular, and those of the orange complex, are considered as potential pathogens in generalized aggressive periodontitis. These types of bacterial findings closely resemble those found for chronic periodontitis, representing a mixed polymicrobial infection without a clear association with any specific microorganism. In aggressive periodontitis, the role of novel and not-yet-cultivable bacteria has not yet been elucidated. There are geographic and ethnic differences in the carriage of periodontitis-associated microorganisms, and they need to be taken into account when comparing study reports on periodontal microbiology in different study populations. In the present review, we provide an overview on the colonization of potential periodontal pathogens in childhood and adolescence, and on specific microorganisms that have been suspected for their role in the initiation and progression of aggressive

  12. Expression of Caveolin-1 in Periodontal Tissue and Its Role in Osteoblastic and Cementoblastic Differentiation In Vitro.

    PubMed

    Lee, So-Youn; Yi, Jin-Kyu; Yun, Hyung-Mun; Bae, Cheol-Hyeon; Cho, Eui-Sic; Lee, Kook-Sun; Kim, Eun-Cheol

    2016-05-01

    It has been previously reported that caveolin-1 (Cav-1) knockout mice exhibit increased bone size and stiffness. However, the expression and role of Cav-1 on periodontal tissue is poorly understood. The aim of this study was to investigate the immunohistochemical expression of Cav-1 in the mouse periodontium and explore the role of Cav-1 on osteoblastic and cementoblastic differentiation in human periodontal ligament cells (hPDLCs), cementoblasts, and osteoblasts. To reveal the molecular mechanisms of Cav-1 activity, associated signaling pathways were also examined. Immunolocalization of Cav-1 was studied in mice periodontal tissue. Differentiation was evaluated by ALP activity, alizarin red S staining, and RT-PCR for marker genes. Signal transduction was analyzed using Western blotting and confocal microscopy. Cav-1 expression was observed in hPDLCs, cementoblasts, and osteoblasts of the periodontium both in vivo and in vitro. Inhibition of Cav-1 expression by methyl-β-cyclodextrin (MβCD) and knockdown of Cav-1 by siRNA promoted osteoblastic and cementoblastic differentiation by increasing ALP activity, calcium nodule formation, and mRNA expression of differentiation markers in hPDLCs, cementoblasts, and osteoblasts. Osteogenic medium-induced BMP-2 and BMP-7 expression, and phosphorylation of Smad1/5/8 were enhanced by MβCD and siRNA knockdown of Cav-1, which was reversed by BMP inhibitor noggin. MβCD and Cav-1 siRNA knockdown increased OM-induced AMPK, Akt, GSK3β, and CREB phosphorylation, which were reversed by Ara-A, a specific AMPK inhibitor. Moreover, OM-induced activation of p38, ERK, JNK, and NF-κB was enhanced by Cav-1 inhibition. This study demonstrates, for the first time, that Cav-1 is expressed in developing periodontal tissue and in vitro in periodontal-related cells. Cav-1 inhibition positively regulates osteoblastic differentiation in hPDLCs, cementoblasts, and osteoblasts via BMP, AMPK, MAPK, and NF-κB pathway. Thus, Cav-1 inhibition may be

  13. MR imaging of cruciate ligaments.

    PubMed

    Naraghi, Ali; White, Lawrence M

    2014-11-01

    Cruciate ligament injuries, and in particular injuries of the anterior cruciate ligament (ACL), are the most commonly reconstructed ligamentous injuries of the knee. As such, accurate preoperative diagnosis is essential in optimal management of patients with cruciate ligament injuries. This article reviews the anatomy and biomechanics of the ACL and posterior cruciate ligament (PCL) and describes the magnetic resonance (MR) imaging appearances of complete and partial tears. Normal postoperative appearances of ACL and PCL reconstructions as well as MR imaging features of postoperative complications will also be reviewed. PMID:25442023

  14. MR Imaging of Wrist Ligaments.

    PubMed

    Ringler, Michael D; Murthy, Naveen S

    2015-08-01

    This article discusses the normal anatomy and pathologic appearances of the intrinsic and extrinsic wrist ligaments using MR Imaging. Technological advances in surface coil design and higher magnetic field strengths have improved radiologists' ability to consistently visualize these small ligaments in their entirety. Wrist ligament anatomy, in the context of proper physiologic function, is emphasized, including common normal variants, and their appearances on MR imaging. The spectrum of disorders, incorporating overlapping appearances of senescent degenerative changes, and destabilizing ligament tears, is outlined. The diagnostic performance of MR imaging to date for various ligament abnormalities is discussed, along with significant limitations. PMID:26216769

  15. Defining periodontal health

    PubMed Central

    2015-01-01

    Assessment of the periodontium has relied exclusively on a variety of physical measurements (e.g., attachment level, probing depth, bone loss, mobility, recession, degree of inflammation, etc.) in relation to various case definitions of periodontal disease. Periodontal health was often an afterthought and was simply defined as the absence of the signs and symptoms of a periodontal disease. Accordingly, these strict and sometimes disparate definitions of periodontal disease have resulted in an idealistic requirement of a pristine periodontium for periodontal health, which makes us all diseased in one way or another. Furthermore, the consequence of not having a realistic definition of health has resulted in potentially questionable recommendations. The aim of this manuscript was to assess the biological, environmental, sociological, economic, educational and psychological relationships that are germane to constructing a paradigm that defines periodontal health using a modified wellness model. The paradigm includes four cardinal characteristics, i.e., 1) a functional dentition, 2) the painless function of a dentition, 3) the stability of the periodontal attachment apparatus, and 4) the psychological and social well-being of the individual. Finally, strategies and policies that advocate periodontal health were appraised. I'm not sick but I'm not well, and it's a sin to live so well. Flagpole Sitta, Harvey Danger PMID:26390888

  16. An Ultrasonographic Periodontal Probe

    NASA Astrophysics Data System (ADS)

    Bertoncini, C. A.; Hinders, M. K.

    2010-02-01

    Periodontal disease, commonly known as gum disease, affects millions of people. The current method of detecting periodontal pocket depth is painful, invasive, and inaccurate. As an alternative to manual probing, an ultrasonographic periodontal probe is being developed to use ultrasound echo waveforms to measure periodontal pocket depth, which is the main measure of periodontal disease. Wavelet transforms and pattern classification techniques are implemented in artificial intelligence routines that can automatically detect pocket depth. The main pattern classification technique used here, called a binary classification algorithm, compares test objects with only two possible pocket depth measurements at a time and relies on dimensionality reduction for the final determination. This method correctly identifies up to 90% of the ultrasonographic probe measurements within the manual probe's tolerance.

  17. Nicotine and periodontal tissues

    PubMed Central

    Malhotra, Ranjan; Kapoor, Anoop; Grover, Vishakha; Kaushal, Sumit

    2010-01-01

    Tobacco use has been recognized to be a significant risk factor for the development and progression of periodontal disease. Its use is associated with increased pocket depths, loss of periodontal attachment, alveolar bone and a higher rate of tooth loss. Nicotine, a major component and most pharmacologically active agent in tobacco is likely to be a significant contributing factor for the exacerbation of periodontal diseases. Available literature suggests that nicotine affects gingival blood flow, cytokine production, neutrophil and other immune cell function; connective tissue turnover, which can be the possible mechanisms responsible for overall effects of tobacco on periodontal tissues. Inclusion of tobacco cessation as a part of periodontal therapy encourages dental professionals to become more active in tobacco cessation counseling. This will have far reaching positive effects on our patients’ oral and general health. PMID:20922084

  18. A clinical and radiological evaluation of the relative efficacy of demineralized freeze-dried bone allograft versus anorganic bovine bone xenograft in the treatment of human infrabony periodontal defects: A 6 months follow-up study

    PubMed Central

    Blaggana, Vikram; Gill, Amarjit Singh; Blaggana, Anshu

    2014-01-01

    Background: The ultimate goal of periodontal therapy entails regeneration of the periodontal tissues lost as a consequence of periodontitis. Predictable correction of vertical osseous defects has however posed as a constant therapeutic challenge. The aim of our present study is to evaluate the relative efficacy of demineralized freeze-dried bone allograft (DFDBA) vs anorganic bovine bone xenograft (ABBX) in the treatment of human infrabony periodontal defects. Materials and Methods: 15 patients with 30 bilaterally symmetrical defect sites in either of the arches, in the age group of 25-50 years were selected as part of split-mouth study design. Defect-A (right side) was grafted with DFDBA while Defect-B (left side) was grafted with ABBX. Various clinical and radiographic parameters viz. probing depth(PD), clinical attachment level(CAL) and linear bone fill were recorded preoperatively, 12- & 24-weeks postoperatively. Results: Both defect-A & defect-B sites exhibited a highly significant reduction in probing depth, and gain in clinical attachment level and linear bone fill at 12-weeks & at the end of 24-weeks. Comparative evaluation between the study groups revealed a statistically non-significant reduction in probing depth (P<0.1) and mean gain in linear bone fill (P<0.1). However, there was a statistically significant gain in clinical attachment level (P<0.05) in Defect-A (CD=0.356) as compared to Defect-B (CD=0.346). Conclusions: Within the limits of this study, both the materials viz. ABBX and DFDBA are beneficial for the treatment of periodontal infrabony defects. Both the materials were found to be equally effective in all respects except the gain in attachment level, which was found to be more with DFDBA. Long-term studies are suggested to evaluate further the relative efficacy of the two grafts. PMID:25425822

  19. Coracoacromial ligament division.

    PubMed

    Johansson, J E; Barrington, T W

    1984-01-01

    The object of this paper is to report on the findings of a retrospective study of 40 patients with 41 shoulders with persistent painful arc syndrome secondary to a chronic coracoacromial ligament inflammation who underwent simple coracoacromial ligament division at the Toronto East General and Orthopaedic Hospital between January 1973 and June 1979. Initial therapy was always nonoperative. Surgical intervention was reserved for patients who did not respond to conservative management and who had a painful arc with tenderness of the coracoacromial ligament. The aim of the coracoacromial ligament division was to relieve impingement by releasing the coracoacromial arch. Patients were carefully examined to rule out associated neck pathology, rotator cuff problems, and lesions of the acromioclavicular joint. Any patients with significantly large osteophytes under the anterior acromion were excluded. Forty patients (41 shoulders) were questioned and examined in followup. There were 29 males and 11 females. The ages ranged from 21 to 72 years (average 43.5 years). In 21 shoulders (51%), there was a history of trauma as the initiating factor. The follow-up ranged from 8 to 76 months (average 36.3 months). According to a described rating system, the results were satisfactory to excellent in 39 of 41 shoulders (95%) and unsatisfactory in two of 41 shoulders (5%). The back to work time ranged from 1 to 16 weeks (average 5.7 weeks).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:6742288

  20. Anti-microbial Activity of Tulsi {Ocimum Sanctum (Linn.)} Extract on a Periodontal Pathogen in Human Dental Plaque: An Invitro Study

    PubMed Central

    Devaraj, C.G.; Agarwal, Payal

    2016-01-01

    Introduction Tulsi is a popular healing herb in Ayurvedic medicine. It is widely used in the treatment of several systemic diseases because of its anti-microbial property. However, studies documenting the effect of Tulsi on oral disease causing organisms are rare. Hence, an attempt was made to determine the effect of Tulsi on a periodontal microorganism in human dental plaque. Aim To determine if Ocimum sanctum (Linn.) has an anti-microbial activity (Minimum Inhibitory Concentration and zone of inhibition) against Actinobacillus actinomycetemcomitans in human dental plaque and to compare the antimicrobial activity of Ocimum sanctum(Linn.) extract with 0.2% chlorhexidine as the positive control and dimethyl sulfoxide as the negative control. Materials and Methods A lab based invitro experimental study design was adopted. Ethanolic extract of Ocimum sanctum (Linn.) was prepared by the cold extraction method. The extract was diluted with an inert solvent, dimethyl sulfoxide, to obtain ten different concentrations (1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%) of extract. Plaque sample was collected from 05 subjects diagnosed with periodontal disease. Isolation of Actinobacillus actinomycetemcomitans from plaque samples was done using Tryptic Soy Serum Bacitracin Vancomycin agar (TSBV) medium. Identification of Actinobacillus actinomycetemcomitans was done based on cultural, microscopic, biochemical characterization and multiple drug resistance patterns. Anti-microbial activity of Ocimum sanctum (Linn.) extract was tested by agar well-diffusion method against 0.2% chlorhexidine as a positive control and dimethyl sulfoxide as a negative control. The zone of inhibition was measured in millimeters using Vernier callipers. Results At the 6% w/v concentration of Ocimum sanctum (Linn.) extract, a zone of inhibition of 22 mm was obtained. This was the widest zone of inhibition observed among all the 10 different concentrations tested. The zone of inhibition for positive control

  1. Unbiased Stereological Estimation of the Spiral Ligament and Stria Vascularis Volumes in Aging and Ménière’s Disease Using Archival Human Temporal Bones

    PubMed Central

    Ishiyama, Gail; Tokita, Joshua; Lopez, Ivan; Tang, Yong

    2006-01-01

    The present study applies the unbiased stereological technique—Cavalieri principle to measure the volumes of the stria vascularis (SV) and the spiral ligament (SL) using postmortem archival human temporal bones from normal young and older subjects and subjects with Ménière’s disease. Normative data was obtained from subjects without ages ranging from 15 to 84 years old who had no history of audiovestibular disease (N = 25). For comparison purposes, the normative specimens were divided into three groups: group 1 (n = 8) had ages ranging from 15 to 38 years old, average age = 23.9; group 2 (n = 8) had ages ranging from 51 to 59 years old, average age = 55.1; group 3 (n = 9) had ages ranging from 64 to 84 years old, average age = 74.3. The average SV volume of group 3 (0.479 mm3) was significantly lower than that of group 1 (0.705 mm3) (p < 0.0005) and was significantly lower than that of group 2 (0.603 mm3) (p = 0.01). The average SL volume of group 3 (8.42 mm3) was significantly lower than that of group 1 (9.54 mm3) (p<0.05), but was not significantly lower than that of group 2 (8.58 mm3). Five subjects with Ménière’s disease, confirmed by histopathological examination (ages ranging from 63 to 91 years old, average age = 73.4), were studied. The average SV volume in Ménière’s subjects (0.378 mm3) was significantly lower than age-matched controls (p<0.05). The average SL volume in Ménière’s subjects (7.01 mm3) was also significantly lower than age-matched controls (p<0.05). The SV and SL volumes were unaffected by gender. The present study demonstrates for the first time the use of the unbiased stereological technique—Cavalieri principle—as a reliable and efficient method to obtain volumetric estimates of the SV and the SL by using archival human temporal bone specimens. PMID:17160359

  2. Bioengineered anterior cruciate ligament

    NASA Technical Reports Server (NTRS)

    Altman, Gregory (Inventor); Kaplan, David (Inventor); Vunjak-Novakovic, Gordana (Inventor); Martin, Ivan (Inventor)

    2001-01-01

    The present invention provides a method for producing an anterior cruciate ligament ex vivo. The method comprises seeding pluripotent stem cells in a three dimensional matrix, anchoring the seeded matrix by attachment to two anchors, and culturing the cells within the matrix under conditions appropriate for cell growth and regeneration, while subjecting the matrix to one or more mechanical forces via movement of one or both of the attached anchors. Bone marrow stromal cells are preferably used as the pluripotent cells in the method. Suitable matrix materials are materials to which cells can adhere, such as a gel made from collagen type I. Suitable anchor materials are materials to which the matrix can attach, such as Goinopra coral and also demineralized bone. Optimally, the mechanical forces to which the matrix is subjected mimic mechanical stimuli experienced by an anterior cruciate ligament in vivo. This is accomplished by delivering the appropriate combination of tension, compression, torsion, and shear, to the matrix. The bioengineered ligament which is produced by this method is characterized by a cellular orientation and/or matrix crimp pattern in the direction of the applied mechanical forces, and also by the production of collagen type I, collagen type III, and fibronectin proteins along the axis of mechanical load produced by the mechanical forces. Optimally, the ligament produced has fiber bundles which are arranged into a helical organization. The method for producing an anterior cruciate ligament can be adapted to produce a wide range of tissue types ex vivo by adapting the anchor size and attachment sites to reflect the size of the specific type of tissue to be produced, and also adapting the specific combination of forces applied, to mimic the mechanical stimuli experienced in vivo by the specific type of tissue to be produced. The methods of the present invention can be further modified to incorporate other stimuli experienced in vivo by the

  3. Nonsurgical periodontal treatment.

    PubMed

    Aimetti, Mario

    2014-01-01

    The primary goal of nonsurgical periodontal therapy is to control microbial periodontal infection by removing bacterial biofilm, calculus, and toxins from periodontally involved root surfaces. A review of the scientific literature indicates that mechanical nonsurgical periodontal treatment predictably reduces the levels of inflammation and probing pocket depths, increases the clinical attachment level and results in an apical shift of the gingival margin. Another parameter to be considered, in spite of the lack of scientific evidence, is the reduction in the degree of tooth mobility, as clinically experienced. It is important to point out that nonsurgical periodontal treatment presents limitations such as the long-term maintainability of deep periodontal pockets, the risk of disease recurrence, and the skill of the operator. A high number of posttreatment residual pockets exhibiting bleeding on probing and > 5 mm deep are related to lower clinical stability. The successful treatment of plaque-induced periodontitis will restore periodontal health, but with reduced periodontium. In such cases, anatomical damage from previous periodontal disease will persist and inverse architecture of soft tissue may impair home plaque removal. The clinician can select one of the following therapeutic options according to the individual patient's needs: - Quadrant/sextant wise instrumentation (conventional staged debridement, CSD). - Instrumentation of all pockets within a 24-hour period with (full mouth disinfection [FMD]) or without (full mouth scaling and root planing [FMSRP]) local antiseptics. Both procedures can be associated with systemic antimicrobials. -CSD or FMD in combination with laser or photodynamic therapy. Patients with aggressive periodontitis constitute a challenge to the clinician. To date there are no established protocols for controlling the disease. However, data from the literature on the application of the FMD protocol combined with amoxicillin

  4. Detection of periodontal markers in chronic periodontitis.

    PubMed

    Leonhardt, Asa; Carlén, Anette; Bengtsson, Lisbeth; Dahlén, Gunnar

    2011-01-01

    The aim was to compare the detection frequency of periodontopathogens by using the Pado Test 4.5 and checkerboard DNA-DNA hybridization technique in chronic periodontitis patients.Thirty patients with chronic periodontitis were tested cross-sectionally with DNA/RNA oligogenomic probe method (IAI Pado Test 4.5) and DNA/DNA whole genomic probe (checkerboard) method. Samples were taken by two paper points at the deepest site in each of the four quadrants and pooled into one sample for each of the two methods. The samples were sent to the two laboratories (IAI, Zuchwil, Switzerland, and Oral Microbiology Laboratory, University of Gothenburg, Sweden) and were analyzed in a routine setting for the presence and amount of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola.While Pado Test 4.5 detected the four periodontal pathogens in 11 (36.7%) of the patients, the checkerboard method showed presence in all patients (100%) using the lower score (Score 1 corresponding to 10(4) bacterial cells) and 16 (53.3%) using a higher treshold (score 3 corresponding to between >10(5) and 10(6) cells).The results of the present study showed low agreement for a positive microbiological outcome using the two diagnostic methods. It was also concluded that microbiological analysis in practice should include a larger number of bacterial species to better serve as markers for a diseased associated flora in chronic periodontitis cases. PMID:21769304

  5. Effects of concomitant use of fibroblast growth factor (FGF)-2 with beta-tricalcium phosphate ({beta}-TCP) on the beagle dog 1-wall periodontal defect model

    SciTech Connect

    Anzai, Jun; Kitamura, Masahiro; Nozaki, Takenori; Nagayasu, Toshie; Terashima, Akio; Asano, Taiji; Murakami, Shinya

    2010-12-17

    Research highlights: {yields} Concomitant use of FGF-2 and {beta}-TCP (an osteo-conductive scaffold) significantly promotes periodontal regeneration in the severe periodontitis model (1-wall defect model) of beagle dog. {yields} FGF-2 enhanced new bone formation via {beta}-TCP at the defects. {yields} In particular, FGF-2 dramatically regenerated new periodontal ligament and cementum formations at the defects, that is one of the most important healing outcomes during the process of periodontal regeneration. {yields} Epithelial downgrowth (undesirable wound healing) was decreased by administration of FGF-2. {yields} This manuscript indicates for the first time that concomitant use of FGF-2 and {beta}-TCP is efficacious in regenerating periodontal tissue following severe destruction of the tissue by progression of periodontitis. -- Abstract: The effects of concomitant use of fibroblast growth factor-2 (FGF-2) and beta-tricalcium phosphate ({beta}-TCP) on periodontal regeneration were investigated in the beagle dog 1-wall periodontal defect model. One-wall periodontal defects were created in the mesial portion of both sides of the mandibular first molars, and 0.3% FGF-2 plus {beta}-TCP or {beta}-TCP alone was administered. Radiographic evaluation was performed at 0, 3, and 6 weeks. At 6 weeks, the periodontium with the defect site was removed and histologically analyzed. Radiographic findings showed that co-administration of FGF-2 significantly increased bone mineral contents of the defect sites compared with {beta}-TCP alone. Histologic analysis revealed that the length of the regenerated periodontal ligament, the cementum, distance to the junctional epithelium, new bone height, and area of newly formed bone were significantly increased in the FGF-2 group. No abnormal inflammatory response or ankylosis was observed in either group. These findings indicate the efficacy of concomitant use of FGF-2 and {beta}-TCP as an osteoconductive material for periodontal

  6. Periodontal innate immune mechanisms relevant to obesity.

    PubMed

    Amar, S; Leeman, S

    2013-10-01

    Obesity affects over 35% of the adult population of the USA, and obesity-related illnesses have emerged as the leading cause of preventable death worldwide, according to the World Health Organization. Obesity's secondary morbidities include increased risk of cardiovascular disease, type II diabetes, and cancer, in addition to increased occurrence and severity of infections. Sedentary lifestyle and weight gain caused by consumption of a high-fat diet contribute to the development of obesity, with individuals having a body mass index (BMI) score > 30 being considered obese. Genetic models of obesity (ob/ob mice, db/db mice, and fa/fa rats) have been insufficient to study human obesity because of the overall lack of genetic causes for obesity in human populations. To date, the diet-induced obese (DIO) mouse model best serves research studies relevant to human health. Periodontal disease presents with a wide range of clinical variability and severity. Research in the past decade has shed substantial light on both the initiating infectious agents and host immunological responses in periodontal disease. Up to 46% of the general population harbors the microorganism(s) associated with periodontal disease, although many are able to limit the progression of periodontal disease or even clear the organism(s) if infected. In the last decade, several epidemiological studies have found an association between obesity and increased incidence of periodontal disease. This review focuses on exploring the immunological consequences of obesity that exacerbate effects of infection by pathogens, with focus on infection by the periodontal bacterium Porphyromonas gingivalis as a running example. PMID:23911141

  7. Effect of incorporation of nanoscale bioactive glass and hydroxyapatite in PCL/chitosan nanofibers for bone and periodontal tissue engineering.

    PubMed

    Shalumon, K T; Sowmya, S; Sathish, D; Chennazhi, K P; Nair, Shantikumar V; Jayakumar, R

    2013-03-01

    A biomimetic scaffold which can very closely mimic the extracellular matrix of the bone was fabricated by incorporating nano-bioceramic particles such as nano bioglass (nBG) and nano hydroxyapatite (nHAp) within electrospun nanofibrous scaffold. A comparative study between nHAp incorporated poly(caprolactone) (PCL)-chitosan (CS) and nBG incorporated PCL-CS nanofibrous scaffolds was carried out and their feasibility in tissue engineering was investigated. All the samples were optimized to obtain fibers of similar diameter from 100-200 nm for the ease of comparison between the samples. Protein adsorption studies showed that PCL-CS incorporated with 3 wt% nHAp and 3 wt% nBG adsorbed more proteins on their surface than other samples. Cell attachment and proliferation studies using human periodontal ligament fibroblast cells (hPLFs) and osteoblast like cells (MG-63 cell lines) showed that nBG incorporated samples are slightly superior to nHAp incorporated counterparts. Cell viability test using alamar blue assay and live/dead staining confirms that the scaffolds are cytocompatible. ALP activity confirmed the osteoblastic behavior of hPDLFs. Also the presence of nHAp and nBG enhanced the ALP activity of hPDLF on the PCH3 and PCB3 scaffolds. These studies indicate that nBG incorporated electrospun scaffolds are comparatively better candidates for orthopedic and periodontal tissue engineering applications. PMID:23620999

  8. Posterior cruciate ligament of the knee (image)

    MedlinePlus

    The posterior cruciate ligament (PCL) is a powerful ligament extending from the top-rear surface of the tibia to the bottom-front surface of the femur. The ligament prevents the knee joint from posterior instability.

  9. Synthetic ligaments. Current status.

    PubMed

    Funk, F J

    1987-06-01

    Many techniques for ligamentous reconstruction have been developed in recent years. In the United States, injuries of the knee have been increasingly treated with innovative methods of surgical reconstruction, most of which have used normal structures. There are obvious theoretic advantages in using synthetic materials that might simplify surgery, spare normal tissues, and possibly facilitate stronger repairs. To these ends, several synthetic substances have been used experimentally and clinically. This is a brief summary of eight of the materials that have been or are being investigated in the United States. Some are no longer in use, others are currently being used in clinical trials. As of this writing, only the Gortex ligament has received a general device release from the Food and Drug Administration (FDA). PMID:3034461

  10. Does Treatment of Periodontal Disease Influence Systemic Disease?

    PubMed

    Borgnakke, Wenche S

    2015-10-01

    Periodontal diseases are the most common human diseases globally, with gingivitis affecting up to 90% and periodontitis affecting 50% of adults. Tooth enamel is the only nonshedding tissue in the human body. In the absence of proper oral hygiene measures, microbial biofilm (dental plaque) develops on the teeth to include more than 700 different bacterial species, along with viruses, fungi, archea, and parasites. With time, ecological imbalances promote the growth of selected commensal species that induce host inflammatory pathways resulting in tissue destruction, including ulceration of the periodontal epithelium. PMID:26427573

  11. Epigenetic Modifications of Histones in Periodontal Disease.

    PubMed

    Martins, M D; Jiao, Y; Larsson, L; Almeida, L O; Garaicoa-Pazmino, C; Le, J M; Squarize, C H; Inohara, N; Giannobile, W V; Castilho, R M

    2016-02-01

    Periodontitis is a chronic infectious disease driven by dysbiosis, an imbalance between commensal bacteria and the host organism. Periodontitis is a leading cause of tooth loss in adults and occurs in about 50% of the US population. In addition to the clinical challenges associated with treating periodontitis, the progression and chronic nature of this disease seriously affect human health. Emerging evidence suggests that periodontitis is associated with mechanisms beyond bacteria-induced protein and tissue degradation. Here, we hypothesize that bacteria are able to induce epigenetic modifications in oral epithelial cells mediated by histone modifications. In this study, we found that dysbiosis in vivo led to epigenetic modifications, including acetylation of histones and downregulation of DNA methyltransferase 1. In addition, in vitro exposure of oral epithelial cells to lipopolysaccharides resulted in histone modifications, activation of transcriptional coactivators, such as p300/CBP, and accumulation of nuclear factor-κB (NF-κB). Given that oral epithelial cells are the first line of defense for the periodontium against bacteria, we also evaluated whether activation of pathogen recognition receptors induced histone modifications. We found that activation of the Toll-like receptors 1, 2, and 4 and the nucleotide-binding oligomerization domain protein 1 induced histone acetylation in oral epithelial cells. Our findings corroborate the emerging concept that epigenetic modifications play a role in the development of periodontitis. PMID:26496800

  12. Collagen metabolic disorder induced by oxidative stress in human uterosacral ligament-derived fibroblasts: A possible pathophysiological mechanism in pelvic organ prolapse

    PubMed Central

    LIU, CHENG; YANG, QING; FANG, GUI; LI, BING-SHU; WU, DE-BIN; GUO, WEN-JUN; HONG, SHA-SHA; HONG, LI

    2016-01-01

    Pelvic organ prolapse (POP) is a global health problem, for which the pathophysiological mechanism remains to be fully elucidated. The loss of extracellular matrix protein has been considered to be the most important molecular basis facilitating the development of POP. Oxidative stress (OS) is a well-recognized mechanism involved in fiber metabolic disorders. The present study aimed to clarify whether OS exists in the uterosacral ligament (USL) with POP, and to investigate the precise role of OS in collagen metabolism in human USL fibroblasts (hUSLFs). In the present study, 8-hydroxyguanosine (8-OHdG) and 4 hydroxynonenal (4-HNE), as oxidative biomarkers, were examined by immunohistochemistry to evaluate oxidative injury in USL sections in POP (n=20) and non-POP (n=20) groups. The primary cultured hUSLFs were treated with exogenous H2O2 to establish an original OS cell model, in which the expression levels of collagen, type 1, α1 (COL1A1), matrix metalloproteinase (MMP)-2, tissue inhibitor of metalloproteinase (TIMP)-2 and transforming growth factor (TGF)-β1 were evaluated by western blot and reverse transcription-quantitative polymerase chain reaction analyses. The results showed that the expression levels of 8-OHdG and 4-HNE in the POP group were significantly higher, compared with those in the control group. Collagen metabolism was regulated by H2O2 exposure in a concentration-dependent manner, in which lower concentrations of H2O2 (0.1–0.2 mM) stimulated the anabolism of COL1A1, whereas a higher concentration (0.4 mM) promoted catabolism. The expression levels of MMP-2, TIMP-2 and TGF-β1 exhibited corresponding changes with the OS levels. These results suggested that OS may be involved in the pathophysiology of POP by contributing to collagen metabolic disorder in a severity-dependent manner in hUSLFs, possibly through the regulation of MMPs, TIMPs and TGF-β1 indirectly. PMID:26936098

  13. Incidental Anterior Cruciate Ligament Calcification: Case Report

    PubMed Central

    Hayashi, Hisami; Fischer, Hans

    2016-01-01

    The calcification of knee ligaments is a finding noted only in a handful of case reports. The finding of an anterior cruciate ligament calcification has been reported once in the literature. Comparable studies involving the posterior cruciate ligament, medial collateral ligament and an ossicle within the anterior cruciate ligament are likewise discussed in reports of symptomatic patients. We report a case of incidentally discovered anterior cruciate ligament calcification. We discuss the likely etiology and clinical implications of this finding. PMID:27200163

  14. Periodontal probing: a review.

    PubMed

    Al Shayeb, Kwthar Nassar A; Turner, Wendy; Gillam, David G

    2014-08-01

    Periodontal probes are the main instruments that are used to assess the status of the periodontium, either for screening purposes or to evaluate periodontal changes throughout the treatment process. With increased knowledge and understanding of periodontal disease, the probes have evolved from a unidimensional manual shape into a more sophisticated computerised instrument. This is due to the need to increase the accuracy and reproducibility of readings and to improve efficiency (time, effort, money). Each probe has characteristic features that makes it unique and, in some cases, specific and limited to use. The aim of this paper is to present a brief introduction to periodontal disease and the methodology of measuring it, followed by probing limitations. The paper will also discuss the methodology of reducing probing error, examiner calibration and probing reproducibility. PMID:25198634

  15. Microbial dysbiosis in periodontitis

    PubMed Central

    Nath, Sameera G.; Raveendran, Ranjith

    2013-01-01

    Periodontitis is a biofilm-associated inflammatory disease of the periodontium. This disease appears to have multiple etiologies with microbial factor contributing to initiation of the disease and immunological factor of the host propagating the disease. This review is on the concept of “microbial dysbiosis” and molecular nature of periodontitis, and the scope of traditional and emerging technologies for treating this disease. PMID:24174742

  16. Role of PHOSPHO1 in Periodontal Development and Function.

    PubMed

    Zweifler, L E; Ao, M; Yadav, M; Kuss, P; Narisawa, S; Kolli, T N; Wimer, H F; Farquharson, C; Somerman, M J; Millán, J L; Foster, B L

    2016-07-01

    The tooth root and periodontal apparatus, including the acellular and cellular cementum, periodontal ligament (PDL), and alveolar bone, are critical for tooth function. Cementum and bone mineralization is regulated by factors including enzymes and extracellular matrix proteins that promote or inhibit hydroxyapatite crystal growth. Orphan Phosphatase 1 (Phospho1, PHOSPHO1) is a phosphatase expressed by chondrocytes, osteoblasts, and odontoblasts that functions in skeletal and dentin mineralization by initiating deposition of hydroxyapatite inside membrane-limited matrix vesicles. The role of PHOSPHO1 in periodontal formation remains unknown and we aimed to determine its functional importance in these tissues. We hypothesized that the enzyme would regulate proper mineralization of the periodontal apparatus. Spatiotemporal expression of PHOSPHO1 was mapped during periodontal development, and Phospho1(-/-) mice were analyzed using histology, immunohistochemistry, in situ hybridization, radiography, and micro-computed tomography. The Phospho1 gene and PHOSPHO1 protein were expressed by active alveolar bone osteoblasts and cementoblasts during cellular cementum formation. In Phospho1(-/-) mice, acellular cementum formation and mineralization were unaffected, whereas cellular cementum deposition increased although it displayed delayed mineralization and cementoid. Phospho1(-/-) mice featured disturbances in alveolar bone mineralization, shown by accumulation of unmineralized osteoid matrix and interglobular patterns of protein deposition. Parallel to other skeletal sites, deposition of mineral-regulating protein osteopontin (OPN) was increased in alveolar bone in Phospho1(-/-) mice. In contrast to the skeleton, genetic ablation of Spp1, the gene encoding OPN, did not ameliorate dentoalveolar defects in Phospho1(-/-) mice. Despite alveolar bone mineralization defects, periodontal attachment and function appeared undisturbed in Phospho1(-/-) mice, with normal PDL

  17. The Effect of Nonsurgical Periodontal Therapy on Trichomonas Tenax and Entamoeba Gingivalis in Patients with Chronic Periodontitis

    PubMed Central

    Rashidi Maybodi, Fahimeh; Haerian Ardakani, Ahmad; Fattahi Bafghi, Ali; Haerian Ardakani, Alireza; Zafarbakhsh, Akram

    2016-01-01

    Statement of the Problem Trichomonas tenax and Entamoeba gingivalis are commensal protozoa which inhabit the human oral cavity. These parasites are found in patients with poor oral hygiene and might be a reason for progressive periodontal diseases. Purpose The aim of this study was to evaluate the effect of nonsurgical periodontal treatment on the frequency of these protozoa in saliva and plaque samples. Materials and Method In this clinical trial, samples of saliva and dental plaque were collected from 46 patients with moderate to severe chronic periodontitis before and after periodontal therapy. The samples were assessed for the frequency of parasites. Results The frequency of Entamoeba gingivalis was reduced in saliva (p= 0.007) and plaque (p= 0.027) three weeks after the treatment. Likewise, the frequency of Trichomonas tenax reduced in saliva (p= 0.030); however, the decrease was not significant in plaque (p= 0.913). Trichomonas tenax frequency in dental plaque directly related to the severity of periodontitis (r= 0.565, p≤ 0.000). In contrast, the number of Entamoeba gingivalis in both saliva (r= -0.405, p≤ 0.005) and plaque (r= -0.304, p= 0.040) was inversely related with the severity of the periodontal disease. Conclusion Nonsurgical periodontal treatment could reduce the number of Trichomonas Tenax and Entamoeba gingivalis in the oral environment of patients with chronic periodontitis. PMID:27602391

  18. Periodontal regeneration of transplanted rat teeth subcutaneously after cryopreservation.

    PubMed

    Izumi, N; Yoshizawa, M; Ono, Y; Kobayashi, T; Hamamoto, Y; Saito, C

    2007-09-01

    The periodontal regeneration of transplanted teeth after cryopreservation in liquid nitrogen overnight was previously examined using an animal model. The results showed that overnight cryopreservation did not have any severe adverse effects on periodontal healing. For clinical application, it is necessary to make the period of storage longer than in the preliminary study. In this study, the regeneration of periodontal tissues after cryopreservation for 4 weeks was examined. The maxillary molars of 4-week-old Wistar rats were extracted and transplanted into the abdominal subcutaneous tissue either immediately or after cryopreservation in a deep freezer at -80 degrees C. The donor teeth were frozen in a rate-controlling freezer. At 1, 2 and 4 weeks after transplantation, they were excised and observed under light microscopy. The cryopreserved teeth had acellular cementum with a rough surface at 1 week. With an increase in cementoblasts and the appearance of periodontal ligament and alveolar bone, the surface had become smooth at 2 weeks. There was no progressive root resorption. Although the process took somewhat more time, the teeth cryopreserved for 4 weeks showed regeneration that was similar to that of the immediately transplanted teeth. PMID:17804198

  19. Advanced Biomatrix Designs for Regenerative Therapy of Periodontal Tissues

    PubMed Central

    Kim, J.H.; Park, C.H.; Perez, R.A.; Lee, H.Y.; Jang, J.H.; Lee, H.H.; Wall, I.B.; Shi, S.; Kim, H.W.

    2014-01-01

    Periodontitis is an inflammatory disease that causes loss of the tooth-supporting apparatus, including periodontal ligament, cementum, and alveolar bone. A broad range of treatment options is currently available to restore the structure and function of the periodontal tissues. A regenerative approach, among others, is now considered the most promising paradigm for this purpose, harnessing the unique properties of stem cells. How to make full use of the body’s innate regenerative capacity is thus a key issue. While stem cells and bioactive factors are essential components in the regenerative processes, matrices play pivotal roles in recapitulating stem cell functions and potentiating therapeutic actions of bioactive molecules. Moreover, the positions of appropriate bioactive matrices relative to the injury site may stimulate the innate regenerative stem cell populations, removing the need to deliver cells that have been manipulated outside of the body. In this topical review, we update views on advanced designs of biomatrices—including mimicking of the native extracellular matrix, providing mechanical stimulation, activating cell-driven matrices, and delivering bioactive factors in a controllable manner—which are ultimately useful for the regenerative therapy of periodontal tissues. PMID:25139364

  20. Molecular Epidemiology of Oral Treponemes Associated with Periodontal Disease

    PubMed Central

    Moter, Annette; Hoenig, Carina; Choi, Bong-Kyu; Riep, Birgit; Göbel, Ulf B.

    1998-01-01

    Periodontitis, a disease responsible for tooth loss worldwide, is characterized by chronic inflammation of the periodontium, eventually leading to destruction of periodontal ligaments and supporting alveolar bone. Spirochetes, identified by dark-field microscopy as being the most predominant bacteria in advanced lesions, are thought to play a causative role. Various spirochetal morphotypes were observed, but most of these morphotypes are as yet uncultivable. To assess the role of these organisms we designed oligonucleotide probes for the identification of both cultivable and so far uncultivable spirochetes in periodontitis patients. Subgingival plaque specimens taken from diseased sites (n = 200) and healthy control sites (n = 44) from 53 patients with rapidly progressive periodontitis (RPP) were submitted to direct in situ hybridization or dot blot hybridization after prior amplification with eubacterial primers. Spirochetes were found in all patients, but their distributions varied considerably. Parallel use of oligonucleotide probes specific for cultivable or so far uncultivable treponemes suggested the presence of novel yet unknown organisms at a high frequency. These uncultivable treponemes were visualized by fluorescence in situ hybridization, and their morphologies, sizes, and numbers could be estimated. All RPP patients included in this study harbored oral treponemes that represent either novel species, e.g., Treponema maltophilum, or uncultivable phylotypes. Therefore, it is necessary to include these organisms in etiologic considerations and to strengthen efforts to cultivate these as yet uncultivable treponemes. PMID:9574713

  1. Higher prevalence of Epstein-Barr virus DNA in deeper periodontal pockets of chronic periodontitis in Japanese patients.

    PubMed

    Kato, Ayako; Imai, Kenichi; Ochiai, Kuniyasu; Ogata, Yorimasa

    2013-01-01

    Periodontitis, a complex chronic inflammatory disease caused by subgingival infection, is among the most prevalent microbial diseases in humans. Although traditional microbiological research on periodontitis has focused on putative bacteria such as Porphyromonas gingivalis, the herpes virus is proposed to be involved in the pathogenesis of periodontitis because bacterial etiology alone does not adequately explain various clinical aspects. In this study, we established for the first time, more Epstein-Barr virus (EBV) DNA is found deeper in periodontal pockets of chronic periodontitis in Japanese patients. Subgingival samples were collected from 85 patients with chronic periodontitis having two periodontal sites with probing depths (PD) of ≤ 3 mm (shallow) or ≥ 5 mm (deep) and were subjected to a nested polymerase chain reaction. EBV DNA was more frequently detected in patients with deeper PD sites (66%) than in those with shallow PD sites (48%) or healthy controls (45%). Coexistence of EBV DNA and P. gingivalis was significantly higher in patients with deeper PD sites (40%) than in those with shallow PD sites (14%) or healthy controls (13%). Although no difference in clinical index for periodontitis, the odds ratio of EBV DNA in patients with deeper PD sites was 2.36, which was 2.07-fold higher than that in those with shallow PD sites. Interestingly, the odds of acquiring chronic periodontitis (PD ≥ 5 mm) were higher in the presence of both EBV DNA and P. gingivalis compared with either EBV DNA or P. gingivalis only. In addition, we also observed that EBV-encoded small RNA (EBER) in positive cells of human gingival tissues. These results would suggest that EBV DNA may serve as a pathogenic factor leading to chronic periodontitis among Japanese patients. PMID:23991022

  2. Phylogenetic and functional gene structure shifts of the oral microbiomes in periodontitis patients

    PubMed Central

    Li, Yan; He, Jinzhi; He, Zhili; Zhou, Yuan; Yuan, Mengting; Xu, Xin; Sun, Feifei; Liu, Chengcheng; Li, Jiyao; Xie, Wenbo; Deng, Ye; Qin, Yujia; VanNostrand, Joy D; Xiao, Liying; Wu, Liyou; Zhou, Jizhong; Shi, Wenyuan; Zhou, Xuedong

    2014-01-01

    Determining the composition and function of subgingival dental plaque is crucial to understanding human periodontal health and disease, but it is challenging because of the complexity of the interactions between human microbiomes and human body. Here, we examined the phylogenetic and functional gene differences between periodontal and healthy individuals using MiSeq sequencing of 16S rRNA gene amplicons and a specific functional gene array (a combination of GeoChip 4.0 for biogeochemical processes and HuMiChip 1.0 for human microbiomes). Our analyses indicated that the phylogenetic and functional gene structure of the oral microbiomes were distinctly different between periodontal and healthy groups. Also, 16S rRNA gene sequencing analysis indicated that 39 genera were significantly different between healthy and periodontitis groups, and Fusobacterium, Porphyromonas, Treponema, Filifactor, Eubacterium, Tannerella, Hallella, Parvimonas, Peptostreptococcus and Catonella showed higher relative abundances in the periodontitis group. In addition, functional gene array data showed that a lower gene number but higher signal intensity of major genes existed in periodontitis, and a variety of genes involved in virulence factors, amino acid metabolism and glycosaminoglycan and pyrimidine degradation were enriched in periodontitis, suggesting their potential importance in periodontal pathogenesis. However, the genes involved in amino acid synthesis and pyrimidine synthesis exhibited a significantly lower relative abundance compared with healthy group. Overall, this study provides new insights into our understanding of phylogenetic and functional gene structure of subgingival microbial communities of periodontal patients and their importance in pathogenesis of periodontitis. PMID:24671083

  3. Toll-like receptor activation and mechanical force stimulation promote the secretion of matrix metalloproteinases 1, 3 and 10 of human periodontal fibroblasts via p38, JNK and NF-kB.

    PubMed

    Lisboa, Rodolfo Assis; Andrade, Marcus Vinícius; Cunha-Melo, José Renan

    2013-06-01

    Matrix metalloproteinases (MMPs) are known to play a key role during orthodontic treatment leading to periodontal remodelling and tooth movement. MMPs may be induced by mechanical forces. However, the role played by toll-like receptors (TLRs) in modulating the effects of the mechanical force on periodontal fibroblasts is not known. To investigate the interaction between mechanical force and TLR stimulation, primary cultures of human periodontal fibroblasts were submitted to centrifugation in the presence of LPS and Pam3Cys, which are known TLR-4 and TLR-2 ligands, respectively. The expression of MMP-1, -2, -3, -8, -9, -10 and -13; TIMP (Tissue Inhibitor of Metalloproteinases) -1, -2 and -4; TNF-α (Tumour Necrosis Factor alpha); IL-1β (Interleukin 1 beta); ERK 1/2 (Extracellular Signal-Regulated Kinase 1/2); p38; JNK (c-jun N-terminal Kinase); IRAK1 (Interleukin-1 Receptor-Associated Kinase); and NF-κB (Nuclear Factor kappa B) were measured by antibody array, ELISA and immunoblotting methods. The activation of TLRs associated with centrifugation induced an increase in the secretion of MMPs 1, 3 and 10, with no increase in TNF-α or IL-1β. An increase in the phosphorylation of the MAP kinases p38 and JNK and the transcription factor NF-κB, without an increase in TIMPs was also observed. These findings suggest that the secretion of MMPs by cultured periodontal fibroblasts that is induced by combined TLR activation and mechanical force stimulation is regulated via the p38, JNK and NF-κB pathways. The increased secretion of MMPs by TLR activation may be an important factor that should be considered during orthodontic treatment. PMID:23332208

  4. Hindlimb unloading alters ligament healing

    NASA Technical Reports Server (NTRS)

    Provenzano, Paolo P.; Martinez, Daniel A.; Grindeland, Richard E.; Dwyer, Kelley W.; Turner, Joanne; Vailas, Arthur C.; Vanderby, Ray Jr

    2003-01-01

    We investigated the hypothesis that hindlimb unloading inhibits healing in fibrous connective tissue such as ligament. Male rats were assigned to 3- and 7-wk treatment groups with three subgroups each: sham control, ambulatory healing, and hindlimb-suspended healing. Ambulatory and suspended animals underwent surgical rupture of their medial collateral ligaments, whereas sham surgeries were performed on control animals. After 3 or 7 wk, mechanical and/or morphological properties were measured in ligament, muscle, and bone. During mechanical testing, most suspended ligaments failed in the scar region, indicating the greatest impairment was to ligament and not to bone-ligament insertion. Ligament testing revealed significant reductions in maximum force, ultimate stress, elastic modulus, and low-load properties in suspended animals. In addition, femoral mineral density, femoral strength, gastrocnemius mass, and tibialis anterior mass were significantly reduced. Microscopy revealed abnormal scar formation and cell distribution in suspended ligaments with extracellular matrix discontinuities and voids between misaligned, but well-formed, collagen fiber bundles. Hence, stress levels from ambulation appear unnecessary for formation of fiber bundles yet required for collagen to form structurally competent continuous fibers. Results support our hypothesis that hindlimb unloading impairs healing of fibrous connective tissue. In addition, this study provides compelling morphological evidence explaining the altered structure-function relationship in load-deprived healing connective tissue.

  5. CT of the pulmonary ligament

    SciTech Connect

    Godwin, J.D.; Vock, P.; Osborne, D.R.

    1983-08-01

    Most computed tomographic (CT) scans of the chest show the inferior pulmonary ligament and an associated septum in the lower lobe, although CT descriptions of these structures have not been reported. Conventional radiography of the ligament has relied on indirect signs: the position of the lower lobe in the presence of pneumothorax or pleural effusion, soft-tissue peaks along the upper surface of the diaphragm, and the rare traumatic paramediastinal pneumatocele (attributed to air in the ligament). CT clarifies the anatomic relations of the ligament and alterations caused by pleural effusion and pneumothorax. The ligament is probably responsible for some long linear shadows at the lung bases, and CT helps to distinguish these from scars, walls of bullae, and normal structures such as the phrenic nerve and the interlobar fissures.

  6. Genetic influences in caries and periodontal diseases.

    PubMed

    Hassell, T M; Harris, E L

    1995-01-01

    Deciphering the relative roles of heredity and environmental factors ("nature vs. nurture") in the pathogenesis of dental caries and diseases of the periodontium has occupied clinical and basic researchers for decades. Success in the endeavor has come more easily in the case of caries; the complex interactions that occur between host-response mechanisms and putative microbiologic pathogens in periodontal disease have made elucidation of genetic factors in disease susceptibility more difficult. In addition, during the 30-year period between 1958 and 1987, only meager resources were targeted toward the "nature" side of the nature/nurture dipole in periodontology. In this article, we present a brief history of the development of genetic epistemology, then describe the three main research mechanisms by which questions about the hereditary component of diseases in humans can be addressed. A critical discussion of the evidence for a hereditary component in caries susceptibility is next presented, also from a historical perspective. The evolution of knowledge concerning possible genetic ("endogenous", "idiotypic") factors in the pathogenesis of inflammatory periodontal disease is initiated with an analysis of some foreign-language (primarily German) literature that is likely to be unfamiliar to the reader. We identify a turning point at about 1960, when the periodontal research community turned away from genetics in favor of microbiology research. During the past five years, investigators have re-initiated the search for the hereditary component in susceptibility to common adult periodontal disease; this small but growing body of literature is reviewed. Recent applications of in vitro methods for genetic analyses in periodontal research are presented, with an eye toward a future in which persons who are at risk--genetically predisposed--to periodontal disease may be identified and targeted for interventive strategies. Critical is the realization that genes and environment

  7. Coracoclavicular Ligament Reconstruction

    PubMed Central

    Li, Qi; Hsueh, Pei-ling; Chen, Yun-feng

    2014-01-01

    Abstract Operative intervention is recommended for complete acromioclavicular (AC) joint dislocation to restore AC stability, but the best operative technique is still controversial. Twelve fresh-frozen male cadaveric shoulders (average age, 62.8 ± 7.8 years) were equally divided into endobutton versus the modified Weaver-Dunn groups. Each potted scapula and clavicle was fixed in a custom made jig to allow translation and load to failure testing using a Zwick BZ2.5/TS1S material testing machine (Zwick/Roell Co, Germany). A systematic review of 21 studies evaluating reconstructive methods for coracoclavicular or AC joints using a cadaveric model was also performed. From our biomechanical study, after ligament reconstruction, the triple endobutton technique demonstrated superior, anterior, and posterior displacements similar to that of the intact state (P > 0.05). In the modified Weaver-Dunn reconstruction group, however, there was significantly greater anterior (P < 0.001) and posterior (P = 0.003) translation after ligament reconstruction. In addition, there was no significant difference after reconstruction between failure load of the triple endobutton group and that of the intact state (686.88 vs 684.9 N, P > 0.05), whereas the failure load after the modified Weaver-Dunn reconstruction was decreased compared with the intact state (171.64 vs 640.86 N, P < 0.001). From our systematic review of 21 studies, which involved comparison of the modified Weaver-Dunn technique with other methods, the majority showed that the modified Weaver-Dunn procedure had significantly (P < .05) greater laxity than other methods including the endobutton technique. The triple endobutton reconstruction proved superior to the modified Weaver-Dunn technique in restoration of AC joint stability and strength. Triple endobutton reconstruction of the coracoclavicular ligament is superior to the modified Weaver-Dunn reconstruction in controlling both superior and

  8. [Biologico-periodontal considerations in restoration of teeth partially destroyed by caries or traumatism].

    PubMed

    Carrillo Martínez, J J; Zermeño Ibarra, J A; Mercado Martínez, E G; Villanueva Neuman, Y; Castellanos Olmedo, R

    1990-01-01

    Since a great number of teeth could be rehabilitated and not extracted, in this paper we analyze the relation Perio-protesis by the point of the biology of marginal periodontal ligament, and the different options to establish this relations when are lost by decay or traumatism. We discuss the contraindications to avoid greater problems than benefits when intend to rehabilitate lost teeth. PMID:1975497

  9. Periodontal disease and diabetes mellitus

    PubMed Central

    NEGRATO, Carlos Antonio; TARZIA, Olinda; JOVANOVIČ, Lois; CHINELLATO, Luiz Eduardo Montenegro

    2013-01-01

    Periodontal disease (PD) is one of the most commonly known human chronic disorders. The relationship between PD and several systemic diseases such as diabetes mellitus (DM) has been increasingly recognized over the past decades. Objective: The purpose of this review is to provide the reader with knowledge concerning the relationship between PD and DM. Many articles have been published in the english and Portuguese literature over the last 50 years examining the relationship between these two chronic diseases. Data interpretation is often confounded by varying definitions of DM, PD and different clinical criteria were applied to determine the prevalence, extent and severity of PD, levels of glycemic control and diabetes-related complications. Methods: This paper provides a broad overview of the predominant findings from research conducted using the BBO (Bibliografia Brasileira de Odontologia), MEDLINE, LILACS and PubMed for Controlled Trials databases, in english and Portuguese languages published from 1960 to October 2012. Primary research reports on investigations of relationships between DM/DM control, PD/periodontal treatment and PD/DM/diabetes-related complications identified relevant papers and meta-analyses published in this period. Results: This paper describes the relationship between PD and DM and answers the following questions: 1- The effect of DM on PD, 2- The effects of glycemic control on PD and 3- The effects of PD on glycemic control and on diabetes-related complications. Conclusions: The scientific evidence reviewed supports diabetes having an adverse effect on periodontal health and PD having an adverse effect on glycemic control and on diabetes-related complications. Further research is needed to clarify these relationships and larger, prospective, controlled trials with ethnically diverse populations are warranted to establish that treating PD can positively influence glycemic control and possibly reduce the burden of diabetes

  10. Response of individual thoracolumbar spine ligaments under high-rate deformation.

    PubMed

    Iwaskiw, Alexander S; Armiger, Robert S; Ott, Kyle A; Wickwire, Alexis C M; Merkle, Andrew C

    2012-01-01

    Under-Body Blast (UBB) has emerged as the predominant threat to ground vehicles and Warfighter survivability. The force transference from the vehicle structure to the human body has resulted in serious injuries, with the thoracolumbar spine frequently damaged. Computational models of the human body are being generated to model human response and develop injury mitigation strategies. To effectively model the spine mechanics, the thoracolumbar ligaments, which serve varying roles in contributing to spine stability, must be characterized at relevant strains and strain rates. Adaptation of cervical spine testing methods has allowed for testing of isolated spinal ligaments including the Anterior Longitudinal Ligament (ALL), Posterior Longitudinal Ligament (PLL), and Ligamentum Flavum (LF). A high-rate servo-hydraulic test machine was used to execute a tensile test protocol for 24 complexes with loading rates ranging from 240 - 2800 mm/s and displacements of 25%, 50%, 75%, 100%, and 300% of the measured ligament length. Non-contact strain field measurements were recorded to produce a three dimensional strain field of the ligament surface. In order to provide the ligament data in a form which can be incorporated in the human computational models, analytical methods for modeling the ligament response are being investigated. Ultimately, this model will be optimized to be utilized in computational models of the lumbar spine. PMID:22846283

  11. Plasmin is essential in preventing periodontitis in mice.

    PubMed

    Sulniute, Rima; Lindh, Tomas; Wilczynska, Malgorzata; Li, Jinan; Ny, Tor

    2011-08-01

    Periodontitis involves bacterial infection, inflammation of the periodontium, degradation of gum tissue, and alveolar bone resorption, which eventually leads to loss of teeth. To study the role of the broad-spectrum protease plasmin in periodontitis, we examined the oral health of plasminogen (Plg)-deficient mice. In wild-type mice, the periodontium was unaffected at all time points studied; in Plg-deficient mice, periodontitis progressed rapidly, within 20 weeks. Morphological study results of Plg-deficient mice revealed detachment of gingival tissue, resorption of the cementum layer, formation of necrotic tissue, and severe alveolar bone degradation. IHC staining showed massive infiltration of neutrophils in the periodontal tissues. Interestingly, doubly deficient mice, lacking both tissue- and urokinase-type plasminogen activators, developed periodontal disease similar to that in Plg-deficient mice; however, mice lacking only tissue- or urokinase-type plasminogen activator remained healthy. Supplementation by injection of Plg-deficient mice with human plasminogen for 10 days led to necrotic tissue absorption, inflammation subsidence, and full regeneration of gum tissues. Notably, there was also partial regrowth of degraded alveolar bone. Taken together, our results show that plasminogen is essential for the maintenance of a healthy periodontium and plays an important role in combating the spontaneous development of chronic periodontitis. Moreover, reversal to healthy status after supplementation of Plg-deficient mice with plasminogen suggests the possibility of using plasminogen for therapy of periodontal diseases. PMID:21704601

  12. Probiotics and periodontal health.

    PubMed

    Gupta, G

    2011-11-14

    Periodontitis is one of the most common chronic inflammatory diseases. The etiology is clearly bacterial and a number of putative bacterial pathogens have been associated with the disease, including Aggregatibacter actinomycetemcomitans, Tannerella forsythus and Porphyromonas gingivalis. Comparatively, little attention has been paid to the identification of health-associated and potentially beneficial bacterial species that may reside in the gingival sulcus. Probiotic technology represents a breakthrough approach to maintaining oral health by using natural beneficial bacteria, commonly found in healthy mouths, to provide a natural defense against those bacteria which are thought to be harmful to teeth and gums. This article endeavors to introduce the concepts of probiotics in periodontics. PMID:22514571

  13. Periodontitis and cardiovascular disease.

    PubMed

    Jeftha, A; Holmes, H

    2013-03-01

    Periodontal medicine has been studied and reviewed extensively since its introduction to the dental fraternity. The association of periodontal disease with and its effects on the cardiovascular system are amongst the many topics explored. A summary of the research into these associations and the possible mechanisms of any relationship is presented. Although a link between these two chronic inflammatory diseases is evident, the very heterogeneity of the relevant studies has not provided evidence sufficient to support an actual causal relationship. More stringent epidemiologic and intervention studies are required. PMID:23951765

  14. Probiotics and periodontal health

    PubMed Central

    2011-01-01

    Periodontitis is one of the most common chronic inflammatory diseases. The etiology is clearly bacterial and a number of putative bacterial pathogens have been associated with the disease, including Aggregatibacter actinomycetemcomitans, Tannerella forsythus and Porphyromonas gingivalis. Comparatively, little attention has been paid to the identification of health-associated and potentially beneficial bacterial species that may reside in the gingival sulcus. Probiotic technology represents a breakthrough approach to maintaining oral health by using natural beneficial bacteria, commonly found in healthy mouths, to provide a natural defense against those bacteria which are thought to be harmful to teeth and gums. This article endeavors to introduce the concepts of probiotics in periodontics. PMID:22514571

  15. Periodontitis in Chronic Heart Failure

    PubMed Central

    Fröhlich, Hanna; Herrmann, Kristina; Franke, Jennifer; Karimi, Alamara; Täger, Tobias; Cebola, Rita; Katus, Hugo A.; Zugck, Christian

    2016-01-01

    Periodontal disease has been associated with an increased risk of cardiovascular events. The purpose of our study was to investigate whether a correlation between periodontitis and chronic heart failure exists, as well as the nature of the underlying cause. We enrolled 71 patients (mean age, 54 ± 13 yr; 56 men) who had stable chronic heart failure; all underwent complete cardiologic and dental evaluations. The periodontal screening index was used to quantify the degree of periodontal disease. We compared the findings to those in the general population with use of data from the 4th German Dental Health Survey. Gingivitis, moderate periodontitis, and severe periodontitis were present in 17 (24%), 17 (24%), and 37 (52%) patients, respectively. Severe periodontitis was more prevalent among chronic heart failure patients than in the general population. In contrast, moderate periodontitis was more prevalent in the general population (P <0.00001). The severity of periodontal disease was not associated with the cause of chronic heart failure or the severity of heart failure symptoms. Six-minute walking distance was the only independent predictor of severe periodontitis. Periodontal disease is highly prevalent in chronic heart failure patients regardless of the cause of heart failure. Prospective trials are warranted to clarify the causal relationship between both diseases. PMID:27547136

  16. Periodontitis in Chronic Heart Failure.

    PubMed

    Fröhlich, Hanna; Herrmann, Kristina; Franke, Jennifer; Karimi, Alamara; Täger, Tobias; Cebola, Rita; Katus, Hugo A; Zugck, Christian; Frankenstein, Lutz

    2016-08-01

    Periodontal disease has been associated with an increased risk of cardiovascular events. The purpose of our study was to investigate whether a correlation between periodontitis and chronic heart failure exists, as well as the nature of the underlying cause. We enrolled 71 patients (mean age, 54 ± 13 yr; 56 men) who had stable chronic heart failure; all underwent complete cardiologic and dental evaluations. The periodontal screening index was used to quantify the degree of periodontal disease. We compared the findings to those in the general population with use of data from the 4th German Dental Health Survey. Gingivitis, moderate periodontitis, and severe periodontitis were present in 17 (24%), 17 (24%), and 37 (52%) patients, respectively. Severe periodontitis was more prevalent among chronic heart failure patients than in the general population. In contrast, moderate periodontitis was more prevalent in the general population (P <0.00001). The severity of periodontal disease was not associated with the cause of chronic heart failure or the severity of heart failure symptoms. Six-minute walking distance was the only independent predictor of severe periodontitis. Periodontal disease is highly prevalent in chronic heart failure patients regardless of the cause of heart failure. Prospective trials are warranted to clarify the causal relationship between both diseases. PMID:27547136

  17. Interface and biocompatibility of polyethylene terephthalate knee ligament prostheses. A histological and ultrastructural device retrieval analysis in failed synthetic implants used for surgical repair of anterior cruciate ligaments.

    PubMed

    Kock, H J; Stürmer, K M; Letsch, R; Schmit-Neuerburg, K P

    1994-01-01

    In a prospective clinical study of 54 patients with acute anterior cruciate ligament instability, 56 artificial ligaments made of polyethylene terephthalate (Trevira hochfest) were implanted to restore knee stability. The average follow-up of these artificial knee ligaments was 40.2 (12-79) months; five implants (10%) had to be explanted due to failure after an average of 17.8 (6-50) months. All explants were examined by histological and ultrastructural methods in a device retrieval analysis. With regard to short- and medium-term artificial ligament failure in the human knee joint, a non-isometric surgical implantation technique, inappropriate strain during rehabilitation and implant fatigue and wear were responsible for ligament failures. PMID:7696041

  18. The role of the anterolateral ligament in ACL insufficient and reconstructed knees on rotatory stability: A biomechanical study on human cadavers.

    PubMed

    Tavlo, M; Eljaja, S; Jensen, J T; Siersma, V D; Krogsgaard, M R

    2016-08-01

    Studies suggest that the anterolateral ligament (ALL) is important for knee stability. The purpose was to clarify ALL's effect on rotatory and anterior-posterior stability in the anterior cruciate ligament (ACL)-insufficient and reconstructed knees and the effect of reconstruction of an insufficient ALL. Eighteen cadaveric knees were included. Stability was tested for intact (+ALL), detached (-ALL) and reconstructed (+ reALL) ALL, with ACL removed (-ACL) and reconstructed (+ACL) in six combinations. All were tested in 0, 30, 60, and 90 °C flexion. Anterior-posterior stability was measured with a rolimeter. Rotation with a torque of 8.85 Nm was measured photographically. The ALL was well defined in 78% of knees. ACL reconstruction had a significant effect on anterior-posterior stability. Detaching the ALL had a significant effect on internal rotatory stability and on anterior-posterior stability in ACL-insufficient knees. Reconstruction of ACL and ALL reestablished knee stability. The appearance of the ALL was not uniform. The ALL was an internal rotational stabilizer. Anatomical ALL reconstruction in combination with ACL reconstruction could reestablish stability. ALL reconstruction might be considered in patients with combined ACL and ALL tears, but the clinical effect should be established in a controlled clinical study. PMID:26247376

  19. Mechanical Forces Exacerbate Periodontal Defects in Bsp-null Mice

    PubMed Central

    Soenjaya, Y.; Foster, B.L.; Nociti, F.H.; Ao, M.; Holdsworth, D.W.; Hunter, G.K.; Somerman, M.J.

    2015-01-01

    Bone sialoprotein (BSP) is an acidic phosphoprotein with collagen-binding, cell attachment, and hydroxyapatite-nucleating properties. BSP expression in mineralized tissues is upregulated at onset of mineralization. Bsp-null (Bsp-/-) mice exhibit reductions in bone mineral density, bone turnover, osteoclast activation, and impaired bone healing. Furthermore, Bsp-/- mice have marked periodontal tissue breakdown, with a lack of acellular cementum leading to periodontal ligament detachment, extensive alveolar bone and tooth root resorption, and incisor malocclusion. We hypothesized that altered mechanical stress from mastication contributes to periodontal destruction observed in Bsp-/- mice. This hypothesis was tested by comparing Bsp-/- and wild-type mice fed with standard hard pellet diet or soft powder diet. Dentoalveolar tissues were analyzed using histology and micro–computed tomography. By 8 wk of age, Bsp-/- mice exhibited molar and incisor malocclusion regardless of diet. Bsp-/- mice with hard pellet diet exhibited high incidence (30%) of severe incisor malocclusion, 10% lower body weight, 3% reduced femur length, and 30% elevated serum alkaline phosphatase activity compared to wild type. Soft powder diet reduced severe incisor malocclusion incidence to 3% in Bsp-/- mice, supporting the hypothesis that occlusal loading contributed to the malocclusion phenotype. Furthermore, Bsp-/- mice in the soft powder diet group featured normal body weight, long bone length, and serum alkaline phosphatase activity, suggesting that tooth dysfunction and malnutrition contribute to growth and skeletal defects reported in Bsp-/- mice. Bsp-/- incisors also erupt at a slower rate, which likely leads to the observed thickened dentin and enhanced mineralization of dentin and enamel toward the apical end. We pr