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Autoradiographic study of 3H-proline incorporation by rat periodontal ligament, gingival connective tissue and dental pulp  

International Nuclear Information System (INIS)

The rates of 3H-proline incorporation by the rat periodontal ligament, the gingival connective tissue and the dental pulp were studied by autoradiography. The rate of 3H-proline incorporation by the periodontal ligament was 2.8 times higher than by the gingival connective tissue and 5 times higher than by the dental pulp. These differences were significant (p3H-proline incorporation by the periodontal ligament was significantly different (p3H-proline incorporation. The ratio of the rates of 3H-proline incorporation by the three tissues did not correlate with the ratio of the cellular densities in the same three tissues. (author).

1975-01-01

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Characterization of mesenchymal stem cells from human dental pulp, preapical follicle and periodontal ligament  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Human dental stem cells have high proliferative potential for self-renewal that is important to the regenerative capacity of the tissue. Objective: The aim was to isolate human dental pulp stem cells (DPSC), periodontal ligament stem cells (PDLSC) and periapical follicle stem cells (PAFSC) for their potential role in tissue regeneration. Materials and Methods: In this experimental study, the postnatal stem cells were isolated from dental pulp, preapical follicle and periodontal ligament .The cells were stained for different stem cell markers by immunocytochemistry. To investigate the mesenchymal nature of cells, differentiation potential along osteoblastic and adipogenic lineages and gene expression profile were performed. For proliferation potential assay, Brdu staining and growth curve tests were performed. Finally, all three cell types were compared together regarding their proliferation, differentiation and displaying phenotype. Results: The isolated cell populations have similar fibroblastic like morphology and expressed all examined cell surface molecule markers. These cells were capable of differentiating into osteocyte with different capability and adipocyte with the same rate. PAFSCs showed more significant proliferation rate than others. Reverse transcriptase PCR (RT-PCR) for nanog, oct4, Alkaline phosphatase (ALP) and glyceraldehydes-3-phosphate dehydrogenease (GADPH) as control gene showed strong positive expression of these genes in all three isolated cell types. Conclusion: PDLSCs, DPSCs and PAFSCs exist in various tissues of the teeth and can use as a source of mesenchymal stem cells for developing bioengineered organs and also in craniomaxillofacial reconstruction with varying efficiency in differentiation and proliferation.

Ali Reza Navabazam; Fatemeh Sadeghian Nodoshan; Mohammad Hasan Sheikhha; Sayyed Mohsen Miresmaeili; Mehrdad Soleimani; Farzaneh Fesahat

2013-01-01

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Proteome of Human Stem Cells from Periodontal Ligament and Dental Pulp  

Science.gov (United States)

Background Many adult tissues contain a population of stem cells with the ability to regenerate structures similar to the microenvironments from which they are derived in vivo and represent a promising therapy for the regeneration of complex tissues in the clinical disorder. Human adult stem cells (SCs) including bone marrow stem cells (BMSCs), dental pulp stem cells (DPSCs) and periodontal ligament stem cells (PDLSCs) have been characterized for their high proliferative potential, expression of characteristic SC-associated markers and for the plasticity to differentiate in different lineage in vitro. Methodology/Principal Findings The aim of this study is to define the molecular features of stem cells from oral tissue by comparing the proteomic profiles obtained with 2-DE followed by MALDI-TOF/TOF of ex-vivo cultured human PDLSCs, DPSCs and BMSCs. Our results showed qualitative similarities in the proteome profiles among the SCs examined including some significant quantitative differences. To enrich the knowledge of oral SCs proteome we performed an analysis in narrow range pH 4–7 and 6–9, and we found that DPSCs vs PDLSCs express differentially regulated proteins that are potentially related to growth, regulation and genesis of neuronal cells, suggesting that SCs derived from oral tissue source populations may possess the potential ability of neuronal differentiation which is very consistent with their neural crest origin. Conclusion/Significance This study identifies some differentially expressed proteins by using comparative analysis between DPSCs and PDLSCs and BMSCs and suggests that stem cells from oral tissue could have a different cell lineage potency compared to BMSCs.

Sulpizio, Marilisa; Di Giuseppe, Fabrizio; Pierdomenico, Laura; Marchisio, Marco; Giancola, Raffaella; Giammaria, Gianluigi; Miscia, Sebastiano; Caputi, Sergio; Di Ilio, Carmine; Angelucci, Stefania

2013-01-01

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Simvastatin induces apoptosis and disruption of the actin cytoskeleton in human dental pulp cells and periodontal ligament fibroblasts.  

UK PubMed Central (United Kingdom)

OBJECTIVE: Simvastatin, a competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, and widely used as cholesterol-lowering agent, has been suggested for its beneficial effects on alveolar bone formation, regeneration of dental pulp tissue and periodontal ligament. High doses of simvastatin appear to induce apoptosis in several cell types, but little is known about its possible effect on tooth-associated cells. Therefore, the effects of simvastatin were studied on apoptosis and cell morphology of human dental pulp cells (HDPCs) and periodontal ligament fibroblasts (HPLFs). METHODS: HDPCs/HPLFs obtained from 4 patients were cultured with or without various concentrations of simvastatin (0.1, 1, and 10?M) for 24, 48, and 72h. The 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to evaluate cell viability. The levels of apoptosis of HDPCs and HPLFs were measured by flow cytometry after Annexin V/propidium iodide double staining. Phalloidin-FITC and 4',6-diamidino-2-phenylindole dihydrochloride (DAPI) staining was used to examine differences in the actin cytoskeleton and nuclear morphology, respectively. RESULTS: The viability of HDPCs and HPLFs was significantly reduced after simvastatin treatment in a dose- and time-dependent manner (p<0.05). The apoptosis of HDPCs and HPLFs was significantly increased in 10?M simvastatin-treated cells (p<0.05). The effect on apoptosis was comparable for HDPCs and HPLFs. Nuclear staining showed typical apoptotic nuclear condensation and fragmentation in simvastatin-treated HDPCs/HPLFs. A dose- and time-dependent simvastatin-induced disruption of the actin cytoskeleton was observed in both cell types. CONCLUSION: Our data demonstrated that simvastatin decreases the viability of HDPCs and HPLFs, probably by inducing apoptosis.

Saewong S; Thammasitboon K; Wattanaroonwong N

2013-08-01

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Importance of periodontal ligament thickness  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english This study evaluated whether periodontal ligament (PL) thickness varied with root size and examined the possible influence of this variation on orthodontic mechanics. Measurements were taken of the maxillary left first molar in 54 male Wistar rats. Mean mesial and distal PL thicknesses were compared between the intermediate buccal and mesiobuccal roots using paired Student's t-tests with a 5% significance level. Mean values differed significantly between roots (p

Cuoghi, Osmar Aparecido; Tondelli, Pedro Marcelo; Aiello, Carlos Alberto; Mendonça, Marcos Rogério de; Costa, Silvano Cesar da

2013-02-01

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Proteomic characterization of mesenchymal stem cell-like populations derived from ovine periodontal ligament, dental pulp, and bone marrow: analysis of differentially expressed proteins.  

UK PubMed Central (United Kingdom)

Postnatal mesenchymal stem/stromal-like cells (MSCs) including periodontal ligament stem cells (PDLSCs), dental pulp stem cells (DPSCs), and bone marrow stromal cells (BMSCs) are capable of self-renewal and differentiation into multiple mesenchymal cell lineages. Despite their similar expression of MSC-associated and osteoblastic markers, MSCs retain the capacity to generate structures resembling the microenvironments from which they are derived in vivo and represent a promising therapy for the regeneration of complex tissues in the clinical setting. With this in mind, systematic approaches are required to identify the differential protein expression patterns responsible for lineage commitment and mediating the formation of these complex structures. This is the first study to compare the differential proteomic expression profiles of ex vivo-expanded ovine PDLSCs, DPSCs, and BMSCs derived from an individual donor. The two-dimensional electrophoresis was performed and regulated proteins were identified by liquid chromatography--electrospray-ionization tandem mass spectrometry (MS and MS/MS), database searching, and de novo sequencing. In total, 58 proteins were differentially expressed between at least 2 MSC populations in both sheep, 12 of which were up-regulated in one MSC population relative to the other two. In addition, the regulation of selected proteins was also conserved between equivalent human MSC populations. We anticipate that differential protein expression profiling will provide a basis for elucidating the protein expression patterns and molecular cues that are crucial in specifying the characteristic growth and developmental capacity of dental and non-dental tissue-derived MSC populations. These expression patterns can serve as important tools for the regeneration of particular tissues in future stem cell-based tissue engineering studies using animal models.

Mrozik KM; Zilm PS; Bagley CJ; Hack S; Hoffmann P; Gronthos S; Bartold PM

2010-10-01

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Importance of periodontal ligament thickness.  

UK PubMed Central (United Kingdom)

This study evaluated whether periodontal ligament (PL) thickness varied with root size and examined the possible influence of this variation on orthodontic mechanics. Measurements were taken of the maxillary left first molar in 54 male Wistar rats. Mean mesial and distal PL thicknesses were compared between the intermediate buccal and mesiobuccal roots using paired Student's t-tests with a 5% significance level. Mean values differed significantly between roots (p < 2.2 × 10(-16)). PL thickness in rats is directly proportional to root dimensions.

Cuoghi OA; Tondelli PM; Aiello CA; Mendonça MR; Costa SC

2013-01-01

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Importance of periodontal ligament thickness  

Directory of Open Access Journals (Sweden)

Full Text Available This study evaluated whether periodontal ligament (PL) thickness varied with root size and examined the possible influence of this variation on orthodontic mechanics. Measurements were taken of the maxillary left first molar in 54 male Wistar rats. Mean mesial and distal PL thicknesses were compared between the intermediate buccal and mesiobuccal roots using paired Student's t-tests with a 5% significance level. Mean values differed significantly between roots (p < 2.2 × 10-16). PL thickness in rats is directly proportional to root dimensions.

Osmar Aparecido Cuoghi; Pedro Marcelo Tondelli; Carlos Alberto Aiello; Marcos Rogério de Mendonça; Silvano Cesar da Costa

2013-01-01

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Periodontal regeneration using periodontal ligament stem cell-transferred amnion.  

UK PubMed Central (United Kingdom)

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 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 tri-lineage 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.

Iwasaki K; Komaki M; Yokoyama N; Tanaka Y; Taki A; Honda I; Kimura Y; Takeda M; Akazawa K; Oda S; Izumi Y; Morita I

2013-09-01

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Human periodontal ligament fibroblast responses to compression in chronic periodontitis.  

UK PubMed Central (United Kingdom)

AIM: Test whether human periodontal ligament fibroblasts (PDLFs) retain homeostatic responses to a physiological compressive force during chronic periodontitis. MATERIAL AND METHODS: Six cell lines were established from periodontally healthy individuals (H-PDLFs) and another six were cultured from patients diagnosed with chronic periodontitis (D-PDLFs). Compressive force at 150 psi was applied to H-and D-PDLFs for 3 h on 2 consecutive days. After compression, comparisons between H-and D-PDLFs were performed by gene expression analysis of IL-6, proteases and 84 inflammation-related targets using real-time PCR. RESULTS: Compression of H-PDLFs resulted in a significant increase only in MMP-1 mRNA. In contrast, the same compressive force on D-PDLFs produced significant increases in the expression of MMPs-1,-7,-9 and -16. Moreover, compression of H-PDLFs resulted in down-regulation of IL-6, while IL-6 was significantly up-regulated in compressed D-PDLFs. Compression of H-PDLFs slightly up-regulated 3 and significantly down-regulated 15 inflammation-related genes, while the same treatment strongly up-regulated 21 inflammation-related genes in D-PDLFs. CONCLUSION: These results suggest a fundamental difference in the inflammatory response of healthy versus diseased PDLFs under physiological compression. Maintenance of these characteristics in vitro suggests that these cells may be at least partly responsible for the persistence of inflammation and localized susceptibility in chronic periodontitis.

El-Awady AR; Lapp CA; Gamal AY; Sharawy MM; Wenger KH; Cutler CW; Messer RL

2013-07-01

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Previously undescribed pulpal and periodontal ligament calcifications in systemic sclerosis: a case report.  

UK PubMed Central (United Kingdom)

Systemic sclerosis (SSc), a multisystem autoimmune disease characterized by widespread fibrosis, vascular alterations, autoimmunity, and inflammation, has effects on the hard and soft tissues of the orofacial region. The most common oral radiographic features correspond to widening of the periodontal ligament space and to mandibular resorption. In this report, cone-beam computerized tomography (CBCT) confirmed not only the well described periodontal features associated with SSc but also revealed previously undescribed calcifications within the periodontal ligament space of most maxillary teeth. Moreover, CBCT showed pulp calcifications in some incisors and premolars with these calcifications leading to root canal obliterations. Such manifestations (which could be linked to different major pathogenic features of SSc such as calcinosis, vasculopathy, and fibrosis) contribute to the phenotypic spectrum of the disease.

Jung S; Minoux M; Manière MC; Martin T; Schmittbuhl M

2013-04-01

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Role of integrins in the periodontal ligament: organizers and facilitators.  

Science.gov (United States)

The periodontal ligament is the tissue that connects teeth to bone. The periodontal ligament is a fascinating tissue from a cell biologist's point of view, and because of its special properties and stem-cell content it has also come into the limelight in emerging fields of regenerative medicine. An increased range of genetically modified mouse models offer new tools for studying molecular mechanisms of tooth development. However, owing to species-specific organization of the tooth apparatus, the use of genetic animal models to study the role of the periodontal ligament in normal human tooth physiology and tooth pathology is challenging. PMID:23931052

Barczyk, Malgorzata; Bolstad, Anne Isine; Gullberg, Donald

2013-10-01

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Neutrophil elastase is involved in the initial destruction of human periodontal ligament.  

UK PubMed Central (United Kingdom)

BACKGROUND AND OBJECTIVE: It has been reported that noncollagenous proteins may provide mechanical strength to the periodontal ligament. Several proteolytic activities, including that of neutrophil elastase, are reported to increase significantly in periodontal disease. The aim of this study was to investigate the function of neutrophil elastase in the initial destruction of periodontal ligament at early stages of periodontal disease. MATERIAL AND METHODS: The detection and identification of proteinases in chronic periodontitis and healthy periodontal ligament were examined by zymographic and zymo-Western analysis. The morphological changes of periodontal ligament, digested with or without authentic proteinases, were observed using scanning electron microscopy. RESULTS: Increases in neutrophil elastase, plasminogen, and matrix metalloproteinase-9 were detected in periodontal ligament from chronic periodontitis, compared with healthy periodontal ligament. Among these proteinases, only neutrophil elastase digested the intact noncollagenous proteins of periodontium. When human healthy periodontal ligament was directly digested by neutrophil elastase in an in vitro system, the morphological features were quite similar to that of the periodontal ligament in chronic periodontitis . In healthy periodontal ligament, the collagen fibrils are covered with noncollagenous proteins containing 110 kDa acidic glycoprotein, which was degraded initially by the neutrophil elastase. CONCLUSION: It was concluded that neutrophil elastase is involved in the degradation of noncollagenous protein-covered collagen fibrils in the early destructive stages of periodontal disease.

Ujiie Y; Oida S; Gomi K; Arai T; Fukae M

2007-08-01

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Autologous dental pulp stem cells in regeneration of defect created in canine periodontal tissue.  

Science.gov (United States)

This study aimed to investigate effects of dental pulp stem cells (DPSCs) on regeneration of a defect experimentally created in the periodontium of a canine model. Surgically created mesial 3-walled periodontal defects with ligature-induced periodontitis were produced bilaterally in the first lower premolar teeth of 10 mongrel dogs. Simultaneously, DPSCs were derived from the maxillary premolar teeth of the same dogs. Four weeks after creation of the periodontitis model, autologous passaged-3 DPSCs combined with Bio-Oss were implanted on one side as the test group. On the other side, only Bio-Oss was implanted as a control. Eight weeks after surgery, regeneration of the periodontal defects was evaluated histologically and histomorphometrically in terms of bone, periodontal ligament (PDL), and cement formation. Histologically, in all test specimens (10 defects), regeneration of cementum, bone, and PDL was observed. In the control groups, although we observed the regeneration of bone in all defects, the formation of cementum was seen in 9 defects and PDL was seen in 8 defects. Histomorphometric analyses showed that the amount of regenerated cementum and PDL in the test groups (3.83 ± 1.32 mm and 3.30 ± 1.12 mm, respectively) was significantly higher than that of the control groups (2.42 ± 1.40 mm and 1.77 ± 1.27 mm, respectively; P < .05). A biocomplex consisting of DPSCs and Bio-Oss would be promising in regeneration of periodontal tissues. PMID:23964777

Khorsand, Afshin; Eslaminejad, Mohamadreza Baghaban; Arabsolghar, Mohadeseh; Paknejad, Mojghan; Ghaedi, Baharak; Rokn, Amir Reza; Moslemi, Neda; Nazarian, Hamid; Jahangir, Shahrbanoo

2013-08-01

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A study on cryopreservation of cultured rabbit periodontal ligament cells.  

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Cultured rabbit periodontal ligament cells were subjected to short term cryopreservation in liquid nitrogen, for a period of 84 hours and 168 hours, to study the effect of cryopreservation on coll viability and culturing ability. The vital cell count performed by Trypan Blue exclusion was 14.93 x 10...

Pal Tamal; Aibara Farzan; Ali N

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Histopathological Effect of Advanced Periodontal Disease on the Dental Pulp  

Directory of Open Access Journals (Sweden)

Full Text Available Statement of Problem: Many authors have claimed that pulpal inflammation may occur following periodontal diseases. Appropriate diagnosis of different lesions that have affected the dental pulp or periodontium is critical for prevention of unnecessary or harmful treatments; this must be taken into account before treatment.Purpose: The purpose of this study was histological evaluation of the pulp in the teeth with advanced periodontitis.Materials and Method: 30 permanent single teeth root that had advanced periodontitis with attachment loss ? 5 mm at least in one surface were used. The teeth were not maintainable and did not have caries, restoration and any sign of primary trauma from occlusion and did not receive any periodontal professional treatment in the past 6 months with no background of trauma. After clinical and radiographical examination and confirmation of the existence of advanced periodontitis, the teeth were extracted. Then cracks were created in the teeth by special clips. After fixation of the teeth in 10% formalin solution and decalcification by 10% nitric acid, the sections were prepared and stained by hematoxylin and eosin and then evaluated from histological perspectives. The data were analyzed by Spearman correlation coefficient ANOVA, t-test and Kruskal wallis tests.Results: In this survey, we did not find any significant correlation between clinical findings and histopathological situation. The relationship between clinical attachment loss and pulp diagnosis was statistically significant ( p =0.043). Also there was a statistically significant relationship between clinical attachment loss and calcification in the pulp ( p =0.014).Conclusion: According to the result of this research, it seems that periodontal condition affects the pulpal condition and it should be considered in future treatments on these teeth.

Seyedmajidi M.; Khosravi M.; Bijani A.; Babak M.

2011-01-01

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Periodontal tissue engineering with stem cells from the periodontal ligament of human retained deciduous teeth.  

UK PubMed Central (United Kingdom)

BACKGROUND AND OBJECTIVE: Periodontal ligament stem cells from human permanent teeth (PePDLSCs) have been investigated extensively in periodontal tissue engineering and regeneration. However, little knowledge is available on the periodontal ligament stem cells from human retained deciduous teeth (DePDLSCs). This study evaluated the potential of DePDLSCs in periodontal tissue regeneration. MATERIAL AND METHODS: DePDLSCs were isolated and purified by limited dilution. The characteristics of DePDLSCs were evaluated and compared with PePDLSCs both in vitro and in vivo. RESULTS: DePDLSCs presented a higher proliferation rate and colony-forming capacity than PePDLSCs in vitro. During the osteogenic induction, alkaline phosphatase (ALP) activity, mineralized matrix formation and expression of mineralization-related genes, including runt-related transcription factor 2 (RUNX2), ALP, collagen type I (COLI) and osteocalcin (OCN) were significantly enhanced in DePDLSCs compared with PePDLSCs. Furthermore, DePDLSC cell sheets showed a stronger synthesis of collagen type I in the extracellular matrix than did PePDLSC cell sheets. After in vivo transplantation, DePDLSC cell sheets recombined with human dentin blocks were able to generate new cementum/periodontal ligament-like tissues. CONCLUSION: Our findings suggest that DePDLSCs can be used as a promising candidate for periodontal tissue engineering.

Ji K; Liu Y; Lu W; Yang F; Yu J; Wang X; Ma Q; Yang Z; Wen L; Xuan K

2013-02-01

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Pulp revascularization of immature dens invaginatus with periapical periodontitis.  

UK PubMed Central (United Kingdom)

INTRODUCTION: Dens invaginatus is a rare developmental malformation of a tooth caused by the invagination of the tooth crown before biological mineralization occurs. The complex anatomy of these teeth makes nonsurgical endodontic treatment difficult and more so when there is presence of periapical periodontitis with open apex. The endodontic treatment of dens invaginatus is a challenge, especially in the case of periapical periodontitis with open apex. Pulp revascularization is a conservative endodontic treatment that has been introduced in recent years. Presented here is a variant approach for the treatment of immature dens invaginatus type II with periapical periodontitis, which combines filling of the invagination and pulp revascularization. METHODS: After accessing the pulp chamber, the main canal and the invagination were explored. The root was thoroughly disinfected by irrigating and medication, invagination was filled, and the main canal was revascularized. Then the coronal sealing was made by glass ionomer cement and composite resin. Radiograph taken regularly and computed tomography scan were used to investigate the healing of the periapical lesion and development of the root. RESULTS: In the subsequent follow-up, the periapical lesion was completely eliminated, the open apex was closed, and the wall of the root was thickened. CONCLUSIONS: For type II immature dens invaginatus with large periapical lesion, conservative endodontic treatment should be considered before periapical surgery. With sufficient infection control, pulp revascularization can be an effective alternative method.

Yang J; Zhao Y; Qin M; Ge L

2013-02-01

19

Regeneration of bone and periodontal ligament induced by recombinant amelogenin after periodontitis.  

UK PubMed Central (United Kingdom)

Regeneration of mineralized tissues affected by chronic diseases comprises a major scientific and clinical challenge. Periodontitis, one such prevalent disease, involves destruction of the tooth-supporting tissues, alveolar bone, periodontal-ligament and cementum, often leading to tooth loss. In 1997, it became clear that, in addition to their function in enamel formation, the hydrophobic ectodermal enamel matrix proteins (EMPs) play a role in the regeneration of these periodontal tissues. The epithelial EMPs are a heterogeneous mixture of polypeptides encoded by several genes. It was not clear, however, which of these many EMPs induces the regeneration and what mechanisms are involved. Here we show that a single recombinant human amelogenin protein (rHAM(+)), induced in vivo regeneration of all tooth-supporting tissues after creation of experimental periodontitis in a dog model. To further understand the regeneration process, amelogenin expression was detected in normal and regenerating cells of the alveolar bone (osteocytes, osteoblasts and osteoclasts), periodontal ligament, cementum and in bone marrow stromal cells. Amelogenin expression was highest in areas of high bone turnover and activity. Further studies showed that during the first 2 weeks after application, rHAM(+) induced, directly or indirectly, significant recruitment of mesenchymal progenitor cells, which later differentiated to form the regenerated periodontal tissues. The ability of a single protein to bring about regeneration of all periodontal tissues, in the correct spatio-temporal order, through recruitment of mesenchymal progenitor cells, could pave the way for development of new therapeutic devices for treatment of periodontal, bone and ligament diseases based on rHAM(+).

Haze A; Taylor AL; Haegewald S; Leiser Y; Shay B; Rosenfeld E; Gruenbaum-Cohen Y; Dafni L; Zimmermann B; Heikinheimo K; Gibson CW; Fisher LW; Young MF; Blumenfeld A; Bernimoulin JP; Deutsch D

2009-06-01

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Progenitor cell populations in the periodontal ligament of mice  

International Nuclear Information System (INIS)

Stem cells in a variety of renewal tissues exhibit a slow rate of cell proliferation. The periodontal ligament of mouse molars was examined for the presence of slowly cycling progenitor cells to provide evidence for the existence of stem cells in this tissue. A pulse injection of 3H-thymidine was administered and mice were sacrificed between 1 hour and 14 days after injection. Analysis of radioautographs using percentage of labeled cells and grain counts demonstrated that a population of label-retaining cells within 10 micron of blood vessels traversed the cell cycle more slowly than proliferating cells located greater than 10 micron from blood vessels. These data suggest that there is a slowly dividing population of progenitor cells in paravascular sites in mouse molar periodontal ligament which may be stem cells.

1985-01-01

 
 
 
 
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Progenitor cell populations in the periodontal ligament of mice  

Energy Technology Data Exchange (ETDEWEB)

Stem cells in a variety of renewal tissues exhibit a slow rate of cell proliferation. The periodontal ligament of mouse molars was examined for the presence of slowly cycling progenitor cells to provide evidence for the existence of stem cells in this tissue. A pulse injection of /sup 3/H-thymidine was administered and mice were sacrificed between 1 hour and 14 days after injection. Analysis of radioautographs using percentage of labeled cells and grain counts demonstrated that a population of label-retaining cells within 10 micron of blood vessels traversed the cell cycle more slowly than proliferating cells located greater than 10 micron from blood vessels. These data suggest that there is a slowly dividing population of progenitor cells in paravascular sites in mouse molar periodontal ligament which may be stem cells.

McCulloch, C.A.

1985-03-01

22

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

Science.gov (United States)

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.

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

2009-10-01

23

Presence of oxytalan fibers in human regenerated periodontal ligament.  

UK PubMed Central (United Kingdom)

The aim of the present study was to investigate whether oxytalan fibers are formed in the regenerated human periodontal ligament. 6 patients, each of them exhibiting an advanced intrabony defect, were treated with a bioresorbable membrane according to the GTR-principle. Following a healing period of 6 months, the teeth were extracted together with their surrounding soft and hard tissues and subsequently fixed in 10% buffered formalin. Following decalcification in EDTA, the specimens were embedded in paraffin and 8-microm histological sections were cut in the mesio-distal direction, parallel to the long axes of the teeth. The sections were stained with hematoxylin and eosin, or with the oxone-aldehyde-fuchsin-Halmi staining method and examined in the light microscope. A regenerated periodontal ligament containing newly-formed oxytalan fibers was observed in all specimens. Many of them inserted into the newly formed cementum on the root surface. It is concluded that oxytalan fibers are formed de novo in human regenerated periodontal ligament tissue.

Sculean A; Donos N; Windisch P; Reich E; Gera I; Brecx M; Karring T

1999-05-01

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Capturing the Regenerative Potential of Periodontal Ligament Fibroblasts  

Directory of Open Access Journals (Sweden)

Full Text Available The cell population within the periodontal ligament (PDL) tissue is remarkably heterogeneous1. Fibroblasts, a mixed population of cells, are the main cellular component of the PDL and the cell type most often studied for periodontal regeneration. Osteoblasts and osteoclasts are found on the bone side, while fibroblasts, macrophages, undifferentiated adult/mesenchymal stem cells, neural elements, and endothelial cells are found throughout the PDL. Epithelial rests of Malassez cells and cementoblasts are focused near the root surface. PDL tissue also includes loose connective tissue between dense fiber bundles that contain branches of the periodontal blood vessels and nerves2. The complexity of the PDL tissue, with its various cell types and cell progenitor components, explains the challenges involved in therapies to restore tissue following periodontal disease. Cementoblasts, osteoblasts, and endothelial cells must migrate, differentiate, and coordinately interact with a variety of soluble mediators to regenerate the periodontium3. Stem cells located in the PDL tissue are key contributors to this process4. Stem cells in the PDL are important not only for formation and maintenance of the tissue but also for repair, remodeling, and regeneration of adjacent alveolar bone and cementum5. Our laboratory has shown that progenitor cells isolated from PDL tissue by selection with cell surface markers STRO-1+ and CD146+ are capable of differentiating into chondrogenic, osteogenic, and adipogenic phenotypes under appropriate culture conditions6.

Christina Springstead Scanlon; Julie Teresa Marchesan; Stephen Soehren; Masato Matsuo; Yvonne L. Kapila

2011-01-01

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Cryopreservation induces macrophage colony stimulating factor from human periodontal ligament cells in vitro.  

Science.gov (United States)

Cryopreservation is used to protect vital periodontal ligaments during the transplantation of teeth. We investigated which gene products implicated in root resorption are upregulated in human periodontal ligament cells by cryopreservation, and whether cryopreservation affects the expression of macrophage-colony stimulating factor (M-CSF) in human periodontal ligament cells. We used customized microarrays to compare gene expression in human periodontal ligament cells cultured from teeth immediately after extraction and from cryopreserved teeth. Based on the result of these assays, we examined M-CSF expression in periodontal ligament cells from the immediately extracted tooth and cryopreserved teeth by real-time PCR, enzyme-linked immunosorbent assay (ELISA), Western blot analysis, and immunofluorescence. We also investigated whether human bone marrow cells differentiate into tartrate-resistant acid phosphatase (TRAP) positive osteoclasts when stimulated with RANKL (Receptor Activator for Nuclear Factor ? B Ligand) together with any secreted M-CSF present in the supernatants of the periodontal ligament cells cultured from the various groups of teeth. M-CSF was twofold higher in the periodontal ligament cells from the rapid freezing teeth than in those from the immediately extracted group (p<0.05). Cryopreservation increased M-CSF expression in the periodontal ligament cells when analyzed by real time PCR, ELISA, Western blotting, and immunofluorescence (p<0.05). TRAP positive osteoclasts were formed in response to RANKL and the secreted M-CSF present in the supernatants of all the experimental groups except negative control. These results demonstrate that cryopreservation promotes the production of M-CSF, which plays an important role in root resorption by periodontal ligament cells. PMID:23810633

Rhim, E-M; Ahn, S-J; Kim, J-Y; Chang, Y-R; Kim, K-H; Lee, H-W; Jung, S-H; Kim, E-C; Park, S-H

2013-06-25

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Cryopreservation induces macrophage colony stimulating factor from human periodontal ligament cells in vitro.  

UK PubMed Central (United Kingdom)

Cryopreservation is used to protect vital periodontal ligaments during the transplantation of teeth. We investigated which gene products implicated in root resorption are upregulated in human periodontal ligament cells by cryopreservation, and whether cryopreservation affects the expression of macrophage-colony stimulating factor (M-CSF) in human periodontal ligament cells. We used customized microarrays to compare gene expression in human periodontal ligament cells cultured from teeth immediately after extraction and from cryopreserved teeth. Based on the result of these assays, we examined M-CSF expression in periodontal ligament cells from the immediately extracted tooth and cryopreserved teeth by real-time PCR, enzyme-linked immunosorbent assay (ELISA), Western blot analysis, and immunofluorescence. We also investigated whether human bone marrow cells differentiate into tartrate-resistant acid phosphatase (TRAP) positive osteoclasts when stimulated with RANKL (Receptor Activator for Nuclear Factor ? B Ligand) together with any secreted M-CSF present in the supernatants of the periodontal ligament cells cultured from the various groups of teeth. M-CSF was twofold higher in the periodontal ligament cells from the rapid freezing teeth than in those from the immediately extracted group (p<0.05). Cryopreservation increased M-CSF expression in the periodontal ligament cells when analyzed by real time PCR, ELISA, Western blotting, and immunofluorescence (p<0.05). TRAP positive osteoclasts were formed in response to RANKL and the secreted M-CSF present in the supernatants of all the experimental groups except negative control. These results demonstrate that cryopreservation promotes the production of M-CSF, which plays an important role in root resorption by periodontal ligament cells.

Rhim EM; Ahn SJ; Kim JY; Chang YR; Kim KH; Lee HW; Jung SH; Kim EC; Park SH

2013-10-01

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Identification and Cementoblastic / Osteoblastic Differentiation of Postnatal Stem Cells from Human Periodontal Ligament  

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Full Text Available Background. Periodontal diseases that lead to the destruction of periodontal tissues, including periodontal ligament (PDL), cementum, and bone, are a major cause of tooth loss in adults and are a substantial public health burden worldwide. PDL is a specialized connective tissue that connects cementum and alveolar bone to maintain and support teeth in situ and preserve tissue homoeostasis. In this study we aimed to isolate, identify periodontal ligament stem cells and their osteoblastic/ cementoblastic differentiation.Methods. Periodontal ligament tissue was obtained from human impacted third molars (n=5) from different individuals from the oral surgery department, Department of Oral and Maxillofacial Surgery, Capital Medical University School of Stomatology (Beijing, China) following which a colony forming unit – fibroblast assay, identification of periodontal ligament stem cells (PDLSCs; STRO-1 + & CD146+) by using immunocytofluorescence and isolation of PDLSCs (STRO-1+) by using flow cytometry and cementoblastic/osteoblastic exvivo induction were performed.Results. Mesenchymal stem cells were identified in the periodontal ligament derived by their capacity to form adherent clonogenic cell clusters. Ex-vivo expanded periodontal ligament stem cells were found to express the mesenchymal stem cell markers STRO-1 and CD146. Flow cytometric study showed that a total of 24.53% of periodontal ligament cell population stained positive for the STRO-1 antibody and of that population 1.14% were strongly positive. Conclusions. The finding of this study indicated that some PDL cells possess crucial stem cells properties, such as self renewal and express the mesenchymal stem cell markers (STRO-1 and CD 146) on their cell surface and small round alizarin red-positive nodules formed in the PDLSC cultures after 4 weeks of induction, indicating calcium accumulation in vitro. Thus, PDL cells can be used for periodontal regenerative procedures.

Maha Abd El Fattah; Gang Ding; Fulan Wei; Chunmei Zhang; Eman Aboul Ezz; Songlin Wang

2011-01-01

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Periodontal Ligament Cell Sheet Engineering: A new Possible Strategy to Promote Periodontal Regeneration  

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Full Text Available Introduction: Osseointegration represents a direct structural and functional connection between ordered, living bone and the surface of a load-carrying implant without the periodontium. As a result, im-plant fracture or aggressive bone loss sometime occurs because the patient cannot feel the mechanical overloads exerted on the implant. Until now, no available method has been used to solve this problem.The hypothesis: Periodontal ligament (PDL) cells are a desirable cell population capable of regenerating a functional periodontal at-tachment apparatus. Cell sheet engineering has emerged as a novel alternative approach for periodontal tissue engineering without the disruption of both critical cell surface proteins such as ion channels, growth factor receptors and cell-to-cell junction proteins. PDL cells can be isolated from an extracted tooth and can be cultured on temperature-responsive culture dishes at 37°C. Transplantable cell sheets can be harvested by reducing the temperature to 20°C, and would be transplanted into the implant beds before insertion of the implant.Evaluation of the hypothesis: Controlling the differentiation of PDL cell sheets to different functional peri-implant periodontal tissues is very difficult. Further studies are required to determine the fate of implanted cells. Fluorescence protein-labeled cell sheets would be a good approach to investigate the fate of the grafted cell sheet.

Sheng-yun Huang; Dong-sheng Zhang

2010-01-01

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A study on cryopreservation of cultured rabbit periodontal ligament cells.  

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Full Text Available Cultured rabbit periodontal ligament cells were subjected to short term cryopreservation in liquid nitrogen, for a period of 84 hours and 168 hours, to study the effect of cryopreservation on coll viability and culturing ability. The vital cell count performed by Trypan Blue exclusion was 14.93 x 10(0) cells/ml in vial A and 9.11 x 10(6) cell/ml in vial B, before cryopreservation. The loss of viability was minimal--vital cell count being 14.64 x 10(6) cells/ml in vial A and 8.87 x 10(6) cells/ml in vial B after 84 hrs of cryopreservation and 14.6 x 10(6) cells/ml in vial A and 8.82 x 10(6) cells/ml in vial B after 168 hours of cryopreservation. The cryopreserved cells after thawing could grow again in cultured.

Pal Tamal; Aibara Farzan; Ali N

2002-01-01

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Gap-junction-mediated communication in human periodontal ligament cells.  

Science.gov (United States)

Periodontal tissue homeostasis depends on a complex cellular network that conveys cell-cell communication. Gap junctions (GJs), one of the intercellular communication systems, are found between adjacent human periodontal ligament (hPDL) cells; however, the functional GJ coupling between hPDL cells has not yet been elucidated. In this study, we investigated functional gap-junction-mediated intercellular communication in isolated primary hPDL cells. SEM images indicated that the cells were in contact with each other via dendritic processes, and also showed high anti-connexin43 (Cx43) immunoreactivity on these processes. Gap-junctional intercellular communication (GJIC) among hPDL cells was assessed by fluorescence recovery after a photobleaching (FRAP) analysis, which exhibited dye coupling between hPDL cells, and was remarkably down-regulated when the cells were treated with a GJ blocker. Additionally, we examined GJs under hypoxic stress. The fluorescence recovery and expression levels of Cx43 decreased time-dependently under the hypoxic condition. Exposure to GJ inhibitor or hypoxia increased RANKL expression, and decreased OPG expression. This study shows that GJIC is responsible for hPDL cells and that its activity is reduced under hypoxia. This is consistent with the possible role of hPDL cells in regulating the biochemical reactions in response to changes in the hypoxic environment. PMID:23677649

Kato, R; Ishihara, Y; Kawanabe, N; Sumiyoshi, K; Yoshikawa, Y; Nakamura, M; Imai, Y; Yanagita, T; Fukushima, H; Kamioka, H; Takano-Yamamoto, T; Yamashiro, T

2013-05-15

31

[Effects of emdogain on human periodontal ligament cells in vitro].  

UK PubMed Central (United Kingdom)

OBJECTIVE: To investigate the effects of emdogain, enamel matrix derivative (EMD), on the proliferation, cell cycle, mineralization and ultrastructure of human periodontal ligament (PDL) cells in vitro. METHODS: The influence of cell growth on PDL cells was evaluated by Cell Counting Kit-8 (CCK-8) in the presence and absence of emdogain, after 1, 3, and 5 d of culture. DNA synthesis and ultrastructure of PDL cells were observed by flow cytometry(FCM) and transmission electron microscopy (TEM) in the presence and absence of emdogain after 3 d of culture. The increasing of osteogenic capacity was verified by the expression changes of osteogenic differentiation markers of bone sialoprotein (BSP) and osteopontin (OPN) in emdogain-treated PDL cells by immunohistochemicl staining. RESULTS: Incubation of PDL cells with emdogain after 3 d significantly stimulated cell growth and DNA synthesis. Emdogain enhanced the osteogenic potential of PDL cells by high expression of osteogenic differentiation markers of BSP and OPN. CONCLUSION: The data indicate that Emdogain enhances cell proliferation and promotes differentiation of PDL cells, which contributes to periodontal tissue regeneration .

Zhang FQ; Meng HX; Han J; Liu KN

2012-02-01

32

Effects of enamel matrix proteins on multi-lineage differentiation of periodontal ligament cells in vitro.  

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The adult periodontal ligament (PDL) is considered to contain progenitor cells that are involved in the healing of periodontal wounds. Treatment with enamel matrix derivative (EMD), a heat-treated preparation derived from enamel matrix proteins (EMPs), has been shown to be of some clinical benefit i...

Amin, HD; Olsen, I; Knowles, JC; Dard, M; Donos, N

33

Assessment of the regenerative potential of allogeneic periodontal ligament stem cells in a rodent periodontal defect model.  

UK PubMed Central (United Kingdom)

BACKGROUND AND OBJECTIVE: The complex microenvironment of the periodontal wound creates many challenges associated with multitissue regeneration of periodontal lesions. Recent characterization of mesenchymal stem cell-like populations residing in periodontal ligament tissues has shown that these cells exhibit features of postnatal stem cells. Despite these advances, a lack of consistency in design of preclinical studies and a limited study of allogeneic transplantation applications has restricted our understanding of their clinical utility in the treatment of periodontal disease. The aim of this study was to assess the regenerative potential of allogeneic periodontal ligament stem cells (PDLSCs) in a rat periodontal fenestration defect mode and to identify an optimal end time-point suitable for quantitative assessment of tissue regeneration. MATERIAL AND METHODS: Periodontal fenestration defects, created in Sprague Dawley rats, were treated with allogeneic PDLSCs seeded onto Gelfoam(®) (Absorbable gelatin sponge; Pharmacia Corporation, Kalamazoo, MI, USA) or with Gelfoam(®) alone, or remained untreated. Experimental rats were killed at 7, 14, 21 or 28 d after surgery and the tissues were processed for immunohistochemical and histomorphometric examination. RESULTS: Defects treated with PDLSCs showed significantly greater percentage bone fill and length of new bone bridge compared with the untreated group or the group treated withGelfoam(®) alone on days 14 and 21. Similarly, a statistically significant difference was achieved within specimens retrieved on day 21 for analysis of regeneration of cementum/periodontal ligament (PDL)-like structures. CONCLUSION: The present investigation shows that allogeneic PDLSCs have a marked ability to repair periodontal defects by forming bone, PDL and cementum-like tissue in vivo. The results suggest that treatment periods of 14 and 21 d are optimal end time-points for quantitative assessment of periodontal regeneration within the rodent fenestration-defect model utilized in the present study.

Han J; Menicanin D; Marino V; Ge S; Mrozik K; Gronthos S; Bartold PM

2013-07-01

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Effect of storage media on the proliferation of periodontal ligament fibroblasts  

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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.

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

1987-07-01

35

Effect of storage media on the proliferation of periodontal ligament fibroblasts  

International Nuclear Information System (INIS)

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. [3H]-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

1987-01-01

36

High levels of glucose induced the caspase-3/PARP signaling pathway, leading to apoptosis in human periodontal ligament fibroblasts.  

UK PubMed Central (United Kingdom)

Periodontitis is one of the main complications of diabetes mellitus, and much research has been conducted on their relationship. However, the mechanism by which high glucose levels induce damage of periodontal ligament fibroblasts is still unclear. In this study, we investigated the effects of high glucose levels on apoptosis in human periodontal ligament fibroblasts and the possible mechanisms involved. Human periodontal ligament fibroblasts were cultured in DMEM with normal glucose (5.5 mM) and high glucose (35 mM) levels for 6, 12, or 24 h. Apoptosis was studied by flow cytometry, caspase assays, fluorescent real-time PCR, and Western-blot analysis. The different durations of high glucose incubation induced a time-dependent increase of apoptosis and caspase-3 activity in cultured human periodontal ligament fibroblasts. In addition, concentrations of caspase-3 and its substrate PARP in cultured human periodontal ligament fibroblasts increased in a time-dependent manner. Furthermore, a caspase-3 inhibitor could prevent the high glucose-induced apoptosis in human periodontal ligament fibroblasts. These data indicate that high glucose induces a time- and caspase-3-dependent increase in apoptosis in cultured human periodontal ligament fibroblasts. These results elucidate the mechanism for the regulation of human periodontal ligament fibroblast apoptosis caused by high glucose.

Liu J; Wu Y; Wang B; Yuan X; Fang B

2013-06-01

37

An experimental study on the effect of irradiation on deciduous dental pulp and periodontal membrane  

International Nuclear Information System (INIS)

[en] Left mandibular third deciduous molars of young dogs were irradiated for 3,000 R with 200 kVp X-ray and the effect on the dental pulp and periodontal membrane was investigated histopathologically. 1. From 3rd to 7th days after irradiation, localized inflammatory cell infiltration was observed in part in the dental pulp tissue. No abnormal findings were observed in the periodontal membrane. 2. On 14th day after irradiation in the coronal dental pulp, cells decreased; karyopycnosis occurred; cells were connected only by cellular processes, and large and small reticular networks were formed. In the periodontal membrane, fibers ran irregularly although in part and findings of atrophy were seen. Fibroblasts showed a decreasing tendency. 3. In the cases from 1 to 2 months after irradiation, the pulp tissue showed marked atrophy of odontoblasts and the dental pulp showed hyalinization-like changes. In the periodontal membrane, Sharpey's fibers ran irregularly or became indistinct, and fibroblasts decreased extensively. The periodontal membrane in general showed hyalinization. 4. In the cases of 4 months after irradiation, the pulp tissue on the whole showed marked atrophy and disappearance of odontoblast layers. In the periodontal membrane, inflammatory cell infiltration was seen in part and membrane fibers, as those in 2nd month, showed marked atrophy, became enlarged, and presented findings of hyalinization. 5. At 8th month, the necleoli nearly disappeared in the pulp tissue from the crown to the root and the cells were connected like filaments by cellular processes. Nearly all the blood vessels and fibers disappeared. In the periodontal membrane, most of Sharpey's fibers disappeared. Fibroblasts showed marked atrophy and disappearance, and few normal fibloblasts could be found. (J.P.N.)

1986-01-01

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[Experiments to determine the time dependent material properties of the periodontal ligament].  

Science.gov (United States)

The periodontal ligament is a tissue that attaches the tooth (root) to its alveolar socket, and thus plays an important role in the regulation of tooth movements. Detailed knowledge of the material properties of the periodontal ligament is therefore essential to an understanding of tooth reaction to forces applied during orthodontic treatment. A knowledge of material parameters can also be used in simulations of long-term tooth movements with the aim of improving orthodontic treatment. To this end, this study investigated time-dependent material properties, namely the hysteresis behaviour of the periodontal ligament under constant-velocity loading, the influence of loading velocity on the hysteresis, and its failure under constant loading. Specimens obtained from pigs were used for testing purposes, and the experiments were conducted in a special test setup using a material testing device. The material behaviour of the periodontal ligament was shown to be viscoelastic, and the elastic parameters of material behaviour were also determined. Under constant-velocity loading, material behaviour showed a nonlinear course of the stress-strain curve, also known as hysteresis. When loading was repeated several times, the maximum stress of the hysteresis decreased with each cycle. Determination of the deflection of the specimen at different velocities showed maximum stress to be dependent on the loading rate. The measured stress-strain curves were approximated by bilinear behaviour, permitting the use of finite element calculations. Also investigated was the failure behaviour of the periodontal ligament, which revealed tissue rupture to be inconstant. PMID:12201015

Krstin, N; Dorow, Ch; Franke, R P; Sander, F G

39

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

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Full Text Available 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.

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

2008-01-01

40

Focal adhesion kinase mediates ?-catenin signaling in periodontal ligament cells.  

UK PubMed Central (United Kingdom)

Periodontal ligament (PDL) cells convert the orthodontic forces into biological responses by secreting signaling molecules to induce modeling of alveolar bone and tooth movement. Beta-catenin pathway is activated in response to mechanical loading in PDL cells. The upstream signaling pathways activated by mechanical loading resulting in the activation of ?-catenin pathway through Wnt-independent mechanism remains to be characterized. We hypothesized that mechanical loading induces activation of ?-catenin signaling by mechanisms that dependent on focal adhesion kinase (FAK) and nitric oxide (NO). We found that mechanical or pharmacological activation of ?-catenin signaling in PDL cells upregulated the expression of ?-catenin target genes. Pre-treatment of PDL cells with FAK inhibitor-14 prior to mechanical loading abolished the mechanical loading-induced phosphorylation of Akt and dephosphorylation of ?-catenin. PDL cells pre-treated with NO donor or NO inhibitor and subjected to mechanical loading. Western blot analysis showed that the mechanical loading or pre-treatment with NO donor increased the levels of dephosphorylated ?-catenin, pAkt, and pGSK-3?. Pre-treatment with NO inhibitor blocked the mechanical loading-induced phosphorylation of Akt and dephosphorylation of ?-catenin. These data indicate that mechanical loading-induced ?-catenin stabilization in PDL cells involves phosphorylation of Akt by two parallel pathways requiring FAK and NO.

Premaraj S; Souza I; Premaraj T

2013-10-01

 
 
 
 
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Regenerative potential of human periodontal ligament derived stem cells on three-dimensional biomaterials: a morphological report.  

Science.gov (United States)

Recent studies have shown that mesenchymal stem cells obtained from periodontal ligament (PDL-MSCs) are multipotent cells that have similar features of the bone marrow and dental pulp MSCs and are capable of proliferating and producing different types of tissue such as bone and tooth associated-tissues. Human PDL-MSCs expanded ex vivo were induced to osteogenesis, seeded in three-dimensional biocompatible scaffolds (fibrin sponge, bovine-derived substitutes) and examined using light, scanning and transmission electron microscopy. Morphological observations showed extensive growth of cellular biomass partially covering the scaffolds after 4 weeks of incubation in mineralization medium. These findings indicate that periodontal ligament can be an easily and efficient autologous source of stem cells with a high expansion capacity and ability to differentiate in osteogenic cells that can colonize and grow connected to bio-compatible scaffold. It can be suggested that the use of PDL-MSCs for generating graft biomaterials is advantageous for bone tissue engineering in regenerative dentistry. PMID:18257082

Trubiani, O; Orsini, G; Zini, N; Di Iorio, D; Piccirilli, M; Piattelli, A; Caputi, S

2008-12-15

42

Regenerative potential of human periodontal ligament derived stem cells on three-dimensional biomaterials: a morphological report.  

UK PubMed Central (United Kingdom)

Recent studies have shown that mesenchymal stem cells obtained from periodontal ligament (PDL-MSCs) are multipotent cells that have similar features of the bone marrow and dental pulp MSCs and are capable of proliferating and producing different types of tissue such as bone and tooth associated-tissues. Human PDL-MSCs expanded ex vivo were induced to osteogenesis, seeded in three-dimensional biocompatible scaffolds (fibrin sponge, bovine-derived substitutes) and examined using light, scanning and transmission electron microscopy. Morphological observations showed extensive growth of cellular biomass partially covering the scaffolds after 4 weeks of incubation in mineralization medium. These findings indicate that periodontal ligament can be an easily and efficient autologous source of stem cells with a high expansion capacity and ability to differentiate in osteogenic cells that can colonize and grow connected to bio-compatible scaffold. It can be suggested that the use of PDL-MSCs for generating graft biomaterials is advantageous for bone tissue engineering in regenerative dentistry.

Trubiani O; Orsini G; Zini N; Di Iorio D; Piccirilli M; Piattelli A; Caputi S

2008-12-01

43

Stereological Analysis of the Dental Pulp in Patients with Advanced Periodontitis  

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Full Text Available Background: The adverse effects of periodontitis on dental pulp have long been argued. The purpose of this study was to investigate stereological indices of dental pulp in patients with advanced periodontitis compared with healthy people. Materials and Methods: In this case-control study, 15 single-rooted permanent teeth of patients with advanced periodontal diseases and that of people with healthy periodontium, as control group, were investigated. All teeth were intact, and without filling and decay. After tissue processing, longitudinal serial sections of the tooth were prepared and stained by Masson’s trichrome. A grid containing organized points superimposed on the images of each section randomly. Then, the points hit with each subject were counted. The volume of pulp and its components in both groups were estimated, using Cavalieri’s principle. Data were analyzed using Mann-Whitney U test. The significance level was considered as p<0.05.Results: No significant difference was observed between the groups in terms of inflammation and calcification intensity (p<0.05). Microscopic evaluations of tissue sections showed significant increase in predentin thickness in periodontitis group than control group (p<0.05). In addition, statistically significant reduction was observed in periodontitis group with respect to pulp absolute volume, volume density, odontoblastic layer absolute volume, collagen fibers absolute volume, and absolute pulp blood vessels volume, compared with control group (p<0.05).Conclusion: Results showed periodontal disease affects stereological parameters of pulp. Because of reduction of pulp volume and narrowing of root canal, precise diagnostic and therapeutic considerations are recommended during treatment of those teeth.

Zahra Heidari; Eshagh Ali Saberi; Hamidreza Mahmoudzadeh-Sagheb; Narges Farhad-Mollashahi; Firouz Zadfatah

2013-01-01

44

Degenerative alterations of the cementum-periodontal ligament complex and early tooth loss in a young patient with periodontal disease.  

Science.gov (United States)

Premature exfoliation of primary or permanent teeth in children or adolescents is extremely rare and it can be a manifestation of an underlying systemic disease. This study aims to present the histological aspects associated with early tooth loss in a case of periodontal disease developed without local inflammation and with minimal periodontal pockets and attachment loss. The maxillary left second premolar was extracted together with a gingival collar attached to the root surface. The histological analysis recorded the resorption of the cementum in multiple areas of the entire root surface with the connective tissue of the desmodontium invading the lacunae defects. The connective tissue rich in cells occupied the periodontal ligamentar space and the resorptive areas. No inflammation was obvious in the periodontal ligament connective tissue. This report may warn clinicians about the possibility of the association of cemental abnormalities with early tooth loss. PMID:23303038

Petru?iu, S A; Buiga, Petronela; Roman, Alexandra; Danciu, Theodora; Mihu, Carmen Mihaela; Mihu, D

2012-01-01

45

Degenerative alterations of the cementum-periodontal ligament complex and early tooth loss in a young patient with periodontal disease.  

UK PubMed Central (United Kingdom)

Premature exfoliation of primary or permanent teeth in children or adolescents is extremely rare and it can be a manifestation of an underlying systemic disease. This study aims to present the histological aspects associated with early tooth loss in a case of periodontal disease developed without local inflammation and with minimal periodontal pockets and attachment loss. The maxillary left second premolar was extracted together with a gingival collar attached to the root surface. The histological analysis recorded the resorption of the cementum in multiple areas of the entire root surface with the connective tissue of the desmodontium invading the lacunae defects. The connective tissue rich in cells occupied the periodontal ligamentar space and the resorptive areas. No inflammation was obvious in the periodontal ligament connective tissue. This report may warn clinicians about the possibility of the association of cemental abnormalities with early tooth loss.

Petru?iu SA; Buiga P; Roman A; Danciu T; Mihu CM; Mihu D

2012-01-01

46

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

International Nuclear Information System (INIS)

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.

2006-10-27

47

Gingival crevicular fluid can degrade Emdogain and inhibit Emdogain-induced proliferation of periodontal ligament fibroblasts.  

UK PubMed Central (United Kingdom)

BACKGROUND AND OBJECTIVE: Emdogain (EMD), consisting mostly of amelogenin, is used in periodontal therapy to regenerate lost connective tissue. Emdogain is applied onto periodontally affected root surfaces, where it becomes exposed to proteolytic enzymes. In this study, we aimed to find out whether gingival crevicular fluid or matrix metalloproteinases (MMPs) could degrade EMD, and whether this degradation has consequences for in vitro cell proliferation. MATERIAL AND METHODS: We studied the effects of 156 gingival crevicular fluid samples collected from subjects with different stages of periodontal disease and from healthy control subjects and the effects of MMP-1, -2, -8, -9, -13 and -14 on the degradation of EMD using EMD-embedded zymography. The effects of gingival crevicular fluid with or without EMD and the effects of amelogenin on the proliferation of cultured periodontal ligament fibroblasts were studied by cell proliferation enzyme-linked immunosorbent assay kit. RESULTS: Degradation of Emdogain induced by gingival crevicular fluid was greater in samples from all stages of periodontal diseases compared with healthy control samples. Of the MMPs studied, only MMP-2 and MMP-8 showed limited EMD-degrading activities. One hundred micrograms per millilitre of EMD increased proliferation of periodontal ligament fibroblasts on average by 24% (confidence interval 0.60-0.64) and at 200 microg/mL by 30% (confidence interval 0.62-0.68) compared with control fibroblasts (confidence interval 0.48-0.52). However, gingival crevicular fluid (10 microg/mL) together with 100 microg/mL EMD induced the proliferation only by 6% (confidence interval 0.51-0.55) and with 200 microg/mL EMD by 12% (confidence interval 0.54-0.58). Amelogenin at 200 microg/mL decreased the proliferation of periodontal ligament fibroblasts by 54% (confidence interval 0.22-0.25). CONCLUSION: We suggest that diseased gingival crevicular fluid containing various proteases leads to degradation of EMD and decreased proliferation of periodontal ligament fibroblasts.

Laaksonen M; Salo T; Vardar-Sengul S; Atilla G; Saygan BH; Simmer JP; Baylas H; Sorsa T

2010-06-01

48

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

Scientific Electronic Library Online (English)

Full Text Available Abstract in english 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 period (more) ontal 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.

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

2008-09-01

49

Microvascular response in the periodontal ligament following mucoperiosteal flap surgery.  

UK PubMed Central (United Kingdom)

BACKGROUND: When the mucoperiosteal flap is elevated, the gingivo-periosteal vascular plexus and periodontal ligament (PDL) vascular plexus sever their connection with the circulatory tracts that pass through alveolar bone. We studied the effect exerted on the PDL vascular plexus during restoration of the circulatory tract. METHODS: We performed experimental mucoperiosteal flap surgery in adult beagle dogs. Histological specimens, prepared after injecting India ink into the blood vessels on postoperative days 5, 7, 14, 21, 28, and 42, were examined under a light microscope. In addition, vascular corrosion cast specimens of the PDL, into which acrylic resin was injected, were observed using a scanning electron microscope. RESULTS: On postoperative day 5, the PDL vascular plexus had formed new blood vessels toward the bone side and root side, and bone resorption of the alveolar bone proper had initiated primarily around the opening of the Volkmann's canal. From postoperative day 7 to 14, the PDL vascular plexus formed new vessels on the bone side and root side accompanied by bone resorption of the alveolus, and demonstrated a complicated vascular architecture, which gradually organized and transformed into a mesh structure from postoperative day 21. Osteogenesis was initiated and encircled the newly formed vessels, and the alveolar bone proper recovered to a flat morphology. Judging from the quantity of new vessels and bone resorption, the width of the PDL space seemed to be the greatest on postoperative day 14. CONCLUSIONS: When the mucoperiosteal flap was elevated, active wound healing was activated because of angiogenesis from the PDL, which possesses a microcirculatory system. Moreover, it was suggested that angiogenesis of the PDL vascular plexus and subsequent bone resorption of alveolar bone might temporarily reduce the tooth-supporting function and cause postoperative mobility.

Nobuto T; Imai H; Suwa F; Kono T; Suga H; Jyoshi K; Obayashi K

2003-04-01

50

Histomorphological study of myelinated nerve fibres in the periodontal ligament of human canine  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Objective. This study aims to describe the human periodontal ligament (PDL) using serial sections, with a focus on mechanoreceptor distribution and morphology. Materials and methods. One permanent lower canine with surrounding PDL and alveolar bone tissues was retrieved from a human cadaver. After b...

Huang, Yan; Corpas, Livia S.; MARTENS, Wendy; Jacobs, Reinhilde; LAMBRICHTS, Ivo

51

Role of the epithelial cell rests of Malassez in the development, maintenance and regeneration of periodontal ligament tissues.  

Science.gov (United States)

Periodontitis is a highly prevalent inflammatory disease that results in damage to the tooth-supporting tissues, potentially leading to tooth loss. Periodontal tissue regeneration is a complex process that involves the collaboration of two hard tissues (cementum and alveolar bone) and two soft tissues (gingiva and periodontal ligament). To date, no periodontal-regenerative procedures provide predictable clinical outcomes. To understand the rational basis of regenerative procedures, a better understanding of the events associated with the formation of periodontal components will help to establish reliable strategies for clinical practice. An important aspect of this is the role of the Hertwig's epithelial root sheath in periodontal development and that of its descendants, the epithelial cell rests of Malassez, in the maintenance of the periodontium. An important structure during tooth root development, the Hertwig's epithelial root sheath is not only a barrier between the dental follicle and dental papilla cells but is also involved in determining the shape, size and number of roots and in the development of dentin and cementum, and may act as a source of mesenchymal progenitor cells for cementoblasts. In adulthood, the epithelial cell rests of Malassez are the only odontogenic epithelial population in the periodontal ligament. Although there is no general agreement on the functions of the epithelial cell rests of Malassez, accumulating evidence suggests that the putative roles of the epithelial cell rests of Malassez in adult periodontal ligament include maintaining periodontal ligament homeostasis to prevent ankylosis and maintain periodontal ligament space, to prevent root resorption, to serve as a target during periodontal ligament innervation and to contribute to cementum repair. Recently, ovine epithelial cell rests of Malassez cells have been shown to harbor clonogenic epithelial stem-cell populations that demonstrate similar properties to mesenchymal stromal/stem cells, both functionally and phenotypically. Therefore, the epithelial cell rests of Malassez, rather than being 'cell rests', as indicated by their name, are an important source of stem cells that might play a pivotal role in periodontal regeneration. PMID:23931062

Xiong, Jimin; Gronthos, Stan; Bartold, P Mark

2013-10-01

52

Histopathological Features of Dental Pulp in Teeth with Different Levels of Chronic Periodontitis Severity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Purpose. To evaluate the histopathological condition of the pulp in teeth with different levels of chronic periodontitis in humans. Methods. Twenty-five single-root nondecayed teeth were divided into three groups as follows: group 1, clinical attachment level (CAL) 3 to 4?mm and alveolar bone loss ...

Zuza, Elizangela Partata; Carrareto, Ana Luiza Vanzato; Lia, Raphael Carlos Comelli; Pires, Juliana Rico; de Toledo, Benedicto Egbert Corrêa

53

Effects of enamel matrix proteins on multi-lineage differentiation of periodontal ligament cells in vitro.  

UK PubMed Central (United Kingdom)

The adult periodontal ligament (PDL) is considered to contain progenitor cells that are involved in the healing of periodontal wounds. Treatment with enamel matrix derivative (EMD), a heat-treated preparation derived from enamel matrix proteins (EMPs), has been shown to be of some clinical benefit in eliciting periodontal regeneration in vivo. Although there is extensive information available about the effects of EMD on periodontal regeneration, the precise influence of this material on alveolar bone and the formation of blood vessels and proprioceptive sensory nerves, prominent features of functionally active periodontal tissue, remain unclear. The aim of the present study was therefore to examine the effects of EMD on the ability of human periodontal ligament cells (HPCs) to undergo multi-lineage differentiation in vitro. Our results showed that HPCs treated with EMD under non-selective growth conditions did not show any evidence of osteogenic, adipogenic, chondrogenic, neovasculogenic, neurogenic and gliogenic "terminal" differentiation. In contrast, under selective lineage-specific culture conditions, EMD up-regulated osteogenic, chondrogenic and neovasculogenic genes and "terminal" differentiation, but suppressed adipogenesis, neurogenesis and gliogenesis. These findings thus demonstrate for the first time that EMD can differentially modulate the multi-lineage differentiation of HPCs in vitro.

Amin HD; Olsen I; Knowles JC; Dard M; Donos N

2013-01-01

54

Effects of enamel matrix proteins on multi-lineage differentiation of periodontal ligament cells in vitro.  

Science.gov (United States)

The adult periodontal ligament (PDL) is considered to contain progenitor cells that are involved in the healing of periodontal wounds. Treatment with enamel matrix derivative (EMD), a heat-treated preparation derived from enamel matrix proteins (EMPs), has been shown to be of some clinical benefit in eliciting periodontal regeneration in vivo. Although there is extensive information available about the effects of EMD on periodontal regeneration, the precise influence of this material on alveolar bone and the formation of blood vessels and proprioceptive sensory nerves, prominent features of functionally active periodontal tissue, remain unclear. The aim of the present study was therefore to examine the effects of EMD on the ability of human periodontal ligament cells (HPCs) to undergo multi-lineage differentiation in vitro. Our results showed that HPCs treated with EMD under non-selective growth conditions did not show any evidence of osteogenic, adipogenic, chondrogenic, neovasculogenic, neurogenic and gliogenic "terminal" differentiation. In contrast, under selective lineage-specific culture conditions, EMD up-regulated osteogenic, chondrogenic and neovasculogenic genes and "terminal" differentiation, but suppressed adipogenesis, neurogenesis and gliogenesis. These findings thus demonstrate for the first time that EMD can differentially modulate the multi-lineage differentiation of HPCs in vitro. PMID:22985741

Amin, Harsh D; Olsen, Irwin; Knowles, Jonathan C; Dard, Michel; Donos, Nikolaos

2012-09-14

55

Regulation of Periodontal Ligament Cell Behaviour by Cyclic Mechanical Loading and Substrate Nanotexture.  

UK PubMed Central (United Kingdom)

Background: Periodontal ligament (PDL) cells play an important role in regulating osseous remodeling and ligament formation. Mechanical loading as well as the specific cellular environment are involved in these processes, regulating cell behaviour. However, most in vitro experimental setups investigate mechanical loading or substrate texture separately and thus are atypical to represent the PDL micro-environment. Therefore, we investigated the influence of combined mechano-topographical stimuli on PDL cell morphology, proliferation, as well as osteogenic and ligament differentiation. Methods: Human PDL cells were subjected to nanometric substrate patterning and cyclic tensile stress for 2 days. Cell morphology was assessed by fluorescent staining. Further, DNA content, mRNA expression of osteogenic (Runx2 transcription factor, Osteocalcin) and ligament related (Scleraxis transcription factor, Elastin) genes were determined. Results: PDL cells adapted to the topography of nanometric groove patterns, aligning parallel toward the texture. When subjected to mechanical stress, cells lost their initial orientation to the nano-pattern. When subjected to dual stimuli, total DNA amount was enhanced at 3 days of culture. Moreover, a significant synergistic effect on upregulation of Runx2 was observed in the combined group. For ligament-related markers, Sleraxis and Elastin expression increased upon mechanical loading, while decreased on nano-patterned surfaces. Conclusions: These results suggest that mechanical stimulation is crucial in regulating periodontal cell behavior, through modulation of osteogenic and ligament gene activity, while extracellular matrix-resembling structures induce different responses from PDL cells in morphology and gene expression.

Yu N; Prodanov L; Riet JT; Yang F; Walboomers XF; Jansen JA

2012-12-01

56

Regulation of Periodontal Ligament Cell Behaviour by Cyclic Mechanical Loading and Substrate Nanotexture.  

Science.gov (United States)

Background: Periodontal ligament (PDL) cells play an important role in regulating osseous remodeling and ligament formation. Mechanical loading as well as the specific cellular environment are involved in these processes, regulating cell behaviour. However, most in vitro experimental setups investigate mechanical loading or substrate texture separately and thus are atypical to represent the PDL micro-environment. Therefore, we investigated the influence of combined mechano-topographical stimuli on PDL cell morphology, proliferation, as well as osteogenic and ligament differentiation. Methods: Human PDL cells were subjected to nanometric substrate patterning and cyclic tensile stress for 2 days. Cell morphology was assessed by fluorescent staining. Further, DNA content, mRNA expression of osteogenic (Runx2 transcription factor, Osteocalcin) and ligament related (Scleraxis transcription factor, Elastin) genes were determined. Results: PDL cells adapted to the topography of nanometric groove patterns, aligning parallel toward the texture. When subjected to mechanical stress, cells lost their initial orientation to the nano-pattern. When subjected to dual stimuli, total DNA amount was enhanced at 3 days of culture. Moreover, a significant synergistic effect on upregulation of Runx2 was observed in the combined group. For ligament-related markers, Sleraxis and Elastin expression increased upon mechanical loading, while decreased on nano-patterned surfaces. Conclusions: These results suggest that mechanical stimulation is crucial in regulating periodontal cell behavior, through modulation of osteogenic and ligament gene activity, while extracellular matrix-resembling structures induce different responses from PDL cells in morphology and gene expression. PMID:23215671

Yu, Na; Prodanov, Ljupcho; Riet, Joost Te; Yang, Fang; Walboomers, X Frank; Jansen, John A

2012-12-01

57

NASA-approved rotary bioreactor enhances proliferation and osteogenesis of human periodontal ligament stem cells.  

Science.gov (United States)

Previous studies have suggested that periodontal ligament stem cells (PDLSCs) play crucial role in regeneration of periodontal defects, and recently tissue engineering based on PDLSCs to enhance periodontal regeneration has been the focus of periodontal research. A theoretical way to achieve this goal would be to provide a "stimulatory'' environment to rapidly expand PDLSCs in vitro to expedite tissue engineering of periodontium. We hypothesize that three-dimensional (3D) dynamic simulated microgravity (SMG) culture system have effect on periodontal stem cells, and would benefit periodontal stem cells proliferation and differentiation, but up to now, there are no related reports on this aspect. In this study, we investigated the biological effect of three-dimensional dynamic SMG induced by rotary cell culture system (RCCS) on human periodontal ligament stem cells (hPDLSCs) in vitro. hPDLSCs were isolated from surgically extracted human teeth and enriched by collecting multiple colonies. hPDLSCs were inoculated on Cytodex 3 microcarriers and cultured in RCCS. The results showed that SMG affected the biology of hPDLSCs as indicated by promotion of proliferation and viability, alterations of morphology, and disorganization of microfilament system. Besides, SMG-treated hPDLSCs presented increased matrix mineralization and up-regulated expression of mineralization associated genes after incubation in osteogenic medium. For it is the first time to investigate effects of SMG on PDLSCs, the research may lend insight into variations of cell response in 3D environment, and contribute to achievement of desirable periodontal regeneration utilizing PDLSCs-based tissue engineering approaches. PMID:19327006

Li, Shi; Ma, Zhaofeng; Niu, Zhongying; Qian, Hong; Xuan, Dongying; Hou, Rui; Ni, Longxing

2009-11-01

58

NASA-approved rotary bioreactor enhances proliferation and osteogenesis of human periodontal ligament stem cells.  

UK PubMed Central (United Kingdom)

Previous studies have suggested that periodontal ligament stem cells (PDLSCs) play crucial role in regeneration of periodontal defects, and recently tissue engineering based on PDLSCs to enhance periodontal regeneration has been the focus of periodontal research. A theoretical way to achieve this goal would be to provide a "stimulatory'' environment to rapidly expand PDLSCs in vitro to expedite tissue engineering of periodontium. We hypothesize that three-dimensional (3D) dynamic simulated microgravity (SMG) culture system have effect on periodontal stem cells, and would benefit periodontal stem cells proliferation and differentiation, but up to now, there are no related reports on this aspect. In this study, we investigated the biological effect of three-dimensional dynamic SMG induced by rotary cell culture system (RCCS) on human periodontal ligament stem cells (hPDLSCs) in vitro. hPDLSCs were isolated from surgically extracted human teeth and enriched by collecting multiple colonies. hPDLSCs were inoculated on Cytodex 3 microcarriers and cultured in RCCS. The results showed that SMG affected the biology of hPDLSCs as indicated by promotion of proliferation and viability, alterations of morphology, and disorganization of microfilament system. Besides, SMG-treated hPDLSCs presented increased matrix mineralization and up-regulated expression of mineralization associated genes after incubation in osteogenic medium. For it is the first time to investigate effects of SMG on PDLSCs, the research may lend insight into variations of cell response in 3D environment, and contribute to achievement of desirable periodontal regeneration utilizing PDLSCs-based tissue engineering approaches.

Li S; Ma Z; Niu Z; Qian H; Xuan D; Hou R; Ni L

2009-11-01

59

Periodontal ligament stem cells regulate B lymphocyte function via programmed cell death protein 1.  

UK PubMed Central (United Kingdom)

Periodontal ligament stem cells (PDLSCs) have provided novel cell sources for tooth and periodontal tissue regeneration. Allogeneic PDLSCs can reconstruct periodontal ligament tissue that has been damaged by periodontal diseases and regulate T-cell immunity. However, the effect of PDLSCs on B cells remains unknown. Here, we treated periodontitis in a miniature pig model using allogeneic PDLSCs and showed a reduction in humoral immunity in the animals. When cocultured with normal B cells, human PDLSCs (hPDLSCs) had similar effects as bone marrow mesenchymal stem cells in suppressing B cell proliferation, differentiation, and migration, while intriguingly, hPDLSCs increased B cell viability by secreting interleukin-6. Mechanistically, hPDLSCs suppressed B cell activation through cell-to-cell contact mostly mediated by programmed cell death protein 1 and programmed cell death 1 ligand 1. Our data revealed a previously unrecognized function of PDLSCs in regulating humoral immune responses, which may represent a novel therapeutic strategy for immune-related disorders.

Liu O; Xu J; Ding G; Liu D; Fan Z; Zhang C; Chen W; Ding Y; Tang Z; Wang S

2013-07-01

60

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

Science.gov (United States)

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.

Shelly, Ahuja; Shaila, Kothiwale; Kishore, Bhat

2006-03-01

 
 
 
 
61

Application of modified superposition model to viscoelastic behavior of periodontal ligament  

Directory of Open Access Journals (Sweden)

Full Text Available The periodontal ligament (PDL) is a soft bio-logical tissue which shows a strongly nonlinear and time dependent mechanical behavior. Re-cent experiments on rabbit PDL revealed that the rate of stress relaxation is strain dependent. This nonlinear behavior of PDL cannot be de-scribed well by the separable quasi linear vis-coelasticity theory which is usually used in tis-sue biomechanics. Therefore, PDL requires a more general description which considers this nonlinearity and time dependency. The purpose of this study was to model strain dependent stress relaxation behavior of PDL using modi-fied superposition method. It is shown herein that modified superposition method describes viscoelastic nonlinearties well and shows a good compatibility with available experimental PDL data. Hence, the modified superposition model is suggested to describe periodontal ligament data, because it can suitably demon-strate both elastic nonlinearity and strain-dependent stress relaxation behavior of PDL.

J. Hazrati; F. Ghalichi; B. Mirzakouchaki

2008-01-01

62

Experimental study on the effect of x-irradiation in the rat periodontal ligament  

International Nuclear Information System (INIS)

[en] The author studied on the effects of X-ray irradiation to the development of periodontal ligament in gestation rats. They were irradiated in their abdomen with 100, 200 and 300 rads respectively in one shot irradiation with deep radiation therapy equipment(MAXIMAR 250-III). In 7th, 14th, 21th and 28th day after delivery, those new born rats were respectively sacrificed with ether anesthesia and removed of their mandibles. After removal, those mandibles were fixed in 10% neutral buffer formalin, decalcified with 5% trichloroacetic acid for 5 days and embedded with paraffin. Staining was performed with H-E, Van Gieson, Mallory azan, Bielshowsky-Gomori silver stain and Halmi's oxytalan fiber stain. The results were as follows: 1. Before tooth eruption, all the fiber components in dental sac were almost always oriented near the outer enamel epithelial layer. But in irradiated new born rats, those collagen fiber orientation was more irregular than those of control groups, and this phenomenon was more severe in proportion to the amount of irradiation in the gestation period. 2. Before tooth eruption, the connective tissue fibers in periodontal ligament were stained with lighter in the irradiated groups than those of control groups. Oxytalan fibers of irradiated groups were thin and splitting pattern of their fiber morphology to compare with those of control groups. 3. After tooth eruption, the periodontal ligament fibers of irradiated groups were oriented functionally and their morphology was thick, fine and heavy staining. Oxytalan fibers were revealed with oblique parallel arrangement in the periodontal ligament of irradiated groups.

1980-01-01

63

Experimental study on the effect of x-irradiation in the rat periodontal ligament  

Energy Technology Data Exchange (ETDEWEB)

The author studied on the effects of X-ray irradiation to the development of periodontal ligament in gestation rats. They were irradiated in their abdomen with 100, 200 and 300 rads respectively in one shot irradiation with deep radiation therapy equipment(MAXIMAR 250-III). In 7th, 14th, 21th and 28th day after delivery, those new born rats were respectively sacrificed with ether anesthesia and removed of their mandibles. After removal, those mandibles were fixed in 10% neutral buffer formalin, decalcified with 5% trichloroacetic acid for 5 days and embedded with paraffin. Staining was performed with H-E, Van Gieson, Mallory azan, Bielshowsky-Gomori silver stain and Halmi's oxytalan fiber stain. The results were as follows: 1. Before tooth eruption, all the fiber components in dental sac were almost always oriented near the outer enamel epithelial layer. But in irradiated new born rats, those collagen fiber orientation was more irregular than those of control groups, and this phenomenon was more severe in proportion to the amount of irradiation in the gestation period. 2. Before tooth eruption, the connective tissue fibers in periodontal ligament were stained with lighter in the irradiated groups than those of control groups. Oxytalan fibers of irradiated groups were thin and splitting pattern of their fiber morphology to compare with those of control groups. 3. After tooth eruption, the periodontal ligament fibers of irradiated groups were oriented functionally and their morphology was thick, fine and heavy staining. Oxytalan fibers were revealed with oblique parallel arrangement in the periodontal ligament of irradiated groups.

Cho, Won Pyo; You, Dong Soo [Dept. of Radiology, Graduate School, Seoul National University, Seoul (Korea, Republic of)

1980-11-15

64

Proliferation of human periodontal ligament mesenchymal cells on polished and plasma nitriding titanium surfaces  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english AIM: To evaluate the proliferative capacity of mesenchymal cells derived from human periodontal ligament on polished and plasma-treated titanium surfaces. METHODS: Eighteen titanium disks were polished and half of them (n=9) were submitted to plasma nitriding using the cathodic cage technique. Mesenchymal cells were isolated from periodontal ligament of impacted third molars (n=2) and cultured on titanium disks (polished and nitrided) and on a plastic surface as a positiv (more) e control of cell proliferation. Cell proliferation was analyzed and growth curves were constructed for the different groups by determining the number of cells adhered to the different surfaces at 24, 48 and 72 h after plating. RESULTS: Higher cell number was observed for the nitrided surface at 24 and 48 h. However, no statistically significant difference in cell proliferation was observed between the two different surface treatments (p>0.05). CONCLUSIONS: We concluded that plasma nitriding produced surfaces that permitted the proliferation of human periodontal ligament mesenchymal cells. Associated to other physical and chemical properties, it is possible to assume the feasibility of plasma nitriding method and its positive effect on the early cellular events of osseointegration.

Ribeiro, Rodrigo Alves; Vasconcelos, Rodrigo Gadelha; Ginani, Fernanda; Silva, José Sandro Pereira da; Alves-Júnior, Clodomiro; Barboza, Carlos Augusto Galvão

2013-06-01

65

Dentists' level of knowledge of the treatment plans for periodontal ligament injuries after dentoalveolar trauma  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english This study investigated the level of knowledge held by dentists about the possible treatment plan procedures for periodontal ligament injuries after dentoalveolar trauma. A 5-item self-applied questionnaire was prepared with questions referring to the professional profile of the interviewees and to the treatment plan they would propose for periodontal ligament injuries secondary to dentoalveolar trauma. The questionnaires were filled out by 693 dentists attending the 23rd (more) Annual Meeting of the Brazilian Society for Dental Research, and the data obtained were subjected to descriptive analysis. Either the chi-square test or Fisher's exact test was applied to assess associations among variables, at a 5% level of significance. The results revealed that dentists experienced difficulty in establishing a treatment plan for subluxation, and for extrusive, lateral and intrusive luxations. In general, holding a dental specialty degree had no influence on the knowledge about treatment plan procedures for the most severe injuries. It could be concluded that the dentists participating in this study, whether specialists or not, did not have sufficient knowledge to treat most of the periodontal ligament injuries resulting from dentoalveolar trauma adequately.

Pedrini, Denise; Panzarini, Sônia Regina; Poi, Wilson Roberto; Sundefeld, Maria Lúcia Marçal Mazza; Tiveron, Adelisa Rodolfo Ferreira

2011-08-01

66

Dentists' level of knowledge of the treatment plans for periodontal ligament injuries after dentoalveolar trauma  

Directory of Open Access Journals (Sweden)

Full Text Available This study investigated the level of knowledge held by dentists about the possible treatment plan procedures for periodontal ligament injuries after dentoalveolar trauma. A 5-item self-applied questionnaire was prepared with questions referring to the professional profile of the interviewees and to the treatment plan they would propose for periodontal ligament injuries secondary to dentoalveolar trauma. The questionnaires were filled out by 693 dentists attending the 23rd Annual Meeting of the Brazilian Society for Dental Research, and the data obtained were subjected to descriptive analysis. Either the chi-square test or Fisher's exact test was applied to assess associations among variables, at a 5% level of significance. The results revealed that dentists experienced difficulty in establishing a treatment plan for subluxation, and for extrusive, lateral and intrusive luxations. In general, holding a dental specialty degree had no influence on the knowledge about treatment plan procedures for the most severe injuries. It could be concluded that the dentists participating in this study, whether specialists or not, did not have sufficient knowledge to treat most of the periodontal ligament injuries resulting from dentoalveolar trauma adequately.

Denise Pedrini; Sônia Regina Panzarini; Wilson Roberto Poi; Maria Lúcia Marçal Mazza Sundefeld; Adelisa Rodolfo Ferreira Tiveron

2011-01-01

67

In vitro cytotoxicity of white MTA, MTA Fillapex® and Portland cement on human periodontal ligament fibroblasts.  

UK PubMed Central (United Kingdom)

The aim of this study was to compare the in vitro cytotoxicity of white mineral trioxide aggregate (MTA), MTA Fillapex® and Portland cement (PC) on human cultured periodontal ligament fibroblasts. Periodontal ligament fibroblast culture was established and the cells were used for cytotoxic tests after the fourth passage. Cell density was set at 1.25 X10 4 cells/well in 96-well plates. Endodontic material extracts were prepared by placing sealer/cement specimens (5x3mm) in 1mL of culture medium for 72 h. The extracts were then serially two-fold diluted and inserted into the cell-seeded wells for 24, 48 and 72 h. MTT assay was employed for analysis of cell viability. Cell supernatants were tested for nitric oxide using the Griess reagent system. MTA presented cytotoxic effect in undiluted extracts at 24 and 72 h. MTA Fillapex® presented the highest cytotoxic levels with important cell viability reduction for pure extracts and at ½ and ¼ dilutions. In this study, PC did not induce alterations in fibroblast viability. Nitric oxide was detected in extract-treated cell supernatants and also in the extracts only, suggesting presence of nitrite in the soluble content of the tested materials. In the present study, MTA Fillapex displayed the highest cytotoxic effect on periodontal ligament fibroblasts followed by white MTA and PC.

Yoshino P; Nishiyama CK; Modena KC; Santos CF; Sipert CR

2013-01-01

68

Cell proliferation and 3H-proline incorporation in periodontal ligament exposed to mechanical stress  

International Nuclear Information System (INIS)

In order to study the metabolic processes induced in the periodontal ligament by mechanical influences, a tension spring was implanted in rats between the incisor and the first maxillary molar on the right-hand side, while the left maxilla of these animals as well as non-operated rats served as controls. Under such mechanical stress, there occurred at 3, 10 and 21 days after implantation a significant increase in the 3H-thymidine labelling index, which was demonstrate histoautoradiographically. A change in cell density was not discovered. Therefore, the increase in S-phase fraction as equally recorded in both pressure and tension zones is regarded as an expression of an enhanced cell turnover. Cell renewal in the periodontal ligament can be modified by inflammatory processes within the gingival region. There is a slight enlargement of the periodontal space in the tension zone. Under experimental conditions, no change occurs in the silver grain number per cell after 3H-proline administration. The results indicate that, following the impact of orthodontic forces, the reactivity of periodontal cell proliferation as compared to collagen synthesis is enhanced. (author).

1988-01-01

69

Histopatologic Evaluation of the Effect of Advanced Periodontal Diseases on Pulp Tissue  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction: The diagnosis of the origin of the lesions is one of the basic problems in Endo-Perio lesion. In order to prevent unnecessary and harmful treatment, the accurate diagnosis must be developed. The aim of this study was to evaluate the effect of advanced periodontal diseases on pulp tissue.Methods and materials: In this experimental study, fourty two anterior teeth were extracted from 22 patients referred to dental clinic of Isfahan university with advanced periodontal disease and 5 intact teeth as control were sectioned immediately after extraction. Teeth were fixed in 10% formalin solution. They were decalcified with Nitric Acid 10% and finally two histopathologic sections were prepared and evaluated. The results were statistically analyzed by Fisher’s exact test.Results: From total of 42 teeth; 13 teeth had normal pulp (30.95%), and the other 29 teeth (69.05%) had pulpal problem. The control group showed 100% normal results. Statistical analysis of the results showed significant difference between two groups.Conclusion: Under the limitations of the present study it was concluded that periodontal disease can develop inflammatory lesions, atrophic and degenerative changes in pulp.

A - Moghareabed; H Karimi

2006-01-01

70

[Effect of Osterix overexpression on osteogenic differentiation of human periodontal ligament cells].  

UK PubMed Central (United Kingdom)

OBJECTIVE: To investigate the effects of Osterix (Osx) overexpression on the osteogenic differentiation of human periodontal ligament cells in response to mechanical force. METHODS: Human periodontal ligament cells were isolated and cultured in vitro with explant method. Cells were transfected with either an Osx expression vector pcDNA3.1 flag-Osx or the mock control vector pcDNA3.1 flag. Then, cells were centrifuged for 6 h. After transfection and centrification, the expression of Osx mRNA and protein in untransfected cells, mock-transfected cells and Osx-transfected cells were measured by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot respectively. Furthermore, the changes of mRNA expressions of core-binding factor cal (Cbfal), alkaline phosphatase (ALP), osteopontin (OPN), osteocalcin (OC), bone sialoprotein(BSP) and collagen protein al (Col I ) genes were measured to assess the differentiation of human periodontal ligament cells. RESULTS: At 24 h after transfection, Osx mRNA and protein level increased significantly in Osx-transfected cells (P < 0.01), while there were no significant difference in Osx mRNA and protein levels between mock-transfected cells and untransfected cells(P > 0.05). Simultaneously, the upregulated mRNA expressions of all the five osteogenic genes were observed (P < 0.05, P < 0.01). After 6 h of mechanical stimulation, a significant increase in Osx expression was shown in all three groups. However, compared to mock-transfected and untransfected cells, Osx-transfected cells further showed the highest Osx mRNA and protein expression level. Furthermore, the mRNA expressions of all five osteogenic markers in Osx-transfected cells also exhibited the greater increase and showed the highest levels. CONCLUSION: The overexpression of Osx promotes the mechanical stress-induced osteogenic differentiation of human periodontal ligament cells. Osx may be essential for mechanical stress-induced differentiation of human periodontal ligament cells to osteoblas tic-like cells and be involved in orthodontic osteogenic remodeling.

Zhao Y; Li H; Wang C; Yang Q; Zheng Z; Fu Y

2013-04-01

71

Chronic periodontal disease may influence the pulp sensitivity response: clinical evaluation in consecutive patients.  

UK PubMed Central (United Kingdom)

Purpose. The aim of the present study was to evaluate the clinical response of the pulp in teeth with chronic periodontitis. Methods. Consecutive patients who had been admitted to the Clinics of Periodontology and fulfilled the criteria of inclusion were enrolled from January to December 2007. Ninety-eight single-root teeth from 27 patients with chronic periodontitis were evaluated clinically with regard to clinical attachment level (CAL), probing depth (PD), and gingival recession (REC). After periodontal measurements, Pulpal Sensitivity (PS) was evaluated with the use of a cooling stimulus test. Data was analyzed with Student's t test and contingency C coefficient. Results. Teeth that responded positively to PS test presented lower values of CAL (7.8 ± 2.8?mm), PD (5.0 ± 2.3?mm), and REC (2.8 ± 1.8?mm) in comparison to those that responded negatively (CAL = 12.0 ± 2.2?mm; PD = 7.9 ± 1.6?mm; REC = 4.1 ± 2.4?mm) (P < 0.01, Student's t test). In addition, significant correlations were observed between PS and periodontal parameters. Conclusions. Within the limits of this study, it could be suggested that the progression of periodontitis may significantly influence the negative pulpal response.

Zuza EP; Vanzato Carrareto AL; Pontes AE; Brunozzi M; Pires JR; Toledo BE

2012-01-01

72

Acemannan sponges stimulate alveolar bone, cementum and periodontal ligament regeneration in a canine class II furcation defect model.  

Science.gov (United States)

BACKGROUND AND OBJECTIVE: Periodontal disease is a common infectious disease, found worldwide, causing the destruction of the periodontium. The periodontium is a complex structure composed of both soft and hard tissues, thus an agent applied to regenerate the periodontium must be able to stimulate periodontal ligament, cementum and alveolar bone regeneration. Recent studies demonstrated that acemannan, a polysaccharide extracted from Aloe vera gel, stimulated both soft and hard tissue healing. This study investigated effect of acemannan as a bioactive molecule and scaffold for periodontal tissue regeneration. MATERIAL AND METHODS: Primary human periodontal ligament cells were treated with acemannan in vitro. New DNA synthesis, expression of growth/differentiation factor 5 and runt-related transcription factor 2, expression of vascular endothelial growth factor, bone morphogenetic protein-2 and type I collagen, alkaline phosphatase activity, and mineralized nodule formation were determined using [(3) H]-thymidine incorporation, reverse transcription-polymerase chain reaction, enzyme-linked immunoabsorbent assay, biochemical assay and alizarin red staining, respectively. In our in vivo study, premolar class II furcation defects were made in four mongrel dogs. Acemannan sponges were applied into the defects. Untreated defects were used as a negative control group. The amount of new bone, cementum and periodontal ligament formation were evaluated 30 and 60 d after the operation. RESULTS: Acemannan significantly increased periodontal ligament cell proliferation, upregulation of growth/differentiation factor 5, runt-related transcription factor 2, vascular endothelial growth factor, bone morphogenetic protein 2, type I collagen and alkaline phosphatase activity, and mineral deposition as compared with the untreated control group in vitro. Moreover, acemannan significantly accelerated new alveolar bone, cementum and periodontal ligament formation in class II furcation defects. CONCLUSION: Our data suggest that acemannan could be a candidate biomolecule for periodontal tissue regeneration. PMID:23710575

Chantarawaratit, P; Sangvanich, P; Banlunara, W; Soontornvipart, K; Thunyakitpisal, P

2013-05-28

73

Acemannan sponges stimulate alveolar bone, cementum and periodontal ligament regeneration in a canine class II furcation defect model.  

UK PubMed Central (United Kingdom)

BACKGROUND AND OBJECTIVE: Periodontal disease is a common infectious disease, found worldwide, causing the destruction of the periodontium. The periodontium is a complex structure composed of both soft and hard tissues, thus an agent applied to regenerate the periodontium must be able to stimulate periodontal ligament, cementum and alveolar bone regeneration. Recent studies demonstrated that acemannan, a polysaccharide extracted from Aloe vera gel, stimulated both soft and hard tissue healing. This study investigated effect of acemannan as a bioactive molecule and scaffold for periodontal tissue regeneration. MATERIAL AND METHODS: Primary human periodontal ligament cells were treated with acemannan in vitro. New DNA synthesis, expression of growth/differentiation factor 5 and runt-related transcription factor 2, expression of vascular endothelial growth factor, bone morphogenetic protein-2 and type I collagen, alkaline phosphatase activity, and mineralized nodule formation were determined using [(3) H]-thymidine incorporation, reverse transcription-polymerase chain reaction, enzyme-linked immunoabsorbent assay, biochemical assay and alizarin red staining, respectively. In our in vivo study, premolar class II furcation defects were made in four mongrel dogs. Acemannan sponges were applied into the defects. Untreated defects were used as a negative control group. The amount of new bone, cementum and periodontal ligament formation were evaluated 30 and 60 d after the operation. RESULTS: Acemannan significantly increased periodontal ligament cell proliferation, upregulation of growth/differentiation factor 5, runt-related transcription factor 2, vascular endothelial growth factor, bone morphogenetic protein 2, type I collagen and alkaline phosphatase activity, and mineral deposition as compared with the untreated control group in vitro. Moreover, acemannan significantly accelerated new alveolar bone, cementum and periodontal ligament formation in class II furcation defects. CONCLUSION: Our data suggest that acemannan could be a candidate biomolecule for periodontal tissue regeneration.

Chantarawaratit P; Sangvanich P; Banlunara W; Soontornvipart K; Thunyakitpisal P

2013-05-01

74

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

UK PubMed Central (United Kingdom)

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 previously suggested.

Leblanc AR; Reisz RR

2013-01-01

75

Effect of the treatment of root surface-adhered necrotic periodontal ligament with propolis or fluoride in delayed rat tooth replantation.  

UK PubMed Central (United Kingdom)

OBJECTIVES: The purpose of this study was to evaluate the application of 15 % propolis and 2 % acidulated-phosphate sodium fluoride solutions on the root surface-adhered necrotic cemental periodontal ligament in delayed tooth replantation. MATERIALS AND METHODS: Thirty Wistar rats (Rattus norvegicus, albinus) had their right upper incisor extracted and maintained in dry storage for 60 min. After this period, the dental papilla, enamel organ, and pulp tissue were removed, and the animals were randomly assigned to three groups: group I = immersion in saline for 10 min; group II = immersion in a 2 % acidulated-phosphate sodium fluoride solution for 10 min; and group III = immersion in a 15 % propolis and propylene glycol solution for 10 min. The root canals were filled with a calcium hydroxide paste and the teeth were replanted. RESULTS: Inflammatory resorption, replacement resorption, and ankylosis were observed in all groups without a statistically significant difference (p?>?0.05) among them. CONCLUSIONS: Under the tested conditions, the application of fluoride or propolis on root surface-adhered necrotic periodontal ligament did not favor the healing process in delayed tooth replantation.

Panzarini SR; Nonato CC; Gulinelli JL; Poi WR; Sonoda CK; Saito CT; Marão HF

2013-09-01

76

Effect of nano-hydroxyapatite suspension on cell proliferation and cycle in human periodontal ligament cells.  

UK PubMed Central (United Kingdom)

The study was aimed to provide insights into the effect of nano-hydroxyapatite (nHA) suspension on cell proliferation and cycle of human periodontal ligament cells, offering the evidence for nHA being used in periodontal therapy. Human periodontal ligament cells (HPDLCs) were cultured in different concentrations of nano-hydroxyapatite/sodium carboxymethyl cellulose (nHA-CMCNa) suspension in vitro. After that, cell proliferation ability was examined by MTT [3(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and flow cytometry. MTT assay demonstrated that the Relative Proliferation Rate (RPR) of 0.5% nHA-CMCNa group was significantly higher than other groups (p <0.05), which means that nHA-CMCNa might increase cell proliferation ability. Flow cytometry showed that cells in G1 phase decreased, whilst cells in S phase increased after cultured in nHA-CMCNa suspension for 48 h. The result suggested that part of cells finished G1 phase in advance and get into S phase earlier, which speed up the cell proliferation, nHA-CMCNa suspension had great effect on cell proliferation. The high concentration of nHA-CMCNa could shorten the time in G1 phase, impel part of cells into S phase, and accelerate proliferation rate of HPDLCs.

Li F; Peng J; Hu R; Dong X; Chen W; Pan Y; Tang X; Xie P

2013-07-01

77

Movement of fibroblasts in the periodontal ligament of the mouse incisor is related to eruption  

International Nuclear Information System (INIS)

Movement of fibroblasts in the periodontal ligament of the lower incisor of the mouse was studied by pulse-labeling with tritiated thymidine and proline. 3H-Thymidine was administered to mark the nuclei of the cells in the proliferative compartment near the basal end of the tooth; 3H-proline gave rise to a narrow band of radioactivity in the dentin, which served as a reference line for measurement of eruption. One or three weeks after injection in each animal, the lower right incisor was prevented from further eruption by being pinned to its alveolar process. The animals were killed 0, 1, or 2 weeks later, and their mandibles processed for LM-radioautography. It was found that in the left incisors, which were not inhibited in their eruption, labeled cells in the tooth-half of the periodontal ligament moved incisally at a rate similar to the eruption rate. In the pinned incisors, no further incisal migration could be established. It is concluded that fibroblast migration in the tooth-half of the ligament is strictly coupled to the eruptive process.

1987-01-01

78

Movement of fibroblasts in the periodontal ligament of the mouse incisor is related to eruption  

Energy Technology Data Exchange (ETDEWEB)

Movement of fibroblasts in the periodontal ligament of the lower incisor of the mouse was studied by pulse-labeling with tritiated thymidine and proline. /sup 3/H-Thymidine was administered to mark the nuclei of the cells in the proliferative compartment near the basal end of the tooth; 3H-proline gave rise to a narrow band of radioactivity in the dentin, which served as a reference line for measurement of eruption. One or three weeks after injection in each animal, the lower right incisor was prevented from further eruption by being pinned to its alveolar process. The animals were killed 0, 1, or 2 weeks later, and their mandibles processed for LM-radioautography. It was found that in the left incisors, which were not inhibited in their eruption, labeled cells in the tooth-half of the periodontal ligament moved incisally at a rate similar to the eruption rate. In the pinned incisors, no further incisal migration could be established. It is concluded that fibroblast migration in the tooth-half of the ligament is strictly coupled to the eruptive process.

Beertsen, W.; Hoeben, K.A.

1987-05-01

79

Pneumatic pressure bioreactor for cyclic hydrostatic stress application: mechanobiology effects on periodontal ligament cells.  

UK PubMed Central (United Kingdom)

A bioreactor system was developed to provide high-amplitude cyclic hydrostatic compressive stress (cHSC) using compressed air mixed commercially as needed to create partial pressures of oxygen and carbon dioxide appropriate for the cells under investigation. Operating pressures as high as 300 psi are achievable in this system at cyclic speeds of up to 0.2 Hz. In this study, ligamentous fibroblasts from human periodontal ligaments (n = 6) were compressed on two consecutive days at 150 psi for 3 h each day, and the mRNA for families of extracellular matrix protein and protease isoforms was evaluated by real-time PCR array. Several integrins were significantly upregulated, most notably alpha-3 (6.4-fold), as was SPG7 (12.1-fold). Among the collagens, Col8a1 was highly upregulated at 53.5-fold, with Col6a1, Col6a2, and Col7a1 also significantly upregulated 4.4- to 8.5-fold. MMP-1 was the most affected at 122.9-fold upregulation. MMP-14 likewise increased 17.8-fold with slight reductions for the gelatinases and a significant increase of TIMP-2 at 5.8-fold. The development of this bioreactor system and its utility in characterizing periodontal ligament fibroblast mechanobiology in intermediate-term testing hold promise for better simulating the conditions of the musculoskeletal system and the large cyclic compressive stresses joints may experience in gait, exertion, and mastication.

Wenger KH; El-Awady AR; Messer RL; Sharawy MM; White G; Lapp CA

2011-10-01

80

Histopathological features of dental pulp in teeth with different levels of chronic periodontitis severity.  

UK PubMed Central (United Kingdom)

Purpose. To evaluate the histopathological condition of the pulp in teeth with different levels of chronic periodontitis in humans. Methods. Twenty-five single-root nondecayed teeth were divided into three groups as follows: group 1, clinical attachment level (CAL) 3 to 4?mm and alveolar bone loss (BL) from 4 to 6?mm without reaching the tooth apex; group 2, CAL ? 5?mm and BL > 6?mm without reaching the tooth apex; group 3, CAL ? 5?mm and BL > 6?mm up to the tooth apex. Histological analyses were accomplished after laboratorial processing. Results. The mean of CAL was 3.2 ± 0.7?mm in group 1, 7.6 ± 2.0?mm in group 2, and 12.1 ± 2.8?mm in group 3, while for BL it was 4.8 ± 0.9?mm, 7.6 ± 2.2?mm, and 11.9 ± 2.1?mm, respectively. Histopathological data in the pulpal chambers were similar among the three groups showing normal aspects, and, the radicular pulps showed variable levels of reactive dentin, fibrosis, dystrophic mineralizations, atrophy, and mononuclear inflammatory infiltrate. Conclusions. Gradual progression of the chronic periodontitis led to changes in the histopathological aspects of the radicular pulp with progressive involvement.

Zuza EP; Carrareto AL; Lia RC; Pires JR; de Toledo BE

2012-01-01

 
 
 
 
81

Antigen-presenting cell marker expression and phagocytotic activity in periodontal ligament cells.  

UK PubMed Central (United Kingdom)

BACKGROUND: Periodontal ligament (PDL) cells are the main cellular constituents of the periodontium, maintain the integrity of the connective tissue, and impact pathology in periodontitis. The aim of this study was to analyze whether PDL cells recognize foreign particles and participate in the immune response to periodontal pathogens. METHODS: Expression of surface proteins characteristic of antigen-presenting cells (APCs) (major histocompatibility complex [MHC] class II, CD40, CD80, CD86) was analyzed in PDL cells after challenge with the cytokines interleukin (IL)-1?, IL-17A, and interferon-gamma (IFN-?) or with heat-killed Aggregatibacter actinomycetemcomitans using real-time PCR and flow cytometry. Confocal laser scanning microscopy, transmitted light microscopy, flow cytometry, and time-lapse microscopy were applied to analyze their phagocytotic capacity of collagen (carboxylate-modified microspheres), non-periodontal (Escherichia coli) and periodontal (Aggregatibacter actinomycetemcomitans) pathogens. Furthermore, it was examined whether cytokine activation of PDL cells affects the phagocytosis of collagen or bacteria. RESULTS: PDL cells upregulated MHC class II after cytokine stimulation on transcriptional level, whereas co-stimulatory molecules characteristic of professional APCs were not induced. Analyses on protein level revealed that MHC class II was not constitutively expressed in all PDL cell lines used. PDL cells phagocytosed both collagen and bacteria via acidic vesicles, suggesting the formation of phagosomes. Phagocytosis could be partially inhibited by inhibitors of phagocytosis, i.e., dynasore and wortmannin. Pre-incubation with cytokines did not further enhance the phagocytosis rate of collagen or bacteria. CONCLUSIONS: These results suggest that PDL cells do not only represent bystanders in periodontal infections, but display non-professional APC characteristics, suggesting possible participation in immune reactions of the oral cavity.

Konermann A; Deschner J; Allam JP; Novak N; Winter J; Baader SL; Jepsen S; Jäger A

2012-04-01

82

Study of tension in the periodontal ligament using the finite elements method  

Directory of Open Access Journals (Sweden)

Full Text Available Orthodontic movement is process of transformation of a physical stimulation into a force applied to a tooth, with a biological response identified as bone remodelling. Although it is possible to measure the force applied on a tooth, its distribution around the root is irregular forming areas of higher concentration of tensions, which do not correspond to the force initially applied. To evaluate the behavior of the periodontal ligament after the application of an external action and to prove which would be the areas of higher tension generated in the periodontium, the Finite Elements Method (FEM) was used in comparison to the results obtained in vivo on experimental models in rat. To test the error susceptibility of the technique used in the experimental model, the force application was simulated in three different heights on the mesial surface of the molar. The resulting histological analysis was compared with the result obtained for the computational code and disclosed that the greater focus of osteoclasts in activity had coincided with the compressed areas of the periodontal ligament. The alteration of points of force application generated areas of more extensive deformations in the periodontal ligament, as the point of application was more distant of the initial point, the horizontal force vector became bigger. These results demonstrate that the FEM is an adequate tool to study the distribution of orthodontic forces. The sensitivity of the experimental model used was also observed in relation to the installation of the dental movement device, which should be considered depending on the objective of the research.

Eliziane Cossetin; Selma Hissae S. da Nóbrega; Maria Goretti Freire de Carvalho

2012-01-01

83

Clinical and Histochemical Alterations of the Periodontal Ligament in Gerbils after Malocclusion Induced Alteraciones Clínicas e Histoquímicas del Ligamento Periodontal en Gerbiles Después de Maloclusión Inducida  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this article is to show the clinical and histochemical alterations of the first periodontal ligament, on the right side, after upper molars teeth extraction on the left side in gerbils. After two months, the periodontal ligaments were removed and processed for histochemical analysis. The data showed that TRAP reaction was able to evidence the osteoclastic activity in the hyperfunction hemimandible, right side, explaining the functional changes in the periodontal ligament after teeth extraction, and a little gingival recession and radicular exposure of teeth without function was observed at inferior molars of the left sideEl objetivo de este artículo es mostrar las alteraciones clínicas e histoquímicas del primer ligamento periodontal del lado derecho, después de la extracción del molar superior izquierdo en gerbiles {Meriones unguiculatus). Luego de dos meses, los ligamentos periodontales fueron retirados y procesados para el análisis histoquímico. Los resultados mostraron que la reacción de TRAP es capaz de evidenciar la actividad osteoclástica en la hiperfunción de la semimandíbula derecha, explicando los cambios funcionales del ligamento periodontal después de la extracción dental, siendo observada una pequeña recesión gingival y exposición radicular de los dientes sin función, en los molares inferiores izquierdos

Leandro Moura Leite Naves; João Paulo Mardegan Issa; Dimitrius Leonardo Pitol; Sandra Yasuyo Fukada; Miguel Ángel Sala di Matteo; Mamie Mizusaki Iyomasa

2007-01-01

84

Hypoxia induces apoptosis and autophagic cell death in human periodontal ligament cells through HIF-1? pathway.  

UK PubMed Central (United Kingdom)

OBJECTIVES: Oxygen deficiency caused by occlusal trauma and smoking can be present in patients with periodontitis. However, biochemical events important in periodontal tissues during hypoxia remain unclear. The aim of this study was to investigate effects of hypoxia on apoptosis and autophagy of human periodontal ligament cells (PDLCs) in vitro. MATERIALS AND METHODS: Human PDLCs were obtained and cultured in vitro. Cell viability, apoptosis, autophagy and gene and protein expression were measured in presence and absence of cobalt chloride (CoCl(2)). RESULTS: CoCl(2) induced cytotoxicity of human PDLCs in a concentration-dependent manner dependent on macromolecular synthesis, and resulted in apoptosis and mitochondrial dysfunction. CoCl(2) also induced redistribution of autophagy marker LC3, increased ratio of LC3-IIto LC3-Iand function of lysosomes. Furthermore, CoCl(2) promoted expression of HIF-1? following upregulation of expressions of Bnip3. Significant increases in expression of IL-1? and MMP-8 were also observed. All these results were reversed by pre-treatment with antioxidant N-acetylcysteine. CONCLUSIONS: Our data showed that CoCl(2) could induce cytotoxicity through mitochondria- apoptotic and autophagic pathways involved in HIF-1?. CoCl(2 -treated PDLCs may serve as an in vitro model for studies of molecular mechanisms in periodontitis.

Song ZC; Zhou W; Shu R; Ni J

2012-06-01

85

The effect of cultured autologous periodontal ligament cells on the healing of delayed autotransplanted dog's teeth.  

UK PubMed Central (United Kingdom)

INTRODUCTION: The regeneration of the periodontal structure for avulsed teeth extended dry times has been a goal of dentists. The aim of this study was to investigate a new strategy of delayed replantation for avulsed teeth that were not suitable for immediate replantation. METHODS: Extracted dog's premolar teeth were maintained in a dry environment for a month after isolation and proliferation of the periodontal ligament (PDL) cells. Then, tooth roots coated with 1 x 10(6) cultured autologous PDL cells were autotransplanted in artificial sockets created in the mandible. The dogs were sacrificed 60 days after transplantation. Histologic analyses showed that a root-PDL-bone complex was found in all cases of the PDL cell-loaded samples. RESULTS: The new PDL-like connective tissue was located between the alveolar bone and the transplanted roots, with fibers inserting into the newborn cementum on one end and alveolar bone on the other. For the control samples, no PDL-like tissue was found, and ankylosis was commonly observed. CONCLUSIONS: The results indicated that cultured autologous PDL cells assist in the re-establishment of periodontal architecture of autotransplanted teeth that is devoid of viable periodontal cells.

Wang Y; Cheung GS; Xu X; Zhao S; Zhang C

2010-02-01

86

The expression of estrogen receptors and the effects of estrogen on human periodontal ligament cells.  

UK PubMed Central (United Kingdom)

Osteoporotic women exhibit high frequency of alveolar bone loss and low bone density. Estrogen deficiency, which is vital in the pathogenesis of postmenopausal osteoporosis, has received increasing attention in the studies related to the periodontal diseases. Similar to most hormones, estrogen exerts its influence by binding to specific receptors, estrogen receptor (ER)-alpha and -beta. The periodontal ligament cells (PDLcs) are very important in maintaining the integrity of the periodontal tissue, which is the connective tissue located between the alveolar bone and the root surface of tooth. In this study, we evaluated the effects of estrogen deficiency on the alveolar bone in ovariectomized rats by histometric measurement of attachment level in vivo. Using the reverse transcriptase polymerase chain reaction (RT-PCR) and Western-blot procedure, we also detected mRNA and protein products of ERs and investigated the effects of estrogen on bone-forming capability by monitoring alkaline phosphatase (ALP) activity and osteocalcin production in cultured human PDLcs. Our results demonstrated that both ER-alpha and -beta were expressed in PDLcs. Moreover, when exposed to 17-beta estradiol, PDLcs exhibited positive modulation on ALP activity and osteocalcin production. The study suggests that estrogen and ERs may play an important role in periodontal diseases.

Cao M; Shu L; Li J; Su J; Zhang W; Wang Q; Guo T; Ding Y

2007-06-01

87

The significance of epithelial rests of Malassez in the periodontal ligament.  

UK PubMed Central (United Kingdom)

INTRODUCTION: The purpose of this review was to describe the function of epithelial rests of Malassez (ERMs) in a variety of physiologic and pathologic conditions. METHODS: The authors performed a PubMed search on the term "epithelial rests" alone or in combination with "Malassez." Relevant articles were categorized into primary subtopics and related to current and historic literature. RESULTS: The review was divided into 7 subtopics. Those sections discuss possible roles for ERM in a variety of physiologic and pathologic processes. CONCLUSIONS: ERMs have a fundamental role in root development, protect against root resorption, and are involved in reparative and regenerative functions of the pulp and periodontal tissues including apexogenesis and periodontal healing. They also appear to be involved in pathologic processes such as the development of oral cysts and tumors.

Keinan D; Cohen RE

2013-05-01

88

Periodontal ligament cell behavior on different titanium surfaces.  

UK PubMed Central (United Kingdom)

AIM: The purpose of this study was to investigate proliferation, morphology, mineralization and mRNA expressions of mineralized tissue associated proteins of PDL cells on smooth (S), sandblasted small-grit (SSG), sandblasted large-grit (SLG) and sodium titanate (NaTi) coated titanium alloys, in vitro. MeTHODS AND MATERIALS: PDL cells were cultured with DMEM media containing 10% FBS on the S, SSG, SLG and NaTi titanium surfaces. PDL cell proliferation, mineralization and immunohistochemistry experiments for Bone Sialoprotein (BSP) were performed. The morphology of the PDL cells was examined using confocal and scanning electron microscopy (SEM). Gene expression profiles of cells were evaluated using a quantitative-polymerase chain reaction (Q-PCR) for type I collagen (COL I), Osteocalcin (OCN), osteopontin (OPN) and Runt-related transcription factor-2 (Runx2) on days 7 and 14. RESULTS: Proliferation results on days 6 and 10 were similar in groups, while those of day 13 revealed a decrease in the NaTi group when compared to the S group. NaTi surface induced BSP mRNA expression which was correlated with mineralization tests and BSP immunostaining results. Increased Runx2 mRNA expression was also noted in the NaTi surface when compared to other surfaces. CONCLUSIONS: This study considers the NaTi surface as a potential alternative to SSG and SLG surfaces. This surface might provide a promising environment for PDL ligament-anchored implants.

Hakki SS; Korkusuz P; Purali N; Korkusuz F; Bozkurt BS; Hakki EE; Onder ME; Gorur I; Nohutcu RM; Timucin M; Ozturk A

2013-05-01

89

Alteraciones radiculares en las lesiones traumáticas del ligamento periodontal: revisión sistemática/ Root alterations in traumatisms of the periodontal ligament: systematic review  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Las lesiones del ligamento periodontal son muy frecuentes tras golpes o caídas. Si el diente no es capaz de absorber toda la energía del choque, éste se desplaza, por lo que se lesiona el ligamento periodontal. En este artículo se analiza, desde el punto de vista histopatológico y clínico, la complicación periodontal más frecuente, la reabsorción radicular; para ello se ha llevado a cabo una búsqueda bibliográfica de los artículos y monografías relacionadas c (more) on el tema a través de la base de datos Pubmed, realizándose un medline con sus resúmenes correspondientes. Conclusión: hasta el momento no se conoce el mecanismo exacto por el que la raíz es resistente, en algunas situaciones clínicas, a la reabsorción radicular. Abstract in english Periodontal ligament damage is very common as a result of falls or trauma. If the tooth is unable to fully absorb the energy of impact, displacement results, with damage to the periodontal ligament. This study offers a histological evaluation of the most frequent periodontal alteration, i. e. root resorption. Accordingly, a search of the articles and monographs on the subject has been made based on the Pubmed database, with a Medline search of the corresponding abstracts. (more) Conclusion: to date, the precise mechanism responsible for root resistance to resorption under certain clinical conditions remains uncertain.

García Ballesta, Carlos; Pérez Lajarín, Leonor; Cortés Lillo, Olga

2003-04-01

90

Human periodontal ligament cells reaction on a novel hydroxyapatite-collagen scaffold.  

UK PubMed Central (United Kingdom)

BACKGROUND: Periodontal tissue regeneration presents a highly promising method for restoring periodontal structures. The development of a suitable bioactive scaffold that promotes cell proliferation and differentiation is critical in periodontal tissue engineering. The aim of this study was to evaluate the biocompatibility of a novel 3-dimensional hydroxyapatite-collagen scaffold with human periodontal ligament (hPDL) cell culture. METHODS: The scaffold was produced from a natural collagen matrix - purified porcine acellular dermal matrix (PADM), which was then treated with hydroxyapatite (HA) through a biomimetic chemical process to obtain hydroxyapatite-porcine acellular dermal matrix (HA-PADM) scaffold. The hPDL cells were cultured with HA-PADM scaffolds for 1, 3, 6, 14, and 28 days. The cell viability assay, scanning electron microscopy (SEM), hematoxylin and eosin (H&E) staining, immunohistochemistry, and confocal microscopy were employed in different time points to evaluate the biocompatibility of the scaffolds with hPDL cells. RESULTS: The cell viability assay (WST-1 test) verified cell proliferation on the HA-PADM scaffolds. The SEM study showed unique morphology of hPDL cells, which attach and spread on the surface of the scaffolds. The H&E staining, immunohistochemistry, and confocal microscopy demonstrated that hPDL cells were able to grow into the HA-PADM scaffolds and maintain viability after prolonged culture. CONCLUSIONS: This study proved that HA-PADM scaffold is -biocompatible for hPDL cells. The cells were able to proliferate and migrate into the scaffold. These observations suggest that HA-PADM is a potential cell carrier for periodontal tissue regeneration.

Guo J; Wang Y; Cao C; Dziak R; Preston B; Guan G

2013-04-01

91

Increased PELP1 expression in rat periodontal ligament tissue in response to estrogens treatment.  

UK PubMed Central (United Kingdom)

Estrogens and their receptors are important factors involved in periodontal ligament (PDL) tissue health. As a regulator of estrogen receptors (ER), the proline-, glutamic acid-, and leucine-rich protein 1 (PELP1) may play a role in alveolar bone formation and PDL homeostasis. The aim of the present study was to observe PELP1 expression in rat PDL tissue during estrogen levels manipulations. Twenty-one 8-week old normal female Sprague-Dawley rats were randomly divided into three equal groups: sham-operated controls, ovariectomized (OVX) group, and OVX given 17?-estradiol intraperitoneally (OVX + E2) for 16 weeks. PELP1 expression was down-regulated in the OVX group and was up-regulated in the OVX + E2 group. Periodontal ligament fibroblast cells (PDLFCs) were isolated from PDL tissue, and characterized by immunohistochemical staining. Estradiol treatment of PDLFCs induced PELP1 protein level compared to untreated cells. PELP1 mRNA expression in estradiol-treated cells was relatively low at the beginning of treatment and then steadily increased from hour 4. In conclusion, results indicate that PELP1 is expressed in rat PDL tissue and PDLFCs, and that its expression is up-regulated during estrogen treatment.

Wang J; Zhu Q; Song S; Dong J; Shi L; Tao R; Ding Y; Hong B

2013-06-01

92

The effect of electrospun fibre alignment on the behaviour of rat periodontal ligament cells  

Directory of Open Access Journals (Sweden)

Full Text Available It is envisioned that for the regeneration of highly organized structures, like tendon and ligaments, only aligned fibrous scaffolds can provide adequate topographic guidance to cells. In this study, a novel method to electrospin an aligned scaffold is presented. Electrospun fibres were deposited into a water bath and then the fibres were drawn to a rotating mandrel in a controlled manner. In this way, parallel and cross-aligned fibrous poly (lactide-co-glycolide) (PLGA) scaffolds were fabricated, which were subsequently used to study their effect on the growth behaviour of rat periodontal ligament (PDL) cells. First, the scaffolds were characterized regarding mechanical properties, scaffold stability and degradation in vitro. Then, rat PDL cells were seeded and cultured on these scaffolds for up to 7 days. Randomly oriented PLGA and solvent cast plain PLGA films served as controls. Results showed that the alignment of fibres resulted in a higher tensile stress and Young’s modulus. Aligned scaffolds maintained their structural stability better compared to the controls after incubation in phosphate-buffered saline for 6 weeks. Further, cells were observed to elongate along the fibre after 3 days of culture. Proliferation and migration of PDL cells was significantly more prevalent on the aligned fibres compared to the controls. It was concluded that aligned scaffolds seem to be able to promote the organized regeneration of periodontal tissue.

S Shang; F Yang; X Cheng; XF Walboomers; JA Jansen

2010-01-01

93

Cytotoxicity of intracanal bleaching agents on periodontal ligament cells in vitro.  

Science.gov (United States)

Intracoronal bleaching of nonvital teeth is a simple and conservative procedure for esthetic restoration of discolored teeth. However it is possible that damage to the periodontal ligament may occur if the bleaching agents contact this tissue. The purpose of this study was to examine the cytotoxicity of intracanal bleaching agents on human periodontal ligament (PDL) cells in vitro. Three bleaching agents, 30% hydrogen peroxide (H2O2), 2.0 g/ml sodium perborate (SP) solution, and 2.0 g/ml SP in H2O2, were diluted from 10(-3) to 10(-7) with Eagle's minimal essential medium and incubated with PDL cells isolated and cultured from extracted teeth. Cytotoxicity was assessed quantitatively by determining the amount of lactic dehydrogenase activity released from the cells after exposure to the agents for 24 or 72 h. Dose-response curves were plotted, and TD50 values (dilution causing the release of 50% of control lactate dehydrogenase activity) and 95% confidence limits determined. The rank order of the TD50 values after exposure for 24 h was SP in H2O2 (most toxic) > H2O2 > SP solution (least toxic). After 72 h SP in H2O2 still produced the greatest cytotoxic effect. However the SP solution was more cytotoxic than H2O2 at this time point. It is concluded that the mixture of SP with H2O2 was the most toxic to the PDL cells in vitro. PMID:11556561

Kinomoto, Y; Carnes, D L; Ebisu, S

2001-09-01

94

Histological evaluation of the periodontal ligament from aged wistar rats supplemented with ascorbic acid.  

UK PubMed Central (United Kingdom)

Ascorbic acid (AA) is able to neutralize reactive oxygen species and is essential for collagen synthesis. In aging process oxidative stress is elevated. This study aims to investigate the effects of AA supplementation on the periodontal ligament (PL) of rats during aging. Twenty five rats were used and divided into groups: J90 (90-day-old control), E345 (345-day-old control), E428 (428-day-old control), EA345 (345-day-old supplemented with AA from 90-day-old on) and EA428 (428-day-old supplemented with AA from 90-day-old on). We analyzed the thickness, density of fibroblasts and blood vessels and collagen fibers types in the PL. In group J90 there was predominantly type III collagen fibers (87.64%). In animals supplemented with AA, the area filled by type I fibers (group EA345: 65.67%, group EA428: 52.23%) was higher than type III fibers. PL in group EA428 was thicker than the one observed in group E428 (P < 0.05). During natural aging process, AA promoted the maturation of collagen fibers and enhanced angiogenesis in periodontal ligament. One can conclude that the supplementation with AA represented a beneficial factor for the development of PL in aged rats.

Zanoni JN; Lucas NM; Trevizan AR; Souza ID

2013-01-01

95

Histological evaluation of the periodontal ligament from aged Wistar rats supplemented with ascorbic acid.  

UK PubMed Central (United Kingdom)

Ascorbic acid (AA) is able to neutralize reactive oxygen species and is essential for collagen synthesis. In aging process oxidative stress is elevated. This study aims to investigate the effects of AA supplementation on the periodontal ligament (PL) of rats during aging. Twenty five rats were used and divided into groups: J90 (90-day-old control), E345 (345-day-old control), E428 (428-day-old control), EA345 (345-day-old supplemented with AA from 90-day-old on) and EA428 (428-day-old supplemented with AA from 90-day-old on). We analyzed the thickness, density of fibroblasts and blood vessels and collagen fibers types in the PL. In group J90 there was predominantly type III collagen fibers (87.64%). In animals supplemented with AA, the area filled by type I fibers (group EA345: 65.67%, group EA428: 52.23%) was higher than type III fibers. PL in group EA428 was thicker than the one observed in group E428 (P < 0.05). During natural aging process, AA promoted the maturation of collagen fibers and enhanced angiogenesis in periodontal ligament. One can conclude that the supplementation with AA represented a beneficial factor for the development of PL in aged rats.

Zanoni JN; Lucas NM; Trevizan AR; Souza ID

2013-03-01

96

Clinical and Histochemical Alterations of the Periodontal Ligament in Gerbils after Malocclusion Induced/ Alteraciones Clínicas e Histoquímicas del Ligamento Periodontal en Gerbiles Después de Maloclusión Inducida  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish El objetivo de este artículo es mostrar las alteraciones clínicas e histoquímicas del primer ligamento periodontal del lado derecho, después de la extracción del molar superior izquierdo en gerbiles {Meriones unguiculatus). Luego de dos meses, los ligamentos periodontales fueron retirados y procesados para el análisis histoquímico. Los resultados mostraron que la reacción de TRAP es capaz de evidenciar la actividad osteoclástica en la hiperfunción de la semimand (more) íbula derecha, explicando los cambios funcionales del ligamento periodontal después de la extracción dental, siendo observada una pequeña recesión gingival y exposición radicular de los dientes sin función, en los molares inferiores izquierdos Abstract in english The aim of this article is to show the clinical and histochemical alterations of the first periodontal ligament, on the right side, after upper molars teeth extraction on the left side in gerbils. After two months, the periodontal ligaments were removed and processed for histochemical analysis. The data showed that TRAP reaction was able to evidence the osteoclastic activity in the hyperfunction hemimandible, right side, explaining the functional changes in the periodonta (more) l ligament after teeth extraction, and a little gingival recession and radicular exposure of teeth without function was observed at inferior molars of the left side

Naves, Leandro Moura Leite; Issa, João Paulo Mardegan; Pitol, Dimitrius Leonardo; Fukada, Sandra Yasuyo; di Matteo, Miguel Ángel Sala; Iyomasa, Mamie Mizusaki

2007-12-01

97

Effect Of Recombinant Human Bone Morphogenetic Protein-7 On Proliferation And Differentiation Of Human Periodontal Ligament Cells  

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Objective: To Study The Effect Of Recombinant Human Bone Morphogenetic Protein-7 (Rhbmp-7) On Proliferation And Differentiation Of Human Periodontal Ligament Cells (Hpdlcs) Cultivated In Vitro. Methods: The Hpdlcs Were Tested Vimentin Positive And Ck (Pan) Negative. Different Dosages (50, 100, 200 A...

Jiang, L-Q; Chen, X; Cai, L-S; Liu, J-L; Dai, J

98

Effect of connective tissue growth factor (CCN2/CTGF) on proliferation and differentiation of mouse periodontal ligament-derived cells  

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Full Text Available Abstract Background CCN2/CTGF is known to be involved in tooth germ development and periodontal tissue remodeling, as well as in mesenchymal tissue development and regeneration. In this present study, we investigated the roles of CCN2/CTGF in the proliferation and differentiation of periodontal ligament cells (murine periodontal ligament-derived cell line: MPL) in vitro. Results In cell cultures of MPL, the mRNA expression of the CCN2/CTGF gene was stronger in sparse cultures than in confluent ones and was significantly enhanced by TGF-?. The addition of recombinant CCN2/CTGF (rCCN2) to MPL cultures stimulated DNA synthesis and cell growth in a dose-dependent manner. Moreover, rCCN2 addition also enhanced the mRNA expression of alkaline phosphatase (ALPase), type I collagen, and periostin, the latter of which is considered to be a specific marker of the periosteum and periodontium; whereas it showed little effect on the mRNA expression of typical osteoblastic markers, e.g., osteopontin and osteocalcin. Finally, rCCN2/CTGF also stimulated ALPase activity and collagen synthesis. Conclusion These results taken together suggest important roles of CCN2/CTGF in the development and regeneration of periodontal tissue including the periodontal ligament.

Asano Masahiro; Kubota Satoshi; Nakanishi Tohru; Nishida Takashi; Yamaai Tomoichiro; Yosimichi Gen; Ohyama Kazumi; Sugimoto Tomosada; Murayama Yoji; Takigawa Masaharu

2005-01-01

99

Autologous periodontal ligament cells in the treatment of Class III furcation defects: a study in dogs.  

UK PubMed Central (United Kingdom)

AIM: This study aimed to evaluate, histomorphometrically, the use of periodontal ligament cells (PDL cells) in the treatment of class III furcation defects. MATERIAL AND METHODS: PDL cells were obtained from the mandibular tooth extracted from each dog (7), cultured in vitro and phenotypically characterized. Bilateral class III furcation defects were created at mandibular 3rd and 4th premolars and were randomly assigned to: Control Group: coronally positioned flap, GTR Group: GTR, Sponge Group: carrier + GTR, Cell Group: carrier + PDL cells + GTR. RESULTS: After 3 months of healing, data analysis demonstrated that the Cell Group presented a superior length of new cementum (4.82 ± 0.61 mm; 3.66 ± 0.95 mm; 2.87 ± 0.74 mm and 1.70 ± 0.60 mm, p < 0.001), a greater extension of periodontal regeneration (3.43 ± 1.44 mm; 2.33 ± 0.95 mm; 1.52 ± 0.39 mm and 0.69 ± 0.59 mm, p = 0.001) and a larger area of new bone (5.45 ± 1.58 mm(2) ; 3.94 ± 1.52 mm(2) ; 2.91 ± 0.56 mm(2) and 1.89 ± 0.95 mm(2) , p = 0.0012), when compared with Sponge, GTR and Control Group, respectively. CONCLUSION: The PDL cells in association with GTR may significantly promote periodontal regeneration in class III furcation defects surgically created in dogs.

Suaid FF; Ribeiro FV; Gomes TR; Silvério KG; Carvalho MD; Nociti FH Jr; Casati MZ; Sallum EA

2012-04-01

100

[Isolation, cultivation and characterisation of stem cells in human periodontal ligament].  

Science.gov (United States)

Recent studies have revealed the presence of postnatal stem cells in tissues of dental origin. Our objective was to establish a standardized in vitro model system to investigate periodontal regenerative procedures for potential clinical application. We aimed to prepare primary cell cultures from human periodontal ligament and to identify clonogenic progenitor cells. After scraping PDL tissue from extracted wisdom teeth, the extracellular matrix was enzymatically degraded to obtain isolated cells for culturing. The effect of FCS and Emdogain on cell viability of the cultures was estimated by MTT-assay. Cell populations expressing STRO-1 mesenchymal, c-kit embryonic and CD34 hematopoietic stem cell markers were identified by FACS-analysis. We successfully established primary cell cultures from the human PDL. The proliferation rate of the cultures was enhanced by the supplementation of the culture medium by serum or Emdogain. The PDL cultures contained cells capable of colony-formation, as well as cells with STRO-1, c-kit and CD-34 expression. The primary cultures were maintained through multiple passages. These findings present a novel opportunity to further investigate the differentiation and proliferation of PDL derived cells potentially capable of periodontal regeneration. PMID:19055131

Molnár, Bálint; Kádár, Kristóf; Király, Marianna; Porcsalmy, Balázs; Somogyi, Eszter; Hermann, Péter; Grimm, Wolf-Dieter; Gera, István; Varga, Gábor

2008-08-01

 
 
 
 
101

In Vitro Cytotoxicity of White MTA, MTA Fillapex® and Portland Cement on Human Periodontal Ligament Fibroblasts  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese Resumo O objetivo deste estudo foi comparar a citotoxicidade in vitro de agregado trióxido mineral (MTA) branco, MTA Fillapex® e cimento Portland (PC) em cultura de fibroblastos de ligamento periodontal humano. A cultura de fibroblastos de ligamento periodontal foi estabelecida e as células foram utilizadas para os testes citotóxicos após a quarta passagem. A densidade celular foi ajustada em 1,25X10 4 células/poç (more) ;o em placas de 96 poços. Extratos dos materiais endodônticos foram preparados por meio da inserção de corpos de prova dos cimentos (5 X 3 mm) em 1 mL de meio de cultura durante 72 h. Os extratos foram diluídos serialmente na razão de ½ e inseridos aos poços contendo as células por 24, 48 e 72 h. Ensaio de MTT foi realizado para a avaliação da viabilidade celular. O sobrenadante das células foi testado em relação à presença de óxido nítrico utilizando o sistema de reagentes de Griess. O MTA apresentou efeito citotóxico quando o extrato era aplicado sem diluição durante 24 e 72 h. O MTA Fillapex apresentou os maiores níveis de citotoxicidade com importante redução da viabilidade celular quando o extrato foi aplicado puro e em diluições de ½ e ¼. Neste estudo, PC não induziu alterações na viabilidade de fibroblastos. Óxido nítrico foi detectado no sobrenadante de células tratadas com os extratos e ainda nos extratos somente, o que sugere a presença de nitrito no conteúdo solúvel dos materiais testados. No presente estudo, MTA Fillapex foi o material que demonstrou o maior efeito citotóxico sobre fibroblastos de ligamento periodontal seguido do MTA branco e do PC. Abstract in english The aim of this study was to compare the in vitro cytotoxicity of white mineral trioxide aggregate (MTA), MTA Fillapex® and Portland cement (PC) on human cultured periodontal ligament fibroblasts. Periodontal ligament fibroblast culture was established and the cells were used for cytotoxic tests after the fourth passage. Cell density was set at 1.25 X10 4 cells/well in 96-well plates. Endodontic material extracts were prepared by placing sealer/cement spe (more) cimens (5X3mm) in 1mL of culture medium for 72 h. The extracts were then serially two-fold diluted and inserted into the cell-seeded wells for 24, 48 and 72 h. MTT assay was employed for analysis of cell viability. Cell supernatants were tested for nitric oxide using the Griess reagent system. MTA presented cytotoxic effect in undiluted extracts at 24 and 72 h. MTA Fillapex® presented the highest cytotoxic levels with important cell viability reduction for pure extracts and at ½ and ¼ dilutions. In this study, PC did not induce alterations in fibroblast viability. Nitric oxide was detected in extract-treated cell supernatants and also in the extracts only, suggesting presence of nitrite in the soluble content of the tested materials. In the present study, MTA Fillapex displayed the highest cytotoxic effect on periodontal ligament fibroblasts followed by white MTA and PC.

Yoshino, Patrícia; Nishiyama, Celso Kenji; Modena, Karin Cristina da Silva; Santos, Carlos Ferreira; Sipert, Carla Renata

2013-04-01

102

Modificações no periodonto de ratos diabéticos após a movimentação ortodôntica Periodontal ligament changes after induced dental movement in diabetic rats  

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Full Text Available OBJETIVOS: o objetivo deste trabalho foi avaliar as modificações do ligamento periodontal de incisivos de ratos diabéticos submetidos a forças ortodônticas. MÉTODOS: vinte ratos machos Wistar (Rattus norvegicus) com 105 dias de idade foram empregados. Os ratos foram divididos em quatro grupos: C - animais normoglicêmicos não submetidos à movimentação dentária; CAO - animais normoglicêmicos submetidos à movimentação dentária; D - animais diabéticos não submetidos à movimentação dentária; DAO - animais diabéticos submetidos à movimentação dentária. Os animais permaneceram com o dispositivo de movimentação dentária por 5 dias. Foram avaliados o número de vasos sangüíneos e a espessura do ligamento periodontal nos terços cervical, médio e apical dos cortes histológicos. RESULTADOS E CONCLUSÕES: no lado de tensão, a movimentação dentária nos animais do grupo CAO resultou em um ligamento periodontal mais espesso (17,64% no terço apical, 39,28% no terço médio e 51,35% na região cervical), quando comparado ao grupo C (p 0,05). Ainda no lado de tensão, foram observadas lacunas de reabsorção nos animais dos grupos CAO, D e DAO. O lado de pressão não foi examinado nesta fase do estudo.AIM: The aim of this study was to evaluate the periodontal ligament changes after induced dental movement of the upper incisor in diabetic rats. METHODS: Twenty Wistar rats (Rattus norvegicus) with 105 days of age were used. The rats were divided in four groups: C - normoglicemic animals not submitted to dental movement; CAO - normoglicemic animals submitted to dental movement; D - diabetic animals not submitted the dental movement; DAO - diabetic animals submitted to dental movement. The animals had remained with dental movement devices during 5 days. The number of sanguine vessels and the thickness of the periodontal ligament were evaluated at cervical, medium and apical histological cut regions. RESULTS AND CONCLUSION: At tension side, the dental movement in the animals of group CAO resulted in a thicker periodontal ligament (17.64% apical, 39.28% medium, 51.35% cervical) when compared to C group (p < 0.05 for medium and cervical area). Group DAO exhibited an increase of periodontal ligament thickness of 50.55% (apical), 48.14% (average) and 50% (cervical) when compared to group D (p < 0.05). The periodontal ligament sanguine vessels number did not differed significantly for all groups (p < 0.05). At tension side, bone reabsorption lacunae were observed in CAO, D and DAO groups. The pressure side was not examined in this study phase.

Luis Alberto Sabino Vila Real; Adilson Luiz Ramos; Jacqueline Nelisis Zanoni

2009-01-01

103

Histological evaluation of the periodontal ligament from aged wistar rats supplemented with ascorbic acid  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese O ácido ascórbico (AA) neutraliza essas espécies reativas de oxigênio e é imprescindível para a síntese do colágeno. No processo de envelhecimento ocorre aumento do estresse oxidativo. Objetivamos investigar o efeito da suplementação com AA sobre o ligamento periodontal (LP) de ratos durante o processo de envelhecimento. Foram utilizados 25 ratos divididos em cinco grupos: J90 (90 dias de idade), E345 (345 dias de idade), (more) E428 (428 dias de idade), EA345 (tratados com AA do 90º ao 345º dia) e EA428 (tratados com AA do 90º ao 428º dia). Foram analisadas espessura, densidade de fibroblastos e vasos sanguíneos, e o tipo de fibra colágena presente no LP. No grupo J90 houve um predomínio de fibras colágenas do tipo III (87,64%). Nos animais suplementados com AA, a área ocupada pelas fibras tipo I (grupo EA345 - 65,67%; grupo EA428 - 52,23%) foi maior que aquelas do tipo III. A espessura do LP no grupo EA428 foi maior do que a observada no grupo E428 (P < 0,05). No processo de envelhecimento natural o AA atuou na maturação das fibras colágenas e estimulou a angiogênese no ligamento periodontal. Pode-se concluir que a suplementação com AA foi positiva para o LP de ratos envelhecidos. Abstract in english Ascorbic acid (AA) is able to neutralize reactive oxygen species and is essential for collagen synthesis. In aging process oxidative stress is elevated. This study aims to investigate the effects of AA supplementation on the periodontal ligament (PL) of rats during aging. Twenty five rats were used and divided into groups: J90 (90-day-old control), E345 (345-day-old control), E428 (428-day-old control), EA345 (345-day-old supplemented with AA from 90-day-old on) and EA428 (more) (428-day-old supplemented with AA from 90-day-old on). We analyzed the thickness, density of fibroblasts and blood vessels and collagen fibers types in the PL. In group J90 there was predominantly type III collagen fibers (87.64%). In animals supplemented with AA, the area filled by type I fibers (group EA345: 65.67%, group EA428: 52.23%) was higher than type III fibers. PL in group EA428 was thicker than the one observed in group E428 (P < 0.05). During natural aging process, AA promoted the maturation of collagen fibers and enhanced angiogenesis in periodontal ligament. One can conclude that the supplementation with AA represented a beneficial factor for the development of PL in aged rats.

Zanoni, Jacqueline N.; Lucas, Nathalia M.; Trevizan, Aline R.; Souza, Ivan D.S.

2013-03-01

104

Expression profiling of periodontal ligament cells stimulated with enamel matrix proteins in vitro: a model for tissue regeneration.  

UK PubMed Central (United Kingdom)

Several studies have examined the role of enamel matrix proteins in root formation and periodontal regeneration, although most of these have focused on a few specific genes which had previously been implicated. However, recent advances in expressional profiling have made it possible to examine the range of genetic responses involved in these processes. In the present experiments, we have therefore utilized this technique to determine the effects of enamel matrix proteins on the gene activities of periodontal ligament cells in vitro. Such cells were found to have an elevated level of RNA synthesis compared with control cells. Moreover, hybridization of the cDNA prepared from this RNA to gene array filters showed that there was differential expression of 121 genes, most of which had not previously been associated with periodontal regeneration. Some of these selective changes in gene activity might thus reflect the fundamental events that underlie periodontal development.

Brett PM; Parkar M; Olsen I; Tonetti M

2002-11-01

105

Application of the iodide clearance technique to monitor local changes in periodontal ligament blood flow  

Energy Technology Data Exchange (ETDEWEB)

The present study was undertaken to validate a newly developed technique for monitoring blood flow changes with local clearance of /sup 125/I in the periodontal ligament (PDL). The tracer substance was allowed to diffuse into the intact PDL via a cavity that was drilled from the root canal out towards the root surface. Electric stimulation of the cervical sympathetic trunk caused a reduction in the clearance rate of the tracer from the cavity in a frequency-dependent manner. Intra-arterial infusions of noradrenaline also induced decreases in clearance rate. Intra-arterial infusions of the vasodilators substance P and vasoactive intestinal peptide induced increases in clearance rate. The present technique makes it possible to monitor local blood flow changes in the intact PDL during both decreases and increases in blood flow. 27 refs.

Edwall, B.

1988-01-01

106

Application of the iodide clearance technique to monitor local changes in periodontal ligament blood flow  

International Nuclear Information System (INIS)

The present study was undertaken to validate a newly developed technique for monitoring blood flow changes with local clearance of 125I in the periodontal ligament (PDL). The tracer substance was allowed to diffuse into the intact PDL via a cavity that was drilled from the root canal out towards the root surface. Electric stimulation of the cervical sympathetic trunk caused a reduction in the clearance rate of the tracer from the cavity in a frequency-dependent manner. Intra-arterial infusions of noradrenaline also induced decreases in clearance rate. Intra-arterial infusions of the vasodilators substance P and vasoactive intestinal peptide induced increases in clearance rate. The present technique makes it possible to monitor local blood flow changes in the intact PDL during both decreases and increases in blood flow.

1988-01-01

107

Evaluation of fibronectin, type I collagen and TGF-ß expression by human periodontal ligament fibroblasts exposed to root end filling materials  

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Full Text Available Background and Aim: Several materials have been introduced for retrograde fillings, pulp capping and sealing root perforations, but their biological effect on vital tissues and cells is not clear. The purpose of this study was to evaluate the reaction of human periodontal ligament fibroblasts to four root canal filling materials: Pro Root MTA, Root MTA, Portland cement and amalgam. Materials and Methods: In this experimental study, impacted or semi impacted third molar teeth were extracted in aseptic conditions and tissues around the roots were used to obtain fibroblast cell line. After proliferation, cells were cultured in chamber slides and extracts of materials were added to wells. Fibronectin, type I collagen and TGF-  expression were measured by immunocytochemistry method. Data were analyzed by SPSS 11.0 using one way ANOVA and Tukey test. P<0.05 was considered as the limit of significance. Results: Collagen I expression was higher in Pro Root MTA group after 24 hours (p<0.05) and in Portland cement group and positive controls after 48  hours. Portland cement group showed the highest expression of collagen after 1 week. There was no significant difference in fibronectin expression after 24 hours. After 1 week the highest expression of fibronectin was seen in Portland cement, Root MTA and Pro Root MTA groups. TGF-  expression was higher in amalgam, Root MTA and Pro Root MTA specimens after 24 hours and was the highest in Pro Root MTA group after 48 hours. Conclusion: Based on the results of this study, Portland cement and Root MTA are comparable with Pro Root MTA and better than amalgam regarding their effects on human periodontal ligament fibroblasts.

Razmi H.; Bashizade H.; Talaeipour AR.

2008-01-01

108

Primary cell culture from human oral tissue: gingival keratinocytes,gingival fibroblasts and periodontal ligament fibroblasts  

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Full Text Available Primary cell culture of human oral tissue has many applications for oral biology research. There are two techniques in primary culture, which includes the enzymatic and direct explant technique. The objectives of this study were (1) to isolate and investigate the difference in percentage the success in culturing three cell types from human oral tissue: gingival keratinocytes, gingival fibroblasts and periodontal ligament fibroblasts by using the direct explant technique; (2) to compare the effect of sex and age on the success of tissue culturing. Twenty seven tissue samples were obtained from healthy human gingival tissue, 19 female and 8 male patients aged 14-67 years (37.7±17.5). The tissue was cut into 1x1 mm pieces and placed on plastic culture plates containing Dulbecco’s Modified Eagle’s Medium supplemented with 10% fetal calf serum, 100 U/ml penicillin, 100 µg/ml streptomycin and 1% amphotericin B. For the keratinocytes culture, after the epithelial cells started to multiply around the gingival origin and the diameter was 2-5 mm., the fibroblasts were liminated by mechanical removal under inverted microscope to prevent fibroblast overgrowth and the medium was changed to keratinocyte-SFM (Gibco, BRL) supplemented with 5 µg/ml gentamycin. The results revealed that gingival fibroblast gave the highest success rate in culture (96.3%), followed by gingival keratinocytes (88.9%) and periodontal ligament fibroblasts (81.5%). There was no significant difference in the success rate of cultivation between younger and older individuals, as between sex of the subjects (p>0.05). The risk of failure in culture techniques is mainly caused by microbiological contamination from the tissue samples.

Supreya Wanichpakorn; Ureporn Kedjarune-Laggat

2010-01-01

109

Appropriateness of viscoelastic soft materials as in vitro simulators of the periodontal ligament.  

UK PubMed Central (United Kingdom)

The periodontal ligament is a viscoelastic soft tissue that connects the tooth to the alveolar bone. This tissue should be simulated in numerical as well as in laboratory models. The mechanical properties of this tissue were previously determined ex vivo and in vivo. The aim of the study was to analyse the appropriateness of impression and reline materials used in dentistry to simulate viscoelastic behaviour of the periodontal ligament. Two reline [Durabase (Reliance Dental MFG, Co.) and Soft Liner (GC Corporation)] and two impression [President Plus (Coltene) and Prestige L (Vanini Dental Industry)] materials were examined in recovery and tensile relaxation tests. Recovery: This experiment simulated in vivo test. Roots of a pair of plastic maxillary premolar teeth were covered with each test material and embedded in acryl while maintaining the contact point. A 0·1-mm stainless steel strip, inserted at the contact point and maintained for 10 s, was used to tip the teeth. After removal, the tightness of dental contact point was measured over 30 min by determining the force needed to insert a 0·05-mm metal strip. Tensile relaxation: strips were elongated to 120%, 140% and 160% of their initial length and maintained at that length for 30 min. Two-phase decay function was applied. The results showed that elastic modulus and relaxation behaviour were significantly different between materials. Elastic modulus values were in the same range of those reported in the literature. However, the recovery values and behaviour showed that impression materials, especially President, are the materials of choice for this purpose because they simulated better the in vivo test.

Brosh T; Porat N; Vardimon AD; Pilo R

2011-12-01

110

Appropriateness of viscoelastic soft materials as in vitro simulators of the periodontal ligament.  

Science.gov (United States)

The periodontal ligament is a viscoelastic soft tissue that connects the tooth to the alveolar bone. This tissue should be simulated in numerical as well as in laboratory models. The mechanical properties of this tissue were previously determined ex vivo and in vivo. The aim of the study was to analyse the appropriateness of impression and reline materials used in dentistry to simulate viscoelastic behaviour of the periodontal ligament. Two reline [Durabase (Reliance Dental MFG, Co.) and Soft Liner (GC Corporation)] and two impression [President Plus (Coltene) and Prestige L (Vanini Dental Industry)] materials were examined in recovery and tensile relaxation tests. Recovery: This experiment simulated in vivo test. Roots of a pair of plastic maxillary premolar teeth were covered with each test material and embedded in acryl while maintaining the contact point. A 0·1-mm stainless steel strip, inserted at the contact point and maintained for 10 s, was used to tip the teeth. After removal, the tightness of dental contact point was measured over 30 min by determining the force needed to insert a 0·05-mm metal strip. Tensile relaxation: strips were elongated to 120%, 140% and 160% of their initial length and maintained at that length for 30 min. Two-phase decay function was applied. The results showed that elastic modulus and relaxation behaviour were significantly different between materials. Elastic modulus values were in the same range of those reported in the literature. However, the recovery values and behaviour showed that impression materials, especially President, are the materials of choice for this purpose because they simulated better the in vivo test. PMID:21707697

Brosh, T; Porat, N; Vardimon, A D; Pilo, R

2011-06-27

111

Bone repair by periodontal ligament stem cell-seeded nanohydroxyapatite-chitosan scaffold  

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Full Text Available Shaohua Ge,1 Ning Zhao,1 Lu Wang,1 Meijiao Yu,1 Hong Liu,2 Aimei Song,1 Jing Huang,1 Guancong Wang,2 Pishan Yang11Key Laboratory of Oral Biomedicine of Shandong Province, Department of Periodontology, School of Stomatology, 2Center of Bio and Micro/Nano Functional Materials, State Key Laboratory of Crystal Materials, Shandong University, Jinan, ChinaBackground: 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.Keywords: periodontal ligament, stem cells, hydroxyapatite, chitosan, scaffold, tissue engineering

Ge S; Zhao N; Wang L; Yu M; Liu H; Song A; Huang J; Wang G; Yang P

2012-01-01

112

[Odontogenic differentiation of bone marrow-derived mesenchymal stem cells induced by periodontal ligament stem cells].  

UK PubMed Central (United Kingdom)

Objective To investigate the mechanism underlying the mechanism of odontogenic differentiation of bone marrow-derived mesenchymal stem cells (BMMSCs) induced by periodontal ligament stem cells (PDLSCs), and offer an experimental evidence for the combination of the two types of stem cells to make regenerative periodontal complex. Methods By means of Transwell(R); chamber, PDLSCs and BMMSCs from miniature pigs were co-cultured indirectly at different mixing ratios of PDLSCs to BMMSCs, 10:1 (group A), 1:1 (group B), 1:10 (group C). On the other hand, PDLSCs and BMMSCs were respectively cultured alone as positive and negative control group. Fourteen days later, the expressions of scleraxis, matrix extracellular phosphoglycoprotein (MEPE), osteocalcin (OCN), osterix (OSX) were detected by immunofluorescence and real-time quantitative PCR (qRT-PCR) to determine the optimal ratio of PDLSCs to BMMSCs for odontogenic differentiation. Results Immunofluorescence and qRT-PCR showed that the expression levels of sceleraxi, OCN and OSX protein and relative mRNA had no statistically significant difference in the A, B, C groups (P>0.05), but as for MEPE, its relative mRNA expression level in group A was significantlly higher than that in group B or C (P<0.01). Conclusion In the indirect co-culture of PDLSCs and BMMSCs, BMMSCs can obtain PDLSCs' biological characteristics to different extent, and meanwhile, a small number of PDLSCs can also induce the odontogenic differentiation of BMMSCs.

Wang X; Liu Y; Ma Y; Bi X; Zheng S; Liu J; Li B; Sun D; Zhao J

2013-08-01

113

Cellular uptake and processing of enamel matrix derivative by human periodontal ligament fibroblasts.  

UK PubMed Central (United Kingdom)

OBJECTIVE: Enamel matrix derivative (EMD), is an extract of porcine developing enamel matrix. Its commercialised form Emdogain, is claimed to stimulate periodontal regeneration by recapitulating original developmental processes, although the mechanism remains unclear. Our objective was to investigate interactions between EMD and human periodontal ligament (HPDL) fibroblasts in vitro. DESIGN: HPDL fibroblasts were cultured in the presence of fluorescently labelled EMD and cellular EMD uptake was monitored using confocal laser scanning microscopy and immunohistochemistry. Internalised EMD proteins were characterised using SDS-PAGE. RESULTS: EMD was internalised by HPDL fibroblasts leading to the appearance of multiple, vesicle-like structure in the cytoplasm. The internalised protein was composed mainly of the major 20kDa amelogenin component of EMD which was subsequently processed with time to generate a cumulative 5kDa component. CONCLUSIONS: Cellular uptake and subsequent intracellular processing of EMD components by dental mesenchymal cells may play a role in EMD bioactivity and in part explain the turnover of Emdogain when placed clinically.

Lees JD; Robinson C; Shore RC; Paine ML; Brookes SJ

2013-04-01

114

Asiaticoside induces type I collagen synthesis and osteogenic differentiation in human periodontal ligament cells.  

Science.gov (United States)

Asiaticoside, an active ingredient extracted from Centella asiatica, has been widely used to promote wound healing. In this study, the effects of asiaticoside on proliferation, protein synthesis, and osteogenic differentiation in human periodontal ligament cells (HPDLs) were investigated. HPDLs were treated with asiaticoside at concentrations of 25, 50, and 100 µg/mL. Cell number was determined by MTT assay. The mRNA expression was analyzed by reverse transcription-polymerase chain reaction. Western blot analysis and immunocytochemistry were used to confirm protein synthesis. Osteogenic differentiation was determined by alkaline phosphatase activity, osteoblast marker gene expression, and in vitro mineralization. The results showed that asiaticoside treatment, ranging from 25 to 100 mg/mL, had no effect on cytotoxicity or cell proliferation. When HPDLs were treated with asiaticoside in serum-free medium, dose-dependent increases in the levels of fibronectin and collagen type I mRNA and protein were observed at 72 h. Moreover, asiaticoside attenuated matrix metalloproteinase-1 but enhanced tissue inhibitor of metalloproteinase-1 mRNA expression. The addition of asiaticoside to osteogenic medium resulted in an increase in alkaline phosphatase enzymatic activity, up-regulation of osteoblast marker gene mRNA expression, and enhancement of mineralization by HPDLs. These results suggest the potential application of asiaticoside for enhancing periodontal tissue healing. PMID:22628285

Nowwarote, Nunthawan; Osathanon, Thanaphum; Jitjaturunt, Peachaya; Manopattanasoontorn, Sukuman; Pavasant, Prasit

2012-05-25

115

Asiaticoside induces type I collagen synthesis and osteogenic differentiation in human periodontal ligament cells.  

UK PubMed Central (United Kingdom)

Asiaticoside, an active ingredient extracted from Centella asiatica, has been widely used to promote wound healing. In this study, the effects of asiaticoside on proliferation, protein synthesis, and osteogenic differentiation in human periodontal ligament cells (HPDLs) were investigated. HPDLs were treated with asiaticoside at concentrations of 25, 50, and 100 µg/mL. Cell number was determined by MTT assay. The mRNA expression was analyzed by reverse transcription-polymerase chain reaction. Western blot analysis and immunocytochemistry were used to confirm protein synthesis. Osteogenic differentiation was determined by alkaline phosphatase activity, osteoblast marker gene expression, and in vitro mineralization. The results showed that asiaticoside treatment, ranging from 25 to 100 mg/mL, had no effect on cytotoxicity or cell proliferation. When HPDLs were treated with asiaticoside in serum-free medium, dose-dependent increases in the levels of fibronectin and collagen type I mRNA and protein were observed at 72 h. Moreover, asiaticoside attenuated matrix metalloproteinase-1 but enhanced tissue inhibitor of metalloproteinase-1 mRNA expression. The addition of asiaticoside to osteogenic medium resulted in an increase in alkaline phosphatase enzymatic activity, up-regulation of osteoblast marker gene mRNA expression, and enhancement of mineralization by HPDLs. These results suggest the potential application of asiaticoside for enhancing periodontal tissue healing.

Nowwarote N; Osathanon T; Jitjaturunt P; Manopattanasoontorn S; Pavasant P

2013-03-01

116

Load response of periodontal ligament: assessment of fluid flow, compressibility, and effect of pore pressure.  

Science.gov (United States)

The periodontal ligament (PDL) functions both in tension and in compression. The presence of an extensive vascular network inside the tissue suggests a significant contribution of the fluid phase to the mechanical response. This study examined the load response of bovine PDL under different pore pressure levels. A custom-made pressure chamber was constructed. Rod-shaped specimens comprising portions of dentine, bone, and intervening layer of PDL were extracted from bovine mandibular molars. The dentine ends of the specimens were secured to the actuator while the bone ends were affixed to the load cell. The entire assemblage was surrounded by the pressure chamber, which was then filled with saline. Specimens loaded at 1.0 Hz sinusoidal displacement were subjected to four different environmental fluid pressures (i.e., pressures of 0.0-1.0 MPa). The video images recorded during the tests were analyzed to determine whether or not fluid exchange between the PDL and the surrounding medium took place during mechanical loading. A value for the tissue's apparent Poisson ratio was also determined. The following observations were made: (1) fluid was squeezed out and pumped into the ligament during the compressive and tensile loading phases, (2) the PDL was highly compressible, and (3) the pore pressure had no influence on the mechanical response of the PDL. The present tests emphasized the biphasic structure of PDL tissue, which should be considered as a porous solid matrix through which fluid can freely flow. PMID:20524752

Bergomi, Marzio; Wiskott, H W Anselm; Botsis, John; Mellal, Aïssa; Belser, Urs C

2010-01-01

117

Load response of periodontal ligament: assessment of fluid flow, compressibility, and effect of pore pressure.  

UK PubMed Central (United Kingdom)

The periodontal ligament (PDL) functions both in tension and in compression. The presence of an extensive vascular network inside the tissue suggests a significant contribution of the fluid phase to the mechanical response. This study examined the load response of bovine PDL under different pore pressure levels. A custom-made pressure chamber was constructed. Rod-shaped specimens comprising portions of dentine, bone, and intervening layer of PDL were extracted from bovine mandibular molars. The dentine ends of the specimens were secured to the actuator while the bone ends were affixed to the load cell. The entire assemblage was surrounded by the pressure chamber, which was then filled with saline. Specimens loaded at 1.0 Hz sinusoidal displacement were subjected to four different environmental fluid pressures (i.e., pressures of 0.0-1.0 MPa). The video images recorded during the tests were analyzed to determine whether or not fluid exchange between the PDL and the surrounding medium took place during mechanical loading. A value for the tissue's apparent Poisson ratio was also determined. The following observations were made: (1) fluid was squeezed out and pumped into the ligament during the compressive and tensile loading phases, (2) the PDL was highly compressible, and (3) the pore pressure had no influence on the mechanical response of the PDL. The present tests emphasized the biphasic structure of PDL tissue, which should be considered as a porous solid matrix through which fluid can freely flow.

Bergomi M; Wiskott HW; Botsis J; Mellal A; Belser UC

2010-01-01

118

Identification and characterization of neural crest-derived cells in adult periodontal ligament of mice.  

UK PubMed Central (United Kingdom)

OBJECTIVE: Cells derived from the neural crest (NC) contribute to the development of several adult tissues, including tooth and periodontal tissue. Here, two transgenic lines, Wnt1-Cre/ZEG and P0-Cre/ZEG, were analysed to determine the fate and distribution of neural crest cells (NCCs) in adult mouse periodontal ligament (PDL). DESIGN: Paraffin-embedded and decalcified histology samples were prepared from Wnt1-Cre/ZEG and P0-Cre/ZEG mice that were 4-, 8-, or 12-weeks old. Expression of GFP (NC-derived cells), NC-markers (Slug, AP-2 alpha, HNK-1, p75NTR and Nestin), and mesenchymal stem cell markers (CD29 and STRO-1) were examined using immunohistochemistry. RESULTS: In four-week-old Wnt1-Cre/ZEG mice, GFP((+)) NC-derived cells were specifically detected in the mid-zone of PDL. The GFP((+)) cells constituted 1.4% of all cells in PDL, and this percentage decreased as the mice aged. The distribution and prevalence of GFP((+)) cells were comparable between Wnt1-Cre/ZEG and P0-Cre/ZEG mice. NC-marker((+)) cells were expressed only in GFP((+)) cells while MSC markers were detected only in GFP((-)) cells. CONCLUSION: The prevalence and specific distribution of NC-derived cells in adult PDL of Wnt1-Cre/ZEG and P0-Cre/ZEG mouse were examined. Interestingly, various NC markers, including markers for undifferentiated NCCs, were still expressed at high levels in GFP((+)) cells. These observations may indicate that labelled cells in the Wnt1-Cre/ZEG and P0-Cre/ZEG mice did not constituted all NC-derived cells, but rather an interesting subset of NC-derived cells. These findings may be useful in understanding the homeostatic character of the PDL and contribute to establishing successful periodontal tissue maintenance.

Kaku M; Komatsu Y; Mochida Y; Yamauchi M; Mishina Y; Ko CC

2012-12-01

119

Comparison of mesenchymal stem cells derived from gingival tissue and periodontal ligament in different incubation conditions.  

Science.gov (United States)

Gingival tissue-derived mesenchymal stem cells (MSCs) were recently identified and characterized as having multipotential differentiation and immunomodulatory properties in vitro and in vivo, and they represent new postnatal stem cell types for cytotherapy and regenerative medicine. However, the utility of gingival MSCs (GMSCs) as alternatives to periodontal ligament stem cells (PDLSCs), which have been demonstrated to be effective but with limited cell availability and reduced clinical feasibility, for periodontal regeneration in a previously diseased/inflamed environment remains obscure. In this study, patient-matched human GMSCs and PDLSCs were evaluated in terms of their colony-forming ability, proliferative capacity, cell surface epitopes, multi-lineage differentiation potentials, and related gene expression when incubated in different designed culture conditions, with or without the presence of inflammatory cytokines. An in vivo ectopic transplantation model using transplants from inflammatory cytokine-treated or untreated cells was applied to assess bone formation. We found that cells derived from both tissues expressed MSC markers, including CD146, CD105, CD90, CD29, and STRO-1. Both cells successfully differentiated under osteogenic, adipogenic, and chondrogenic microenvironments; PDLSCs displayed a more effective differentiation potential in all of the incubation conditions compared to GMSCs (P < 0.01). Although inflammatory cytokine-treated GMSCs and PDLSCs are inferior to normally cultured, patient and tissue-matched cells in terms of their osteogenic capacity and regenerative potential (P < 0.05), they retain the capacity for osteoblastic and adipose differentiation, as well as ectopic bone formation, similar to what has been demonstrated for other MSCs. Interestingly, GMSCs exhibited fewer inflammation-related changes in terms of osteogenic potential in vitro and bone formation in vivo compared to PDLSCs (P < 0.01). These results suggest that both gingiva and PDL tissues are putative cell sources for future cytotherapeutic applications. Whether GMSCs act as an adjunctive or alternative cell source for cytotherapy of inflammatory periodontal disease warrants further investigation. PMID:23768902

Yang, Hao; Gao, Li-Na; An, Ying; Hu, Cheng-Hu; Jin, Fang; Zhou, Jun; Jin, Yan; Chen, Fa-Ming

2013-06-13

120

[Effect of lipopolysaccharide on proliferation and inflammatory factors expression of human periodontal ligament stem cells].  

UK PubMed Central (United Kingdom)

OBJECTIVE: To investigate the effect of Porphyromonas gingivalis lipopolysaccharide (LPS) on proliferation and inflammatory factors expression of human periodontal ligament stem cells (HPDLSCs). METHODS: HPDLSCs were cultivated and identified. Experiment was divided into 3 groups according to culture solution: Group A with alpha-MEM culture solution containing 10 microg.mL-1 LPS, group B with supernatant fluid containing 10ng.mL-1 LPS stimulated monocyte, group C with alpha-MEM culture solution. The proliferation ability of HPDLSCs was analyzed by MTF assay. The expression levels of interleukin-1beta (IL-1beta), interleukin-6 (IL-6), tumor necrosis factor (TNF-alpha) mRNA of HPDLSCs were detected by reverse transcriptase polymerase chain reaction(RT-PCR). RESULTS: HPDLSCs had clonality, bone and fat differentiation ability. Compared with group C, the proliferation ability of HPDLSCs of group A and group B was significantly inhibited, and the proliferation ability of HPDLSCs of group B were more significantly inhibited than that of group A (P<0.05). The expression of IL-1beta, IL-6 and TNF-alpha mRNA of group A and group B increased compared with the control group, and the expression of IL-1beta, IL-6 and TNF-alpha mRNA of group B increased more than that of group A (P<0.05). CONCLUSION: Porphyromonas gingivalis may inhibit the proliferation of HPDLSCs directly or indirectly through LPS and increase expression of inflammatory factor, exacerbate periodontal inflammatory tissue damage and delay the self-repairing of periodontal tissue.

Wang L; Xia J; Liu Q; Jin Y

2013-06-01

 
 
 
 
121

Bone morphogenic protein-2 induces apoptosis and cytotoxicity in periodontal ligament cells.  

UK PubMed Central (United Kingdom)

BACKGROUND: Periodontal ligament (PDL) expresses endogenous growth factors, such as bone morphogenic proteins (BMPs), which facilitate maintenance of tissue homeostasis. Inflammatory conditions, such as chronic periodontitis, could disrupt this homeostasis, and physiologic levels of growth factors may be insufficient to maintain tissue homeostasis. BMPs facilitate periodontal bone regeneration but also are implicated in causing tooth ankylosis and root resorption. The underlying mechanism of tooth ankylosis is unclear. However, there is evidence that BMPs induce apoptosis in progenitor cells. Little is known about BMP-induced cytotoxicity in PDL cells, which contain a population of progenitor cells. The aim of this study is to determine BMP2-induced osteogenic mediators and cytotoxic effects in PDL cells and compare these cells to osteoblasts. METHODS: Human PDL cells and primary osteoblasts were stimulated with doses of 1 to 200 ng/mL BMP2. Expression of alkaline phosphatase (ALP), in vitro mineralization along with osteonectin expression, induction of apoptosis, and cytotoxicity assays were performed. RESULTS: PDL cells and osteoblasts upregulated ALP and in vitro mineralization in a dose-dependent manner with BMP2 stimulation. However, at BMP2 concentrations >10 ng/mL, ALP, in vitro mineralization, and osteonectin were downregulated in PDL cells. Relative to osteoblasts, PDL cells were susceptible to apoptosis and cytotoxicity with 10 times lower concentration of BMP2. CONCLUSIONS: Relative to osteoblasts, PDL cells are susceptible to BMP2-induced cytotoxicity. BMP-induced tooth ankylosis is controversial and is poorly understood. Disruption of PDL homeostasis by BMP-induced apoptosis could play a role in tooth ankylosis.

Muthukuru M

2013-06-01

122

Interactions of regenerative, inflammatory and biomechanical signals on bone morphogenetic protein-2 in periodontal ligament cells.  

UK PubMed Central (United Kingdom)

BACKGROUND AND OBJECTIVE: Regeneration of periodontal tissues by EMD remains a major challenge because a number of modifying factors are as yet unknown. The effects of EMD seem to be mediated, at least in part, by bone morphogenetic protein-2 (BMP-2). This in vitro study was performed to examine whether the effects of EMD on BMP-2 activity are modulated by inflammatory and/or biomechanical signals. MATERIAL AND METHODS: ? Periodontal ligament cells were seeded on BioFlex(®) plates and exposed to EMD under normal, inflammatory or biomechanical loading conditions for 1 and 6 d. In order to mimic proinflammatory or biomechanical loading conditions in vitro, cells were stimulated with interleukin-1? (IL-1?), which is increased at inflamed periodontal sites, and cyclic tensile strain of various magnitudes, respectively. The synthesis of BMP-2, its receptors (BMPR-1A, BMPR-1B and BMPR-2) and its inhibitors (follistatin, matrix gla protein and noggin) were analyzed using real-time RT-PCR and ELISA. RESULTS: In EMD-treated cells, BMP-2 synthesis was increased significantly at 1 d. EMD also induced the expression of all BMP receptors, and of the BMP inhibitors follistatin and noggin. In general, IL-1? and biomechanical loading neither down-regulated BMP-2 nor up-regulated BMP inhibitors in EMD-stimulated cells. However, IL-1? and biomechanical loading, when applied for a longer time period, caused a down-regulation of EMD-induced BMP receptors. CONCLUSION: EMD induces not only BMP-2, but also its receptors and inhibitors, in PDL cells. IL-1? and biomechanical forces may counteract the beneficial effects of EMD on BMP-2 activity via the down-regulation of BMP receptors.

Nokhbehsaim M; Deschner B; Winter J; Bourauel C; Rath B; Jäger A; Jepsen S; Deschner J

2011-06-01

123

A biphasic scaffold design combined with cell sheet technology for simultaneous regeneration of alveolar bone/periodontal ligament complex.  

UK PubMed Central (United Kingdom)

This study describes the design of a biphasic scaffold composed of a Fused Deposition Modeling scaffold (bone compartment) and an electrospun membrane (periodontal compartment) for periodontal regeneration. In order to achieve simultaneous alveolar bone and periodontal ligament regeneration a cell-based strategy was carried out by combining osteoblast culture in the bone compartment and placement of multiple periodontal ligament (PDL) cell sheets on the electrospun membrane. In vitro data showed that the osteoblasts formed mineralized matrix in the bone compartment after 21 days in culture and that the PDL cell sheet harvesting did not induce significant cell death. The cell-seeded biphasic scaffolds were placed onto a dentin block and implanted for 8 weeks in an athymic rat subcutaneous model. The scaffolds were analyzed by ?CT, immunohistochemistry and histology. In the bone compartment, a more intense ALP staining was obtained following seeding with osteoblasts, confirming the ?CT results which showed higher mineralization density for these scaffolds. A thin mineralized cementum-like tissue was deposited on the dentin surface for the scaffolds incorporating the multiple PDL cell sheets, as observed by H&E and Azan staining. These scaffolds also demonstrated better attachment onto the dentin surface compared to no attachment when no cell sheets were used. In addition, immunohistochemistry revealed the presence of CEMP1 protein at the interface with the dentine. These results demonstrated that the combination of multiple PDL cell sheets and a biphasic scaffold allows the simultaneous delivery of the cells necessary for in vivo regeneration of alveolar bone, periodontal ligament and cementum.

Vaquette C; Fan W; Xiao Y; Hamlet S; Hutmacher DW; Ivanovski S

2012-08-01

124

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

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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).

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

1981-12-01

125

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

International Nuclear Information System (INIS)

Analysis of electron microscopic radioautographs revealed a maximum labeling with 3H-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.

1981-01-01

126

Expression of type IV collagen and laminin at the interface between epithelial cells and fibroblasts from human periodontal ligament.  

UK PubMed Central (United Kingdom)

The present study was undertaken to examine whether synthesis of type IV collagen and laminin around the epithelial rests of Malassez (ERM) requires direct contact between cells from ERM and periodontal ligament fibroblasts. Human periodontal ligament (HPDL) explants produced outgrowths containing both ERM cells and fibroblasts when cultured in a modified serum-free medium. The interface between ERM cells and fibroblasts was examined using phase-contrast microscopy (PCM) and scanning electron microscopy (SEM). Expression of type IV collagen and laminin was studied by immunohistochemistry and in situ hybridization. It was observed that ERM cells grew underneath fibroblasts or attached to them. At the interface, type IV collagen and laminin and their respective mRNAs were abundant in both ERM cells and fibroblasts, while these proteins and mRNAs showed little if any staining in cells further away from the interface. Hence, these findings indicate that synthesis of type IV collagen and laminin is induced by direct interaction between ERM cells and periodontal ligament fibroblasts.

Shimonishi M; Sato J; Takahashi N; Komatsu M

2005-02-01

127

In vitro clonogenic capacity of periodontal ligament fibroblasts cultured with Emdogain.  

Science.gov (United States)

The aim of the present study was to evaluate the efficiency of Emdogain (EMD) in preserving the size of the periodontal ligament progenitor pool (clonogenic capacity) and in promoting their proliferation. Periodontal ligament fibroblasts (PDLF) were obtained from explants of young permanent healthy tooth. After initial outgrowth (10 days to 2 weeks following explantation), the culture medium of experimental flasks was replaced with medium supplemented with 100 microg ml(-1) EMD, whereas the other served as controls and were fed with regular medium. Following 5 weeks, the cells were washed (3x), harvested (trypsin + EDTA), and evaluated for their viability. Viable cells from each group were inoculated into six 96-well plates at a concentration of one viable cell per two wells and were allowed to grow for 5 weeks. The percentage of cells with clonogenic capacity was determined as the number of colonies formed/number of cells seeded x 100 in the experimental and control groups. Three degrees of dish area coverage were utilized: up to 25%, between 25% and 75% and higher than 75%. This experiment was repeated four times from four different donors. A total of 2328 cells were evaluated, half of which, were cultured with EMD. The mean percentage of cells (from all donors) who exhibited any clonogenic capacity in the presence of EMD was comparable with that of cells cultured in the absence of EMD: 26.6 +/- 14.3% when compared with 34.6 +/- 20.6% respectively (P = 0.186). Similarly, the percentage of clones that proliferated to cover up to 25% of the well area was comparable in the two groups 7.5 +/- 8.6 for EMD-treated clones and 7.1 +/- 7.8 for untreated clones (P = 0.674). The percentage of clones that proliferated to cover 25% up to 75% of the well area was greater EMD-treated clones as compared with the untreated cells: 8.1 +/- 6.7% vs 3.8 +/- 3%. However this difference was not statistically significant (P = 0.277). In contrast, the percentage of clones that covered more than 75% of the well area was significantly lower in the EMD-treated clones when compared with the untreated clones (10.9 +/- 11.1 vs 23.8 +/- 14.7; P = 0.022) . In conclusion, EMD decreased the percentage of PDLF with capabilities of arising colonies with 75-100% confluency probably by increasing their differentiation. PMID:16422755

Ashkenazi, Malka; Shaked, Ilanit

2006-02-01

128

Proliferation and osteogenic differentiation of human periodontal ligament cells on akermanite and ?-TCP bioceramics  

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Full Text Available The purpose of this study was to investigate the effects of akermanite as compared to ?-TCP on attachment, proliferation, and osteogenic differentiation of human periodontal ligament cells (hPDLCs). Scanning electron microscopy (SEM) and actin filament labeling were used to reveal attachment and growth of hPDLCs seeded on ?-TCP and akermanite ceramic. Cell proliferation was tested by lactic acid production and MTT analysis, while osteogenic differentiation was assayed by alkaline phosphatase (ALP) expression and real-time polymerase chain reaction (PCR) analysis on markers of osteopontin (OPN), dentin matrix acidic phosphoprotein-1 (DMP-1), and osteocalcin (OCN), and further detected by enzyme-linked immunosorbent analysis (ELISA) analysis for OCN expression. Besides, the ions released from akermanite and their effect on hPDLCs was also measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES), MTT analysis, ALP expression and real-time PCR analysis. hPDLCs attached well on both ceramics, but showed better spreading on akermanite. hPDLCs proliferated more rapidly on akermanite than ?-TCP. Importantly, osteogenic differentiation of hPDLCs was enhanced on akermanite compared to ?-TCP. Besides, Ca, Mg and Si ions were released from akermanite, while only Ca ions were released from ?-TCP. Moreover, more pronounced proliferation and higher osteogenic gene expression for hPDLCs cultured with akermanite extract were detected as compared to cells cultured on akermanite. Therefore, akermanite ceramic showed an enhanced effect on proliferation and osteogenic differentiation of hPDLCs, which might be attributed to the release of ions containing Ca, Mg and Si from the material. It is suggested that akermanite ceramics may serve as a potential material for periodontal bone regeneration.

L Xia; L Xia; Z Zhang; L Chen; W Zhang; D Zeng; X Zhang; J Chang; X Jiang

2011-01-01

129

Early root surface colonization by human periodontal ligament fibroblasts following treatment with different biomaterials.  

UK PubMed Central (United Kingdom)

Abstract Objectives. The present in-vitro study examined the effects of different biomaterials on early root surface colonization by human periodontal ligament (PDL) fibroblasts using confocal-laser-scanning-microscopy (CLSM). Materials and methods. Fifteen periodontally-diseased teeth were extracted, treated with scaling/root planing and longitudinally cut to obtain 30 root fragments. Fragments were treated either with 24% EDTA following application of enamel matrix derivative (EMD), 24% EDTA or EMD only, nanocrystalline hydroxyapatite (NHA) paste or oily calcium hydroxide suspension (OCHS) for 1 h each. The analogue untreated root specimens served as controls. Root fragments were incubated with human PDL fibroblasts and cellular proliferation and morphology were evaluated after 1, 3, 5 and 8 days using CLSM-visualization and image recognition software. Results. The rate of cellular proliferation was different among treatment modalities examined (p = 0.019). Except treatment with NHA paste all treatment modalities improved cellular proliferation on root surfaces at all different points of time compared with the control specimens. A significant difference between treatment modalities was observed between EMD and NHA paste (p = 0.008). No synergistic effect could be demonstrated comparing root surface conditioning with 24% EDTA and EMD application compared to 24% EDTA or EMD application only. Conclusion. The present results suggest that initial root surface colonization by PDL fibroblasts may be enhanced by root surface conditioning with 24% EDTA and application of EMD, application of 24% EDTA or EMD alone and OCHS. The addition of 24% EDTA for root surface conditioning prior to EMD application provided no synergistic effects in terms of early root surface colonization by PDL fibroblasts.

Kasaj A; Klein MO; Dupont J; Willershausen B; Krahn U; Götz H; Zeiler J; Brüllmann D; Duschner H

2013-04-01

130

Early root surface colonization by human periodontal ligament fibroblasts following treatment with different biomaterials.  

Science.gov (United States)

Abstract Objectives. The present in-vitro study examined the effects of different biomaterials on early root surface colonization by human periodontal ligament (PDL) fibroblasts using confocal-laser-scanning-microscopy (CLSM). Materials and methods. Fifteen periodontally-diseased teeth were extracted, treated with scaling/root planing and longitudinally cut to obtain 30 root fragments. Fragments were treated either with 24% EDTA following application of enamel matrix derivative (EMD), 24% EDTA or EMD only, nanocrystalline hydroxyapatite (NHA) paste or oily calcium hydroxide suspension (OCHS) for 1 h each. The analogue untreated root specimens served as controls. Root fragments were incubated with human PDL fibroblasts and cellular proliferation and morphology were evaluated after 1, 3, 5 and 8 days using CLSM-visualization and image recognition software. Results. The rate of cellular proliferation was different among treatment modalities examined (p = 0.019). Except treatment with NHA paste all treatment modalities improved cellular proliferation on root surfaces at all different points of time compared with the control specimens. A significant difference between treatment modalities was observed between EMD and NHA paste (p = 0.008). No synergistic effect could be demonstrated comparing root surface conditioning with 24% EDTA and EMD application compared to 24% EDTA or EMD application only. Conclusion. The present results suggest that initial root surface colonization by PDL fibroblasts may be enhanced by root surface conditioning with 24% EDTA and application of EMD, application of 24% EDTA or EMD alone and OCHS. The addition of 24% EDTA for root surface conditioning prior to EMD application provided no synergistic effects in terms of early root surface colonization by PDL fibroblasts. PMID:23627845

Kasaj, Adrian; Klein, Marcus O; Dupont, Julia; Willershausen, Brita; Krahn, Ulrike; Götz, Hermann; Zeiler, Johannes; Brüllmann, Dan; Duschner, Heinz

2013-04-29

131

Enhanced compatibility of chemically modified titanium surface with periodontal ligament cells  

Science.gov (United States)

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.

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

2012-12-01

132

Modulus of elasticity of human periodontal ligament by optical measurement and numerical simulation.  

UK PubMed Central (United Kingdom)

OBJECTIVE: To determine the elastic modulus of the periodontal ligament (PDL). MATERIALS AND METHODS: This study was carried out on eight human maxillary jaw segments containing central incisors. Displacements were measured under load using a laser sensing system, electronic speckle pattern interferometry (ESPI). Subsequently, finite element models presenting the same individual geometry as the respective autopsy material were developed by the software of Mimics and Ansys, based on scanning data from micro computed tomography (micro CT), to simulate tooth mobility numerically under the same force systems as were used in the experiment. Numerical force/deflection curves obtained from the models were fitted to the experimental curves by repeatedly calculating theoretical tooth deflections and varying the elasticity parameters of the human PDL. RESULTS: A bilinear material parameter set was assumed to simulate tooth deflections. Mean values of E? ?=? 0.04 MPa, E? ?=? 0.16 MPa, and ultimate strain of ??? ?=? 7.3% were derived for the elastic behavior of the PDL. CONCLUSION: Force/deflection curves from the measurements showed a significant nonlinear behavior of elastic stiffness of the PDL. A bilinear material parameter set was suitably assumed to be a description of nonlinear properties of the PDL.

Dong-Xu L; Hong-Ning W; Chun-Ling W; Hong L; Ping S; Xiao Y

2011-03-01

133

[Differentiation of human periodontal ligament stem cells into neuron-like cells in vitro].  

UK PubMed Central (United Kingdom)

OBJECTIVE: To isolate and purify the human periodontal ligament stem cells (PDLSC) and investigate the differentiation potentials of PDLSC into neuron-like cells in vitro. METHODS: PDLSC were isolated and cultivated. PDLSC of passage 2 was plated at a density of 5 x 10(3) per mL. At 80% confluence, the PDLSC were preinduced for 24 hours, and were subsequently replaced with an inducing medium containing certain concentration of 13-mercaptoethanal (beta-ME). After 6 hours of induction, the results were evaluated by morphological observation, immunocytochemical staining for neuron specific enolase (NSE), neurofilament (NF) and glial fibrillary acid protein (GFAP) expression and RT-PCR for NSE, NF, GFAP mRNA. Meanwhile, the uninduced PDLSC were used as a negative control. RESULTS: PDLSC could be differentiate into cells with typical neuronal morphology. Immunohisto-chemistry and RT-PCR confirmed that the induced cells expressed NSE and NF, two marked enzymes of neuron cell. CONCLUSION: PDLSC can be induced into neuron-like cells in vitro. PDLSC have the capability of multilineage differentiations.

Zhen L; Liu HW

2009-02-01

134

Effects of icariin on the alkline phosphatase activity of human periodontal ligament cells inhibited by lipopolysaccharide.  

UK PubMed Central (United Kingdom)

Icariin (ICA), a flavanoid isolated from herbal Epimedium, has multiple biological activities. The present study investigated the effects of ICA on the proliferation and alkaline phosphatase (ALP) activity (an index for PDLC differentiation) of human periodontal ligament cells (hPDLCs) inhibited by lipopolysaccharide (LPS). hPDLCs were cultured in vitro and stimulated with various concentrations of ICA. The proliferation ability of hPDLCs was detected by an MTT assay. The activity of ALP was determined by the p?Nitrophenyl phosphate method, and the expression of ALP was analyzed by reverse transcription polymerase chain reaction and western blot analysis. ICA exhibited a dose-dependent effect on the proliferation of hPDLCs in a suitable concentration range, from 10?6 to 10?8 mol/l, and with a mediate optimal concentration (10-6 mol/l). The alkaline phosphatase activity was markedly inhibited in 10 µg/ml LPS?treated PDLCs and this inhibition was suppressed in the presence of icariin at a concentration of 10-6 mol/L following prolonged treatment (96 h). Therefore, this study provided insight into the use of ICA for periapical tissue regeneration.

Lv XC; Bi LJ; Jiang Y; Wang X

2013-09-01

135

Effects of icariin on the alkline phosphatase activity of human periodontal ligament cells inhibited by lipopolysaccharide.  

Science.gov (United States)

Icariin (ICA), a flavanoid isolated from herbal Epimedium, has multiple biological activities. The present study investigated the effects of ICA on the proliferation and alkaline phosphatase (ALP) activity (an index for PDLC differentiation) of human periodontal ligament cells (hPDLCs) inhibited by lipopolysaccharide (LPS). hPDLCs were cultured in vitro and stimulated with various concentrations of ICA. The proliferation ability of hPDLCs was detected by an MTT assay. The activity of ALP was determined by the p?Nitrophenyl phosphate method, and the expression of ALP was analyzed by reverse transcription polymerase chain reaction and western blot analysis. ICA exhibited a dose-dependent effect on the proliferation of hPDLCs in a suitable concentration range, from 10?6 to 10?8 mol/l, and with a mediate optimal concentration (10-6 mol/l). The alkaline phosphatase activity was markedly inhibited in 10 µg/ml LPS?treated PDLCs and this inhibition was suppressed in the presence of icariin at a concentration of 10-6 mol/L following prolonged treatment (96 h). Therefore, this study provided insight into the use of ICA for periapical tissue regeneration. PMID:24042495

Lv, Xue-Chao; Bi, Liang-Jia; Jiang, Ying; Wang, Xiang

2013-09-13

136

Electrochemical dissolution of nickel-titanium endodontic files induces periodontal ligament cell death.  

UK PubMed Central (United Kingdom)

INTRODUCTION: Fractured endodontic files present a major problem. A novel method has been proposed to retrieve fractured nickel-titanium (NiTi) endodontic files by using electrochemical dissolution. However, the effect of file dissolution on adjacent soft tissues such as the periodontal ligament (PDL) has not been investigated. The aim of this study was to determine the effects of the dissolution products on PDL fibroblasts. METHODS: Endodontic files were dissolved in sodium fluoride (NaF) by passing a 50-mA current through the NiTi files while immersed in the NaF solution. NaF/NiTi solutions were diluted with minimal essential medium-? media containing 10% serum. PDL cells were treated for up to 24 hours, and cell viability was quantified by using calcein AM to label live cells and ethidium homodimer to label dead cells. This was repeated by using artificial saliva (AS) as an alternative to NaF. RESULTS: NaF solution reduced PDL cell survival, and the NaF/NiTi solution further reduced PDL cell survival. AS alone did not reduce cell survival, whereas AS/NiTi solution reduced PDL cell survival. Particles that resulted from the electrochemical dissolution of NiTi files were highly cytotoxic. CONCLUSIONS: Electrochemically dissolving NiTi files in NaF results in solutions that are cytotoxic to PDL fibroblasts. AS may be a less toxic alternative for dissolving NiTi files.

Mitchell Q; Jeansonne BG; Stoute D; Lallier TE

2013-05-01

137

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

UK PubMed Central (United Kingdom)

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.

Soares DM; Ginani F; Henriques AG; Barboza CA

2013-09-01

138

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

International Nuclear Information System (INIS)

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. (paper)

2013-08-28

139

[Comparison between gingival and periodontal ligament fibroblasts from the same subject].  

UK PubMed Central (United Kingdom)

The objective of this study was to compare fibroblasts from the periodontal ligament (PLF) and gingival fibroblasts (GF) as to morphology, proliferation rate and protein synthesis. PLF and GF were explanted from tissues of the same patient. To characterize and compare the morphology of cells, PLF and GF were plated and analyzed under phase-contrast and optical microscopies. Proliferation rates were determined by means of automated counts carried out in days 1, 4, 7, 15 and 21, and also by means of the bromodeoxyuridine labelling index (BrdU). Total protein content was analyzed by means of electrophoresis in 10% polyacrylamide gel and zimography containing gelatin as substrate. PLF were bigger and more elongated than GF in subconfluence and confluence conditions. The proliferative rate of PLF was higher than that of GF at 1, 4, and 7 days (p < 0.05). At 15 and 21 days, there was no statistically significant difference as to the number of cells. PLF presented a significantly greater proliferative potential, in relation to GF (p < 0.05). The synthesis of protein in a period of 24 hours was similar for both PLF and GF. Our results demonstrated that PLF and GF are different as to morphology and proliferative capacity, however, they do not differ as to protein synthesis.

Palioto DB; Della Coletta R; Martelli Júnior H; Joly JC; Graner E; de Lima AF

2002-10-01

140

Effect of storage in media with different ion strengths and osmolalities on human periodontal ligament cells  

International Nuclear Information System (INIS)

The viability of the periodontal ligament (PDL) cells is critical for a successful healing of replanted exarticulated teeth. It is mainly dependent on the duration of the extra-alveolar time and the storage medium. Saliva has usually been recommended as the most suitable storage medium, but recent experimental studies indicate that milk is preferable. In the present study the effect on cultured PDL cells of saliva and milk has been compared with some reference media such as tap water or saline by means of a 3H-uridine leakage test. Storage in milk or saline was found to cause much less 3H-uridine leakage than storage in saliva or tap water. Cells stored in milk for 60-180 min showed about the same leakage as cells stored in saline or Hanks' balanced salt solution. Osmolality measurements showed that saliva was hypotonic, while the osmolality of milk ranged within physiological limits. When the osmolality of saliva was increased by addition of NaCl the leakage of the stored cells decreased to the level of cells stored in 0.9% NaCl or milk. (author).

1981-01-01

 
 
 
 
141

Human periodontal ligament cell response to a newly developed calcium phosphate-based root canal sealer.  

UK PubMed Central (United Kingdom)

OBJECTIVES: The aim of this study was to investigate the cellular effects of newly developed calcium phosphate-based sealers (CAPSEAL I and II) using cultured human periodontal ligament cells (HPDLCs) compared with epoxy resin sealer (AH26; Dentsply, DeTrey, Konstanz, Germany), zinc oxide eugenol [ZOE] sealer (extended working time [EWT]; Kerr Corporation, Orange, CA), and CPC sealer (Sankin apatite sealer; Sankin-kogyo, Tokyo, Japan). METHODS: Cell viability by -(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazoliumbromide assay, cell attachment by scanning electron microscopy, osteoblastic differentiation and inflammatory mediators by reverse-transcriptase polymerase chain reaction, Western blotting, and alizarin red staining were evaluated. RESULTS: The cytotoxicities of CAPSEAL I and II were less than those of AH 26 and EWT after 1 and 14 days. Cells on CAPSEAL I and II were spread better as compared with those on other sealers. Mineralization after 14 days and the expression of osteoblastic differentiation markers such as alkaline phosphate and osteonectin messenger RNA increased in CAPSEAL I- and II-exposed HPDLCs after 1 and 3 days, whereas the production of inflammatory mediators, including cyclooxygenase-2, inducible nitric oxide synthetase, and reactive oxygen species (ROS), were lower than in other sealers. CONCLUSIONS: These results suggest that both CAPSEAL I and II show less cytotoxicity and inflammatory mediators compared with other sealers and have the potential to promote bone regeneration as root canal sealers.

Bae WJ; Chang SW; Lee SI; Kum KY; Bae KS; Kim EC

2010-10-01

142

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

Science.gov (United States)

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.

Mileti?, M.; Mojsilovi?, S.; Oki? ?or?evi?, I.; Maleti?, D.; Pua?, N.; Lazovi?, S.; Malovi?, G.; Milenkovi?, P.; Petrovi?, Z. Lj; Bugarski, D.

2013-08-01

143

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

UK PubMed Central (United Kingdom)

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 (?-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 ?-XRF. Interestingly, the hygroscopic 10-30?m 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.

Ho SP; Kurylo MP; Grandfield K; Hurng J; Herber RP; Ryder MI; Altoe V; Aloni S; Feng J; Webb S; Marshall GW; Curtis D; Piennatta P; Hayter JA

2013-09-01

144

Real-time PCR focused-gene array profiling of gingival and periodontal ligament fibroblasts.  

UK PubMed Central (United Kingdom)

The techniques for the establishment of primary gingival and periodontal ligament fibroblast cultures have been well established for over 30 years. It is only more recently, with the commercial availability of real-time PCR (RT-PCR) gene arrays that the expression profiles of up to 84 genes can be carried out simultaneously. Each focused panel of genes can identify the up- or down-regulation of genes associated with any one of over 100 biological pathways or specific disease states. Fibroblasts for RNA extraction and subsequent gene expression analysis can be collected under various experimental conditions and stored in RNA-preserving solution (e.g., RNAlater) for processing at a later date or extracted immediately. The "gold standard" method for the extraction of RNA from fibroblasts for RT-PCR purposes is the TRIzol reagent method. With the addition of a spin-column clean-up step, any phenol carried over from the TRIzol step is removed, thus ensuring a high yield of quality RNA. The RNA is then reverse transcribed to cDNA and analyzed using the RT-PCR focused-gene arrays. Data analysis is made easy using on-line array analysis software packages.

Chou P; Milne TJ

2010-01-01

145

Real-time PCR focused-gene array profiling of gingival and periodontal ligament fibroblasts.  

Science.gov (United States)

The techniques for the establishment of primary gingival and periodontal ligament fibroblast cultures have been well established for over 30 years. It is only more recently, with the commercial availability of real-time PCR (RT-PCR) gene arrays that the expression profiles of up to 84 genes can be carried out simultaneously. Each focused panel of genes can identify the up- or down-regulation of genes associated with any one of over 100 biological pathways or specific disease states. Fibroblasts for RNA extraction and subsequent gene expression analysis can be collected under various experimental conditions and stored in RNA-preserving solution (e.g., RNAlater) for processing at a later date or extracted immediately. The "gold standard" method for the extraction of RNA from fibroblasts for RT-PCR purposes is the TRIzol reagent method. With the addition of a spin-column clean-up step, any phenol carried over from the TRIzol step is removed, thus ensuring a high yield of quality RNA. The RNA is then reverse transcribed to cDNA and analyzed using the RT-PCR focused-gene arrays. Data analysis is made easy using on-line array analysis software packages. PMID:20717796

Chou, Patty; Milne, Trudy J

2010-01-01

146

The Ruffini ending as the primary mechanoreceptor in the periodontal ligament: its morphology, cytochemical features, regeneration, and development.  

UK PubMed Central (United Kingdom)

The periodontal ligament receives a rich sensory nerve supply and contains many nociceptors and mechanoreceptors. Although its various kinds of mechanoreceptors have been reported in the past, only recently have studies revealed that the Ruffini endings--categorized as low-threshold, slowly adapting, type II mechanoreceptors--are the primary mechanoreceptors in the periodontal ligament. The periodontal Ruffini endings display dendritic ramifications with expanded terminal buttons and, furthermore, are ultrastructurally characterized by expanded axon terminals filled with many mitochondria and by an association with terminal or lamellar Schwann cells. The axon terminals of the periodontal Ruffini endings have finger-like projections called axonal spines or microspikes, which extend into the surrounding tissue to detect the deformation of collagen fibers. The functional basis of the periodontal Ruffini endings has been analyzed by histochemical techniques. Histochemically, the axon terminals are reactive for cytochrome oxidase activity, and the terminal Schwann cells have both non-specific cholinesterase and acid phosphatase activity. On the other hand, many investigations have suggested that the Ruffini endings have a high potential for neuroplasticity. For example, immunoreactivity for p75-NGFR (low-affinity nerve growth factor receptor) and GAP-43 (growth-associated protein-43), both of which play important roles in nerve regeneration/development processes, have been reported in the periodontal Ruffini endings, even in adult animals (though these proteins are usually repressed or down-regulated in mature neurons). Furthermore, in experimental studies on nerve injury to the inferior alveolar nerve, the degeneration of Ruffini endings takes place immediately after nerve injury, with regeneration beginning from 3 to 5 days later, and the distribution and terminal morphology returning to almost normal at around 14 days. During regeneration, some regenerating Ruffini endings expressed neuropeptide Y, which is rarely observed in normal animals. On the other hand, the periodontal Ruffini endings show stage-specific configurations which are closely related to tooth eruption and the addition of occlusal forces to the tooth during postnatal development, suggesting that mechanical stimuli due to tooth eruption and occlusion are a prerequisite for the differentiation and maturation of the periodontal Ruffini endings. Further investigations are needed to clarify the involvement of growth factors in the molecular mechanisms of the development and regeneration processes of the Ruffini endings.

Maeda T; Ochi K; Nakakura-Ohshima K; Youn SH; Wakisaka S

1999-01-01

147

Effect of human platelet-derived growth factor-BB on attachment of periodontal ligament cells on root surfaces.  

UK PubMed Central (United Kingdom)

OBJECTIVE: To evaluate the effects of platelet-derived growth factor-BB (PDGF-BB) on the attachment of human periodontal ligament cells (HPLCs) on the root surfaces demineralized with different agents. METHODS: We performed this study at Ege University, Izmir, Turkey between 2005 and 2006. Eighty root slices were subjected to one of following treatments after root planing: 1) only root planing, 2) Platelet derived growth factor-BB (PDGF-BB), 3) citric acid demineralization, 4) citric acid demineralization + PDGF-BB, 5) tetracycline hydrochloric acid (T-HCl) demineralization, 6) T-HCl demineralization + PDGF-BB, 7) ethylenediamine tetra-acetic acid (EDTA) demineralization, and 8) EDTA demineralization + PDGF-BB. Human periodontal ligament cells were seeded on the root surfaces. Following the 2-hour incubation period, the number of cells was calculated by the colorimetric assay. Three slices from each group were processed for scanning electron microscopy. The number of attached cells was tested by analysis of variance (p=0.050). RESULTS: There were no significant differences among the groups with regard to the mean number of attached cells (p=0.843), which was highest in the fourth group, and lowest in the sixth group. CONCLUSION: Root planing is the most important treatment to make the diseased root surfaces biocompatible to HPLCs adherence. Application of PDGF-BB to root surfaces demineralized with citric acid may be advocated to enhance periodontal regeneration.

Becerik S; Sonmez S; Sen BH; Deliloglu-Gurhan I; Evrenosoglu E

2009-01-01

148

Immunohistochemical and gene expression analysis of stem-cell-associated markers in rat dental pulp.  

Science.gov (United States)

Stem cells in the dental pulp comprise rare populations lacking definitive cytological markers and thus are poorly characterized in vivo, especially in rat species. To gain more insight into the phenotypical characteristics and tissue distribution of these cells, we examined the distribution of stem-cell-associated marker-expressing cells and mRNA expression levels of stem-cell-associated markers in the rat molar. CD146-positive cells co-expressing microtubule-associated protein 1B were counted following double-labeling immunoperoxidase staining and their density in the coronal pulp, root pulp and periodontal ligament was compared. Moreover, mRNA expression levels of CD146, CD105, CD166 and secreted phosphoprotein 1 (SPP1; also known as osteopontin, a negative regulatory element of the stem cell niche) were analyzed in these regions by using real time polymerase chain reaction. The double-positive cells could be clearly distinguished from non-stem cells single-stained by either of the markers and showed a significantly higher density in the coronal pulp compared with the other regions (PSPP1 mRNA expression was significantly higher in the periodontal ligament than in the pulp. Thus, the density of stem-cell-associated marker-expressing cells and stem-cell-associated gene expression levels are higher in the coronal pulp than in the root pulp and periodontal ligament, suggesting that the coronal pulp harbors more stem cells than the other regions. PMID:23263462

Kaneko, Tomoatsu; Arayatrakoollikit, Uthaiwan; Yamanaka, Yusuke; Ito, Takafumi; Okiji, Takashi

2012-12-21

149

Expresión de la osteocalcina en el ligamento periodontal al inducir fuerzas ortodóncicas/ Osteocalcin expression in periodontal ligament when inducing orthodontic forces  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish La osteocalcina es una proteína no colágena presente en hueso alveolar, cemento radicular y subpoblaciones del ligamento periodontal. Esta proteína juega un papel importante en la biomineralización y en la matriz extracelular regulando la maduración de los cristales de hidroxiapatita y en el reclutamiento de los osteoclastos participando en la remodelación ósea. La remodelación y la nueva formación de tejido periodontal es parte esencial durante los movimientos o (more) rtodóncicos, los cuales al aplicar fuerzas causan tensión en las células provocando una adaptación que se traduce en respuestas celulares y moleculares que pueden afectar la matriz extracelular. Por ello, el propósito de esta investigación fue determinar la expresión de la osteocalcina asociada a la remodelación periodontal cuando se aplican fuerzas ortodóncicas. En primeros premolares superiores e inferiores se colocó aparatología fija prescripción Roth 0.022 con un arco NiTi 0.016, la cual se aplicó a todos los dientes de ambas arcadas con excepción de los premolares superiores e inferiores izquierdos. Los premolares sin aparatología (t = 0) y en presencia de aparatología para inducir movimientos ortodóncicos durante 1, 3, 5, 7 y 9 días; fueron extraídos para analizar la expresión de la osteocalcina en la matriz extracelular del ligamento periodontal. Para determinar la expresión temporal y espacial de los mensajeros de la osteocalcina en el ligamento periodontal se llevó a cabo la técnica RT-PCR. La expresión de la osteocalcina en el grupo experimental estuvo presente en todos los días de prueba, sugiriendo que los movimientos ortodónticos generan cambios que son susceptibles en las concentraciones del mensajero de la proteína osteocalcina. Abstract in english Osteocalcin is a non-collagenous protein located in alveolar bone, root cementum and subpopulations of periodontal ligament cells. This protein plays an important role in the biomineralization process and in the extra-cellular matrix, regulating maturation of hydroxyapatite and osteoclast recruitment which participate in bone remodeling. Periodontal tissue new formation and remodeling is a vital part of the process during orthodontic movements. These movements, when force (more) is exerted, cause tension in the cells, provoking adaptation which results in molecular and cellular responses which, in turn, can affect the extracellular matrix. Due to the aforementioned facts, the aim of the present research was to determine osteocalcin expression associated to periodontal remodeling when orthodontic forces are applied. Roth 0.022 " fixed brackets with a NiTi 0.016" archwire were applied to first upper and lower bicuspids. This was applied to all teeth of both arches except to left lower and upper bicuspids. Bicuspids without brackets (t = 0) as well as with brackets to elicit orthodontic movements during 1, 3, 5, 7 and 9 days were extracted to assess osteocalcin expression in the extra-cellular matrix of the periodontal ligament. The RT-PCR technique was followed to determine temporal and spatial expression of osteocalcin messengers. Osteocalcin expression in the experimental group was present in all test days, suggesting thus the fact that orthodontic movements elicit changes that are susceptible in osteocalcin protein messenger concentrations.

Villarreal Brito, Maritere; Álvarez Pérez, Marco Antonio; Marichi Rodríguez, Francisco Javier

2013-09-01

150

Hypoxia Regulates the Proliferation and Osteogenic Differentiation of Human Periodontal Ligament Cells Under Cyclic Tensile Stress via MAPK Pathways.  

UK PubMed Central (United Kingdom)

Background: Previous studies have shown that periodontal ligament (PDL) exists in a hypoxic microenvironment, especially under the condition of periodontitis or physical stress. The present study was designed to investigate the effects and mechanisms of hypoxia on regulating the proliferation and osteogenic differentiation of human periodontal ligament cells (hPDLCs) under cyclic tensile stress (CTS). Methods: hPDLCs were cultured in 2% O2 (hypoxia) or 20% O2 (normoxia) and then subjected to a cyclic in-plane tensile deformation of 10% for 0.5 Hz. The following parameters were measured: 1) cell proliferation by flow cytometry; 2) cell ultrastructure by transmission electron microscopy; 3) the expressions of hypoxia-inducible factor-1? (HIF-1?) and osteogenic relative factors, i.e., secreted phosphoprotein 1 (SPP1; also known as bone sialoprotein I/osteopontin), runt-related transcription factor 2 (RUNX2) and transcription factor Sp7 (SP7) were assessed by Real-time PCR and Western blot; 4) the involvement of mitogen-activated protein kinase (MAPK) signaling pathways were investigated by Western blot with specific inhibitor. Results: Proliferation index in hypoxia with CTS group was significantly higher than that in other groups. Significant increases in HIF-1?, SPP1, RUNX2 and SP7 occurred in the presence of hypoxia for 24 h. In addition, MAPK inhibitor (PD 98,059) significantly attenuated hypoxia and CTS-induced phosphor-ERK1/2, phosphor-JNK and phosphor-P38 expressions. Conclusion: Hypoxia regulates CTS-responsive changes in proliferation and osteogenic differentiation of hPDLCs via MAPK pathways. Hypoxia-treated hPDLCs may serve as an in vitro model to explore the molecular mechanisms of periodontitis.

Li L; Han MX; Li S; Xu Y; Wang L

2013-06-01

151

Low-level laser effects on simulated orthodontic tension side periodontal ligament cells.  

UK PubMed Central (United Kingdom)

OBJECTIVE: The purpose of this study was to analyze proliferation, inflammation, and osteogenic effects on periodontal ligament (PDL) cells after low-level laser therapy (LLLT) under simulated orthodontic tension conditions. Background data: Low-level lasers affect fibroblast proliferation and collagen synthesis and reduce inflammation. Few studies have focused on the LLLT changes in the PDL caused by moving teeth. MATERIALS AND METHODS: A human PDL cell line was cultured in a -100?kPa tension incubator. The PDL cells were treated with a 670?nm low-level diode laser, output power of 500?mW (continuous wave modus) for 2.5 or 5?sec, spot area 0.25?cm(2), corresponding to 1.25 and 2.5?J at an energy density of 5 or 10?J/cm(2), respectively. PDL cell viability was assayed by detecting the ability of the cells to cleave tetrazolium salt to formazan dye. Inflammation and osteogenic markers were analyzed by Western blot analysis. RESULTS: PDL cell viablity increased in the experimental group, based on the ability of the cells to cleave tetrazolium salt at day 7 (p<0.05). The experimental group showed no difference in PDL cellular morphology compared with the control group. The inflammation markers inducible NO synthase (iNOS), cyclooxygenase (COX)-2 and interleukin (IL)-1 showed stronger expression in 5 and 10?J/cm(2) therapy at days 1 and 5, but decreased in expression at day 7. The osteogenic marker osteocalcin (OC) expression level was significantly higher at day 7 (p<0.05) than in the control cells. CONCLUSIONS: LLLT significantly increased PDL cell proliferation, decreased PDL cell inflammation, and increased PDL OC activity under the tension conditions used in this study.

Huang TH; Liu SL; Chen CL; Shie MY; Kao CT

2013-02-01

152

Directing adult human periodontal ligament-derived stem cells to retinal fate.  

UK PubMed Central (United Kingdom)

PURPOSE: To investigate the retinal fate competence of human postnatal periodontal ligament (PDL)-derived stem cells (PDLSC) through a directed differentiation mimicking mammalian retinogenesis. METHODS: Human teeth were collected from healthy subjects younger than 35 years old. Primary PDLSC were isolated by collagenase digestion and cultivated. PDLSC at passage 3 were cultured in the induction media containing Noggin (antagonist of bone morphogenic protein) and Dkk-1 (antagonist of Wnt/?-catenin signaling). Gene expression of neural crest cells, retinal progenitors, and retinal neurons, including photoreceptors, was revealed by RNA analyses, immunofluorescence, and flow cytometry. The neuronal-like property of differentiated cells in response to excitatory glutamate was examined by fluo-4-acetoxymethyl calcium imaging assay. RESULTS: Primary human PDLSC stably expressed marker genes for neural crest (Notch1, BMP2, Slug, Snail, nestin, and Tuj1), mesenchymal stem cell (CD44, CD90, and vimentin), and embryonic stem cell (c-Myc, Klf4, Nanog, and SSEA4). Under low attachment culture, PDLSC generated neurospheres expressing nestin, p75/NGFR, Pax6, and Tuj1 (markers of neural progenitors). When neurospheres were plated on Matrigel-coated surface, they exhibited rosette-like outgrowth. They expressed eye field transcription factors (Pax6, Rx, Lhx, Otx2). By flow cytometry, 94% of cells were Pax6(nuclear)Rx(+), indicative of retinal progenitors. At prolonged induction, they expressed photoreceptor markers (Nrl, rhodopsin and its kinase) and showed significant responsiveness to excitatory glutamate. CONCLUSIONS: Primary human PDLSC could be directed to retinal progenitors with competence for photoreceptor differentiation. Human neural crest-derived PDL is readily accessible and can be an ample autologous source of undifferentiated cells for retinal cell regeneration.

Huang L; Liang J; Geng Y; Tsang WM; Yao X; Jhanji V; Zhang M; Cheung HS; Pang CP; Yam GH

2013-06-01

153

Storage media enhance osteoclastogenic potential of human periodontal ligament cells via RANKL-independent signaling.  

UK PubMed Central (United Kingdom)

BACKGROUND: Hank's balanced salt solution (HBSS) and milk have gained wide acceptance as storage media for avulsed tooth. However, the effect of the media and storage time on the periodontal ligament (PDL) cells involvement in the development of root resorption is still unclear. The purpose of this study was to evaluate whether precultured PDL cells in HBSS, milk, or modified Eagle's medium alpha (?-MEM) would affect osteoclastogenesis. MATERIALS AND METHODS: PDL cells were precultured in HBSS, milk, or ?-MEM for 1 h or 6 h before being co-cultured with RAW 264.7 cells for an additional 3 days for mRNA analysis and 11 days for osteoclastogenesis assay. RESULTS: Cyclooxygenase-2 (COX-2) mRNA was detected immediately in PDL cells precultured in the three storage media. The expression was up-regulated markedly in all co-cultures when compared with RAW cells alone. As a result of the co-culture, interleukin-1? (IL-1?) expression was detectable in both PDL and RAW cells. TRAP+ multinucleated, osteoclast-like cells developed in all co-cultures; the number of TRAP+ cells was highest (P??0.05). CONCLUSIONS: PDL cells kept in the three storage media led to TRAP+ multinucleated, osteoclast-like cells formation via RANKL-independent signaling. The ability to induce osteoclastogenesis may be considered as one of the factors to evaluate the ability of storage medium to maintain PDL viability after tooth avulsion.

Zhan X; Zhang C; Dissanayaka WL; Cheung GS; Jin L; Yang Y; Yan F; Tong EH

2013-02-01

154

Analysis of time-course gene expression profiles of a periodontal ligament tissue model under compression.  

UK PubMed Central (United Kingdom)

OBJECTIVE: We recently reported establishment of a periodontal ligament (PDL) tissue model, which may mimic the biological behaviour of human PDL under static compression in orthodontic tooth movement (OTM). In the present study, we aimed at investigating the time-course gene expression profiles of the PDL tissue model under compression. DESIGN: The PDL tissue model was established through 3-D-culturing human PDL cells (PDLCs) in a thin sheet of porous poly lactic-co-glycolic acid (PLGA) scaffolds, which was subjected to 25g/cm(2) static compression for 6, 24 and 72h respectively. After that, its gene expression profiles were investigated using microarray assay, followed by signalling pathway and gene ontology (GO) analysis. Real-time RT-PCR verification was done for 15 identified genes of interest. The cell proliferation alteration was detected through EdU labelling. RESULTS: (1) Among the genes identified as differentially expressed, there were numerous osteoclastogenesis inducers (including CCL20, COX-1, COX-2, RANKL, PTHrP, IL-11, IL-8, etc.), osteoclastogenesis inhibitors (including IL-1Ra, NOG, OPG, etc.), and other potential bone remodelling regulators (including STC1, CYR61, FOS, etc.). (2) According to analysis of the microarray data, the most significant pathways included Cytokine-cytokine receptor interaction (containing CCL20, RANKL, IL-11, IL-8, etc.), MAPK (containing FGF7, FOS, MAP3K8, JUN, etc.) and Cell cycle (containing CDK1, CCNA2, etc.); the most significant GOs included Cell-cell signalling (containing CCL20, STC1, FGF7, PTHrP, IL-11, IL-8, etc.), Extracellular space (containing CCL20, IL-1Ra, NOG, PTHrP, IL-11, IL-8, etc.) and Microtubule-based movement (containing KIF11, KIF23, etc.). (3) After prolonged compression, cell proliferation was significantly inhibited. CONCLUSION: The present findings have expanded our understandings to the roles that PDL plays under static compression in OTM.

Li Y; Li M; Tan L; Huang S; Zhao L; Tang T; Liu J; Zhao Z

2013-05-01

155

Differential effects of amelogenin on mineralization of cementoblasts and periodontal ligament cells.  

UK PubMed Central (United Kingdom)

BACKGROUND: Amelogenin is a major component of developing extracellular enamel matrix proteins and plays a crucial role during the formation of tooth enamel. In addition, amelogenins are suggested to exert biologic functions as signaling molecules through cell-surface receptors. The purpose of this study is to examine the effect of recombinant human full-length amelogenin (rh174) on the mineralization of human cementoblasts (HCEMs) and human periodontal ligament cells (HPDLs). METHODS: HCEMs, namely, a cell line immortalized by transfection of human telomerase reverse transcription gene, and HPDLs isolated from human first premolars were cultured and treated with 0 to 1,000 ng/mL rh174. The messenger ribonucleic acid (mRNA) levels of alkaline phosphatase (ALP), osteocalcin (OCN), and bone sialoprotein (BSP) were examined by real-time polymerase chain reaction analysis. The protein levels of OCN and BSP were examined by Western blot analysis. ALP activity and calcium deposition of cell cultures were also determined. Mineralization of cells was evaluated by red dye staining. RESULTS: The treatment of HCEMs with rh174 upregulated the ALP, OCN, and BSP mRNA levels. In addition, the protein levels of OCN and BSP, ALP activity, and calcium deposition were enhanced, resulting in enhanced mineralization. Conversely, there were no significant effects of rh174 on the mineralization of HPDLs. CONCLUSION: The present study shows that rh174 enhances mineralization accompanied by upregulation of mineralization markers in HCEMs, whereas it has no effect on that in HPDLs, suggesting different effects of amelogenin on PDL and cementum.

Tanimoto K; Kunimatsu R; Tanne Y; Huang YC; Michida M; Yoshimi Y; Miyauchi M; Takata T; Tanne K

2012-05-01

156

Stimulation of Periodontal Ligament Stem Cells by Dentin Matrix Protein 1 Activates Mitogen-Activated Protein Kinase and Osteoblast Differentiation  

Science.gov (United States)

Background Periodontitis can ultimately result in tooth loss. Many natural and synthetic materials have been tried to achieve periodontal regeneration, but the results remain variable and unpredictable. We hypothesized that exogenous treatment with dentin matrix protein 1 (DMP1) activates specific genes and results in phenotypic and functional changes in human periodontal ligament stem cells (hPDLSCs). Methods hPDLSCs were isolated from extracted teeth and cultured in the presence or absence of DMP1. Quantitative polymerase chain reactions were performed to analyze the expression of several genes involved in periodontal regeneration. hPDLSCs were also processed for immunocytochemical and Western blot analysis using phosphorylated extracellular signal-regulated kinase (pERK) and ERK antibodies. Alkaline phosphatase and von Kossa staining were performed to characterize the differentiation of hPDLSCs into osteoblasts. Field emission scanning electron microscopic analysis of the treated and control cell cultures were also performed. Results Treatment with DMP1 resulted in the upregulation of genes, such as matrix metalloproteinase-2, alkaline phosphatase, and transforming growth factor ?1. Activation of ERK mitogen-activated protein kinase signaling pathway and translocation of pERK from the cytoplasm to the nucleus was observed. Overall, DMP1-treated cells showed increased expression of alkaline phosphatase, increased matrix, and mineralized nodule formation when compared with untreated controls. Conclusion DMP1 can orchestrate a coordinated expression of genes and phenotypic changes in hPDLSCs by activation of the ERK signaling pathway, which may provide a valuable strategy for tissue engineering approaches in periodontal regeneration.

Chandrasekaran, Sangeetha; Ramachandran, Amsaveni; Eapen, Asha; George, Anne

2013-01-01

157

"THE STUDY OF DOSE-RESPONSE MITOGENIC EFFECT OF L-DOPA ON THE HUMAN PERIODONTAL LIGAMENT FIBROBLAST CELLS"  

Directory of Open Access Journals (Sweden)

Full Text Available Avulsion is one of the most serious emergencies in dental office. In the event of any problem, the tooth should be stored in a medium that supports the periodontal ligament cell viability. In other clinical situations, preserving media, growth factors and mitogenic products may be useful in repairing the traumatized tissues. It has been previously reported that levodopa (L-dopa) accelerates healing by increasing the growth hormone level. In this study, the local effect of L-dopa, as a mitogen, on human periodontal ligament fibroblast (HPLF) cells was evaluated. Samples from impacted or semiimpacted wisdom or canine teeth, which were devoid of inflammation, were taken. The cells obtained from this tissue were cultured in an appropriate medium. The passage numbers between 3-6 were taken for further experiments. The viability of HPLF cells, which were treated by L-dopa, was evaluated by trypan blue dye exclusion and neutral red assay. Results indicated that low concentration of L-dopa produces significant increase of these cells compared to control group. These results confirmed previous studies about direct action of L- dopa on the viability of HPLF cells. On the basis of this study and previous reports, presence of L-dopa in preserving media may be useful in increasing the self-life transferring HPLF cells.

M. Zarabian; F. Salehipour S.N. Ostad

2004-01-01

158

Acute changes in intra-alveolar tooth position and local clearance of /sup 125/I from the periodontal ligament  

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Changes in intra-alveolar tooth position and local /sup 125/I clearance from the periodontal ligament (PDL) were monitored simultaneously in cats. Axial tooth movements, reflecting periodontal ligament volume changes, were measured with an ultrasonic transit time technique. Local blood flow changes in the PDL were studied indirectly by measuring the local clearance of /sup 125/I. Stimulation of the cervical sympathetic trunk caused an intrusive movement of the tooth with a concomitant reduction of the /sup 125/I-clearance. Infusion of noradrenaline induced a similar respone. Stimulation of the inferior alveolar nerve during systemic treatment with phentolamine caused an extrusive movement of the tooth with a concomitant increase in the clearance of the tracer from the PDL. Intra-arterial infusion of the vasodilator substance P mimicked that response. Fization of the tooth to the jaw bone, thus preventing an intrusive movement, did not change the reductions in clearance seen on sympathetic stimulation, indicating that this blood flow reduction was not dependent on tooth movement. A qualitative relation between PDL blood flow (as measured by local /sup 125/I clearance) and PDL volume (as measured by tooth position) in shown. The two variables measured are suggested to reflect two aspects of blood flow in the PDL. 22 refs.

Edwall, B.; Berg, J.O.; Gazelius, B.; Edwall L.; Aars, H.

1987-01-01

159

Acute changes in intra-alveolar tooth position and local clearance of 125I from the periodontal ligament  

International Nuclear Information System (INIS)

Changes in intra-alveolar tooth position and local 125I clearance from the periodontal ligament (PDL) were monitored simultaneously in cats. Axial tooth movements, reflecting periodontal ligament volume changes, were measured with an ultrasonic transit time technique. Local blood flow changes in the PDL were studied indirectly by measuring the local clearance of 125I. Stimulation of the cervical sympathetic trunk caused an intrusive movement of the tooth with a concomitant reduction of the 125I-clearance. Infusion of noradrenaline induced a similar respone. Stimulation of the inferior alveolar nerve during systemic treatment with phentolamine caused an extrusive movement of the tooth with a concomitant increase in the clearance of the tracer from the PDL. Intra-arterial infusion of the vasodilator substance P mimicked that response. Fization of the tooth to the jaw bone, thus preventing an intrusive movement, did not change the reductions in clearance seen on sympathetic stimulation, indicating that this blood flow reduction was not dependent on tooth movement. A qualitative relation between PDL blood flow (as measured by local 125I clearance) and PDL volume (as measured by tooth position) in shown. The two variables measured are suggested to reflect two aspects of blood flow in the PDL.

1987-01-01

160

Establishment of immortalized periodontal ligament progenitor cell line and its behavioural analysis on smooth and rough titanium surface  

Directory of Open Access Journals (Sweden)

Full Text Available Periodontal ligament (PDL) can be obtained from patients undergoing orthodontic treatment. PDL contains progenitor cells that can be expanded and differentiated towards several mesenchymal lineages in vitro. Furthermore, PDL-derived cells have been shown to generate bone- and PDL-like structures in vivo. Thus, PDL cells, combined with suitable biomaterials, represent a promising tool for periodontitis-related research and PDL engineering.Here, a new PDL cell line using lentiviral gene transfer of human telomerase reverse transcriptase (hTERT) was created. HTERT-expressing PDL cells showed similar morphology and population doubling time but an extended lifespan compared to the primary cells. In addition, PDL-hTERT cells expressed several characteristic genes and upon osteogenic stimulation produced a calcified matrix in vitro. When cultivated on two topographically different titanium scaffolds (MA and SLA), PDL-hTERT cells exhibited augmented spreading, survival and differentiation on smooth (MA) compared to rough (SLA) surfaces. These findings differ from previously reported osteoblast behaviour, but they are in agreement with the behaviour of chondrocytes and gingival fibroblasts, suggesting a very cell type-specific response to different surface textures.In summary, we report the testing of titanium biomaterials using a new PDL-hTERT cell line and propose this cell line as a useful model system for periodontitis research and development of novel strategies for PDL engineering.

D Docheva; D Padula; C Popov; P Weishaupt; M Prägert; N Miosge; R Hickel; W Böcker; H Clausen-Schaumann; M Schieker

2010-01-01

 
 
 
 
161

Establishment of immortalized periodontal ligament progenitor cell line and its behavioural analysis on smooth and rough titanium surface.  

UK PubMed Central (United Kingdom)

Periodontal ligament (PDL) can be obtained from patients undergoing orthodontic treatment. PDL contains progenitor cells that can be expanded and differentiated towards several mesenchymal lineages in vitro. Furthermore, PDL-derived cells have been shown to generate bone- and PDL-like structures in vivo. Thus, PDL cells, combined with suitable biomaterials, represent a promising tool for periodontitis-related research and PDL engineering. Here, a new PDL cell line using lentiviral gene transfer of human telomerase reverse transcriptase (hTERT) was created. HTERT-expressing PDL cells showed similar morphology and population doubling time but an extended lifespan compared to the primary cells. In addition, PDL-hTERT cells expressed several characteristic genes and upon osteogenic stimulation produced a calcified matrix in vitro. When cultivated on two topographically different titanium scaffolds (MA and SLA), PDL-hTERT cells exhibited augmented spreading, survival and differentiation on smooth (MA) compared to rough (SLA) surfaces. These findings differ from previously reported osteoblast behaviour, but they are in agreement with the behaviour of chondrocytes and gingival fibroblasts, suggesting a very cell type-specific response to different surface textures. In summary, we report the testing of titanium biomaterials using a new PDL-hTERT cell line and propose this cell line as a useful model system for periodontitis research and development of novel strategies for PDL engineering.

Docheva D; Padula D; Popov C; Weishaupt P; Prägert M; Miosge N; Hickel R; Böcker W; Clausen-Schaumann H; Schieker M

2010-01-01

162

Establishment of immortalized periodontal ligament progenitor cell line and its behavioural analysis on smooth and rough titanium surface.  

Science.gov (United States)

Periodontal ligament (PDL) can be obtained from patients undergoing orthodontic treatment. PDL contains progenitor cells that can be expanded and differentiated towards several mesenchymal lineages in vitro. Furthermore, PDL-derived cells have been shown to generate bone- and PDL-like structures in vivo. Thus, PDL cells, combined with suitable biomaterials, represent a promising tool for periodontitis-related research and PDL engineering. Here, a new PDL cell line using lentiviral gene transfer of human telomerase reverse transcriptase (hTERT) was created. HTERT-expressing PDL cells showed similar morphology and population doubling time but an extended lifespan compared to the primary cells. In addition, PDL-hTERT cells expressed several characteristic genes and upon osteogenic stimulation produced a calcified matrix in vitro. When cultivated on two topographically different titanium scaffolds (MA and SLA), PDL-hTERT cells exhibited augmented spreading, survival and differentiation on smooth (MA) compared to rough (SLA) surfaces. These findings differ from previously reported osteoblast behaviour, but they are in agreement with the behaviour of chondrocytes and gingival fibroblasts, suggesting a very cell type-specific response to different surface textures. In summary, we report the testing of titanium biomaterials using a new PDL-hTERT cell line and propose this cell line as a useful model system for periodontitis research and development of novel strategies for PDL engineering. PMID:20473831

Docheva, D; Padula, D; Popov, C; Weishaupt, P; Prägert, M; Miosge, N; Hickel, R; Böcker, W; Clausen-Schaumann, H; Schieker, M

2010-05-14

163

Nanohydroxyapatite increases BMP-2 expression via a p38 MAP kinase dependent pathway in periodontal ligament cells.  

UK PubMed Central (United Kingdom)

OBJECTIVE: Bone morphogenetic protein (BMP)-2 promotes the osteoblastic differentiation of human periodontal ligament (PDL) cells, which play a pivotal role in periodontal regeneration. Recently, nano-sized hydroxyapatite (nano-HA) has been highlighted due to its advantageous features over micro-sized materials. DESIGN AND RESULTS: We investigated the effect of nano-HA on BMP-2 expression in human PDL cells. Real time PCR analysis revealed that the expression of BMP-2 increased upon stimulation with nano-HA in dose- and time-dependent manners. An immunofluorescence assay demonstrated the synthesis of BMP-2 proteins. Concentrations of Ca(2+) as well as phosphate (Pi) in culture supernatants were unchanged, suggesting that nano-HA functioned as a nanoparticle rather than as a possible source for releasing Ca(2+) and/or Pi extracellularly, which were shown to also enhance the expression of BMP-2. Nano-HA-induced BMP-2 expression was dependent on the p38 MAP kinase pathway because increases in BMP-2 expression were inhibited by treatment with SB203580, a p38 inhibitor, and phosphorylation of p38 was detected by Western blotting. CONCLUSIONS: This novel mechanism of nano-HA will be important for the rational design of future periodontal regeneration.

Suto M; Nemoto E; Kanaya S; Suzuki R; Tsuchiya M; Shimauchi H

2013-08-01

164

Effects of hydroxyapatite nanostructure on channel surface of porcine acellular dermal matrix scaffold on cell viability and osteogenic differentiation of human periodontal ligament stem cells.  

UK PubMed Central (United Kingdom)

A new nanostructured hydroxyapatite-coated porcine acellular dermal matrix (HAp-PADM) was fabricated by a biomimetic mineralization method. Human periodontal ligament stem cells were seeded on HAp-PADM and the effects of this scaffold on cell shape, cytoskeleton organization, cell viability, and osteogenic differentiation were examined. Periodontal ligament stem cells cultured on HAp-PADM exhibited different cell shape when compared with those on pure PADM. Moreover, HAp-PADM promoted cell viability and alkaline phosphatase activity significantly. Based on quantitative real-time polymerase chain reaction, the expression of bone-related markers runt-related transcription factor 2 (Runx2), osteopontin (OPN), and osteocalcin (OCN) upregulated in the HAp-PADM scaffold. The enhancement of osteogenic differentiation of periodontal ligament stem cells on the HAp-PADM scaffold was proposed based on the research results. The results of this study highlight the micro-nano, two-level, three-dimensional HAp-PADM composite as a promising scaffold for periodontal tissue engineering.

Ge S; Zhao N; Wang L; Liu H; Yang P

2013-01-01

165

Biomechanical validation of an artificial tooth-periodontal ligament-bone complex for in vitro orthodontic load measurement.  

UK PubMed Central (United Kingdom)

OBJECTIVES: To develop an artificial tooth-periodontal ligament (PDL)-bone complex (ATPBC) that simulates clinical crown displacement. MATERIAL AND METHODS: An ATPBC was created. It had a socket hosting a tooth with a thin layer of silicon mixture in between for simulating the PDL. The complex was attached to a device that allows applying a controlled force to the crown and measuring the resulting crown displacement. Crown displacements were compared to previously published data for validation. RESULTS: The ATPBC that had a PDL made of two types of silicones, 50% gasket sealant No. 2 and 50% RTV 587 silicone, with a thickness of 0.3 mm, simulated the PDL well. The mechanical behaviors (1) force-displacement relationship, (2) stress relaxation, (3) creep, and (4) hysteresis were validated by the published results. CONCLUSION: The ATPBC simulated the crown displacement behavior reported from biological studies well.

Xia Z; Chen J

2013-05-01

166

Endothelin-1 Stimulates Proinflammatory Cytokine Expression in Human Periodontal Ligament Cells Via Mitogen-Activated Protein Kinases Pathway.  

UK PubMed Central (United Kingdom)

Background: Endothelin-1(ET-1) is a 21-amino-acid peptide with multifunctional regulation. Initial research indicated that ET-1 is related to the inflammatory pathogenesis of periodontitis and involved in the regulation of cytokines, but the mechanisms involved remain unclear. The primary aim of this study was to investigate how ET-1 affects proinflammatory cytokine expression in human periodontal ligament (hPDL) cells. Methods: hPDL cells were obtained from both healthy (H-hPDL cells) and periodontitis-affected periodontal tissues (P-hPDL cells). The H-hPDL cells and P-hPDL cells were treated with ET-1 (1nM, 10nM, and 100nM) for 12, 24, and 48 hours(hrs). The untreated cells served as a normal control. To confirm the specificity of the ET-1 effects, we used 100nM of the specific endothelin A receptor(ETA) antagonist BQ123, and 100nM of the specific endothelin B receptor (ETB) antagonist BQ788 , as negative control. To examine the signaling pathways and molecular mechanisms involved in ET-1-mediated cytokine expression, The H-hPDL cells and P-hPDL cells were pre-treated with specific inhibitors for signal-regulated kinase (ERK1/2)(PD98059), c-Jun N-terminal kinase(JNK)(SP600125), and p38 kinase(SB203580) for 1 hrs before 100nM ET-1 stimulation. The tumour necrosis factor-alpha (TNF-?), interleukin(IL)-1? (IL-1?) and IL-6 mRNA and protein levels were evaluated by quantitative real-time PCR and ELISA, respectively. Results: ET-1 dose- and time- dependently induced the production of proinflammatory cytokines TNF-?, IL-1?, and IL-6 by H-hPDL cells and P-hPDL cells at both mRNA and protein levels. However, The ETA and ETB receptor antagonists inhibited the stimulatory effects of ET-1 on inflammatory cytokine expression in H-hPDL cells and P-hPDL cells. Furthermore, inhibitors of the Mitogen-activated protein kinases (MAPKs) significant reduced in ET-1-stimulated TNF-?, IL-1?, and IL-6 expression in H-hPDL cells and P-hPDL cells. Conclusion: ET-1 may be involved in the inflammatory process of periodontitis, at least in part, by stimulating proinflammatory cytokine production via MAPKs pathway in hPDL cells.

Liang L; Yu J; Zhou W; Liu N; E L; Wang D; Liu H

2013-05-01

167

Cementum protein 1 (CEMP1) induces differentiation by human periodontal ligament cells under three-dimensional culture conditions.  

UK PubMed Central (United Kingdom)

PDL (periodontal ligament) is a source of multi-potent stem cells in humans and their differentiation potential to a cementoblast and osteoblast phenotypes has been shown. Tissue construction from PDL-derived cells could be considered as a valuable technique for periodontal regenerative medicine. On these basis, we determined the role of CEMP1 (cementum protein 1) as a factor to induce differentiation of human PDL cells in a 3D (three-dimensional) fashion. Human PDL cells were grown in an RCCS (rotary cell culture system) D-410 RWV (rotating wall vessel) bioreactor, and maintained in either experimental (CEMP1 2.5 ?g/ml) or control media during 4 weeks. Cell proliferation in the presence of CEMP1 was determined. The tissue-like structure formed was analysed histologically, stained with Alizarin Red and Alcian Blue. ALP (alkaline phosphatase)-specific activity, immunostaining, RT-PCR (reverse transcription-PCR) and Western blotting were performed to determine the expression of BSP (bone sialoprotein), enamel [AMBN (ameloblastin) and AMEL (amelogenin)], cementum [CAP (cementum attachment protein) and CEMP1] and cartilage-related proteins (Sox9, aggrecan, types II and X collagens). Our results show that hrCEMP1 (human recombinant CEMP1) promoted cell proliferation by human PDL cells in 3D cultures and induced the formation of a tissue-like structure resembling bone and/or cementum and material similar to cartilage. The addition of hrCEMP1 to the 3D human PDL cell cultures increased ALP-specific activity by 2.0-fold and induced the expression of markers for the osteogenic, cementogenic and chondrogenic phenotypes at the mRNA and protein levels. Our data show that human PDL cells in 3D cultures with the addition of CEMP1 has the potential to be used for the bioengineering reconstruction of periodontal tissues and cartilage since our results suggest that CEMP1 stimulates human PDL cells to differentiate towards different phenotypes.

Hoz L; Romo E; Zeichner-David M; Sanz M; Nuñez J; Gaitán L; Mercado G; Arzate H

2012-02-01

168

A three-dimensional cell culture model to study the mechano-biological behavior in periodontal ligament regeneration.  

Science.gov (United States)

Periodontitis is a disease affecting the supporting structures of the teeth, which can eventually result in tooth loss. A three-dimensional (3D) tissue culture model was developed that may serve to grow a 3D construct that not only transplants into defective periodontal sites, but also allows to examine the effect of mechanical load in vitro. In the current in vitro study, green fluorescent protein labeled periodontal ligament (PDL) cells form rat incisors were embedded in a 3D matrix and exposed to mechanical loading alone, to a chemical stimulus (Emdogain; enamel matrix derivative [EMD]) alone, or a combination of both. Loading consisted of unilateral stretching (8%, 1?Hz) and was applied for 1, 3, or 5 days. Results showed that PDL cells were distributed and randomly oriented within the artificial PDL space in static culture. On mechanical loading, the cells showed higher cell numbers. Moreover, cells realigned perpendicular to the stretching force depending on time and position, with great analogy to natural PDL tissue. EMD application gave a significant effect on growth and upregulated bone sialoprotein (BSP) and collagen type-I (Col-I), whereas Runx-2 was downregulated. This implies that PDL cells under loading might tend to act similar to bone-like cells (BSP and Col-I) but at the same time, react tendon like (Runx-2). The combination of chemical and mechanical stimulation seems possible, but does not show synergistic effects. In this study, a new model was successfully introduced in the field of PDL-related regenerative research. Besides validating the 3D model to mimic an authentic PDL space, it also provided a useful and well-controlled approach to study cell response to mechanical loading and other stimuli. PMID:21913838

Oortgiesen, Daniel A W; Yu, Na; Bronckers, Antonius L J J; Yang, Fang; Walboomers, X Frank; Jansen, John A

2012-01-04

169

Effects of enamel matrix derivative on bone-related mRNA expression in human periodontal ligament cells in vitro.  

UK PubMed Central (United Kingdom)

BACKGROUND: Enamel matrix derivative (EMD) has demonstrated the potential to stimulate periodontal regeneration with mineralized tissue formation. Molecular regulators of bone metabolism include osteoprotegrin (OPG), receptor activator of nuclear factor kappa B ligand (RANKL), cyclooxygenase 2 (COX2), and core binding factor alpha 1 (Cbfa1). The role of these regulatory molecules within the context of EMD stimulation of mineralized tissue formation is unknown. Therefore, the purpose of this investigation was to explore the effects of EMD on these bone-related molecules in human periodontal ligament (PDL) cells. METHODS: Human PDL-cell cultures were treated with EMD (5 to 100 microg/ml) for 24 hours. Total RNA was isolated using phenolchloroform, and reverse transcription-polymerase chain reaction (RT-PCR) was performed using primers specific for OPG, RANKL, COX2, Cbfa1, and aldolase, with amplification in the exponential range for each molecule studied. RESULTS: The results of this study show that there is a significant (P <0.05) increase in COX2 mRNA levels with EMD treatment, and no effects were noted on mRNA levels for Cbfa1. RANKL mRNA levels were significantly decreased (P <0.01) up to 50% with EMD treatment > or =25 microg/ml. OPG levels showed minimal effects with EMD treatment. However, the RANKL/OPG ratio showed a 40% to 55% reduction with EMD >or =25 microg/ml. CONCLUSION: This study supports a role for EMD stimulation of mineralized tissue formation consistent with periodontal regeneration by modulating regulatory molecules critical to bone metabolism at the RNA level.

Takayanagi K; Osawa G; Nakaya H; Cochran DL; Kamoi K; Oates TW

2006-05-01

170

A three-dimensional cell culture model to study the mechano-biological behavior in periodontal ligament regeneration.  

UK PubMed Central (United Kingdom)

Periodontitis is a disease affecting the supporting structures of the teeth, which can eventually result in tooth loss. A three-dimensional (3D) tissue culture model was developed that may serve to grow a 3D construct that not only transplants into defective periodontal sites, but also allows to examine the effect of mechanical load in vitro. In the current in vitro study, green fluorescent protein labeled periodontal ligament (PDL) cells form rat incisors were embedded in a 3D matrix and exposed to mechanical loading alone, to a chemical stimulus (Emdogain; enamel matrix derivative [EMD]) alone, or a combination of both. Loading consisted of unilateral stretching (8%, 1?Hz) and was applied for 1, 3, or 5 days. Results showed that PDL cells were distributed and randomly oriented within the artificial PDL space in static culture. On mechanical loading, the cells showed higher cell numbers. Moreover, cells realigned perpendicular to the stretching force depending on time and position, with great analogy to natural PDL tissue. EMD application gave a significant effect on growth and upregulated bone sialoprotein (BSP) and collagen type-I (Col-I), whereas Runx-2 was downregulated. This implies that PDL cells under loading might tend to act similar to bone-like cells (BSP and Col-I) but at the same time, react tendon like (Runx-2). The combination of chemical and mechanical stimulation seems possible, but does not show synergistic effects. In this study, a new model was successfully introduced in the field of PDL-related regenerative research. Besides validating the 3D model to mimic an authentic PDL space, it also provided a useful and well-controlled approach to study cell response to mechanical loading and other stimuli.

Oortgiesen DA; Yu N; Bronckers AL; Yang F; Walboomers XF; Jansen JA

2012-02-01

171

Comparação entre fibroblastos gengivais e do ligamento periodontal de um mesmo indivíduo Comparison between gingival and periodontal ligament fibroblasts from the same subject  

Directory of Open Access Journals (Sweden)

Full Text Available O objetivo deste estudo foi comparar as características morfológicas, o potencial proliferativo e a produção protéica de fibroblastos do ligamento periodontal (FLP) e de fibroblastos gengivais (FG). Os fibroblastos foram cultivados pela técnica do explante a partir de fragmentos da gengiva e do ligamento periodontal de um mesmo indivíduo. As células foram isoladas e plaqueadas para análise por microscopia de contraste de fase e microscopia óptica. O índice de proliferação celular foi determinado por contagem automática de células e pelo ensaio de incorporação de bromodioxiuridina (BrdU). A produção de proteína total foi verificada por eletroforese em gel de poliacrilamida e o perfil enzimático por análise zimográfica. Os FLP são maiores e mais alongados que os FG em condições de subconfluência e confluência celular. Os FLP demonstraram um potencial proliferativo significantemente maior que os FG. Os perfis protéico e enzimático foram similares entre os FLP e FG. Os resultados demonstram que os FLP e FG são diferentes na morfologia e na capacidade proliferativa, porém são semelhantes na produção protéica.The objective of this study was to compare fibroblasts from the periodontal ligament (PLF) and gingival fibroblasts (GF) as to morphology, proliferation rate and protein synthesis. PLF and GF were explanted from tissues of the same patient. To characterize and compare the morphology of cells, PLF and GF were plated and analyzed under phase-contrast and optical microscopies. Proliferation rates were determined by means of automated counts carried out in days 1, 4, 7, 15 and 21, and also by means of the bromodeoxyuridine labelling index (BrdU). Total protein content was analyzed by means of electrophoresis in 10% polyacrylamide gel and zimography containing gelatin as substrate. PLF were bigger and more elongated than GF in subconfluence and confluence conditions. The proliferative rate of PLF was higher than that of GF at 1, 4, and 7 days (p < 0.05). At 15 and 21 days, there was no statistically significant difference as to the number of cells. PLF presented a significantly greater proliferative potential, in relation to GF (p < 0.05). The synthesis of protein in a period of 24 hours was similar for both PLF and GF. Our results demonstrated that PLF and GF are different as to morphology and proliferative capacity, however, they do not differ as to protein synthesis.

Daniela Bazan Palioto; Ricardo Della Coletta; Hercílio Martelli Júnior; Julio Cesar Joly; Edgard Graner; Antonio Fernando Martorelli de Lima

2002-01-01

172

The Adaptive Nature of the Bone-Periodontal Ligament-Cementum Complex in a Ligature-Induced Periodontitis Rat Model  

Science.gov (United States)

The novel aspect of this study involves illustrating significant adaptation of a functionally loaded bone-PDL-cementum complex in a ligature-induced periodontitis rat model. Following 4, 8, and 15 days of ligation, proinflammatory cytokines (TNF-? and RANKL), a mineral resorption indicator (TRAP), and a cell migration and adhesion molecule for tissue regeneration (fibronectin) within the complex were localized and correlated with changes in PDL-space (functional space). At 4 days of ligation, the functional space of the distal complex was widened compared to controls and was positively correlated with an increased expression of TNF-?. At 8 and 15 days, the number of RANKL(+) cells decreased near the mesial alveolar bone crest (ABC) but increased at the distal ABC. TRAP(+) cells on both sides of the complex significantly increased at 8 days. A gradual change in fibronectin expression from the distal PDL-secondary cementum interfaces through precementum layers was observed when compared to increased and abrupt changes at the mesial PDL-cementum and PDL-bone interfaces in ligated and control groups. Based on our results, we hypothesize that compromised strain fields can be created in a diseased periodontium, which in response to prolonged function can significantly alter the original bone and apical cementum formations.

Lee, Ji-Hyun; Lin, Jeremy D.; Fong, Justine I.; Ryder, Mark I.; Ho, Sunita P.

2013-01-01

173

Chondrogenesis of periodontal ligament stem cells by transforming growth factor-?3 and bone morphogenetic protein-6 in a normal healthy impacted third molar.  

UK PubMed Central (United Kingdom)

The periodontal ligament-derived mesenchymal stem cell is regarded as a source of adult stem cells due to its multipotency. However, the proof of chondrogenic potential of the cells is scarce. Therefore, we investigated the chondrogenic differentiation capacity of periodontal ligament derived mesenchymal stem cells induced by transforming growth factor (TGF)-?3 and bone morphogenetic protein (BMP)-6. After isolation of periodontal ligament stem cells (PDLSCs) from human periodontal ligament, the cells were cultured in Dulbecco's modified Eagle's medium (DMEM) with 20% fetal bovine serum (FBS). A mechanical force initiated chondrogenic differentiation of the cells. For chondrogenic differentiation, 10 µg·L?¹ TGF-?3 or 100 µg?L?¹ BMP-6 and the combination treating group for synergistic effect of the growth factors. We analyzed the PDLSCs by fluorescence-activated cell sorting and chondrogenesis were evaluated by glycosaminoglycans assay, histology, immunohistochemistry and genetic analysis. PDLSCs showed mesenchymal stem cell properties proved by FACS analysis. Glycosaminoglycans contents were increased 217% by TGF-?3 and 220% by BMP-6. The synergetic effect of TGF-?3 and BMP-6 were shown up to 281% compared to control. The combination treatment increased Sox9, aggrecan and collagen II expression compared with not only controls, but also TGF-?3 or BMP-6 single treatment dramatically. The histological analysis also indicated the chondrogenic differentiation of PDLSCs in our conditions. The results of the present study demonstrate the potential of the dental stem cell as a valuable cell source for chondrogenesis, which may be applicable for regeneration of cartilage and bone fracture in the field of cell therapy.

Choi S; Cho TJ; Kwon SK; Lee G; Cho J

2013-03-01

174

A synthetic oligopeptide derived from enamel matrix derivative promotes the differentiation of human periodontal ligament stem cells into osteoblast-like cells with increased mineralization.  

Science.gov (United States)

Background: In a previous study, the authors obtained a synthetic peptide (SP) for useful periodontal tissue regeneration. Periodontal ligament stem cells (PDLSCs) have multiple potentiality to contribute to tissue regeneration. The aim of this experiment is to investigate the effect of SP on human PDLSCs. Methods: Periodontal ligament cells were obtained from healthy adult human third molars and used to isolate single PDLSC-derived colonies. The mesenchymal stem cell nature of the PDLSCs was confirmed by immunohistochemical evaluation of STRO-1 expression. Proliferation and osteoblastic differentiation were investigated by culturing PDLSCs in normal or osteogenic medium with and without SP (100 ng/mL). Osteoblast differentiation was assessed by measuring alkaline phosphatase (ALP) activity, osteocalcin production, mRNA expression of osteonectin, mineralization, and calcium deposition. Results: Isolated PDLSCs were immunohistochemically positive for vimentin and STRO-1 and negative for cytokeratin. A greater number of calcified nodules were observed in osteogenic medium culture with SP than without. In the early and later stages of PDLSC culture with SP, osteonectin production and osteocalcin production were increased. SP in culture with osteogenic medium significantly enhanced proliferation of PDLSCs, as well as ALP activity, expression of osteonectin, osteocalcin production, formation of calcified nodules, and mineralization. Conclusions: SP enhances the formation of calcified nodules and osteocalcin production in the culture of PDLSCs into osteoblast-like cells and is a useful material for periodontal tissue regeneration. PMID:23173824

Kato, Hirohito; Katayama, Nobuhito; Taguchi, Yoichiro; Tominaga, Kazuya; Umeda, Makoto; Tanaka, Akio

2012-11-23

175

Immunohistochemical and gene expression analysis of stem-cell-associated markers in rat dental pulp.  

UK PubMed Central (United Kingdom)

Stem cells in the dental pulp comprise rare populations lacking definitive cytological markers and thus are poorly characterized in vivo, especially in rat species. To gain more insight into the phenotypical characteristics and tissue distribution of these cells, we examined the distribution of stem-cell-associated marker-expressing cells and mRNA expression levels of stem-cell-associated markers in the rat molar. CD146-positive cells co-expressing microtubule-associated protein 1B were counted following double-labeling immunoperoxidase staining and their density in the coronal pulp, root pulp and periodontal ligament was compared. Moreover, mRNA expression levels of CD146, CD105, CD166 and secreted phosphoprotein 1 (SPP1; also known as osteopontin, a negative regulatory element of the stem cell niche) were analyzed in these regions by using real time polymerase chain reaction. The double-positive cells could be clearly distinguished from non-stem cells single-stained by either of the markers and showed a significantly higher density in the coronal pulp compared with the other regions (P<0.05). Moreover, mRNA expression levels of CD146, CD105 and CD166 were significantly higher in the coronal pulp than in the other regions (P<0.05). On the other hand, SPP1 mRNA expression was significantly higher in the periodontal ligament than in the pulp. Thus, the density of stem-cell-associated marker-expressing cells and stem-cell-associated gene expression levels are higher in the coronal pulp than in the root pulp and periodontal ligament, suggesting that the coronal pulp harbors more stem cells than the other regions.

Kaneko T; Arayatrakoollikit U; Yamanaka Y; Ito T; Okiji T

2013-03-01

176

Fighting for territories: time-lapse analysis of dental pulp and dental follicle stem cells in co-culture reveals specific migratory capabilities  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Stem cell migration is a critical step during the repair of damaged tissues. In order to achieve appropriate cell-based therapies for tooth and periodontal ligament repair it is necessary first to understand the dynamics of tissue-specific stem cell populations such as dental pulp stem cells (DPSC) ...

Schiraldi, C; Stellavato, A; D'Agostino, A; Tirino, V; d'Aquino, R; Woloszyk, A; De Rosa, A; Laino, L; Papaccio, G; Mitsiadis, T A

177

Vitamin D inhibits the expression of interleukin-8 in human periodontal ligament cells stimulated with Porphyromonas gingivalis.  

UK PubMed Central (United Kingdom)

OBJECTIVE: Vitamin D has been known to be closely associated with periodontitis while the exact mechanisms remain unclear. The present study aimed to discover the effects of 1a,25-dihydroxyvitamin D3 (1,25D) on the expressions of interleukin (IL)-6 and IL-8 in human periodontal ligament cells (hPDLCs) stimulated with Porphyromonas gingivalis (P. gingivalis) W83. DESIGN: Primary cultures of hPDLCs from ten donors were established and the cells of passage four were treated with 1,25D or P. gingivalis individually or 1,25D combined with P. gingivalis. The levels of IL-6 and IL-8 protein in hPDLCs were detected with enzyme-linked immunosorbent assay (ELISA) and the mRNA levels were detected with real-time RT-PCR. RESULTS: P. gingivalis significantly promoted the protein expressions of IL-6 and IL-8. P. gingivalis at the multiplicity of infection (MOI) 100 exerted the strongest promotion effect on the IL-6 protein expression by 5.83-fold compared with the controls (2482.88±26.53pg/ml versus 425.80±77.25pg/ml, P<0.0005) and the IL-8 protein expression by 12.39-fold (4965.81±1072.55pg/ml versus 400.75±2.27pg/ml, P=0.005) in hPDLCs at 24h. At 48h, 10(-8)mol/L 1,25D had the best inhibition on the IL-8 protein expression in hPDLCs by 2.00-fold compared with the controls (100.76±21.11pg/ml versus 201.75±18.15pg/ml, P<0.0005) and the IL-8 mRNA expression by 2.13-fold (P<0.0005). 10(-8)mol/L 1,25D combined with P. gingivalis (MOI 100) exerted the strongest inhibition effect on the IL-8 protein expression by 1.54-fold compared with P. gingivalis treatment alone (3077.33±210.04pg/ml versus 4738.24±1386.17pg/ml, P=0.018) and the IL-8 mRNA expression by 1.78-fold (P=0.012) in hPDLCs at 12h. 1,25D did not influence the expression of IL-6 in hPDLCs with or without P. gingivalis treatment. CONCLUSION: Vitamin D may potentially inhibit the periodontal inflammation induced by P. gingivalis partly by decreasing the IL-8 expression in hPDLCs.

Tang X; Pan Y; Zhao Y

2013-04-01

178

Co-Culture With Endothelial Cells Enhances Osteogenic Differentiation of Periodontal Ligament Stem Cells via COX-2/PGE2/VEGF Signaling Under Hypoxia.  

UK PubMed Central (United Kingdom)

Background: During periodontitis and orthodontic tooth movement, periodontal vasculature is severely impaired, leading to hypoxic microenvironment of periodontal cells. However, the impact of hypoxia on periodontal cells is poorly defined. In the present study, we investigated responses of co-cultured endothelial cells (ECs) and periodontal ligament stem cells (PDLSCs) to hypoxia. Methods: Osteogenic differentiation, molecular characterizations and various behaviors of PDLSCs and human umbilical venous ECs (HUVECs) under hypoxia were assessed by quantitative real-time reverse transcriptase PCR, Western blot, and enzyme-linked immunosorbent assay. Moreover, we tested the effect of ECs on PDLSCs osteogenic differentiation by using NS398 (cyclooxygenase-2 blocker), SU5416 (vascular endothelial growth factor/VEGF receptor inhibitor), AH6809, L-798106, L-161982 (EP1/2/3/4 antagonists). Results: Firstly, hypoxia promoted osteogenic differentiation in PDLSCs, enhanced ECs migration, while PD98059 (extracellular signal-regulated protein kinase/ERK inhibitor) blocked and co-cultured ECs further enhanced hypoxia-induced osteogenic differentiation. Secondly, NS398 impaired ECs migration and prostaglandin E2 (PGE2), VEGF release, while co-cultured PDLSCs and exogenous PGE2 partially reversed it. Thirdly, NS398 (pretreated ECs) lessened PGE2, VEGF concentrations of co-culture. NS398-treated ECs and AH6809/SU5416-treated PDLSCs impaired co-cultured ECs-induced enhancement of PDLSCs osteogenic differentiation. Conclusions: Hypoxia enhances ERK-mediated osteogenic differentiation in PDLSCs. Co-culture with EC further augments PDLSCs osteogenic differentiation via cyclooxygenase-2/PGE2/VEGF signaling.

Zhao L; Wu Y; Tan L; Xu Z; Wang J; Zhao Z; Li X; Li Y; Yang P; Tang T

2013-03-01

179

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

UK PubMed Central (United Kingdom)

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.

Brito-Junior M; Braga NM; Rodrigues DC; Camilo CC; Faria-e-Silva AL

2010-09-01

180

[Culturing and characterization of human periodontal ligament stem cells and investigating their chemotactic responses to bone morphogenetic protein-2].  

UK PubMed Central (United Kingdom)

OBJECTIVE: To investigate the chemotactic response of human periodontal ligament stem cells (PDLSCs) to bone morphogenetic protein-2 (BMP-2). METHODS: Human PDLSCs were obtained from clinically healthy premolars extracted for orthodontic reasons and used to isolate PDLSCs by limited dilution method. The expression of Vimentin and stem cell marker STRO-1 on PDLSCs were demonstrated with immunocytochemical staining. Differentiation assay was used to detect the differentiation potential of PDLSCs. Cloning formation experiment and 5-bromo-2-deoxyuridine (BrdU) incorporation assay were used to determine the stem cell characteristics of PDLSCs. The chemotactic effect of BMP-2 on PDLSCs was detected by using a 24-multiwell Transwell cell culture chamber. The number of net migrated cells was counted in different microscope fields. RESULTS: Human PDLSCs displayed positive staining for Vimentin and expressed the stem cell marker STRO-1. These cells differentiated into osteoblasts and adipocytes under defined culture conditions, possessed high self-renewal potential and formed single-cell colonies in vitro. The number of cells migrating at concentrations of 100, 200 ng mL(-1) of BMP-2 in Transwell cell culture chamber was significantly higher than that of negative control (P<0.01). CONCLUSION: BMP-2 may participate in regulating chemotaxis of human PDLSCs.

Du L; Yang P; Zhao N; Ge S

2012-02-01

 
 
 
 
181

Involvement of p38 MAPK pathway in low intensity pulsed ultrasound induced osteogenic differentiation of human periodontal ligament cells.  

UK PubMed Central (United Kingdom)

OBJECTIVE: The purpose of this study was to clarify whether p38 MAPK is involved in the process of low intensity pulsed ultrasound (LIPUS) induced osteogenic differentiation of human periodontal ligament cells (HPDLCs). METHODS: HPDLCs were isolated from premolars extracted for orthodontic reasons from healthy adolescences and used in the study at passage 5. They were pretreated with p38 specific inhibitor SB203580 and exposed daily to LIPUS with frequency of 1 MHz and intensity of 90 mW/cm(2). Osteogenic differentiation was assayed by levels of alkaline phosphatase (ALP) and osteocalcin as well as calcium deposition. The levels of phosphorylated p38 (p-p38) and total p38 in HPDLCs in response to LIPUS for different times were detected by Western blot. RESULTS: The enhanced ALP levels in media and cell lysate, osteocalcin level in media, as well as number of calcium nodules after LIPUS stimulation were decreased by SB203580 treatment. LIPUS stimulation did not change total p38 level, but time-dependently enhanced the level of p-p38; such enhancement was significantly blocked by preincubation with 10 ?mol/L SB203580. CONCLUSION: The p38 MAPK is involved in the process of LIPUS-induced osteogenic differentiation of HPDLCs.

Ren L; Yang Z; Song J; Wang Z; Deng F; Li W

2013-03-01

182

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

Directory of Open Access Journals (Sweden)

Full Text Available ABSTRACT 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.

Manoel Brito-Junior; Neilor Mateus Antunes Braga; Danilo Costa Rodrigues; Carla Cristina Camilo; André Luis Faria-e-Silva

2010-01-01

183

Effect of three different storage media on survival of periodontal ligament cells using collagenase-dispase assay.  

UK PubMed Central (United Kingdom)

AIM: To evaluate and compare the efficacy of propolis, egg albumen and Hank's balanced salt solution (HBSS) in maintaining the viability of human periodontal ligament (PDL) cells using a collagenase-dispase assay. METHODOLOGY: Fifty-five freshly extracted human teeth were divided into three experimental (HBSS, egg albumen and propolis) and two control groups. Fifteen teeth per experimental group were stored dry for 30 min and then immersed for 45 min in one of the three experimental media. The positive and negative controls corresponded to 0-min and 1-h dry time, respectively, with five teeth per control group. The teeth were then treated with collagenase II and dispase II for 30 min and labelled with 0.4% trypan blue for determination of viability. The number of viable cells was counted with a haemocytometer and analysed statistically by anova and post hoc Tukey HSD test. RESULTS: Statistical analysis demonstrated there was no significant difference between HBSS, egg albumen and propolis in maintaining cell viability. CONCLUSION: Egg albumen and propolis may be able to maintain PDL cell viability as well as HBSS.

Mahal NK; Singh N; Thomas AM; Kakkar N

2013-04-01

184

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

International Nuclear Information System (INIS)

Colchicine administered intravenously depolymerized microtubules and disrupted the normal organization of the Golgi apparatus in periodontal ligament fibroblasts. Radioautography with 3H-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 3H-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 3H-proline, also increased in number after colchicine administration. A gradual decline in 3H-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.

1981-01-01

185

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1981-12-01

186

Gravity loading induces adenosine triphosphate release and phosphorylation of extracellular signal-regulated kinases in human periodontal ligament cells.  

UK PubMed Central (United Kingdom)

AIM: The periodontal ligament (PDL) receives mechanical stress (MS) from dental occlusion or orthodontic tooth movement. Mechanical stress is thought to be a trigger for remodeling of the PDL and alveolar bone, although its signaling mechanism is still unclear. So we investigated the effect of MS on adenosine triphosphate (ATP) release and extracellular signal-regulated kinases (ERK) phosphorylation in PDL cells. METHODS: Mechanical stress was applied to human PDL cells as centrifugation-mediated gravity loading. Apyrase, Ca(2+) -free medium and purinergic receptor agonists and antagonists were utilized to analyze the contribution of purinergic receptors to ERK phosphorylation. RESULTS: Gravity loading and ATP increased ERK phosphorylation by 5 and 2.5 times, respectively. Gravity loading induced ATP release from PDL cells by tenfold. Apyrase and suramin diminished ERK phosphorylation induced by both gravity loading and ATP. Under Ca(2+) -free conditions the phosphorylation by gravity loading was partially decreased, whereas ATP-induced phosphorylation was unaffected. Receptors P2Y4 and P2Y6 were prominently expressed in the PDL cells. CONCLUSION: Gravity loading induced ATP release and ERK phosphorylation in PDL fibroblasts, and ATP signaling via P2Y receptors was partially involved in this phosphorylation, which in turn would enhance gene expression for the remodeling of PDL tissue during orthodontic tooth movement.

Ito M; Arakawa T; Okayama M; Shitara A; Mizoguchi I; Takuma T

2013-06-01

187

Influence of root embedment material and periodontal ligament simulation on fracture resistance tests Influência do material de inclusão e da simulação do ligamento periodontal nos ensaios de resistência à fratura  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this study was to evaluate the influence of the embedment material and periodontal ligament simulation on fracture resistance of bovine teeth. Eighty bovine incisor teeth were randomized into 8 groups (n = 10), embedded in acrylic or polystyrene resin using 4 types of periodontal ligament simulation: 1 - absence of the ligament; 2 - polyether impression material; 3 - polysulfide impression material; 4 - polyurethane elastomeric material. The specimens were stored at 37°C and 100% humidity for 24 hours. Specimens were submitted to tangential load on the palatal surface at 0.5 mm/minute crosshead speed until fracture. The fracture modes were analyzed as follows: 1 - coronal fracture; 2 - cemento-enamel junction fracture; 3 - partial root fracture; 4 - total root fracture. Statistical analyses by two-way ANOVA and Tukey's test were applied (p O objetivo deste estudo foi avaliar a influência do material de inclusão e da simulação de ligamento periodontal na resistência à fratura de dentes bovinos. Oitenta incisivos bovinos foram divididos em 8 grupos (n = 10) e, então, incluídos em cilindros com dois materiais, resina acrílica ou resina de poliestireno, usando-se quatro tipos de simulação do ligamento periodontal: 1 - ausência do ligamento; 2 - material de moldagem à base de poliéter; 3 - material de moldagem à base de polissulfeto; e 4 - material elastomérico à base de poliuretano. As amostras foram armazenadas em 100% de umidade a 37°C por 24 horas e então submetidas a carregamento tangencial na superfície palatina com velocidade de 0,5 mm/minuto até a fratura. Os padrões de fratura foram analisados de acordo com: 1 - fraturas coronais; 2 - fratura da junção esmalte-cemento; 3 - fratura parcial da raiz; 4 - fratura radicular total. A análise estatística empregou análise de variância fatorial e teste de Tukey (p < 0,05). Os resultados mostram que o método de inclusão e a simulação do ligamento periodontal tiveram efeito significativo na resistência à fratura. O ligamento periodontal artificial modificou os padrões de fratura.

Carlos José Soares; Eliane Cristina Gava Pizi; Rodrigo Borges Fonseca; Luis Roberto Marcondes Martins

2005-01-01

188

Comparación del efecto citotóxico de tres agentes quelantes sobre fibroblasto del ligamento periodontal humano. Estudio in vitro/ Comparison of the cytotoxic effect of three chelating agents on human periodontal ligament fibroblast. In vitro study  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Objetivo: Comparar in vitro el efecto citotóxico de tres agentes quelantes sobre fibroblastos del ligamento periodontal humano. Materiales y métodos: Se utilizaron cultivos de fibroblastos de ligamento periodontal humano, los cuales fueron colocados en contacto con los agentes quelantes a evaluar (RC-Prep, Glyde, EDTA al 17%) a intervalos de 15, 30 y 60 minutos. Se midió la absorbancia para cada uno de los grupos, para determinar el grado de actividad enzimática, que (more) es indicador de muerte celular. Previo a la cuantificación de la absorbancia se corroboró microscópicamente la formación de los cristales de formazán, los cuales se forman alrededor de los fibroblastos, y su presencia es indicador de integridad de la membrana y de la actividad metabólica. Por microscopia se verificó la formación de cristales de formazan, después de agregar azul de tripán. Resultados: El Glyde mostró mayor grado de citotoxicidad, con una diferencia estadísticamente significativa, al compararlo con EDTA 17% y el RC-PREP. El EDTA presentó mayor citotoxicidad que el RC-PREP a los 15minutos, evento que cambió a los 30 y 60 minutos. Conclusiones: Los agentes quelantes RC-Prep, Glyde y EDTA tienen un efecto citotóxico a nivel de los fibroblastos del ligamento periodontal, siendo el EDTA el de menor efecto citotóxico a los 30 y 60 minutos comparado con RC-Prep y Glyde Abstract in english Objectives: To compare in vitro, the cytotoxic effect of three chelating agents on human periodontal ligament fibroblasts, RC-Prep, Glyde and EDTA. Methods: Fibroblast cultures of human periodontal ligament were used, which are placed in contact with chelating agents to evaluate (RC-Prep, Glyde, 17% EDTA) at time intervals of 15,30 and 60 minutes. Absorbance was measured for each group to determine the degree of enzyme activity, which is an indicator of cell death. Prior (more) to the measurement of absorbance was confirmed microscopically, the formation of formazan crystals, which are formed around fibroblasts, and its presence is an indicator of membrane integrity and metabolic activity. Microscopy verified the formation of formazan crystals, after adding trypan blue. Results: Glyde showed greater cytotoxicity with a statistically significant difference when compared with 17% EDTA and RC-PREPchelants. The EDTA showed higher cytotoxicity than the RC-PREP to 15min, and that event changed at 30 and 60 minutes. Conclusion: It was shown experimentally that the chelating agents RC-Prep, EDTA and Glyde have a cytotoxic effect at the periodontal ligament fibroblasts. EDTA has a lowest cytotoxic effect at 30 and 60 minutes compared to RC-Prep and Glyde.

De la Cruz Rocha, Edwin; Figueredo, Luisa Paola; Gómez, Johana; Jiménez, Idalith; Montes, Ilinka; Roca, Sergio; Vergel, Gabriela

2012-12-01

189

[The effects of oxymatrine on expression of interleukin-6 and interleukin-1beta mRNA of human periodontal ligament cell stimulated by lipopolysaccharides].  

UK PubMed Central (United Kingdom)

OBJECTIVE: To observe the effects of oxymatrine on the expression of interleukin-6 (IL-6), interleukin-1beta (IL-1beta) mRNA of human periodontal ligament cell (PDLC) stimulated by lipopolysaccharides (LPS), and to discuss oxymatrine's inhibition mechanism on periodontal inflammation stimulated by LPS. METHODS: Firstly, isolate PDLC externally and culture them; for oxymatrine experimental group we used different combination of LPS and oxymatrine in different concentration, and for the matched group we use DEME nutrient solutions of 1% FBS. Then reverse transcription-polymerase chain reaction (RT-PCR) for checking the level of IL-6 and IL-1beta mRNA. RESULTS: 25 microg x mL(-1) LPS can significantly enhance the expression of both IL-6 and IL-1beta mRNA's level, and oxymatrine could restrain above phenomena. CONCLUSION: Oxymatrine can restrain the expression of IL-6 and IL-1beta mRNA of human PDLC stimulated by LPS.

Wu Y; Chen L; Luo K; Yan FH

2010-12-01

190

Human adult periodontal ligament-derived cells integrate and differentiate after implantation into the adult mammalian brain.  

UK PubMed Central (United Kingdom)

Previous studies suggest that neural crest (NC)-derived stem cells may reside in NC-derivatives including the human periodontal ligament (hPDL). The isolation and manipulation of autologous NC-derived cells could be an accessible source of adult neural stem cells for their use in cell replacement and gene transfer to the diseased central nervous system. In this study we examined the expression of NC-markers and neural differentiation potential of hPDL-derived cells both in vitro and in vivo. In vitro we found that hPDL-derived cells expressed stem cell markers (Oct3/4, Nestin, Sox2 and Musashi-1) and a subset of NC cell markers (Slug, p75(NTR), Twist and Sox9). hPDL-derived cells differentiated into neural-like cells based on cellular morphology and neural marker expression (TUJ1, MAP2, MAP1b, GAD65/67, GABA, NeuN, ChAT, GAT1, Synaptophysin, GFAP, NG2 and O4). In vivo, hPDL-derived cells survive, migrate and give rise to DCX?, NF-M?, GABA?, GFAP? and NG2? cells after grafted the adult mouse brain. Some of the grafted hPDL-derived cells were located in stem cell niches such as the ventricular epithelium and the subventricular zone of the anterolateral ventricle wall as well as in the subgranular zone of the hippocampal dentate gyrus. Thus, the hPDL contains stem cells that originate from the NC and can differentiate into neural cells. The engraftment and differentiation properties of hPDL-derived cells in the adult brain indicate that they are a potential stem cell source to be used in neuroregenerative and/or neurotrophic medicine.

Bueno C; Ramirez C; Rodríguez-Lozano FJ; Tabarés-Seisdedos R; Rodenas M; Moraleda JM; Jones JR; Martinez S

2012-10-01

191

Human adult periodontal ligament-derived cells integrate and differentiate after implantation into the adult mammalian brain.  

Science.gov (United States)

Previous studies suggest that neural crest (NC)-derived stem cells may reside in NC-derivatives including the human periodontal ligament (hPDL). The isolation and manipulation of autologous NC-derived cells could be an accessible source of adult neural stem cells for their use in cell replacement and gene transfer to the diseased central nervous system. In this study we examined the expression of NC-markers and neural differentiation potential of hPDL-derived cells both in vitro and in vivo. In vitro we found that hPDL-derived cells expressed stem cell markers (Oct3/4, Nestin, Sox2 and Musashi-1) and a subset of NC cell markers (Slug, p75(NTR), Twist and Sox9). hPDL-derived cells differentiated into neural-like cells based on cellular morphology and neural marker expression (TUJ1, MAP2, MAP1b, GAD65/67, GABA, NeuN, ChAT, GAT1, Synaptophysin, GFAP, NG2 and O4). In vivo, hPDL-derived cells survive, migrate and give rise to DCX?, NF-M?, GABA?, GFAP? and NG2? cells after grafted the adult mouse brain. Some of the grafted hPDL-derived cells were located in stem cell niches such as the ventricular epithelium and the subventricular zone of the anterolateral ventricle wall as well as in the subgranular zone of the hippocampal dentate gyrus. Thus, the hPDL contains stem cells that originate from the NC and can differentiate into neural cells. The engraftment and differentiation properties of hPDL-derived cells in the adult brain indicate that they are a potential stem cell source to be used in neuroregenerative and/or neurotrophic medicine. PMID:23043788

Bueno, Carlos; Ramirez, Carmina; Rodríguez-Lozano, Francisco J; Tabarés-Seisdedos, Rafael; Rodenas, Mónica; Moraleda, Jose M; Jones, Jonathan R; Martinez, Salvador

2012-10-01

192

Periodontal ligament influence on the stress distribution in a removable partial denture supported by implant: a finite element analysis  

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Full Text Available OBJECTIVES: The non-homogenous aspect of periodontal ligament (PDL) has been examined using finite element analysis (FEA) to better simulate PDL behavior. The aim of this study was to assess, by 2-D FEA, the influence of non-homogenous PDL on the stress distribution when the free-end saddle removable partial denture (RPD) is partially supported by an osseointegrated implant. MATERIAL AND METHODS: Six finite element (FE) models of a partially edentulous mandible were created to represent two types of PDL (non-homogenous and homogenous) and two types of RPD (conventional RPD, supported by tooth and fibromucosa; and modified RPD, supported by tooth and implant [10.00x3.75 mm]). Two additional Fe models without RPD were used as control models. The non-homogenous PDL was modeled using beam elements to simulate the crest, horizontal, oblique and apical fibers. The load (50 N) was applied in each cusp simultaneously. Regarding boundary conditions the border of alveolar ridge was fixed along the x axis. The FE software (Ansys 10.0) was used to compute the stress fields, and the von Mises stress criterion (svM) was applied to analyze the results. RESULTS: The peak of svM in non-homogenous PDL was higher than that for the homogenous condition. The benefits of implants were enhanced for the non-homogenous PDL condition, with drastic svM reduction on the posterior half of the alveolar ridge. The implant did not reduce the stress on the support tooth for both PDL conditions. Conclusion: The PDL modeled in the non-homogeneous form increased the benefits of the osseointegrated implant in comparison with the homogeneous condition. Using the non-homogenous PDL, the presence of osseointegrated implant did not reduce the stress on the supporting tooth.

Carlos Marcelo Archangelo; Eduardo Passos Rocha; João Antônio Pereira; Manoel Martin Junior; Rodolfo Bruniera Anchieta; Amilcar Chagas Freitas Júnior

2012-01-01

193

Hesperetin alleviates the inhibitory effects of high glucose on the osteoblastic differentiation of periodontal ligament stem cells.  

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Hesperetin (3',5,7-trihydroxy-4-methoxyflavanone) is a metabolite of hesperidin (hesperetin-7-O-rutinoside), which belongs to the flavanone subgroup and is found mainly in citrus fruits. Hesperetin has been reported to be an effective osteoinductive compound in various in vivo and in vitro models. However, how hesperetin effects osteogenic differentiation is not fully understood. In this study, we investigated the capacity of hesperetin to stimulate the osteogenic differentiation of periodontal ligament stem cells (PDLSCs) and to relieve the anti-osteogenic effect of high glucose. Osteogenesis of PDLSCs was assessed by measurement of alkaline phosphatase (ALP) activity, and evaluation of the mRNA expression of ALP, runt-related gene 2 (Runx2), osterix (OSX), and FRA1 as osteogenic transcription factors, as well as assessment of protein expression of osteopontin (OPN) and collagen type IA (COLIA). When PDLSCs were exposed to a high concentration (30 mM) of glucose, osteogenic activity decreased compared to control cells. Hesperetin significantly increased ALP activity at doses of 1, 10, and 100 µM. Pretreatment of cells with hesperetin alleviated the high-glucose-induced suppression of the osteogenic activity of PDLSCs. Hesperetin scavenged intracellular reactive oxygen species (ROS) produced under high glucose condition. Furthermore, hesperetin increased the activity of the PI3K/Akt and ?-catenin pathways. Consistent with this, blockage of Akt or ?-catenin diminished the protective effect of hesperetin against high glucose-inhibited osteogenic differentiation. Collectively, our results suggest that hesperetin alleviates the high glucose-mediated suppression of osteogenic differentiation in PDLSCs by regulating ROS levels and the PI3K/Akt and ?-catenin signaling pathways. PMID:23840726

Kim, So Yeon; Lee, Jin-Yong; Park, Yong-Duk; Kang, Kyung Lhi; Lee, Jeong-Chae; Heo, Jung Sun

2013-06-28

194

Hesperetin alleviates the inhibitory effects of high glucose on the osteoblastic differentiation of periodontal ligament stem cells.  

UK PubMed Central (United Kingdom)

Hesperetin (3',5,7-trihydroxy-4-methoxyflavanone) is a metabolite of hesperidin (hesperetin-7-O-rutinoside), which belongs to the flavanone subgroup and is found mainly in citrus fruits. Hesperetin has been reported to be an effective osteoinductive compound in various in vivo and in vitro models. However, how hesperetin effects osteogenic differentiation is not fully understood. In this study, we investigated the capacity of hesperetin to stimulate the osteogenic differentiation of periodontal ligament stem cells (PDLSCs) and to relieve the anti-osteogenic effect of high glucose. Osteogenesis of PDLSCs was assessed by measurement of alkaline phosphatase (ALP) activity, and evaluation of the mRNA expression of ALP, runt-related gene 2 (Runx2), osterix (OSX), and FRA1 as osteogenic transcription factors, as well as assessment of protein expression of osteopontin (OPN) and collagen type IA (COLIA). When PDLSCs were exposed to a high concentration (30 mM) of glucose, osteogenic activity decreased compared to control cells. Hesperetin significantly increased ALP activity at doses of 1, 10, and 100 µM. Pretreatment of cells with hesperetin alleviated the high-glucose-induced suppression of the osteogenic activity of PDLSCs. Hesperetin scavenged intracellular reactive oxygen species (ROS) produced under high glucose condition. Furthermore, hesperetin increased the activity of the PI3K/Akt and ?-catenin pathways. Consistent with this, blockage of Akt or ?-catenin diminished the protective effect of hesperetin against high glucose-inhibited osteogenic differentiation. Collectively, our results suggest that hesperetin alleviates the high glucose-mediated suppression of osteogenic differentiation in PDLSCs by regulating ROS levels and the PI3K/Akt and ?-catenin signaling pathways.

Kim SY; Lee JY; Park YD; Kang KL; Lee JC; Heo JS

2013-01-01

195

Biocompatibility and Osteogenic Capacity of Periodontal Ligament Stem Cells on nHAC/PLA and HA/TCP Scaffolds.  

UK PubMed Central (United Kingdom)

This study investigated the effects of a newly-developed scaffold, nano-hydroxyapatite/collagen/poly(L-lactide) (nHAC/PLA), on the attachment, proliferation and osteogenic capability of dog periodontal ligament stem cells (PDLSCs) in vitro and in vivo. Hydroxyapatite/tricalcium phosphate (HA/TCP), a commonly used bone substitute, was used as a positive control. PDLSCs isolated from dog molar were incubated in an osteogenic medium to evaluate their osteogenic differentiation in vitro, and then seeded onto nHAC/PLA and HA/TCP scaffolds. In vitro cell attachment, proliferation and differentiation were assessed by scanning electron microscopy (SEM), cell counting, 3-[4,5-dimethythiazol-2-yl]-5-[3-carboxy-phenyl]-2-[4-sulfophenyl]-2H-tetrazolium and alkaline phosphate activity, and reverse transcription-polymerase chain reaction, respectively. Finally, the constructs were implanted subcutaneously into dogs to investigate their osteogenic capacity. After osteogenic induction for 21 days, PDLSCs differentiated into osteogenic lineage, as indicated by the expressions of osteoblastic differentiation genes CoL-I, OCN and OPN mRNA, and the formation of mineral deposits. When seeded onto scaffolds, the cells attached and spread well, and retained their osteogenic phenotypes on both scaffolds. Comparatively, cell number and proliferative viability on nHAC/PLA constructs were greater than those on HA/TCP constructs (P<0.05). Histological results showed that new bone and osteoid was formed in both groups, and histomorphometric analysis demonstrated that the amount of newly formed bone in the nHAC/PLA group was higher than that in the HA/TCP group (P<0.05). This study suggests that nHAC/PLA can be used as a potent scaffold for alveolar bone regeneration.

He H; Yu J; Cao J; E L; Wang D; Zhang H; Liu H

2010-06-01

196

Optimal Medium Formulation for the Long-Term Expansion and Stemness Maintenance of Periodontal Ligament Stem Cells.  

UK PubMed Central (United Kingdom)

Background: Human periodontal ligament stem cells (hPDLSCs) are promising mesenchymal stem cells that are readily accessible. However, there is as yet no consensus as to the optimal culture medium for hPDLSCs. The purpose of the present study was thus to determine the optimal culture medium for long-term expansion of hPDLSCs. Methods: hPDLSCs were isolated from healthy 3(rd) molars and the most widely used medium formultions in previous studies were used: (i) an alpha minimum essential medium (?-MEM)-based medium formulation (MBM), (ii) a Dulbecco's minimum essential medium (DMEM)-based medium formation (DBM). P5 and P8 were evaluated with the two medium for cell proliferation, differentiation, and immunophenotype. Results: hPDLSCs that were primarily cultured in MBM were far more proliferated than those grown in DBM. In general, application of the MBM for longer period produced greater cell growth and osteogenic differentiation. Furthermore, MBM-precultured hPDLSCs exhibited a greater degree of cell proliferation and a greater production of mineralized tissue and ALP activity in vitro, although the levels of both were dependent upon the culture medium used. With respect to long-term expansion, the P5 hPDLSCs grew and produced the largest amount of mineralized nodules faster than the P8 hPDLSCs, but both passages exhibited a similar phenotype for stemness and ALP activity. Conclusion: Present study indicates that the inherent capacity of hPDLSCs could be maintained until a later passage, P8 in MBM, and MBM appears to be an optimal choice for manipulating the finest and most stable hPDLSCs.

Jung IH; Kwon BS; Kim SH; Shim HE; Jun CM; Yun JH

2013-01-01

197

Periodontal ligament cells cultured under steady-flow environments demonstrate potential for use in heart valve tissue engineering.  

UK PubMed Central (United Kingdom)

A major drawback of mechanical and prosthetic heart valves is their inability to permit somatic growth. By contrast, tissue-engineered pulmonary valves potentially have the capacity to remodel and integrate with the patient. For this purpose, adult stem cells may be suitable. Previously, human periodontal ligament cells (PDLs) have been explored as a reliable and robust progenitor cell source for cardiac muscle regeneration (Pelaez, D. Electronic Thesis and Dissertation Database, Coral Gables, FL, May 2011). Here, we investigate the potential of PDLs to support the valve lineage, specifically the concomitant differentiation to both endothelial cell (EC) and smooth muscle cell (SMC) types. We were able to successfully promote PDL differentiation to both SMC and EC phenotypes through a combination of stimulatory approaches using biochemical and mechanical flow conditioning (steady shear stress of 1 dyne/cm(2)), with flow-based mechanical conditioning having a predominant effect on PDL differentiation, particularly to ECs; in addition, strong expression of the marker FZD2 and an absence of the marker MLC1F point toward a unique manifestation of smooth muscle by PDLs after undergoing steady-flow mechanical conditioning alone, possible by only the heart valve and pericardium phenotypes. It was also determined that steady flow (which was performed using a physiologically relevant [for heart valves] magnitude of ~5-6 dynes/cm(2)) augmented the synthesis of the extracellular matrix collagen proteins. We conclude that under steady-flow dynamic culture environments, human PDLs can differentiate to heterogeneous cell populations that are relevant to heart valve tissue engineering. Further exploration of human PDLs for this purpose is thus warranted.

Martinez C; Rath S; Van Gulden S; Pelaez D; Alfonso A; Fernandez N; Kos L; Cheung H; Ramaswamy S

2013-02-01

198

Expression of Pituitary Adenylate Cyclase-Activating Peptide (PACAP) and PAC1 in the Periodontal Ligament After Tooth Luxation.  

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Pituitary adenylate cyclase-activating peptide (PACAP) is widely distributed throughout the nervous system. PACAP not only acts as a neurotransmitter but also elicits a broad spectrum of biological action via the PACAP-specific receptor, PAC1. However, no studies have investigated PACAP and PAC1 in the periodontal ligament (PDL), so we aimed to perform this investigation in rats after tooth luxation. In the PDL of an intact first molar, there are few osteoclasts and osteoblasts. However, at days 3 and 5 after luxation, large PAC1-positive cells, thought to be osteoclasts because of their expression of the osteoclast marker, tartrate-resistant acid phosphatase, were detected in appreciable numbers. Osteoblast numbers increased dramatically on day 7 after luxation, and PAC1-positive mononuclear small cells were increased at day 14, many of which expressed the osteoblast marker, alkaline phosphatase. PACAP-positive nerve fibers were rarely detected in the PDL of intact first molars, but were increasingly evident at this site on days 5 and 7 after luxation. Double-immunofluorescence analysis demonstrated the relationship between PACAP-positive nerve fibers and PAC1-positive osteoclasts/-blasts in the PDL. At 5 days after luxation, PACAP-positive nerve fibers appeared in close proximity to PAC1-positive osteoclasts. At 7 days after luxation, PACAP-positive nerve fibers appeared in close proximity to PAC1-positive osteoblasts. These results suggest that PACAP may have effects on osteoclasts and osteoblasts in the PDL after tooth luxation and thus regulate bone remodeling after these types of injury. PMID:23801193

Nonaka, Sayako; Kitaura, Hideki; Kimura, Keisuke; Ishida, Masahiko; Takano-Yamamoto, Teruko

2013-06-26

199

Essentials in Periodontal Regeneration  

Directory of Open Access Journals (Sweden)

Full Text Available Various materials and techniques have been used in the treatment of periodontal disease to achieve regeneration of lost periodontal tissues including cementum, periodontal ligament (PDL) and alveolar bone. The composition, regenerative potential, application and therapeutic characteristics of several regenerative materials have been evaluated in the present study.

F. Haghighati; G. Saaveh

2007-01-01

200

The initial phase of orthodontic root resorption incident to local compression of the periodontal ligament.  

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The present light microscopic investigation was undertaken in order to study the initial phase of orthodontic root resorption in areas of pressure and, more specifically, to focus on the first cells that penetrate the root surface. Twenty-one upper first molars (rats) and 31 lower first molars (mice) were moved mesially by a fixed orthodontic appliance. The experimental periods were 1, 2, 3, 4, and 5 days in rats, and 1, 2, 3, 4, 5, 6, 7, and 8 days in mice. Tartrate-resistant acid phosphatase (TRAP) and Haematoxylin Eosin (H&E) stains were used. Root resorption related to a hyalinized zone showed a consistent pattern: Root resorption started in the circumference of the necrotic hyalinized tissue. In the central parts of the hyalinized zone frontal root resorption occurred 3-4 days later than in the periphery. Indications that the mechanisms for circumferential and central resorption differed was the reason for presenting only the periphery stage in this paper. The initial penetration of cells into precementum/cementum occurred at the peripheries or at a short distance from the peripheries of the hyalinized zone. These cells were TRAP-negative, indicating that they were not clasts or clast precursors. Before this happened TRAP-negative macrophage-like cells were observed at the borderline between the hyalinized tissue and vital periodontal membrane (PM). TRAP-positive cells were first observed in the bone marrow spaces. During the later stages mono- and multi-nucleated TRAP-positive cells were participating in active removal of the hyalinized tissue toward the root surface, and in resorption of cementum and dentine. PMID:7691628

Brudvik, P; Rygh, P

1993-08-01

 
 
 
 
201

The initial phase of orthodontic root resorption incident to local compression of the periodontal ligament.  

UK PubMed Central (United Kingdom)

The present light microscopic investigation was undertaken in order to study the initial phase of orthodontic root resorption in areas of pressure and, more specifically, to focus on the first cells that penetrate the root surface. Twenty-one upper first molars (rats) and 31 lower first molars (mice) were moved mesially by a fixed orthodontic appliance. The experimental periods were 1, 2, 3, 4, and 5 days in rats, and 1, 2, 3, 4, 5, 6, 7, and 8 days in mice. Tartrate-resistant acid phosphatase (TRAP) and Haematoxylin Eosin (H&E) stains were used. Root resorption related to a hyalinized zone showed a consistent pattern: Root resorption started in the circumference of the necrotic hyalinized tissue. In the central parts of the hyalinized zone frontal root resorption occurred 3-4 days later than in the periphery. Indications that the mechanisms for circumferential and central resorption differed was the reason for presenting only the periphery stage in this paper. The initial penetration of cells into precementum/cementum occurred at the peripheries or at a short distance from the peripheries of the hyalinized zone. These cells were TRAP-negative, indicating that they were not clasts or clast precursors. Before this happened TRAP-negative macrophage-like cells were observed at the borderline between the hyalinized tissue and vital periodontal membrane (PM). TRAP-positive cells were first observed in the bone marrow spaces. During the later stages mono- and multi-nucleated TRAP-positive cells were participating in active removal of the hyalinized tissue toward the root surface, and in resorption of cementum and dentine.

Brudvik P; Rygh P

1993-08-01

202

[Attrition, dentin apposition and protein synthesis in the pulp and desmodont of young and old rats].  

UK PubMed Central (United Kingdom)

Occlusal attrition and responsive adaptations in the pulp-dentinal unit are still problematic. In this study, up to 2 years-old rats were used to measure the amount of occlusal attrition, of dentin apposition and of the incorporation of 3H-proline into the pulpal and periodontal ligament tissues. Two to four SIV-rats each, 45, 365 and 730 days of age, were once injected with 3H-proline 2 hours or 5 days prior to exitus. After cardiac perfusion, the molar blocks of both jaws were decalcified in EDTA and divided into bucco-oral and mesio-distal slices. The latter were embedded in Epon. Semithin sections served to measure the amount of attrition and of tertiary dentin apposition, as well as for autoradiographic labelling and determination of the rate of dentin apposition and proline incorporation in pulpal and periodontal ligament tissues. The results show that (1) the molar cusps lost up to 40% of their initial height during the two years of life, (2) occlusal dentin apposition in the intercuspal region led to an increase in dentinal thickness by 50 to 70%, while in the pulp horn region dentinal apposition occurred early in life and later did not keep phase with attrition, and (3) protein synthesis in pulp and periodontal ligament essentially did not change within the two years of life. These findings are related to that of other authors and discussed in connection with dentinal innervation.

Schroeder HE; Münzel-Pedrazzoli S

1994-01-01

203

In vitro characterization of a synthetic calcium phosphate bone graft on periodontal ligament cell and osteoblast behavior and its combination with an enamel matrix derivative.  

UK PubMed Central (United Kingdom)

OBJECTIVES: Recent studies suggest that a combination of enamel matrix derivative (EMD) with grafting material may improve periodontal wound healing/regeneration. Newly developed calcium phosphate (CaP) ceramics have been demonstrated a viable synthetic replacement option for bone grafting filler materials. AIMS: This study aims to test the ability for EMD to adsorb to the surface of CaP particles and to determine the effect of EMD on downstream cellular pathways such as adhesion, proliferation, and differentiation of primary human osteoblasts and periodontal ligament (PDL) cells. MATERIALS AND METHODS: EMD was adsorbed onto CaP particles and analyzed for protein adsorption patterns via scanning electron microscopy and high-resolution immunocytochemistry with an anti-EMD antibody. Cell attachment and cell proliferation were quantified using CellTiter 96 One Solution Cell Assay (MTS). Cell differentiation was analyzed using real-time PCR for genes encoding Runx2, alkaline phosphatase, osteocalcin, and collagen1?1, and mineralization was assessed using alizarin red staining. RESULTS: Analysis of cell attachment revealed significantly higher number of cells attached to EMD-adsorbed CaP particles when compared to control and blood-adsorbed samples. EMD also significantly increased cell proliferation at 3 and 5 days post-seeding. Moreover, there were significantly higher mRNA levels of osteoblast differentiation markers including collagen1?1, alkaline phosphatase, and osteocalcin in osteoblasts and PDL cells cultured on EMD-adsorbed CaP particles at various time points. CONCLUSION: The present study suggests that the addition of EMD to CaP grafting particles may influence periodontal regeneration by stimulating PDL cell and osteoblast attachment, proliferation, and differentiation. Future in vivo and clinical studies are required to confirm these findings. CLINICAL RELEVANCE: The combination of EMD and CaP may represent an option for regenerative periodontal therapy in advanced intrabony defects.

Miron RJ; Bosshardt DD; Gemperli AC; Dard M; Buser D; Gruber R; Sculean A

2013-04-01

204

In vitro characterization of a synthetic calcium phosphate bone graft on periodontal ligament cell and osteoblast behavior and its combination with an enamel matrix derivative.  

Science.gov (United States)

OBJECTIVES: Recent studies suggest that a combination of enamel matrix derivative (EMD) with grafting material may improve periodontal wound healing/regeneration. Newly developed calcium phosphate (CaP) ceramics have been demonstrated a viable synthetic replacement option for bone grafting filler materials. AIMS: This study aims to test the ability for EMD to adsorb to the surface of CaP particles and to determine the effect of EMD on downstream cellular pathways such as adhesion, proliferation, and differentiation of primary human osteoblasts and periodontal ligament (PDL) cells. MATERIALS AND METHODS: EMD was adsorbed onto CaP particles and analyzed for protein adsorption patterns via scanning electron microscopy and high-resolution immunocytochemistry with an anti-EMD antibody. Cell attachment and cell proliferation were quantified using CellTiter 96 One Solution Cell Assay (MTS). Cell differentiation was analyzed using real-time PCR for genes encoding Runx2, alkaline phosphatase, osteocalcin, and collagen1?1, and mineralization was assessed using alizarin red staining. RESULTS: Analysis of cell attachment revealed significantly higher number of cells attached to EMD-adsorbed CaP particles when compared to control and blood-adsorbed samples. EMD also significantly increased cell proliferation at 3 and 5 days post-seeding. Moreover, there were significantly higher mRNA levels of osteoblast differentiation markers including collagen1?1, alkaline phosphatase, and osteocalcin in osteoblasts and PDL cells cultured on EMD-adsorbed CaP particles at various time points. CONCLUSION: The present study suggests that the addition of EMD to CaP grafting particles may influence periodontal regeneration by stimulating PDL cell and osteoblast attachment, proliferation, and differentiation. Future in vivo and clinical studies are required to confirm these findings. CLINICAL RELEVANCE: The combination of EMD and CaP may represent an option for regenerative periodontal therapy in advanced intrabony defects. PMID:23620149

Miron, Richard J; Bosshardt, Dieter D; Gemperli, Anja C; Dard, Michel; Buser, Daniel; Gruber, Reinhard; Sculean, Anton

2013-04-26

205

Stromal cell-derived factor-1 significantly induces proliferation, migration, and collagen type I expression in a human periodontal ligament stem cell subpopulation.  

UK PubMed Central (United Kingdom)

BACKGROUND: The pivotal role of chemokine stromal cell-derived factor-1 (SDF-1) in bone marrow mesenchymal stem cells recruitment and tissue regeneration has already been reported. However, its roles in human periodontal ligament stem cells (PDLSCs) remain unknown. PDLSCs are regarded as candidates for periodontal tissue regeneration and are used in stem cell-based periodontal tissue engineering. The expression of chemokine receptors on PDLSCs and the migration of these cells induced by chemokines and their subsequent function in tissue repair may be a crucial procedure for periodontal tissue regeneration. METHODS: PDL tissues were obtained from clinically healthy premolars extracted for orthodontic reasons and used to isolate single-cell colonies by the limited-dilution method. Immunocytochemical staining was used to detect the expression of the mesenchymal stem cell marker STRO-1. Differentiation potentials were assessed by alizarin-red staining and oil-red O staining. The expression of SDF-1 receptor CXCR4 was evaluated by real-time polymerase chain reaction (PCR) and immunocytochemical staining. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and bromodeoxyuridine incorporation assay were used to determine the viability and proliferation of the PDLSC subpopulation. Expression of collagen type I and alkaline phosphatase was detected by real-time PCR to determine the effect of SDF-1 on cells differentiation. RESULTS: Twenty percent of PDL single-cell colonies expressed STRO-1 positively, and this specific subpopulation was positive for CXCR4 and formed minerals and lipid vacuoles after 4 weeks induction. SDF-1 significantly increased proliferation and stimulated the migration of this PDLSC subpopulation at concentrations between 100 and 400 ng/mL. CXCR4 neutralizing antibody could block cell proliferation and migration, suggesting that SDF-1 exerted its effects on cells through CXCR4. SDF-1 promoted collagen type I level significantly but had little effect on alkaline phosphatase level. CONCLUSION: SDF-1 may have the potential of promoting periodontal tissue regeneration by the mechanism of guiding PDLSCs to destructive periodontal tissue, promoting their activation and proliferation and influencing the differentiation of these stem cells.

Du L; Yang P; Ge S

2012-03-01

206

Regulation of matrix metalloproteinases, tissue inhibitor of matrix metalloproteinase-1, and extracellular metalloproteinase inducer by interleukin-17 in human periodontal ligament fibroblasts.  

UK PubMed Central (United Kingdom)

INTRODUCTION: Under physiological conditions, matrix metalloproteinases (MMPs) are involved in the turnover of periapical tissue, and their activity is tightly regulated by tissue inhibitors of metalloproteinases (TIMPs). Disturbances in the balance between MMPs and TIMPs may result in excessive tissue destruction. In addition, the extracellular metalloproteinase inducer (EMMPRIN) capable of inducing MMPs may also play a role in the pathologic processes. This study aimed to investigate the effects of interleukin (IL)-17 on the mRNA expression and protein production of MMP-1, MMP-2, MMP-9, MMP-13, TIMP-1, and EMMPRIN through human periodontal ligament cells. METHODS: The cells were stimulated with IL-17 (1, 10, and 50 ng/mL) for different time periods. The mRNA levels of MMP-1, MMP-2, MMP-9, MMP-13, TIMP-1, and EMMPRIN were evaluated via quantitative real-time polymerase chain reaction analysis, whereas the protein secretion into the culture medium was assessed via enzyme-linked immunosorbent assay and zymography analysis. RESULTS: IL-17 significantly up-regulated MMP-1 and MMP-13 mRNA expression but down-regulated MMP-2, MMP-9, and TIMP-1 mRNA expression. Furthermore, IL-17 (50 ng/mL) increased the secreted protein level of MMP-1 and MMP-13 and conversely reduced the level of MMP-2, MMP-9, and TIMP-1. However, IL-17 exerted no effect on EMMPRIN mRNA or protein secretion. CONCLUSIONS: This study first reported the ability of IL-17 to regulate MMP and TIMP-1 production through human periodontal ligament cells, a phenomenon that may contribute to periapical tissue destruction.

Wu Y; Zhu L; Wei H; Peng B

2013-01-01

207

The effect of cyclic mechanical strain on the expression of adhesion-related genes by periodontal ligament cells in two-dimensional culture.  

UK PubMed Central (United Kingdom)

BACKGROUND AND OBJECTIVE: Cell adhesion plays important roles in maintaining the structural integrity of connective tissues and sensing changes in the biomechanical environment of cells. The objective of the present investigation was to extend our understanding of the effect of cyclic mechanical strain on the expression of adhesion-related genes by human periodontal ligament cells. MATERIAL AND METHODS: Cultured periodontal ligament cells were subjected to a cyclic in-plane tensile deformation of 12% for 5 s (0.2 Hz) every 90 s for 6-24 h in a Flexercell FX-4000 Strain Unit. The following parameters were measured: (i) cell viability by the MTT assay; (ii) caspase-3 and -7 activity; and (iii) the expression of 84 genes encoding adhesion-related molecules using real-time RT-PCR microarrays. RESULTS: Mechanical stress reduced the metabolic activity of deformed cells at 6 h, and caspase-3 and -7 activity at 6 and 12 h. Seventy-three genes were detected at critical threshold values < 35. Fifteen showed a significant change in relative expression: five cell adhesion molecules (ICAM1, ITGA3, ITGA6, ITGA8 and NCAM1), three collagen ?-chains (COL6A1, COL8A1 and COL11A1), four MMPs (ADAMTS1, MMP8, MMP11 and MMP15), plus CTGF, SPP1 and VTN. Four genes were upregulated (ADAMTS1, CTGF, ICAM1 and SPP1) and 11 downregulated, with the range extending from a 1.76-fold induction of SPP1 at 12 h to a 2.49-fold downregulation of COL11A1 at 24 h. CONCLUSION: The study has identified several mechanoresponsive adhesion-related genes, and shown that onset of mechanical stress was followed by a transient reduction in overall cellular activity, including the expression of two apoptosis 'executioner' caspases.

Saminathan A; Vinoth KJ; Wescott DC; Pinkerton MN; Milne TJ; Cao T; Meikle MC

2012-04-01

208

The effect of propolis as a biological storage media on periodontal ligament cell survival in an avulsed tooth: an in vitro study.  

UK PubMed Central (United Kingdom)

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.

Ahangari Z; Alborzi S; Yadegari Z; Dehghani F; Ahangari L; Naseri M

2013-01-01

209

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

Science.gov (United States)

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

Li, Lu; Han, Minxuan; Li, Sheng; Wang, Lin; Xu, Yan

2013-06-19

210

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

UK PubMed Central (United Kingdom)

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.

Li L; Han M; Li S; Wang L; Xu Y

2013-09-01

211

Activation of cannabinoid receptor CB2 regulates LPS-induced pro-inflammatory cytokine production and osteoclastogenic gene expression in human periodontal ligament cells  

Directory of Open Access Journals (Sweden)

Full Text Available Background and Objective: It has been found that human periodontal ligament (hPDL) cells express cannabinoid receptor CB2. However, the functional importance of CB2 in hPDL cells exposed to bacterial endotoxins is not known. Here we investigate if the inflammation promoter lipopolysaccharide (LPS) affects CB2 expression and if activation of CB2 regulates LPS-induced pro-inflammatory cytokine production and osteoclastogenic gene expression in hPDL cells. Methods: The hPDL cells were obtained from extracted teeth of periodontally healthy subjects. CB2 expression in hPDL cells exposed to LPS was deter- mined by quantitative real-time PCR analysis. Then, the cells were incubated with or without CB2-specific agonist HU-308 before further stimulation with LPS. In some experiments, the cells were pre-treated with CB2-specific antagonist SR144528. The production of pro-inflammatory cytokines interleukin-1 beta (IL- 1?), interleukin-6 (IL-6) and tumor necrosis factoralpha (TNF-?) was assessed by enzyme-linked immunosorbent assay (ELISA). The mRNA expression of osteoclastogenic genes osteoprotegerin (OPG) and receptor activator of NF-?B ligand (RANKL) was examined using quantitative real-time PCR analysis. Results: CB2 expression in hPDL cells was markedly enhanced by LPS. HU-308 significantly suppressed the production of IL-1?, IL-6 and TNF-? exposed to LPS, whereas SR144528 attenuated this effect. The OPG/RANKL ratio decreased when exposed to LPS, furthermore increased significantly with the addition of HU-308 and finally decreased markedly after pretreatment with SR144528. Conclusion: Our study demonstrated that activation of CB2 had anti-inflammatory and anti-resorptive effects on LPS-stimulated hPDL cells. These findings suggest that activation of CB2 might be an effective therapeutic strategy for the treatment of inflammation and alveolar bone resorption in periodontitis.

Hong Qian; Jun Yi; Jingshi Zhou; Ya Zhao; Yongming Li; Zuolin Jin; Yin Ding

2013-01-01

212

20-Hydroxyecdysone-induced bone morphogenetic protein-2-dependent osteogenic differentiation through the ERK pathway in human periodontal ligament stem cells.  

Science.gov (United States)

20-Hydroxyecdysone, an ecdysteroid hormone, can induce osteogenic differentiation in mesenchymal stem cells. Periodontal ligament stem cells (PDLS cells) have mesenchymal-stem-cell-like qualities and are considered as one of the candidates of future clinical application in periodontitis treatment. However, there are no studies describing the effect of 20-Hydroxyecdysone on PDLS cells. In this paper, we report a detailed study on the effect of 20-Hydroxyecdysone on PDLS cell proliferation in vitro. PDLS cells were developed from human PDL cells and were treated with 20-Hydroxyecdysone to understand different aspects of its effects. 20-Hydroxyecdysone promoted PDLS cell proliferation; significantly increased the gene expression levels of runt-related transcription factor 2, alkaline phosphatase (ALP), type I collagen, and osteocalcin. Moreover, 20-Hydroxyecdysone enhanced bone formation by PDLS cells and significantly increased bone morphogenetic protein-2 (BMP-2) mRNA and protein expression. However, 20-Hydroxyecdysonemediated increase in ALP activity was blocked with a BMP-2-specific neutralizing antibody or with the antagonist noggin; and20-Hydroxyecdysone mediated induction of BMP-2 expression and increase of ALP activity were abolished by the extracellular regulated protein kinase (ERK) MAPK pathway inhibitor PD98059. 20-Hydroxyecdysone also increased the phosphorylation of ERK. These findings provide evidence to state that 20-Hydroxyecdysone stimulates cell proliferation and induces osteogenic differentiation through the induction of BMP-2 expression in PDLS cells. It also shows that the ERK pathway is involved in 20-Hydroxyecdysone induced BMP-2 expression and osteogenic differentiation. These results are suggesting its potential as a drug for periodontal regenerative therapy. PMID:23397605

Jian, Cong-Xiang; Liu, Xiao-Fei; Hu, Jun; Li, Chen-Jun; Zhang, Gang; Li, Yan; Zhu, Ji-Wen; Tan, Ying-Hui

2013-01-01

213

20-Hydroxyecdysone-induced bone morphogenetic protein-2-dependent osteogenic differentiation through the ERK pathway in human periodontal ligament stem cells.  

UK PubMed Central (United Kingdom)

20-Hydroxyecdysone, an ecdysteroid hormone, can induce osteogenic differentiation in mesenchymal stem cells. Periodontal ligament stem cells (PDLS cells) have mesenchymal-stem-cell-like qualities and are considered as one of the candidates of future clinical application in periodontitis treatment. However, there are no studies describing the effect of 20-Hydroxyecdysone on PDLS cells. In this paper, we report a detailed study on the effect of 20-Hydroxyecdysone on PDLS cell proliferation in vitro. PDLS cells were developed from human PDL cells and were treated with 20-Hydroxyecdysone to understand different aspects of its effects. 20-Hydroxyecdysone promoted PDLS cell proliferation; significantly increased the gene expression levels of runt-related transcription factor 2, alkaline phosphatase (ALP), type I collagen, and osteocalcin. Moreover, 20-Hydroxyecdysone enhanced bone formation by PDLS cells and significantly increased bone morphogenetic protein-2 (BMP-2) mRNA and protein expression. However, 20-Hydroxyecdysonemediated increase in ALP activity was blocked with a BMP-2-specific neutralizing antibody or with the antagonist noggin; and20-Hydroxyecdysone mediated induction of BMP-2 expression and increase of ALP activity were abolished by the extracellular regulated protein kinase (ERK) MAPK pathway inhibitor PD98059. 20-Hydroxyecdysone also increased the phosphorylation of ERK. These findings provide evidence to state that 20-Hydroxyecdysone stimulates cell proliferation and induces osteogenic differentiation through the induction of BMP-2 expression in PDLS cells. It also shows that the ERK pathway is involved in 20-Hydroxyecdysone induced BMP-2 expression and osteogenic differentiation. These results are suggesting its potential as a drug for periodontal regenerative therapy.

Jian CX; Liu XF; Hu J; Li CJ; Zhang G; Li Y; Zhu JW; Tan YH

2013-01-01

214

Inhibition of transforming growth factor ?1/Smad3 signaling decreases hypoxia-inducible factor-1? protein stability by inducing prolyl hydroxylase 2 expression in human periodontal ligament cells.  

UK PubMed Central (United Kingdom)

BACKGROUND: Hypoxia-inducible factor-1? (HIF-1?), the ? subunit of the heterodimeric transcription factor HIF-1, maintains oxygen homeostasis by regulating gene expression. Under normoxic conditions, HIF-1? expression is maintained at low steady-state levels by the critical oxygen sensor prolyl hydroxylase 2 (PHD2). Transforming growth factor ?1 (TGF-?1) activates Smad3 signaling and contributes to HIF-1? stabilization under normoxic conditions. In chronic periodontitis, HIF-1? is expressed highly in gingival fibroblasts and upregulates inflammatory factor transcription, which promotes periodontal inflammation. Here, the authors investigated the effect of TGF-?1/Smad3 signaling and its blockade by the specific inhibitor of Smad3 (SIS3) on HIF-1? expression and stability in human periodontal ligament cells. METHODS: The authors investigated the effect of TGF-?1 on HIF-1? protein stability using cycloheximide. Furthermore, they analyzed HIF-1? expression, PHD2 expression, and Smad3 phosphorylation following TGF-?1 stimulation in the presence or absence of SIS3. RESULTS: The half-life of HIF-1? was prolonged in TGF-?1-treated cells. TGF-?1 treatment induced HIF-1? gene expression and enhanced HIF-1? protein stability while decreasing PHD2 expression and activating Smad3 phosphorylation. Notably, HIF-1? protein expression was not detectable prior to TGF-?1 stimulation. Furthermore, SIS3 treatment abrogated Smad3 phosphorylation, impaired TGF-?1-induced HIF-1? gene expression and protein stability, and stimulated TGF-?1-mediated PHD2 inhibition. CONCLUSION: These results demonstrate that HIF-1? transcription and protein synthesis are controlled by TGF-?1/Smad3 signaling, whereas HIF-1? protein stability is controlled by PHD2, which is regulated by TGF-?1/Smad3 signaling.

Watanabe T; Yasue A; Tanaka E

2013-09-01

215

Comparación histomorfométrica in vitro del ligamento periodontal de premolares extraídos mantenidos en cuatro medios de conservación/ In vitro histomorphometric comparison of periodontal ligament of extracted premolar teeth preserved in different media storage  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Objetivo: El propósito de este estudio fue evaluar histológica y morfométricamente los resultados de diferentes tipos de medios de almacenamiento para los dientes avulsionados en el mantenimiento de la preservación de la integridad del ligamento periodontal. Material y métodos: Estudio de tipo experimental de laboratorio, se utilizaron veintitrés premolares extraídos por motivos ortodóncicos. Los medios de conservación evaluados fueron: leche tipo "B" y tipo "C", (more) solución salina y medio seco. Un total de cinco dientes fueron almacenados en cada uno de los medios de conservación durante 120 minutos. Otros tres dientes sirvieron como controles fijados inmediatamente después de la extracción representando el ligamento periodontal íntegro. Los dientes se fijaron, procesaron y tiñeron con hematoxilina y eosina para evaluación histológica a través de microscopia óptica. Resultados: La edad de los pacientes que aportaron los dientes osciló entre 13 a 17 años. Los resultados de la evaluación cualitativa mostraron que la solución fisiológica fue el medio de almacenamiento más adecuado seguido de la leche tipo C y tipo B. En el análisis estadístico no hubo diferencia estadísticamente significativa entre los grupos de solución fisiológica y leche tipo C. Después de 120 minutos se encontraron diferencias estadísticamente significativas entre las alteraciones histomorfométricas del grupo control y los grupos de dientes que se mantuvieron en condiciones de humedad y los secos. Conclusión: Dados los resultados de este estudio, la solución salina (grupo II) y la leche tipo C (Grupo III) pueden considerarse como las formas de conservación más adecuadas de los dientes avulsionados. Abstract in english Objective: The aim of this study was to histologically and morphometrically evaluate the results of different types of storage media for avulsed teeth in the maintenance and preserving the integrity of the periodontal ligament. Material and methods: Experimental study. It was used twenty-three extracted premolars for orthodontic reasons. Preserving methods evaluated were: type "B" and "C" milk, saline and dry environment. A total of five teeth were stored in each storage (more) media for 120 minutes. Three teeth served as controls fixed immediately after extraction representing the entire periodontal ligament. The teeth were fixed, processed and stained with hematoxylin/eosin for histological evaluation by light microscopy. Results: The age of the patients who provided the teeth ranged from 13-17 years. The results of the qualitative assessment showed that saline was the most appropriate storage medium, followed by milk type C and type B. In the statistical analysis there was no statistically significant difference between saline and type C milk. After 120 minutes it was found statistically significant differences between histomorphometric changes in the control group and groups of teeth that were kept in wet conditions and dry. Conclusion: Given the results of this study, saline (group II) and milk type C (Group III) can be considered as the most suitable form of storage of avulsed teeth.

Prokopowitsch, I.; Cabrales Salgado, R.; Díaz Caballero, A.; Simancas Pallares, M.

2013-04-01

216

Remoción del ligamento periodontal por medio de fricción con gasa embebida en solución de hipoclorito de sodio a 1% Periodontal ligament remotion using friction of sodium hypochloride 1% solution absorbed gauze  

Directory of Open Access Journals (Sweden)

Full Text Available Estudios han demostrado la capacidad del hipoclorito de sodio en la remoción del ligamento periodontal sin vitalidad en dientes avulsionados. Sin embargo el uso de esta sustancia puede ocasionar un efecto irritante en el tejido conjuntivo. Siendo así adecuaciones en su utilización se muestran necesarias para que se obtenga un reparo más satisfactorio cuando utilizados en dientes reimplantados. Por lo tanto es propuesta de ese estudio evaluar la capacidad de remoción del ligamento periodontal, por medio de fricción de la superficie radicular de dientes de ratones, con una gasa humedecida en solución de hipoclorito de sodio al 1%. Fueron utilizados 40 dientes divididos en 4 grupos de 10, los cuales después de la extracción, fueron mantenidos en medio seco por 60 minutos. En el grupo control, los dientes fueron mantenidos en 25ml de hipoclorito de sodio a 1% por 5 minutos. En el grupo II, la superficie radicular fue friccionada con gasa humedecida en 25ml de solución de hipoclorito de sodio a 1% por un periodo de 1 minuto y en la secuencia lavados en suero fisiológico por 4 minutos. En el grupo III, la fricción fue de 2 minutos, y el periodo del lavado 2 minuto. En el grupo IV, la fricción con 4 minutos y el periodo del lavado 1 minuto. Después del procesamiento laboratorial, los cortes obtenidos fueron coloreados por el Tricromio de Masson y Hematoxilina y eosina para análisis en microscopia de luz. Los resultados demostraron que en el grupo control 100% de la superficie radicular estaba cubierto por ligamento periodontal. A través del test de proporción, se observó que la fricción por 1 minuto fue menos eficaz, con diferencia estadísticamente significante (pSabe-se que o hipoclorito de sódio pode remover o ligamento periodontal desvitalizado em dentes avulsionados. Adequações em seu uso se mostram necessárias para se obter um reparo mais satisfatório em dentes reimplantados. Portanto, estudou-se neste trabalho a capacidade de remoção do ligamento periodontal, por meio de fricção da superfície radicular de dentes de rato, com uma gaze embebida em solução de hipoclorito de sódio a 1%. Foram utilizados 40 dentes divididos em 4 grupos de 10, os quais após a extração, foram mantidos em meio seco por 60 minutos. No grupo controle, os dentes foram mantidos em 25ml de hipoclorito de sódio a 1% por 5 minutos. No grupo II, a superfície radicular foi friccionada com gaze embebida em 25ml de solução de hipoclorito de sódio a 1% por um período de 1 minuto e na seqüência lavados em soro fisiológico por 4 minutos. No grupo III, a fricção foi de 2 minutos, e o período de lavagem foi de 3 minutos. No grupo IV, a fricção foi de 4 minutos e o período de lavagem foi de 1 minuto. Após o processamento laboratorial, os cortes foram corados pelo Tricrômico de Masson e pela hematoxilina e eosina para análise histomorfométrica. Os resultados demonstraram que no grupo controle, 100% da superfície radicular estava coberta por ligamento periodontal. Mediante o teste de proporção, observou-se que a fricção por 1 minuto foi menos eficaz, sendo estatisticamente significante (pStudies have demonstrated the capacity of the sodium hypochloride in removing the non-vital periodontal ligament in avulsed tooth. Adequacies in its use are necessary to get a repair more satisfactory when teeth are replanted. Therefore, the purpose of this study was to evaluated the capacity of removal the periodontal ligament in root surface of rats, using friction of sodium hypochloride 1% solution absorbed gauze. Forty teeth were divided in 4 groups with 10 teeth, which after the extration, had been kept in dry way per 60 minutes. In control group, the teeth had been kept in 25ml of sodium hypochloride 1% for 5 minutes. In group II, the root surface was rubbed with in 25ml of sodium hypochloride 1% solution absorbed gauze for 1 minute and rinsed for 4 minutes in saline. In group III, the friction was of 2 minutes, and the rinsed period was of 3 minutes. In the group IV, the friction was of 4 minutes

Celso Koogi Sonoda; Wilson Roberto Poi; Sônia Regina Panzarini; Maria Lúcia Marçal Mazza Sundfeld; Fernando Esgaib Kayatt; Tetuo Okamoto

2007-01-01

217

A collagenous cementum-derived attachment protein is a marker for progenitors of the mineralized tissue-forming cell lineage of the periodontal ligament.  

UK PubMed Central (United Kingdom)

The periodontal ligament (PDL) is a fibrous and cellular connective tissue that mediates tooth attachment to bone, and it comprises fibroblastic and mineralized tissue-forming (MTF) progenitors. The MTF progenitors are believed to give rise to the cementoblastic and osteoblastic lineages. Cementum attachment protein (CAP) is a collagenous cementum-derived protein which binds strongly to osteoblasts, moderately to PDL cells, and weakly to gingival fibroblasts. The aim of the present study was to determine the relationship between the capacity of PDL progenitors to bind CAP and their potential to express alkaline phosphatase (ALP) and form mineralized-like tissue in culture. Cloned human PDL progenitor populations obtained from nine human donors were assayed for their constitutive capacity to bind CAP and express ALP, and for the dexamethasone-induced potential to form mineralized-like tissue in culture in the presence of ascorbic acid and beta-glycerophosphate. Forty percent of the progenitor clones produced mineralized-like tissue. Two patterns of mineralization were observed: a spread and flat pattern similar to that produced by human bone cells in culture and a nodular ridge-like type resembling that formed by human cementoma-derived cells. A direct correlation was found between the percentage of ALP positive cells in each progenitor clone and the amount of mineralized-like tissue formed (r = 0.565). Similar correlations were found between the number of ALP positive cells and the binding capacity of each clone (r = 0.392) and between the CAP binding capacity and mineralized-like tissue formation (r = 0.584). Multiple regression analysis indicated that the constitutive capacity of a clone to bind CAP and express ALP is directly correlated to its dexamethasone-induced potential to form mineralized tissue (r = 0.675). These results indicate that CAP binding and ALP expression can serve as markers for the identification of MTF progenitors in the heterogeneous cultured population of the human periodontal ligament. These data show for the first time that binding capacity to extracellular components of mineralized tissues can be a marker for mineralized tissue-forming progenitors.

Liu HW; Yacobi R; Savion N; Narayanan AS; Pitaru S

1997-10-01

218

Distribution of the epithelial rests of Malassez and their relationship to blood vessels of the periodontal ligament during rat tooth development.  

UK PubMed Central (United Kingdom)

BACKGROUND: There is some evidence that the epithelial cell rests of Malassez partition the root surface from the periodontal ligament blood vessels, and may protect the root from resorption. OBJECTIVE: The aim of the present study was to determine the distributions of the epithelial rests of Malassez (ERM) and blood vessels in the periodontal ligament (PDL) of the developing rat first molar before, during and after emergence. METHODS: Four Sprague-Dawley rats were sacrificed at two days, one week, two weeks, three weeks, four weeks and six weeks of age. After processing, the maxillae were embedded in paraffin, and sectioned longitudinally and transversely. The sections were stained with a double immuno-histochemical technique which utilised a keratin antibody AE1-AE3 (1:2,000) and an endothelial antibody Factor VIII (1:10,000) to enable simultaneous labelling of ERM and blood vessels. ERM and blood vessel counts were obtained from the mesio-buccal roots of three week, four week and six week-old rats, whilst qualitative observations were made for the earlier developmental stages. RESULTS: ERM cells and cell clusters were found in the tooth third of the PDL width at the three, four and six week stages. Cells and cell clusters increased in number with age, especially in the upper third of the mesio-buccal root. The largest numbers of cells and clusters were found on the distal surfaces of the roots in all age groups. Cells and clusters in all root surfaces increased from three to four weeks, but decreased from four to six weeks. The greatest number of blood vessels was found in the bone-side third of the PDL. The distal surface had the highest proportion of blood vessels, and the palatal surface the least proportion. The number of blood vessels in all surface quadrants did not vary much from three to four weeks of age, but increased from four to six weeks of age, possibly as a reaction to tooth emergence and occlusal function. Physiological root resorption was only observed after tooth emergence, and appeared to be related to loss of continuity of the ERM network and the incursion of blood vessels. CONCLUSIONS: Orthodontic root resorption can be regarded as an exaggerated response to loss of PDL homeostatic control, possibly mediated by the epithelial rests of Malassez.

Kat PS; Sampson WJ; Wilson DF; Wiebkin OW

2003-11-01

219

Regulation of hyaluronan synthase gene expression in human periodontal ligament cells by tumour necrosis factor-alpha, interleukin-1beta and interferon-gamma.  

UK PubMed Central (United Kingdom)

Accumulation and fragmentation of hyaluronic (HA) accompanies the inflammatory changes in the periodontium and gingival crevicular fluid are involved in periodontitis, but the mechanism for this is unknown. Recently, three human hyaluronan-synthase (HAS1, 2, and 3) genes have been cloned and characterised as synthesising hyaluronans of different molecular weights. Both HAS1 and HAS2 synthesise high molecular-weight HA, whereas HAS3 produces lower molecular weight HA. In the present study the regulation of HAS genes by cytokines in cultured human periodontal ligament (PDL) cells was investigated using a novel real-time fluorescence polymerase chain reaction detection system. Human PDL cells derived from premolars were cultured with or without tumour necrosing factor (TNF)-alpha (1-100 ng/ml), interleukin (IL)-1beta (0.1-10 ng/ml) and interferon (IFN)-gamma (1-100 ng/ml). Expression of HAS mRNA was assessed in cultured cells treated with these cytokines for 0-24 h. The expression of HAS2 mRNA was enhanced about 4.5- and 2.2-fold at maximum after 3-h stimulation with 10 ng/ml TNF-alpha and 1 ng/ml IL-1beta, respectively, whereas IFN-gamma exerted little effect on HAS2 or HAS3 mRNA expression during the experiment. Expression of HAS3 mRNA was increased by about 14- and 10-fold after 3-h stimulation with 10 ng/ml TNF-alpha and 1 ng/ml IL-1beta, respectively. These results suggest that TNF-alpha and IL-1beta regulate HAS expression, and consequently may result in an accumulation of HA and an increase in HA of a lower molecular-weight.

Ijuin C; Ohno S; Tanimoto K; Honda K; Tanne K

2001-08-01

220

MyD88 or TRAM Knockdown Regulates Interleukin (IL)-6, IL-8, and CXCL12 mRNA Expression in Human Gingival and Periodontal Ligament Fibroblasts.  

UK PubMed Central (United Kingdom)

Background: In a previous report, it was shown that Toll-like receptor (TLR) 2 knockdown modulates interleukin (IL)-6 and IL-8 but not the chemokine CXCL12, an important mediator with inflammatory and proangiogenic effects, in human gingival fibroblasts (HGF) and human periodontal ligament fibroblasts (HPDLF). This study investigates whether knocking down two important TLR adaptor molecules, such as myeloid differentiation protein 88 (MyD88) and TRIF-related adaptor molecule (TRAM), could affect mRNA expression of IL-6, IL-8, and CXCL12 in HGF and HPDLF. Methods: After small interfering (si) RNA-mediated silencing of MyD88 or TRAM, HGF and HPDLF were stimulated with Porphyromonas gingivalis (Pg) lipopolysaccharide (LPS) or two synthetic ligands of TLR2 (Pam2CSK4 and Pam3CSK4) for 6 hours. IL-6, IL-8, and CXCL12 mRNAs were evaluated by quantitative polymerase chain reaction. Results: Knockdown of MyD88 or TRAM partially impaired the IL-8 mRNA upregulation in both fibroblast subpopulations. Similarly, IL-6 upregulation was partially prevented by siMyD88 or siTRAM in HGF stimulated with Pg LPS, as well as in both fibroblast subtypes challenged with Pam2CSK4. Conversely, constitutive CXCL12 mRNA levels were upregulated by MyD88 or TRAM knockdown in non-stimulated cells. Conclusions: These results suggest that TLR adaptor molecules knockdown, such as MyD88 or TRAM, can decrease IL-6 and IL-8 mRNA and increase CXCL12 mRNA expression in HGF and HPDLF. This can be an important step for better understanding the mechanisms that control the inflammatory cytokine and chemokine expression, which in turn contributes to periodontal pathogenesis.

Morandini AC; Chaves Souza PP; Ramos-Junior ES; Souza Costa CA; Santos CF

2013-09-01

 
 
 
 
221

Endoglin is involved in BMP-2-induced osteogenic differentiation of periodontal ligament cells through a pathway independent of Smad-1/5/8 phosphorylation.  

UK PubMed Central (United Kingdom)

The periodontal ligament (PDL), a connective tissue located between the cementum of teeth and the alveolar bone of mandibula, plays a crucial role in the maintenance and regeneration of periodontal tissues. The PDL contains fibroblastic cells of a heterogeneous cell population, from which we have established several cell lines previously. To analyze characteristics unique for PDL at a molecular level, we performed cDNA microarray analysis of the PDL cells versus MC3T3-E1 osteoblastic cells. The analysis followed by validation by reverse transcription-polymerase chain reaction and immunochemical staining revealed that endoglin, which had been shown to associate with transforming growth factor (TGF)-beta and bone morphogenetic proteins (BMPs) as signaling modulators, was abundantly expressed in PDL cells but absent in osteoblastic cells. The knockdown of endoglin greatly suppressed the BMP-2-induced osteoblastic differentiation of PDL cells and subsequent mineralization. Interestingly, the endoglin knockdown did not alter the level of Smad-1/5/8 phosphorylation induced by BMP-2, while it suppressed the BMP-2-induced expression of Id1, a representative BMP-responsive gene. Therefore, it is conceivable that endoglin regulates the expression of BMP-2-responsive genes in PDL cells at some site downstream of Smad-1/5/8 phosphorylation. Alternatively, we found that Smad-2 as well as Smad-1/5/8 was phosphorylated by BMP-2 in the PDL cells, and that the BMP-2-induced Smad-2 phosphorylation was suppressed by the endoglin knockdown. These results, taken together, raise a possibility that PDL cells respond to BMP-2 via a unique signaling pathway dependent on endoglin, which is involved in the osteoblastic differentiation and mineralization of the cells.

Ishibashi O; Ikegame M; Takizawa F; Yoshizawa T; Moksed MA; Iizawa F; Mera H; Matsuda A; Kawashima H

2010-02-01

222

Endoglin is involved in BMP-2-induced osteogenic differentiation of periodontal ligament cells through a pathway independent of Smad-1/5/8 phosphorylation.  

Science.gov (United States)

The periodontal ligament (PDL), a connective tissue located between the cementum of teeth and the alveolar bone of mandibula, plays a crucial role in the maintenance and regeneration of periodontal tissues. The PDL contains fibroblastic cells of a heterogeneous cell population, from which we have established several cell lines previously. To analyze characteristics unique for PDL at a molecular level, we performed cDNA microarray analysis of the PDL cells versus MC3T3-E1 osteoblastic cells. The analysis followed by validation by reverse transcription-polymerase chain reaction and immunochemical staining revealed that endoglin, which had been shown to associate with transforming growth factor (TGF)-beta and bone morphogenetic proteins (BMPs) as signaling modulators, was abundantly expressed in PDL cells but absent in osteoblastic cells. The knockdown of endoglin greatly suppressed the BMP-2-induced osteoblastic differentiation of PDL cells and subsequent mineralization. Interestingly, the endoglin knockdown did not alter the level of Smad-1/5/8 phosphorylation induced by BMP-2, while it suppressed the BMP-2-induced expression of Id1, a representative BMP-responsive gene. Therefore, it is conceivable that endoglin regulates the expression of BMP-2-responsive genes in PDL cells at some site downstream of Smad-1/5/8 phosphorylation. Alternatively, we found that Smad-2 as well as Smad-1/5/8 was phosphorylated by BMP-2 in the PDL cells, and that the BMP-2-induced Smad-2 phosphorylation was suppressed by the endoglin knockdown. These results, taken together, raise a possibility that PDL cells respond to BMP-2 via a unique signaling pathway dependent on endoglin, which is involved in the osteoblastic differentiation and mineralization of the cells. PMID:19918795

Ishibashi, Osamu; Ikegame, Mika; Takizawa, Fumio; Yoshizawa, Tatsuya; Moksed, Md Ali; Iizawa, Futabako; Mera, Hisashi; Matsuda, Akio; Kawashima, Hiroyuki

2010-02-01

223

Magnetic fields of 10mT and 120mT change cell shape and structure of F-actins of periodontal ligament cells.  

UK PubMed Central (United Kingdom)

Dental magnetic attachments, usually applied locally to oral cavities, produce stray fields (flux leakage) spreading in adjacent tissues. It has been found that human periodontal ligament (PDL) cells change their geometry and the structure of their cytoskeleton F-actins when the cell cultures are exposed to B-field strengths of B = 10mT and 120mT, respectively, which are similar to those generated by dental magnetic attachments. Analytically, after long-time exposures to B-fields for 12h, 36 h and 60 h, respectively, cytoskeleton F-actins are labeled with a fluorescent dye and observed under a laser scanning confocal microscope. The geometrical cell parameters of cell length and cell width and the fluorescence emission of labeled F-actins, respectively, were determined and subjected to an automatic image analysis using a special software. The results on cell shrinkage and filament reorganizations were statistically analyzed by the program ANOVA (P < 0.05). It was found that only long-time (hours) exposure to high fields in the order of 0.1T may produce tissue irritations during long-time medical treatments using open- and closed-field dental magnetic attachments.

Xu C; Fan Z; Chao YL; Du L; Zhang FQ

2008-02-01

224

Magnetic fields of 10mT and 120mT change cell shape and structure of F-actins of periodontal ligament cells.  

Science.gov (United States)

Dental magnetic attachments, usually applied locally to oral cavities, produce stray fields (flux leakage) spreading in adjacent tissues. It has been found that human periodontal ligament (PDL) cells change their geometry and the structure of their cytoskeleton F-actins when the cell cultures are exposed to B-field strengths of B = 10mT and 120mT, respectively, which are similar to those generated by dental magnetic attachments. Analytically, after long-time exposures to B-fields for 12h, 36 h and 60 h, respectively, cytoskeleton F-actins are labeled with a fluorescent dye and observed under a laser scanning confocal microscope. The geometrical cell parameters of cell length and cell width and the fluorescence emission of labeled F-actins, respectively, were determined and subjected to an automatic image analysis using a special software. The results on cell shrinkage and filament reorganizations were statistically analyzed by the program ANOVA (P < 0.05). It was found that only long-time (hours) exposure to high fields in the order of 0.1T may produce tissue irritations during long-time medical treatments using open- and closed-field dental magnetic attachments. PMID:18160349

Xu, Chun; Fan, Zhen; Chao, Yong-Lie; Du, Li; Zhang, Fu-Qiang

2007-11-24

225

Comprehensive gene expression analysis in human periodontal ligaments of the mandibular third molars performing vertical movement and the maxillary second premolars with occlusal contact.  

UK PubMed Central (United Kingdom)

OBJECTIVES: The periodontal ligament (PDL) is thought to be an important tissue in vertical movement during tooth eruption, but the precise molecular mechanism is not known. Thereto, comprehensive gene expression was analyzed in human PDL of mandibular third molars performing vertical movement and maxillary second premolars with occlusal contact. DESIGN: The expression profile of 9,243 genes in the PDL of one subject was compared between vertically moving third molars and second premolars with occlusal contact by DNA microarray. RESULTS: The expression of 27 genes showed more than a 10-fold difference between third molars and second premolars. The expression of CALB1 (encoding calbindin 1), CYP26A1 (encoding cytochrome P450, family 26, subfamily A, polypeptide 1), SPOCK3 (encoding testican-3), CCK (encoding cholecystokinin) and SCRG1 (encoding scrapie responsive protein 1) was more than 30-fold higher in PDLs of the third molars than the second premolars. CALB1 is reported to increase at the pressure side of PDL during experimental orthodontic tooth movement in rats. Interestingly, in this study, CALB1 expression showed the largest difference. In contrast, CRCT1 (encoding cysteine-rich C-terminal 1), SPRP3 (encoding small proline-rich protein 3), IL8 (encoding interleukin 8) and MMP12 (encoding matrix metalloproteinase 12) showed more than 100-fold higher expression in PDLs of the second premolars than the third molars. CONCLUSION: The present comprehensive gene expression in PDLs provides new insights into the molecular mechanism during the vertical tooth movement.

Suda N

2008-02-01

226

Potential of coconut water and soy milk for use as storage media to preserve the viability of periodontal ligament cells: an in vitro study.  

UK PubMed Central (United Kingdom)

AIM: There is no consensus regarding the ability of coconut water and soy milk to maintain long-term cell viability. This study investigated the ability of pH-adjusted coconut water and soy milk to maintain the viability of periodontal ligament cells over a short and a longer period and compared these abilities with those of other solutions. METHODS: Dog premolar teeth were extracted, dried for 30 min, and stored in the following media for 50 min or 24 h: long shelf-life whole milk (SWM), long shelf-life skim milk (SSM), Hank's Balanced Salt Solution (HBSS), soy milk (SM), and pH-adjusted coconut water (CW). The positive and two negative control groups corresponded to 0-min, 30-min (short-term), and 24-h (long-term) dry times, respectively. Cell viability was analyzed by trypan blue exclusion. Data were statistically analyzed using the Kruskal-Wallis test with post-analysis using the Dunn method. RESULTS: In the short-term experiment, the SSM resulted in significantly lower cell viability than SM and CW. At 24 h, SM and CW resulted in higher viability than HBSS and SSM and in comparable performance with the positive control group. Cell viability decreased over time, except in SM and CW. CONCLUSIONS: Soy milk and pH-adjusted coconut water showed promising results as storage solutions for avulsed teeth, preserving the viability for up to 24 h.

Moura CC; Soares PB; de Paula Reis MV; Fernandes Neto AJ; Zanetta Barbosa D; Soares CJ

2013-04-01

227

The effect of surface microgrooves and anodic oxidation on the surface characteristics of titanium and the osteogenic activity of human periodontal ligament cells.  

UK PubMed Central (United Kingdom)

OBJECTIVE: The purpose of this study was to investigate the effect of titanium (Ti) surface microgrooves and anodic oxidation on the surface characteristics of titanium and the osteogenic activity of human periodontal ligament cells (PLCs) cultured on theses surfaces. DESIGN: Mechanically ground Ti was used as the control substratum (NE0). Truncated V-shaped microgrooves, 60?m-wide and 10?m-deep in cross-sections, were created on the Ti substrata by photolithography (NE60/10). Anodically oxidized Ti (NE0AO) and anodically oxidized microgrooved Ti (NE60/10AO) were also prepared. Scanning electron microscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were performed for surface characterization. Cell proliferation assay, osteoblast differentiation assay, and quantitative real-time PCR analysis were performed to compare the osteogenic activity of PLCs on NE0, NE60/10, NEAO, and NE60/10AO. RESULTS: A decrease in the microgroove-width of NE60/10AO compared to NE60/10 due to Ti oxide layer generation by anodic oxidation was detected with XRD and XPS. Cell proliferation, osteoblast differentiation, and osteo-related gene expression were enhanced on the NE60/10AO substrata compared with NE0, NE60/10, and NE0AO. CONCLUSIONS: The combination of Ti surface microgrooves and subsequent anodic oxidation treatment synergistically upregulated osteo-related gene expression, despite showing limited ability to increase cell proliferation and osteoblast differentiation levels in PLCs.

Lee MH; Kang JH; Lee SW

2013-01-01

228

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

UK PubMed Central (United Kingdom)

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 ?m 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.

Naveh GR; Brumfeld V; Shahar R; Weiner S

2013-02-01

229

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.  

UK PubMed Central (United Kingdom)

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.

Sanghavi T; Shah N; Parekh V; Singbal K

2013-01-01

230

Effects of the. cap alpha. -adrenoceptor antagonists phentolamine, phenoxybenzamine, and Idazoxan on sympathetic blood flow control in the periodontal ligament of the cat  

Energy Technology Data Exchange (ETDEWEB)

Blood flow changes in the periodontal ligament (PDL) were measured indirectly by monitoring the local clearance of /sup 125/I/sup -/ during electric sympathetic nerve stimulation or close intra-arterial infusions of either noradrenaline (NA) or adrenaline (ADR) before and after administration of phentolamine (PA), phenoxybenzamine (PBZ) or Idazoxan (RX). At the doses used in the present study, PA was the only antagonist that significantly reduced the blood flow decrease seen on activation of sympathetic fibers, although PBZ also reduced this response. Idazoxan, however, did not induce the consistent effect on blood flow decreases seen on sympathetic activation. All three ..cap alpha..-adrenoceptor antagonists almost abolished the effects of exogenously administered NA and ADR. The results suggest the presence of functional post-junctional adrenoceptors of both the ..cap alpha.. 1 and ..cap alpha.. 2 subtypes in the sympathetic regulation of the blood flow in the PDL of the cat. A component of the response elicited by electrical sympathetic stimulation appeared to be resistant to ..cap alpha..-adrenoceptor blockade. Administration of guanethidine (which inhibits further release of NA and neuropeptide Y) after PA abolished this residual sympathetic response. 32 refs.

Edwall, B.; Gazelius, B.

1988-01-01

231

Functional analysis of core binding factor a1 and its relationship with related genes expressed by human periodontal ligament cells exposed to mechanical stress.  

Science.gov (United States)

Mechanical stress induces human periodontal ligament (PDL) cells to express an osteoblastic phenotype in vitro. Core binding factor a1 (CBFA1) is a key regulator of osteoblast differentiation. This study was designed to investigate the role of CBFA1 in alveolar bone remodelling, specifically the expression of CBFA1 messenger RNA (mRNA) in human PDL cells under mechanical stress and its up- and downstream relationships with other bone remodelling markers. Cultured human PDL cells were exposed to mechanical stress. The expressions of CBFA1 and alkaline phosphatase (ALP), osteopontin (OPN), osteoprotegrin (OPG), and receptor activator nuclear factor kappa B ligand (RANKL) were detected before and after RNA interference (RNAi) of CBFA1. The data were analysed using a t-test and one-way analysis of variance. After mechanical stress loading, CBFA1 mRNA expression was raised initially, followed by an increased expression of ALP and RANKL, decreased expression of OPG, and a change in OPN expression. After CBFA1 knock-down in human PDL cells by small hairpin (sh) RNA, the expression of ALP, OPN, OPG, and RANKL also changed. These findings suggest that in the present model system CBFA1 may play an important role in PDL-mediated bone remodelling in response to mechanical stimulation. Mechanical stress: CBFA1-ALP and OPG-PDL homeostasis may be one of the signal transduction pathways of human PDL cell differentiation under mechanical stress without exclusion of the involvement of other pathways. PMID:20525800

Yang, Ying; Yang, Yanqi; Li, Xiaotong; Cui, Liang; Fu, Minkui; Rabie, A B; Zhang, Ding

2010-06-04

232

Functional analysis of core binding factor a1 and its relationship with related genes expressed by human periodontal ligament cells exposed to mechanical stress.  

UK PubMed Central (United Kingdom)

Mechanical stress induces human periodontal ligament (PDL) cells to express an osteoblastic phenotype in vitro. Core binding factor a1 (CBFA1) is a key regulator of osteoblast differentiation. This study was designed to investigate the role of CBFA1 in alveolar bone remodelling, specifically the expression of CBFA1 messenger RNA (mRNA) in human PDL cells under mechanical stress and its up- and downstream relationships with other bone remodelling markers. Cultured human PDL cells were exposed to mechanical stress. The expressions of CBFA1 and alkaline phosphatase (ALP), osteopontin (OPN), osteoprotegrin (OPG), and receptor activator nuclear factor kappa B ligand (RANKL) were detected before and after RNA interference (RNAi) of CBFA1. The data were analysed using a t-test and one-way analysis of variance. After mechanical stress loading, CBFA1 mRNA expression was raised initially, followed by an increased expression of ALP and RANKL, decreased expression of OPG, and a change in OPN expression. After CBFA1 knock-down in human PDL cells by small hairpin (sh) RNA, the expression of ALP, OPN, OPG, and RANKL also changed. These findings suggest that in the present model system CBFA1 may play an important role in PDL-mediated bone remodelling in response to mechanical stimulation. Mechanical stress: CBFA1-ALP and OPG-PDL homeostasis may be one of the signal transduction pathways of human PDL cell differentiation under mechanical stress without exclusion of the involvement of other pathways.

Yang Y; Yang Y; Li X; Cui L; Fu M; Rabie AB; Zhang D

2010-12-01

233

[Expression of Osterix mRNA and protein induced by recombinant human bone morphogenetic protein-2 in human periodontal ligament cells].  

UK PubMed Central (United Kingdom)

OBJECTIVE: To detect the changes of Osterix (Osx) mRNA and protein expression in human periodontal ligament cells (HPDLCs) induced by recombinant human bone morphogenetic protein-2 (rhBMP-2), and examine the role of BMP-2 and Osx during the osteogenic differentiation of HPDLCs. METHODS: HPDLCs were isolated and cultured in vitro with explant method. Cells at passage 3 were cultured in DMEM with rhBMP-2 at different concentrations (50, 100, 150, 200, 250, 300, 400, and 600 µg/L) for different times (2, 3, 5, 7, 10, 14 and 21 days). Then the expressions of Osx mRNA and protein were measured by real-time reverse transcription (RT)-PCR and Western blotting respectively. Cells were treated with 10 µmol/L SB203580 (p38 inhibitor) to inhibit p38 phosphorylation induced by rhBMP-2. The mineralization nodules formation and the expressions of phosphorylated p38 and Osx mRNA were detected respectively. RESULTS: During the culture of rhBMP-2, the expression of Osx mRNA significantly increased. Initially Osx protein had a low expression and then increased in a time-dependent manner followed by the production of bone-like nodules in HPDLCs. Under the effect of SB203580, the up-regulation of phosphorylated p38 expression induced by rhBMP-2 was significantly inhibited as well as the expression of Osx (Osx mRNA expression: 0.378 ± 0.034 vs 0.134 ± 0.027, Osx protein expression: 0.353 ± 0.024 vs 0.155 ± 0.031, both P < 0.01). Meanwhile the mineralization nodules formed by HPDLCs induced by rhBMP-2 were fewer and delayed. CONCLUSIONS: BMP-2 has a significant positive regulatory role on the expression of Osx in HPDLCs. And p38 pathway is an important link of this regulatory process. Thus, as an important signaling pathway in osteogenic differentiation of HPDLCs, BMP-2/p38/Osx may be involved in periodontal tissue remodeling.

Zhao YH; Li HF; Yang Q; Wang Y; Zheng Z; Wang CL

2013-04-01

234

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

Science.gov (United States)

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). 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 ?1, 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 administration mode for cell sheet formation (P < 0.05). The results of in vivo transplantation showed that osthole-mediated PDLSC and JBMMSC sheets formed more new bone than those obtained without osthole intervention (P < 0.001). Our data suggest that a suitable concentration and mode of osthole stimulation may enhance ECM production and positively affect cell behavior in cell sheet engineering. PMID:24095254

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

2013-10-01

235

Isolation and characterization of epithelial and myogenic cells by "fishing" for the morphologically distinct cell types in rat primary periodontal ligament cultures.  

Science.gov (United States)

The periodontal ligament (PDL) contains various cell populations and plays a central role in the maintenance, repair, and regeneration of the periodontium, i.e., tooth-supporting structures. Because primary cells isolated from PDL tissue are heterogeneous, the establishment of an effective isolation method for cells of interest is desired. In the present study, two morphologically distinct cell types were identified in confluent primary cultures derived from rat PDL. To isolate these cell populations, a small piece of filter paper soaked with trypsin-EDTA was placed directly onto the target cell population, enabling the cells to detach from the culture dish. The filter papers were then transferred into fresh culture dishes to establish outgrowth cultures; these two steps constitute the "cell fishing" method. The "fished" cell types were propagated and subcultured for further analyses. In morphological evaluation, immunocytochemical analyses, and reverse transcription-polymerase chain reaction, the isolated cells exhibited a polygonal appearance or a mono- or multinucleated appearance, with a high cytoplasm-to-nucleus ratio, leading to their being characterized as epithelial or myogenic cell populations, respectively. Surprisingly, a notable proportion of the multinuclear cells in the primary and subsequent isolated cultures demonstrated dramatic, spontaneous contractions, a feature typical of skeletal muscle cells. Finally, the isolated cell populations maintained a normal karyotype with a diploid chromosomal number. These results demonstrated that physiological epithelial and skeletal muscle cells can be obtained from primary PDL cultures without artificial induction using growth factors or chemicals, and can be propagated as individual lineage-committed cell populations; the populations consisted of differentiated and progenitor cells that maintained chromosomal stability. This simple, classical culture procedure provides new insights into the biological properties of PDL cells, which are potentially important for the differentiation of tissue or somatic stem cells and for the development of future cell-based therapies for dental and muscular diseases. PMID:23649106

Tominaga, Noriko; Nakahara, Taka; Nasu, Masanori; Satoh, Tazuko

2013-05-04

236

Isolation and characterization of epithelial and myogenic cells by "fishing" for the morphologically distinct cell types in rat primary periodontal ligament cultures.  

UK PubMed Central (United Kingdom)

The periodontal ligament (PDL) contains various cell populations and plays a central role in the maintenance, repair, and regeneration of the periodontium, i.e., tooth-supporting structures. Because primary cells isolated from PDL tissue are heterogeneous, the establishment of an effective isolation method for cells of interest is desired. In the present study, two morphologically distinct cell types were identified in confluent primary cultures derived from rat PDL. To isolate these cell populations, a small piece of filter paper soaked with trypsin-EDTA was placed directly onto the target cell population, enabling the cells to detach from the culture dish. The filter papers were then transferred into fresh culture dishes to establish outgrowth cultures; these two steps constitute the "cell fishing" method. The "fished" cell types were propagated and subcultured for further analyses. In morphological evaluation, immunocytochemical analyses, and reverse transcription-polymerase chain reaction, the isolated cells exhibited a polygonal appearance or a mono- or multinucleated appearance, with a high cytoplasm-to-nucleus ratio, leading to their being characterized as epithelial or myogenic cell populations, respectively. Surprisingly, a notable proportion of the multinuclear cells in the primary and subsequent isolated cultures demonstrated dramatic, spontaneous contractions, a feature typical of skeletal muscle cells. Finally, the isolated cell populations maintained a normal karyotype with a diploid chromosomal number. These results demonstrated that physiological epithelial and skeletal muscle cells can be obtained from primary PDL cultures without artificial induction using growth factors or chemicals, and can be propagated as individual lineage-committed cell populations; the populations consisted of differentiated and progenitor cells that maintained chromosomal stability. This simple, classical culture procedure provides new insights into the biological properties of PDL cells, which are potentially important for the differentiation of tissue or somatic stem cells and for the development of future cell-based therapies for dental and muscular diseases.

Tominaga N; Nakahara T; Nasu M; Satoh T

2013-02-01

237

Effect of bone morphogenetic protein-4 on the expression of Sox2, Oct-4, and c-Myc in human periodontal ligament cells during long-term culture.  

UK PubMed Central (United Kingdom)

Recent studies demonstrated that the endogenous expression level of Sox2, Oct-4, and c-Myc is correlated with the pluripotency and successful induction of induced pluripotent stem cells. Periodontal ligament cells (PDLCs) have a multilineage differentiation capability and ability to maintain the undifferentiated stage, which makes PDLCs a suitable cell source for tissue repair and regeneration. To elucidate the effect of an in vitro culture condition on the stemness potential of PDLCs, we explored the cell growth, proliferation, cell cycle, and the expression of Sox2, Oct-4, and c-Myc in PDLCs from the passage 1 to 7 with or without the addition of recombinant human bone morphogenetic protein-4 (rhBMP4). Our results revealed that BMP-4 promoted cell growth and proliferation, arrested PDLCs in the S phase of cell cycle, and upregulated the propidium iodinate value. It was revealed that without the addition of rhBMP4, the expression of Sox2, Oct-4, and c-Myc in PDLCs only maintained the nucleus location until passage 3, and then lost the nucleus location subsequently. The mRNA expression in PDLCs further confirmed that the level of Sox2 and Oct-4 peaked at passage 3 and then decreased afterward, whereas c-Myc maintained consistently the upregulation along the passages. After the treatment with rhBMP4, the expression of Sox2, Oct-4, and c-Myc in PDLCs maintained the nucleus location even at passage 7, and the mRNA expression of Sox2 and Oct-4 significantly upregulated at the passages 5 and 7. These results demonstrated that addition of rhBMP-4 in the culture medium could improve the current culture condition for PDLCs to maintain in an undifferentiated stage.

Liu L; Wei X; Huang R; Ling J; Wu L; Xiao Y

2013-06-01

238

Deferoxamine promotes osteoblastic differentiation in human periodontal ligament cells via the nuclear factor erythroid 2-related factor-mediated antioxidant signaling pathway.  

UK PubMed Central (United Kingdom)

BACKGROUND AND OBJECTIVE: Recently it was reported that deferoxamine (DFO), an iron chelator, stimulates bone formation from MG63 and mesenchymal stem cells, but inhibits differentiation in rat calvarial cells; however, the effect of DFO on osteoblastic differentiation in human periodontal ligament cells (hPDLCs) has not been reported. The aim of this study was to investigate the effects and the possible underlying mechanism of DFO on osteoblastic differentiation of hPDLCs. MATERIAL AND METHODS: The effect of DFO on osteoblast differentiation was determined by the staining intensity of calcium deposits with Alizarin red and by RT-PCR analysis of the expression of osteoblastic markers. Signal transduction pathways were analyzed by western blotting. RESULTS: DFO increased osteogenic differentiation in a concentration-dependent manner by expression of the mRNA for differentiation markers and calcium nodule formation. Exposure of hPDLCs to DFO resulted in increases in the production of reactive oxygen species and in the levels of nuclear factor erythroid 2-related factor (Nrf2) protein in nuclear extractions, as well as a dose-dependent increase in the expression of Nrf2 target genes, including glutathione (GSH), glutathione S-transferase, ?-glutamylcysteine lygase, glutathione reductase and glutathione peroxidase. Pretreatment with Nrf2 small interfering RNA, GSH depletion by buthionine sulfoximine and diethyl maleate, and with antioxidants by N-acetylcysteine and vitamin E, blocked DFO-stimulated osteoblastic differentiation. Furthermore, pretreatment with GSH depletion and antioxidants blocked DFO-induced p38 MAPK, ERK, JNK and nuclear factor-kappaB pathways. CONCLUSION: These data indicate, for the first time, that nontoxic DFO promotes osteoblastic differentiation of hPDLCs via modulation of the Nrf2-mediated antioxidant pathway.

Chung JH; Kim YS; Noh K; Lee YM; Chang SW; Kim EC

2013-10-01

239

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

UK PubMed Central (United Kingdom)

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.

Jung IH; Park JC; Kim JC; Jeon DW; Choi SH; Cho KS; Im GI; Kim BS; Kim CS

2012-03-01

240

Leptin and its receptor expression in dental and periodontal tissues of primates.  

UK PubMed Central (United Kingdom)

Leptin and its receptor (OBR) have attracted much attention since their discovery. They have been reported to play central roles in energy balance, the immune-inflammatory response and bone metabolism. Evidence indicates that leptin and OBR are associated with inflammatory diseases of dental and periodontal tissues. The first step for establishing this is to determine the expression of leptin and OBR in these tissues. Our study is the first to examine systematically the expression of leptin and OBR in dental and periodontal tissues of monkeys (Macaca fascicularis) by immunohistochemistry and in primary cultured cells, isolated from human dental and periodontal tissues, by reverse transcription plus the polymerase chain reaction and immunocytochemistry. Our results show that leptin and OBR are constitutively expressed and widely distributed in dental and periodontal tissues of primates. Their immunoreaction is especially strong in junctional epithelium, a unique front-line defense around teeth and in mineralizing areas of the dental pulp and periodontal ligament. The expression of the long and also functional form of OBR (OBRb) indicates that leptin has a direct effect on these cells. Thus, we can reasonably infer that leptin and OBR exert effects on defense, mineralization and angiogenesis in dental and periodontal tissues of primates.

Li W; Zhu W; Hou J; Huang B; Liu K; Meng H

2013-10-01

 
 
 
 
241

An investigation of dentinal fluid flow in dental pulp during food mastication: simulation of fluid-structure interaction.  

UK PubMed Central (United Kingdom)

This study uses fluid-structure interaction (FSI) simulation to investigate the relationship between the dentinal fluid flow in the dental pulp of a tooth and the elastic modulus of masticated food particles and to investigate the effects of chewing rate on fluid flow in the dental pulp. Three-dimensional simulation models of a premolar tooth (enamel, dentine, pulp, periodontal ligament, cortical bone, and cancellous bone) and food particle were created. Food particles with elastic modulus of 2,000 and 10,000 MPa were used, respectively. The external displacement loading [Formula: see text] was gradually directed to the food particle surface for 1 and 0.1 s, respectively, to simulate the chewing of food particles. The displacement and stress on tooth structure and fluid flow in the dental pulp were selected as evaluation indices. The results show that masticating food with a high elastic modulus results in high stress and deformation in the tooth structure, causing faster dentinal fluid flow in the pulp in comparison with that obtained with soft food. In addition, fast chewing of hard food particles can induce faster fluid flow in the pulp, which may result in dental pain. FSI analysis is shown to be a useful tool for investigating dental biomechanics during food mastication. FSI simulation can be used to predict intrapulpal fluid flow in dental pulp; this information may provide the clinician with important concept in dental biomechanics during food mastication.

Su KC; Chuang SF; Ng EY; Chang CH

2013-08-01

242

Vascular endothelial growth factors signalling in normal human dental pulp: a study of gene and protein expression.  

UK PubMed Central (United Kingdom)

In the well-vascularized dental pulp vascular endothelial growth factor A (VEGF-A) is expressed. Vascular endothelial growth factor A is a member of the VEGF family, which includes VEGFs-B, -C, and -D. The latter three have not been investigated in the pulp. Vascular endothelial growth factors C and D are the only ligands for vascular endothelial growth factor receptor (VEGFR)-3, which is usually expressed in lymphatic endothelium. They can also activate VEGFR-2, the main angiogenic receptor. We aimed to study VEGFs signalling in human dental pulp at the gene level and to identify the cellular source for protein expression using immunolabelling. All VEGFs (-A, -B, -C, and -D) were expressed in the pulp and may exert both autocrine and paracrine effects in blood vessels and immune cells found to be equipped with VEGFRs-2 and -3. Lymphatic vessel endothelial hyaluronan receptor-positive macrophages, known to be involved in angiogenesis, were found in the pulp, whereas lymphatic vessels were not detected. Twenty-six of 84 VEGF signalling genes, including VEGFR-3, were expressed at a significantly higher level in the pulp than in the control periodontal ligament. In conclusion, the normal human pulp represents a tissue with relatively high VEGF signalling involving both immune responses and vascular activity.

Virtej A; Løes S; Iden O; Bletsa A; Berggreen E

2013-04-01

243

Endodontic treatment enhances the regenerative potential of teeth with advanced periodontal disease with secondary endodontic involvement.  

UK PubMed Central (United Kingdom)

PURPOSE: The aim of this study was to identify a role for endodontic intervention in enhancing the regenerative potential of the periodontal ligament when combined with periodontal treatment in seriously involved teeth with a secondary endodontic component. METHODS: Patients who exhibited radiolucency extending to the periapical region, abnormal electric pulp testing values, and deep probing depth derived from primary periodontal disease with secondary endodontic involvement were included. Intentional root canal treatment was applied to those teeth in which the apical lesions were presumed to communicate with those of the periodontal lesion of the teeth that remained vital. In all three selected cases, regenerative periodontal therapy incorporating either bone graft or guided tissue regeneration was instituted 3 months after the endodontic intervention. RESULTS: Remarkable enhancement in radiographic density was noticeable around the affected teeth as evidenced by changes in radiopacity. There was a significant reduction in the probing pocket depth and gain in the clinical attachment level. Chewing discomfort gradually disappeared from the commencement of the combined treatment. CONCLUSIONS: An intentional endodontic intervention may be a worthwhile approach for the sophisticated management of teeth suffering from serious attachment loss and alveolar bone destruction with concomitant secondary endodontic involvement.

Kwon EY; Cho Y; Lee JY; Kim SJ; Choi J

2013-06-01

244

Endodontic treatment enhances the regenerative potential of teeth with advanced periodontal disease with secondary endodontic involvement  

Science.gov (United States)

Purpose The aim of this study was to identify a role for endodontic intervention in enhancing the regenerative potential of the periodontal ligament when combined with periodontal treatment in seriously involved teeth with a secondary endodontic component. Methods Patients who exhibited radiolucency extending to the periapical region, abnormal electric pulp testing values, and deep probing depth derived from primary periodontal disease with secondary endodontic involvement were included. Intentional root canal treatment was applied to those teeth in which the apical lesions were presumed to communicate with those of the periodontal lesion of the teeth that remained vital. In all three selected cases, regenerative periodontal therapy incorporating either bone graft or guided tissue regeneration was instituted 3 months after the endodontic intervention. Results Remarkable enhancement in radiographic density was noticeable around the affected teeth as evidenced by changes in radiopacity. There was a significant reduction in the probing pocket depth and gain in the clinical attachment level. Chewing discomfort gradually disappeared from the commencement of the combined treatment. Conclusions An intentional endodontic intervention may be a worthwhile approach for the sophisticated management of teeth suffering from serious attachment loss and alveolar bone destruction with concomitant secondary endodontic involvement.

Kwon, Eun-Young; Cho, Yunjung; Lee, Ju-Youn; Kim, Sung-Jo

2013-01-01

245

Transplantation of dental pulp stem cells and platelet-rich plasma for pulp regeneration.  

UK PubMed Central (United Kingdom)

INTRODUCTION: The loss of dental pulp may weaken teeth, rendering them susceptible to reinfection, fracture, and subsequent tooth loss. Therefore, regeneration of pulp is considered an ideal treatment to preserve teeth. The aim of this study was to explore the capacity of dental pulp stem cells (DPSCs) and platelet-rich plasma (PRP) to regenerate dental pulp in canine mature permanent teeth. METHODS: Pulpectomy with apical foramen enlarged to a #80 file was performed in 16 upper premolars of 4 beagle dogs. Four experimental groups were randomly established: (1) the blood clot group, (2) the autologous DPSCs group, (3) the PRP group, and (4) the DP + PRP group (a mixture of DPSCs and PRP). Four lower premolars without any further treatment after pulpectomy were used as the control group. All teeth were sealed with mineral trioxide aggregate and composite. Twelve weeks after transplantation, the teeth were subjected to radiographic and histologic examination. RESULTS: Twenty-four of 32 experimental root canals gained newly formed tissues. All canals with an introduction of a blood clot showed histologic evidence of vital tissue formation. Cementum-like and periodontal ligament-like tissues along the internal root canal walls were typical structures in most cases. There is no significant difference between groups with or without autologous DPSC transplantation (exact chi-square test, P < .05). CONCLUSIONS: New vital tissues can be regenerated in permanent canine teeth after pulpectomy and enlargement of the apical foramen. Histologically, transplantation of DPSCs and/or PRP into root canals showed no enhancement in new tissue formation compared with inducement of a blood clot into the root canals alone.

Zhu X; Zhang C; Huang GT; Cheung GS; Dissanayaka WL; Zhu W

2012-12-01

246

Types of Periodontal Disease  

Science.gov (United States)

Types of Periodontal Disease Gingivitis Chronic Periodontitis Aggressive Periodontitis Periodontitis Caused by Conditions of the Body Necrotizing Periodontal Diseases Periodontal disease can refer to any condition that affects ...

247

Analysis of the dentin-pulp complex in teeth submitted to orthodontic movement in rats  

Directory of Open Access Journals (Sweden)

Full Text Available In order to microscopically analyze the pulpal effects of orthodontic movement, 49 maxillary first molars of rats were submitted to orthodontic appliance composed of a closed coil spring anchored to the maxillary incisors, placed for the achievement of mesial movement. MATERIAL AND METHODS: Ten animals were used as the control group and were not submitted to orthodontic force; the other animals were divided into groups according to the study period of tooth movement, namely 1, 2, 3, 4, 5, 6 and 7 days. The investigation of pulp and periodontal changes included hyalinization, fibrosis, reactive dentin and vascular congestion. Statistical evaluation was performed between control and experimental groups and between periods of observation using non-parametric chi-square, Kruskal-Wallis and Dunn tests. RESULTS: There was no statistically significant difference concerning pulpal changes between control and experimental groups nor between periods of observation. The control group, at 3 and 5 days, revealed greater hyalinization of the periodontal ligament (p<0.05), whereas root resorption was significantly greater at 5 and 7 days (p<0.05). CONCLUSION: No morphological change from the effect of induced tooth movement could be found in the dentin-pulp complex. In addition, no inflammatory or pulp degeneration, detectable in optical microscopy, was found in experimental groups.

Camila da Siveira Massaro; Renata Bianco Consolaro; Milton Santamaria Junior; Maria Fernanda Martins-Ortiz Consolaro; Alberto Consolaro

2009-01-01

248

Potential Role of Dentin Sialoprotein by Inducing Dental Pulp Mesenchymal Stem Cell Differentiation and Mineralization for Dental Tissue Repair  

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Full Text Available Introduction: Dentin sialoprotein (DSP) is a dentin extracellular matrix protein, a unique marker of dentinogenesis and plays a vital role in odontoblast differentiation and dentin mineralization. Recently, studies have shown that DSP induces differentiation and mineralization of periodontal ligament stem cells and dental papilla mesenchymal cells in vitro and rescues dentin deficiency and increases enamel mineralization in animal models.The hypothesis: DSP as a nature therapeutic agent stimulates dental tissue repair by inducing endogenous dental pulp mesenchymal stem/progenitor cells into odontoblast-like cells to synthesize and to secrete dentin extracellular matrix forming new tertiary dentin as well as to regenerate a functional dentin-pulp complex. As DSP is a nature protein, and clinical procedure for DSP therapy is easy and simple, application of DSP may provide a new avenue for dentists with additional option for the treatment of substantially damaged vital teeth.Evaluation of the hypothesis: Dental caries is the most common dental disease. Deep caries and pulp exposure have been treated by various restorative materials with limited success. One promising approach is dental pulp stem/progenitor-based therapies to regenerate dentin-pulp complex and restore its functions by DSP induction in vivo.

Guo-Hua Yuan; Guo-Bin Yang; Li-An Wu; Zhi Chen; Shuo Chen

2010-01-01

249

[The use of Emdogain in periodontal and osseous regeneration].  

UK PubMed Central (United Kingdom)

The goal of regenerative periodontal therapy is the reconstitution of the lost periodontal structures (i. e. the new formation of root cementum, periodontal ligament and alveolar bone). Results from basic research have pointed to the important role of an enamel matrix protein derivative (EMD) in periodontal wound healing. Histological results from experiments in animals and from human case reports have shown that treatment with EMD promotes periodontal regeneration. Moreover, clinical studies have indicated that treatment with EMD positively influences periodontal wound healing in humans. The goal of the current overview is to present the clinical indications for regenerative therapy with EMD based on the existing evidence.

Sculean A; Rathe F; Junker R; Becker J; Schwarz F; Arweiler N

2007-01-01

250

[The use of Emdogain in periodontal and osseous regeneration].  

Science.gov (United States)

The goal of regenerative periodontal therapy is the reconstitution of the lost periodontal structures (i. e. the new formation of root cementum, periodontal ligament and alveolar bone). Results from basic research have pointed to the important role of an enamel matrix protein derivative (EMD) in periodontal wound healing. Histological results from experiments in animals and from human case reports have shown that treatment with EMD promotes periodontal regeneration. Moreover, clinical studies have indicated that treatment with EMD positively influences periodontal wound healing in humans. The goal of the current overview is to present the clinical indications for regenerative therapy with EMD based on the existing evidence. PMID:17691421

Sculean, Anton; Rathe, Florian; Junker, Rüdiger; Becker, Jürgen; Schwarz, Frank; Arweiler, Nicole

2007-01-01

251

Bone morphogenetic proteins: periodontal regeneration.  

UK PubMed Central (United Kingdom)

Periodontitis is an infectious inflammatory disease that results in attachment loss and bone loss. Regeneration of the periodontal tissues entails de novo formation of cementum, periodontal ligament, and alveolar bone. Several different approaches are currently being explored to achieve complete, reliable, and reproducible regeneration of periodontal tissues. The therapeutic management of new bone formation is one of the key issues in successful periodontal regeneration. Bone morphogenetic proteins form a unique group of proteins within the transforming growth factor superfamily of genes and have a vital role in the regulation in the bone induction and maintenance. The activity of bone morphogenetic proteins was first identified in the 1960s, but the proteins responsible for bone induction were unknown until the purification and cloning of human bone morphogenetic proteins in the 1980s, because of their osteoinductive potential. Bone morphogenetic proteins have gained a lot of interest as therapeutic agents for treating periodontal defects. A systematic search for data related to the use of bone morphogenetic proteins for the regeneration of periodontal defects was performed to recognize studies on animals and human (PUBMED, MEDLINE, COCHRANE, and Google search). All the studies included showed noticeable regeneration of periodontal tissues with the use of BMP.

Rao SM; Ugale GM; Warad SB

2013-03-01

252

In vivo identification of periodontal progenitor cells.  

UK PubMed Central (United Kingdom)

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 (?SMA) promoter-driven and tamoxifen-inducible Cre system (?SMACreERT2) 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.

Roguljic H; Matthews BG; Yang W; Cvija H; Mina M; Kalajzic I

2013-08-01

253

Periodontitis and diabetes: a two-way relationship.  

UK PubMed Central (United Kingdom)

Periodontitis is a common chronic inflammatory disease characterised by destruction of the supporting structures of the teeth (the periodontal ligament and alveolar bone). It is highly prevalent (severe periodontitis affects 10-15% of adults) and has multiple negative impacts on quality of life. Epidemiological data confirm that diabetes is a major risk factor for periodontitis; susceptibility to periodontitis is increased by approximately threefold in people with diabetes. There is a clear relationship between degree of hyperglycaemia and severity of periodontitis. The mechanisms that underpin the links between these two conditions are not completely understood, but involve aspects of immune functioning, neutrophil activity, and cytokine biology. There is emerging evidence to support the existence of a two-way relationship between diabetes and periodontitis, with diabetes increasing the risk for periodontitis, and periodontal inflammation negatively affecting glycaemic control. Incidences of macroalbuminuria and end-stage renal disease are increased twofold and threefold, respectively, in diabetic individuals who also have severe periodontitis compared to diabetic individuals without severe periodontitis. Furthermore, the risk of cardiorenal mortality (ischaemic heart disease and diabetic nephropathy combined) is three times higher in diabetic people with severe periodontitis than in diabetic people without severe periodontitis. Treatment of periodontitis is associated with HbA(1c) reductions of approximately 0.4%. Oral and periodontal health should be promoted as integral components of diabetes management.

Preshaw PM; Alba AL; Herrera D; Jepsen S; Konstantinidis A; Makrilakis K; Taylor R

2012-01-01

254

TGF-?-Operated Growth Inhibition and Translineage Commitment into Smooth Muscle Cells of Periodontal Ligament-Derived Endothelial Progenitor Cells through Smad- and p38 MAPK-Dependent Signals  

Science.gov (United States)

The periodontal ligament (PDL) is a fibrous connective tissue that attaches the tooth to the alveolar bone. We previously demonstrated the ability of PDL fibroblast-like cells to construct an endothelial cell (EC) marker-positive blood vessel-like structure, indicating the potential of fibroblastic lineage cells in PDL tissue as precursors of endothelial progenitor cells (EPCs) to facilitate the construction of a vascular system around damaged PDL tissue. A vascular regeneration around PDL tissue needs proliferation of vascular progenitor cells and the subsequent differentiation of the cells. Transforming growth factor-? (TGF-?) is known as an inducer of endothelial-mesenchymal transition (EndMT), however, it remains to be clarified what kinds of TGF-? signals affect growth and mesenchymal differentiation of PDL-derived EPC-like fibroblastic cells. Here, we demonstrated that TGF-?1 not only suppressed the proliferation of the PDL-derived EPC-like fibroblastic cells, but also induced smooth muscle cell (SMC) markers expression in the cells. On the other hand, TGF-?1 stimulation suppressed EC marker expression. Intriguingly, overexpression of Smad7, an inhibitor for TGF-?-induced Smad-dependent signaling, suppressed the TGF-?1-induced growth inhibition and SMC markers expression, but did not the TGF-?1-induced downregulation of EC marker expression. In contrast, p38 mitogen-activated protein kinase (MAPK) inhibitor SB 203580 suppressed the TGF-?1-induced downregulation of EC marker expression. In addition, the TGF-?1-induced SMC markers expression of the PDL-derived cells was reversed upon stimulation with fibroblast growth factor (FGF), suggesting that the TGF-?1 might not induce terminal SMC differentiation of the EPC-like fibroblastic cells. Thus, TGF-?1 not only negatively controls the growth of PDL-derived EPC-like fibroblastic cells via a Smad-dependent manner but also positively controls the SMC-differentiation of the cells possibly at the early stage of the translineage commitment via Smad- and p38 MAPK-dependent manners.

Yoshida, Mariko; Okubo, Naoto; Chosa, Naoyuki; Hasegawa, Tomokazu; Ibi, Miho; Kamo, Masaharu; Kyakumoto, Seiko; Ishisaki, Akira

2012-01-01

255

Enamel matrix protein derivatives: role in periodontal regeneration  

Directory of Open Access Journals (Sweden)

Full Text Available Vandana J RathvaDepartment of Periodontics, KM Shah Dental College and Hospital, Sumandeep University, Gujarat, IndiaAbstract: The role of regenerative periodontal therapy is the reconstitution of lost periodontal structures, ie, new formation of root cementum, periodontal ligament, and alveolar bone. The outcome of basic research has pointed to the important role of enamel matrix protein derivative (EMD) in periodontal wound healing. Histologic results from animal and human studies have shown that treatment with EMD promotes periodontal regeneration. Moreover, clinical studies have indicated that treatment with EMD positively influences periodontal wound healing in humans. The goal of this paper is to review the existing literature on EMD.Keywords: enamel matrix protein derivative, Emdogain®, periodontal regeneration

Rathva VJ

2011-01-01

256

TGF-?-Operated Growth Inhibition and Translineage Commitment into Smooth Muscle Cells of Periodontal Ligament-Derived Endothelial Progenitor Cells through Smad- and p38 MAPK-Dependent Signals  

Directory of Open Access Journals (Sweden)

Full Text Available The periodontal ligament (PDL) is a fibrous connective tissue that attaches the tooth to the alveolar bone. We previously demonstrated the ability of PDL fibroblast-like cells to construct an endothelial cell (EC) marker-positive blood vessel-like structure, indicating the potential of fibroblastic lineage cells in PDL tissue as precursors of endothelial progenitor cells (EPCs) to facilitate the construction of a vascular system around damaged PDL tissue. A vascular regeneration around PDL tissue needs proliferation of vascular progenitor cells and the subsequent differentiation of the cells. Transforming growth factor-? (TGF-?) is known as an inducer of endothelial-mesenchymal transition (EndMT), however, it remains to be clarified what kinds of TGF-? signals affect growth and mesenchymal differentiation of PDL-derived EPC-like fibroblastic cells. Here, we demonstrated that TGF-?1 not only suppressed the proliferation of the PDL-derived EPC-like fibroblastic cells, but also induced smooth muscle cell (SMC) markers expression in the cells. On the other hand, TGF-?1 stimulation suppressed EC marker expression. Intriguingly, overexpression of Smad7, an inhibitor for TGF-?-induced Smad-dependent signaling, suppressed the TGF-?1-induced growth inhibition and SMC markers expression, but did not the TGF-?1-induced downregulation of EC marker expression. In contrast, p38 mitogen-activated protein kinase (MAPK) inhibitor SB 203580 suppressed the TGF-?1-induced downregulation of EC marker expression. In addition, the TGF-?1-induced SMC markers expression of the PDL-derived cells was reversed upon stimulation with fibroblast growth factor (FGF), suggesting that the TGF-?1 might not induce terminal SMC differentiation of the EPC-like fibroblastic cells. Thus, TGF-?1 not only negatively controls the growth of PDL-derived EPC-like fibroblastic cells via a Smad-dependent manner but also positively controls the SMC-differentiation of the cells possibly at the early stage of the translineage commitment via Smad- and p38 MAPK-dependent manners.

Mariko Yoshida, Naoto Okubo, Naoyuki Chosa, Tomokazu Hasegawa, Miho Ibi, Masaharu Kamo, Seiko Kyakumoto, Akira Ishisaki

2012-01-01

257

The application of an enamel matrix protein derivative (Emdogain) in regenerative periodontal therapy: a review.  

Science.gov (United States)

Regenerative periodontal therapy aims at reconstitution of the lost periodontal structures such as new formation of root cementum, periodontal ligament and alveolar bone. Findings from basic research indicate that enamel matrix protein derivative (EMD) has a key role in periodontal wound healing. Histological results from animal and human studies have shown that treatment with EMD promotes periodontal regeneration. Moreover, clinical studies have indicated that treatment with EMD positively influences periodontal wound healing in humans. This review aims to present an overview of evidence-based clinical indications for regenerative therapy with EMD. PMID:17409750

Sculean, Anton; Schwarz, Frank; Becker, Jurgen; Brecx, Michel

2007-01-01

258

Gene therapy in periodontics.  

UK PubMed Central (United Kingdom)

GENES are made of DNA - the code of life. They are made up of two types of base pair from different number of hydrogen bonds AT, GC which can be turned into instruction. Everyone inherits genes from their parents and passes them on in turn to their children. Every person's genes are different, and the changes in sequence determine the inherited differences between each of us. Some changes, usually in a single gene, may cause serious diseases. Gene therapy is 'the use of genes as medicine'. It involves the transfer of a therapeutic or working gene copy into specific cells of an individual in order to repair a faulty gene copy. Thus it may be used to replace a faulty gene, or to introduce a new gene whose function is to cure or to favorably modify the clinical course of a condition. It has a promising era in the field of periodontics. Gene therapy has been used as a mode of tissue engineering in periodontics. The tissue engineering approach reconstructs the natural target tissue by combining four elements namely: Scaffold, signaling molecules, cells and blood supply and thus can help in the reconstruction of damaged periodontium including cementum, gingival, periodontal ligament and bone.

Chatterjee A; Singh N; Saluja M

2013-03-01

259

Periodontal disease in HIV-infected adults in the HAART era: Clinical, immunological, and microbiological aspects.  

Science.gov (United States)

The introduction of highly active antiretroviral therapy (HAART) has decreased the incidence and prevalence of several oral manifestations such as oral candidiasis, hairy leukoplakia, and Kaposi's sarcoma in HIV-infected patients. Regarding periodontal disease the findings are not clear. This disease represents a group of chronic oral diseases characterized by infection and inflammation of the periodontal tissues. These tissues surround the teeth and provide periodontal protection (the gingival tissue) and periodontal support (periodontal ligament, root cementum, alveolar bone). Clinical, immunological, and microbiological aspects of these diseases, such as linear gingival erythema (LGE), necrotizing periodontal diseases (NPD) (necrotizing ulcerative gingivitis [NUG], necrotizing ulcerative periodontitis [NUP] and necrotizing stomatitis), and chronic periodontitis, have been widely studied in HIV-infected individuals, but without providing conclusive results. The purpose of this review was to contribute to a better overall understanding of the probable impact of HIV-infection on the characteristics of periodontal infections. PMID:23755999

Gonçalves, Lucio Souza; Gonçalves, Barbara Mulatinho Lopo; Fontes, Tatiana Vasconcellos

2013-06-10

260

Periodontal disease in HIV-infected adults in the HAART era: Clinical, immunological, and microbiological aspects.  

UK PubMed Central (United Kingdom)

The introduction of highly active antiretroviral therapy (HAART) has decreased the incidence and prevalence of several oral manifestations such as oral candidiasis, hairy leukoplakia, and Kaposi's sarcoma in HIV-infected patients. Regarding periodontal disease the findings are not clear. This disease represents a group of chronic oral diseases characterized by infection and inflammation of the periodontal tissues. These tissues surround the teeth and provide periodontal protection (the gingival tissue) and periodontal support (periodontal ligament, root cementum, alveolar bone). Clinical, immunological, and microbiological aspects of these diseases, such as linear gingival erythema (LGE), necrotizing periodontal diseases (NPD) (necrotizing ulcerative gingivitis [NUG], necrotizing ulcerative periodontitis [NUP] and necrotizing stomatitis), and chronic periodontitis, have been widely studied in HIV-infected individuals, but without providing conclusive results. The purpose of this review was to contribute to a better overall understanding of the probable impact of HIV-infection on the characteristics of periodontal infections.

Gonçalves LS; Gonçalves BM; Fontes TV

2013-10-01

 
 
 
 
261

Emdogain in regenerative periodontal therapy. A review of the literature.  

Science.gov (United States)

The goal of regenerative periodontal therapy is the reconstitution of the lost periodontal structures (i.e. the new formation of root cementum, periodontal ligament and alveolar bone). Results from basic research have pointed to the important role of the enamel matrix protein derivative (EMD) in the periodontal wound healing. Histological results from animal and human studies have shown that treatment with EMD promotes periodontal regeneration. Moreover, clinical studies have indicated that treatment with EMD positively influences periodontal wound healing in humans. The goal of the current overview is to present, based on the existing evidence, the clinical indications for regenerative therapy with EMD. Surgical periodontal treatment of deep intrabony defects with EMD promotes periodontal regeneration. The application of EMD in the context of non-surgical periodontal therapy has failed to result in periodontal regeneration. Surgical periodontal therapy of deep intrabony defects with EMD may lead to significantly higher improvements of the clinical parameters than open flap debridement alone. The results obtained following treatment with EMD are comparable to those following treatment with GTR and can be maintained over a longer period. Treatment of intrabony defects with a combination of EMD + GTR does not seem to additionally improve the results compared to treatment with EMD alone or GTR alone. The combination of EMD and some types of bone grafts/bone substitutes may result in certain improvements in the soft and hard tissue parameters compared to treatment with EMD alone. Treatment of recession-type defects with coronally repositioned flaps and EMD may promote formation of cementum, periodontal ligament and bone, and may significantly increase the width of the keratinized tissue. Application of EMD seems to provide better long-term results than coronally repositioned flaps alone. Application of EMD may enhance periodontal regeneration in mandibular Class II furcations. The clinical results are comparable to those obtained following GTR. PMID:18078142

Sculean, Anton; Windisch, Péter; Döri, Ferenc; Keglevich, Tibor; Molnár, Balint; Gera, István

2007-10-01

262

Clinical evaluation of endodotic therapy on periodontal tissue healing in chronic advanced periodontitis  

Directory of Open Access Journals (Sweden)

Full Text Available Statement of Problem: There is a controversy about the relationship between pulpal and periodontal diseases. The interrelationship between pulp and periodontium could have an important effect on the treatment plan of the tooth. Purpose: The aim of the present research is to evaluate root canal therapy effects on periodontal healing of teeth with chronic advanced periodontitis. Materials and Methods: In this randomized controlled clinical trial 32 single rooted teeth which had necrotic pulp or irreversible pulpitis in 7 patients with chronic advanced periodontitis were selected based on specific criteria. Using a split mouth design, teeth were randomly put in two groups of test and control. In the test group root canal therapy ,scaling & root planing were done.In the control group, only scaling & root planing were performed. Clinical parameters including Pocket Depth (PD), Clinical Attachment Level (CAL), mobility, pattern of bone destruction and plaque index (PI) were evaluated in two groups at base line, 1 and 3 months after treatment. Appropriate tests such as paired Wilcoxon and Mann-Whitney were performed. Results: Statistically significant reductions were found in the test group when comparing baseline and one-month post treatment values for Clinical Attachment level (CAL) but not after 3-months. In the control group the CAL reductions were not statistically significant between baseline and one month post-treatment, but a increase were observed between one month and three months after treatment. There was a statstically significant difference between the test and the control groups. Other parameters didn’t show any significant differences in each group and between two groups. Conclusion: Since clinical attachment level was the most important parameter we found it can high lighted the role of pathogene with pulpal origin in progression of periodeontal disease and it is concluded that beside periodontal treatment in some advanced periodontal cases pulp therapy maybe an effective procedure for eleminating destructive pathogens of pulp and causing periodontal healing.

Sadeghi R.; Nazari Moghaddam K.; Jooyandeh J

2004-01-01

263

Advanced reconstructive technologies for periodontal tissue repair.  

UK PubMed Central (United Kingdom)

Reconstructive therapies to promote the regeneration of lost periodontal support have been investigated through both preclinical and clinical studies. Advanced regenerative technologies using new barrier-membrane techniques, cell-growth-stimulating proteins or gene-delivery applications have entered the clinical arena. Wound-healing approaches using growth factors to target the restoration of tooth-supporting bone, periodontal ligament and cementum are shown to significantly advance the field of periodontal-regenerative medicine. Topical delivery of growth factors, such as platelet-derived growth factor, fibroblast growth factor or bone morphogenetic proteins, to periodontal wounds has demonstrated promising results. Future directions in the delivery of growth factors or other signaling models involve the development of innovative scaffolding matrices, cell therapy and gene transfer, and these issues are discussed in this paper.

Ramseier CA; Rasperini G; Batia S; Giannobile WV

2012-06-01

264

Regeneração periodontal em cães Periodontal regeneration in dogs  

Directory of Open Access Journals (Sweden)

Full Text Available A doença periodontal pode ser definida como a condição inflamatória dos tecidos de suporte do dente em resposta ao acúmulo do biofilme. A consequencia é a formação de graves defeitos ósseos, devido à perda dos tecidos periodontais, levando, em última instância, à perda dos dentes, predisposição a fraturas de mandíbula e formação de comunicações oronasais. O principal tratamento é a prevenção, incluindo a escovação dentária diária e a profilaxia periodontal, procedimento realizado pelo médico veterinário para remoção do biofilme e cálculo dentário acumulados. A recuperação dos tecidos perdidos, ou seja, a regeneração periodontal, é um processo mais complexo, pois envolve a formação de três tecidos intimamente ligados: osso alveolar, ligamento periodontal e cemento. Assim, diversos materiais e técnicas foram e são constantemente desenvolvidos, incluindo membranas para regeneração tecidual guiada e a aplicação de enxertos e biomateriais, amplamente estudados na odontologia humana e já disponíveis para aplicação na rotina clínica veterinária. Adicionalmente, novas possibilidades surgem com a associação dessas técnicas a fatores de crescimento e células-tronco e o desenvolvimento das membranas multifuncionais.Periodontal disease can be defined as the inflammatory condition of the tooth-supportive tissues as a response to biofilm accumulation. The consequence is the formation of severe bone defects due to the loss of periodontal tissues that ultimately lead to tooth loss, predispose to mandible fractures and formation of oronasal communications. The main treatment is prevention, including daily tooth brushing and periodontal prophylaxis, a procedure done by veterinaries to remove retained biofilm and calculus. Recovering lost tissues, i.e. periodontal regeneration, is a more complex process involving the formation of three tissues highly connected: alveolar bone, periodontal ligament and cementum. Therefore, several materials and techniques were and are constantly developed, including membranes for guided tissue regeneration and the application of bone grafts and biomaterials, widely studied in human dentistry and already available for veterinary practice. Additionally, new possibilities rise with the association of these techniques to growth factors and stem cells and the development of multifunctional membranes.

Emily Correna Carlo Reis; Andréa Pacheco Batista Borges; Ricardo Junqueira Del Carlo

2011-01-01

265

Regeneração periodontal em cães/ Periodontal regeneration in dogs  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A doença periodontal pode ser definida como a condição inflamatória dos tecidos de suporte do dente em resposta ao acúmulo do biofilme. A consequencia é a formação de graves defeitos ósseos, devido à perda dos tecidos periodontais, levando, em última instância, à perda dos dentes, predisposição a fraturas de mandíbula e formação de comunicações oronasais. O principal tratamento é a prevenção, incluindo a escovação dentária diária e a profilaxia (more) periodontal, procedimento realizado pelo médico veterinário para remoção do biofilme e cálculo dentário acumulados. A recuperação dos tecidos perdidos, ou seja, a regeneração periodontal, é um processo mais complexo, pois envolve a formação de três tecidos intimamente ligados: osso alveolar, ligamento periodontal e cemento. Assim, diversos materiais e técnicas foram e são constantemente desenvolvidos, incluindo membranas para regeneração tecidual guiada e a aplicação de enxertos e biomateriais, amplamente estudados na odontologia humana e já disponíveis para aplicação na rotina clínica veterinária. Adicionalmente, novas possibilidades surgem com a associação dessas técnicas a fatores de crescimento e células-tronco e o desenvolvimento das membranas multifuncionais. Abstract in english Periodontal disease can be defined as the inflammatory condition of the tooth-supportive tissues as a response to biofilm accumulation. The consequence is the formation of severe bone defects due to the loss of periodontal tissues that ultimately lead to tooth loss, predispose to mandible fractures and formation of oronasal communications. The main treatment is prevention, including daily tooth brushing and periodontal prophylaxis, a procedure done by veterinaries to remo (more) ve retained biofilm and calculus. Recovering lost tissues, i.e. periodontal regeneration, is a more complex process involving the formation of three tissues highly connected: alveolar bone, periodontal ligament and cementum. Therefore, several materials and techniques were and are constantly developed, including membranes for guided tissue regeneration and the application of bone grafts and biomaterials, widely studied in human dentistry and already available for veterinary practice. Additionally, new possibilities rise with the association of these techniques to growth factors and stem cells and the development of multifunctional membranes.

Reis, Emily Correna Carlo; Borges, Andréa Pacheco Batista; Del Carlo, Ricardo Junqueira

2011-12-01

266

Periodontal (Gum) Disease  

Science.gov (United States)

... NIDCR Home > Data & Statistics > Find Data by Topic Periodontal (Gum) Disease Periodontal disease is the most common cause of tooth ... Overall, the prevalence of both moderate and severe periodontal disease in adults and Seniors has decreased from ...

267

Preliminary study on dental pulp stem cell-mediated pulp regeneration in canine immature permanent teeth.  

UK PubMed Central (United Kingdom)

INTRODUCTION: The health of human teeth depends on the integrity of the hard tissue and the activity of the pulp and periodontal tissues, which are responsible for nutritional supply. Without the nourishing of the pulp tissue, the possibility of tooth fracture can increase. In immature permanent teeth, root development may be influenced as well. This study explored the potential of using autologous dental pulp stem cells (DPSCs) to achieve pulp regeneration in a canine pulpless model. METHODS: The establishment of the pulpless animal model involved pulp extirpation and root canal preparation of young permanent incisor teeth in beagles. Autologous DPSCs were obtained from extracted first molars and expanded ex vivo to obtain a larger number of cells. The biological characteristics of canine DPSCs (cDPSCs) were analyzed both in vitro and in vivo by using the same method as used in human DPSCs. cDPSCs were transplanted into the pulpless root canal with Gelfoam as the scaffold, and root development was evaluated by radiographic and histologic analyses. RESULTS: cDPSCs with rapid proliferation, multiple differentiation capacity, and development potential were successfully isolated and identified both in vitro and in vivo. After they were transplanted into the pulpless root canal with Gelfoam as the scaffold, DPSCs were capable of generating pulp-like tissues containing blood vessels and dentin-like tissue. Thickening of the root canal wall was also observed. CONCLUSIONS: This study demonstrates the feasibility of using stem cell-mediated tissue engineering to realize pulp regeneration in immature teeth.

Wang Y; Zhao Y; Jia W; Yang J; Ge L

2013-02-01

268

Regeneration of periodontal Ruffini endings in adults and neonates.  

UK PubMed Central (United Kingdom)

We reviewed the regeneration of periodontal Ruffini endings, primary mechanoreceptors in the periodontal ligament, following injury to the inferior alveolar nerve (IAN) in adult and neonatal rats. Morphologically, mature Ruffini endings are characterized by an extensive arborization of axonal terminals and association with specialized Schwann cells, called lamellar or terminal Schwann cells. Following injury to IAN in the adult, the periodontal Ruffini endings of the rat lower incisor ligament regenerate more rapidly than Ruffini endings in other tissues. During regeneration, terminal Schwann cells migrate into regions where they are never found under normal conditions. The development of periodontal Ruffini endings of the rat incisor is closely associated with the eruption of the teeth; the morphology and distribution of the terminal Schwann cells became almost identical to those in adults during postnatal days 15-18 (PN 15-18d) when the first molars appear in the oral cavity, while the axonal elements showed extensive ramification around PN 28d when the functional occlusion commences. When the IAN was injured in neonates, the regeneration of periodontal Ruffini endings was delayed compared with the adults. The migration of terminal Schwann cells is also observed following IAN injury, after which the distribution of terminal Schwann cells became almost identical to that of the adults, i.e., PN 14d. Since the interaction between axon and Schwann cell is important during regeneration and development, further studies are required to elucidate its molecular mechanism during the regeneration as well as the development of the periodontal Ruffini endings.

Wakisaka S; Atsumi Y

2003-04-01

269

Immunohistochemical expression of heat shock proteins in the mouse periodontal tissues due to orthodontic mechanical stress*  

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Full Text Available Abstract The histopathology of periodontal ligament of the mouse subjected to mechanical stress was studied. Immunohistochemical expressions of HSP27 and pHSP27 were examined. Experimental animals using the maxillary molars of ddY mouse by Waldo method were used in the study. A separator was inserted to induce mechanical stress. After 10 minutes, 20 minutes, 1 hour, 3 hours, 9 hours and 24 hours, the regional tissues were extracted, fixed in 4% paraformaldehyde and 0.05 M phosphate-buffered fixative solution. Paraffin sections were made for immunohistochemistry using HSP27 and p-HSP27. In the control group, the periodontal ligament fibroblasts expressed low HSP27 and p-HSP27. However, in the experimental group, periodontal ligament fibroblasts expressed HSP27 10 minutes after mechanical load application in the tension side. The strongest expression was detected 9 hours after inducing mechanical load. p-HSP27 was also expressed in a time-dependent manner though weaker than HSP27. The findings suggest that HSP27 and p-HSP27 were expressed for the maintenance of homeostasis of periodontal ligament by the activation of periodontal ligament fibroblasts on the tension side. It also suggests that these proteins act as molecular chaperones for osteoblast activation and maintenance of homeostasis.

Muraoka R; Nakano K; Kurihara S; Yamada K; Kawakami T

2010-01-01

270

Effects of simvastain and enamel matrix derivative on Portland cement with bismuth oxide-induced growth and odontoblastic differentiation in human dental pulp cells.  

UK PubMed Central (United Kingdom)

INTRODUCTION: We previously reported that bismuth oxide containing Portland cement (BPC) showed similar biocompatibility to Portland cement (PC) in periodontal ligament cells. However, the bioactivity of simvastatin and Emdogain (Biora AB, Malmö, Sweden) on BPC was not reported. The aim of this study was to evaluate the effects of simvastatin and Emdogain on BPC compared with mineral trioxide aggregate (MTA) in human dental pulp cells (HDPCs). METHODS: Cell growth was determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide (MTT) assay. Differentiation was evaluated by alkaline phosphatase (ALP) activity, alizarin red staining, and reverse-transcriptase polymerase chain reaction. RESULTS: The cell growth of HDPCs exposed to Emdogain and simvastatin plus BPC was superior to those administered BPC alone and similar to those that received MTA for 14 days. The simvastatin and Emdogain groups increased the odontogenic potential of the BPC group with respect to ALP activity, mineralization nodules, messenger RNA expression of ALP, osteopontin, osteocalcin, Runx2, and osterix. CONCLUSIONS: These results suggest that simvastatin and Emdogain improved cell growth and the differentiation of the BPC group in HDPCs and may be useful ingredients in BPC as pulp-capping material.

Lee SY; Min KS; Choi GW; Park JH; Park SH; Lee SI; Kim EC

2012-03-01

271

REINFORCING POTENTIAL OF JUTE PULP WITH TREMA ORIENTALIS (NALITA) PULP  

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Full Text Available Two morphologically different pulps, a long-fiber jute pulp from a soda-AQ process and a short-fiber Trema orientalis pulp from a kraft process, were evaluated and compared for their reinforcing potential. T. orientalis pulp needed less beating energy than jute pulp at the same drainage resistance. Addition of jute fiber pulp to the T. orientalis pulp increased tear strength. Sheet density of pulp blends was increased with the increase of beating degree of both pulps and the proportion of T. orientalis pulp. Tensile index and burst index of blended pulp were increased when the beating degree and proportion of T. orientalis pulp increased.

M. Sarwar Jahan; Sabina Rawshan

2009-01-01

272

Development of the oxytalan fiber system in the periodontal space of rat incisors.  

UK PubMed Central (United Kingdom)

The present study clarifies developmental organization of the oxytalan fiber system in the periodontal space of both the enamel (labial) and cementum (lingual) sides of rat incisors. The number of oxytalan fibers per unit area (?m(2)) was counted in rat incisors at stages of embryonic day 20 (E20) to postnatal day 35 (P35). Oxytalan fibers in the periodontal space of the enamel side were apt to decrease in number during the postnatal period, whereas their number remained almost unchanged on the cementum side during the developmental period. When the incisor emerged through the gum at P11, thinner oxytalan fibers distributed in the apical growing periodontium of the cementum side seemed to be fused with one another to become thicker fibers as has been reported for rat molars (Inoue et al., 2012). Thus, the oxytalan fiber system in the periodontal space represented significant differences in its distributional density between the enamel and cementum sides after E23. At the stage of P35, oxytalan fibers presented significantly denser distribution in all territories of the periodontal ligament of the cementum side versus the enamel side. The present findings claim that the oxytalan fiber system might bind the tooth to the periodontal ligament and provide equilibrium of vascular system and control of blood flow in the periodontal ligament of the cementum side, while it might exclusively regulate the high level of physiologically adapted vasculature in the periodontal space of the enamel side.

Inoue K; Hara Y; Kuroda N; Sato T

2013-05-01

273

Enhanced proliferation, attachment and osteopontin expression by porcine periodontal cells exposed to Emdogain.  

Science.gov (United States)

Emdogain (EMD) is an enamel matrix derivative extracted from developing porcine teeth with demonstrated periodontal regenerative potential. EMD has been shown to influence a number of properties of periodontal ligament cells including proliferation, cell attachment and matrix synthesis. To date, the effect of EMD on the epithelial cell rests of Malassez (ERM) is unknown. In this study, periodontal ligament fibroblasts, ERM, alveolar bone cells and gingival fibroblasts were obtained from porcine periodontal ligament, alveolar bone and gingiva. This study investigated, in vitro, the effect of EMD at three concentrations on proliferation, cell attachment and expression of mRNA for two mineralised tissue-related proteins (osteopontin and bone sialoprotein). As for other periodontal cells, the ERM proliferative response was enhanced by EMD. Attachment assays revealed a highly significant increase for ERM and gingival fibroblasts after EMD treatment at all concentrations. This study has also shown that EMD stimulated expression of osteopontin mRNA by ERM and alveolar bone cells. The results from this study provide evidence that EMD enhanced cellular events related with proliferation, attachment and osteopontin mRNA expression by porcine periodontal cells, in a manner consistent with its role in periodontal regenerative therapy. PMID:16342405

Rincon, J C; Xiao, Y; Young, W G; Bartold, P M

2005-12-01

274

Stem cells: A new paradigm in periodontal regeneration  

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Full Text Available Stem cells are a unique type of cell that forms the basis of the development, growth and survival of a living organism. Though the term is often used to describe controversial embryonic stem cells, there are many different types of stem cells, classified by their original location and/or method of formation. Stem cells are undifferentiated cells that go on developing into any of more than 200 type of cells that adult Human body hold. Now a days stem cells have significant use in regenerative periodontal therapy. Recently, reports have begun to emerge demonstrating that populations of adult stem cells reside in the periodontal ligament of humans and other animals. This opens the way for new cell-based therapies for periodontal regeneration.This review provides an overview of adult human stem cells and their potential use in periodontal regeneration.

Marawar Pramod P, Shinde Sagar K, Mani Ameet M, Patil Ishwardas D

2013-01-01

275

Periodontal Disease: Causes and Prevention  

Science.gov (United States)

Periodontal Disease: Causes and Prevention What Is Periodontal Disease? What Causes Periodontal Disease? Risks and Prevention What Is Periodontal Disease? If your hands bled when you washed them, you would be ...

276

Fighting for territories: time-lapse analysis of dental pulp and dental follicle stem cells in co-culture reveals specific migratory capabilities  

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Full Text Available Stem cell migration is a critical step during the repair of damaged tissues. In order to achieve appropriate cell-based therapies for tooth and periodontal ligament repair it is necessary first to understand the dynamics of tissue-specific stem cell populations such as dental pulp stem cells (DPSC) and dental follicle stem cells (DFSC). Using time-lapse imaging, we analysed migratory and proliferative capabilities of these two human stem cell lines in vitro. When cultured alone, both DPSC and DFSC exhibited low and irregular migration profiles. In co-cultures, DFSC, but not DPSC, spectacularly increased their migration activity and velocity. DFSC rapidly surrounded the DPSC, thus resembling the in vivo developmental process, where follicle cells encircle both dental epithelium and pulp. Cell morphology was dependent on the culture conditions (mono-culture or co-culture) and changed over time. Regulatory genes involved in dental cell migration and differentiation such as TWIST1, MSX1, RUNX2, SFRP1 and ADAM28, were also evaluated in co-cultures. MSX1 up-regulation indicates that DPSC and DFSC retain their odontogenic potential. However, DPSC lose their capacity to differentiate into odontoblasts in the presence of DFSC, as suggested by RUNX2 up-regulation and TWIST1 down-regulation. In contrast, the unchanged levels of SFRP1 expression suggest that DFSC retain their potential to form periodontal tissues even in the presence of DPSC. These findings demonstrate that stem cells behave differently according to their environment, retain their genetic memory, and compete with each other to acquire the appropriate territory. Understanding the mechanisms involved in stem cell migration may lead to new therapeutic approaches for tooth repair.

C Schiraldi; A Stellavato; A D’Agostino; V Tirino; R d’Aquino; A Woloszyk; A De Rosa; L Laino; G Papaccio; TA Mitsiadis

2012-01-01

277

Comparative evaluation of lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) levels in periodontal diseases  

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Full Text Available Introduction: Periodontitis is a chronic multi-factorial infectious disease characterized by irreversible destruction of collagen fibers and other matrix constituents of the gingival tissues and periodontal ligament, and resorption of alveolar bone around the teeth with periodontal pocket formation. Host response to periodontal disease includes production of different enzymes that are released by stromal, epithelial or inflammatory cells associated with cell injury and cell death, including aspartate aminotransferase and lactate dehydrogenase. The aim of this study was to compare aspartate aminotransferase and lactate dehydrogenase salivary levels in patients with generalized aggressive periodontitis and chronic mild-to-moderate periodontitis and healthy subjects with normal periodontium. Materials and methods: In this experimental study, unstimulated saliva of 25 patients with mild-to-moderate periodontitis, 15 patients with aggressive periodontitis, and 25 subjects with healthy gingiva were collected. The mean aspartate aminotransferase and lactate dehydrogenase salivary levels were measured by RA-ST autoanalyzer system. Data were analyzed by ANOVA and Tukey test.Results: The mean levels and standard deviations of lactate dehydrogenase salivary enzyme in generalized aggressive periodontitis, chronic mild-to-moderate periodontitis and control groups were 1713±88.4, 1492±65.4, 1108±34.5, respectively, with significant differences between the groups (p value < 0.05) The mean levels and standard deviations of aspartate aminotransferase salivary enzyme in generalized aggressive periodontitis, chronic mild-to-moderate periodontitis and control groups were 55.46±5.6, 47.04±3.3 and 32.04±2.3, respectively, with significant differences (p value < 0.05).Conclusion: Mean levels of aspartate aminotransferase and lactate dehydrogenase salivary enzymes in periodontal patients were higher than those in healthy subjects and these enzymes can be good markers for determining amount of destruction of periodontal tissues. Key words: Aspartate aminotransferase, Lactate dehydrogenase, Periodontal disease, Saliva.

Arash Azizi; Ardeshir Ranjbari; Mohammad Ali Ghafari; Fatemeh Jahan

2011-01-01

278

Lateral collateral ligament (image)  

Science.gov (United States)

The lateral collateral ligament connects the end of the femur (thigh) to the top of the fibula (the thin bone that runs next to the shin bone). The lateral collateral ligament provides stability against varus stress. Varus stress ...

279

Histologic evaluation of an allogeneic mineralized bone matrix in the treatment of periodontal osseous defects.  

UK PubMed Central (United Kingdom)

The aim of this study was to evaluate the potential of an allogeneic bone matrix to regenerate new bone, cementum, and periodontal ligament around a previously diseased root surface. Four patients with severe chronic periodontitis and teeth with hopeless periodontal or restorative prognoses participated in this study. One tooth with a severe intraosseous defect was selected per patient. At baseline, measurements of probing depth, gingival recession, and clinical attachment level were obtained. Following flap reflection, a root notch was placed at the apical extent of the calculus; the root was debrided, and the allogeneic bone graft material was placed into the defect. After a minimum of 6 months of healing, the teeth were removed en bloc and prepared for histologic examination. Two of four teeth demonstrated regeneration of new bone, cementum, and periodontal ligament. One tooth healed by new connective tissue attachment, and another by junctional epthelium.

Koylass JM; Valderrama P; Mellonig JT

2012-08-01

280

Histologic evaluation of an allogeneic mineralized bone matrix in the treatment of periodontal osseous defects.  

Science.gov (United States)

The aim of this study was to evaluate the potential of an allogeneic bone matrix to regenerate new bone, cementum, and periodontal ligament around a previously diseased root surface. Four patients with severe chronic periodontitis and teeth with hopeless periodontal or restorative prognoses participated in this study. One tooth with a severe intraosseous defect was selected per patient. At baseline, measurements of probing depth, gingival recession, and clinical attachment level were obtained. Following flap reflection, a root notch was placed at the apical extent of the calculus; the root was debrided, and the allogeneic bone graft material was placed into the defect. After a minimum of 6 months of healing, the teeth were removed en bloc and prepared for histologic examination. Two of four teeth demonstrated regeneration of new bone, cementum, and periodontal ligament. One tooth healed by new connective tissue attachment, and another by junctional epthelium. PMID:22577646

Koylass, Jana-Marie; Valderrama, Pilar; Mellonig, James T

2012-08-01

 
 
 
 
281

Influence of periodontitis and nonsurgical periodontal intervention on atherosclerosis diseases  

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Full Text Available Objective: Periodontitis and atherosclerosis diseases are chronic inflammatory disorders which are highly prevalent in populations. Nonsurgical periodontal intervention belongs to the initial therapy strategy to periodontal diseases. Periodontal pathogen can enter into blood stream through the ulceration epithelial resulting in bacteraemia when periodontitis is severe. The objective is to investigate the relationship between periodontitis and atherosclerosis diseases, and the influence of nonsurgical periodontal intervention on atheroma and atherosclerosis diseases. Methods: This study reviewed and analyzed the papers which published in the world associated with periodontitis or periodontal intervention on atherosclerosis diseases. Results: Periodontitis and periodontal infectious are important risk factors for atherosclerotic diseases. Much evidence has proved the durative severe periodontitis can result in bacteraemia and systemic inflammation, elevated C-response protein in serum, gingival microcirculation changed, periodontal microorganism reproduced, and endothelial dys-function and endocarditis. Nonsurgical periodontal intervention can remove the pathogenesis bacteria and calculus to recover periodontal health. Effective periodontal therapy can reduce bacteraemia and stop the hurt to vessels. Nonsurgical periodontal therapy may interfere periodontal bacteria, inhibit inflammation response and C-response protein, improving gingival microcirculation and vessel epithelial function to prevent atherosclerosis. Conclusion: Nonsurgical periodontal intervention can improve or decrease the rate of atherosclerotic disease by interfere the severe periodontitis. The detailed mechanism of periodontal intervention on atheroma and atherosclerotic disease is still need to be explored.

Tielou Chen; Shifeng Wang; Guoqin Liu; Xinhai Zhang; Dahai Tang; Zhifen Wu

2012-01-01

282

Cotton pulp production  

Energy Technology Data Exchange (ETDEWEB)

Cotton pulp was manufactured by cooking lint with a 2% NaOH solution at high temperature and pressure. The d.p. of the pulp can be increased by passing gaseous N through NaOH solution at 85 degrees for 5 hours prior to pulping.

Kadyrov, A.N.; Makhkamov, K.M.; Kalontarov, I.Y.; Niyazi, F.F.

1981-05-15

283

Comparison of profiles of key periodontal pathogens in periodontium and endodontium.  

Science.gov (United States)

Despite the established anatomical relationship between the periodontal and pulpal tissues, bacterial migration between endodontium and periodontium is still under discussion. The objective of this study was an investigation of profiles of periodontal pathogens in pulpal and periodontal diseases affecting the same tooth by means of 16S rRNA gene directed polymerase chain reaction (PCR). 31 intact teeth with both pulp and marginal infections were investigated. The diagnosis was based on clinical and radiological examination. Samples were taken from the gingival sulcus or periodontal pocket, respectively, with sterile paper points before trepanation of the teeth. After trepanation sterile paper points and Hedstroem files were used for taking samples from the root canal. Specific PCR methods were used to detect the presence of the following pathogens: Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Eikenella corrodens, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia and Treponema denticola. In addition, quantitative competitive PCR was used to determine the total bacterial count of the samples. The investigated pathogens were proven to be present in the endondontium in all disease categories. Particularly in endodontic samples of "chronic apical periodontitis" and "chronic adult periodontitis" profiles of the periodontal pathogens were found. The results confirmed that periodontal pathogens often accompany endodontic infections and supported the idea that the periodontic-endodontic interrelationships should be considered as critical pathways which might contribute to refractory courses of endodontic or periodontal diseases. PMID:11202893

Rupf, S; Kannengiesser, S; Merte, K; Pfister, W; Sigusch, B; Eschrich, K

2000-12-01

284

Diabetes and periodontitis  

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Full Text Available 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.

Deshpande Kalyani; Jain Ashish; Sharma RaviKant; Prashar Savita; Jain Rajni

2010-01-01

285

Cemental tear: a case report with nonsurgical periodontal therapy/ Dilaceração cementária: relato de caso clínico com terapia periodontal não cirúrgica  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese OBJETIVO: Relatar um caso de dilaceração cementária, uma condição periodontal rara caracterizada pela separação total ou parcial do cemento dental, abordando principalmente aspectos relativos ao seu diagnóstico e tratamento. DESCRIÇÃO DO CASO: Um homem de 50 anos procurou assistência odontológica queixando-se de dor localizada no segundo molar inferior que apresentava profundidade de sondagem de 4 mm com presença de um corpo estranho no sulco gengival da face (more) distal. O exame radiográfico demonstrou um fragmento radiopaco destacado da raiz. O fragmento foi removido sem cirurgia periodontal. O exame histopatológico demonstrou tratar-se de um fragmento de cemento com presença de lamelas cementárias, cementócitos e fibras do ligamento periodontal, confirmando o diagnóstico de dilaceração cementária. CONCLUSÃO: Após dois anos, o tratamento periodontal não cirúrgico demonstrou aspectos clínicos e radiográficos satisfatórios. Portanto, a terapia periodontal não cirúrgica pode ser uma modalidade de tratamento adequada e previsível para a dilaceração cementária. Abstract in english PURPOSE: To report a case of cemental tear, a rare periodontal condition characterized by total or partial separation of the dental cementum, mainly addressing issues related to its diagnosis and treatment. CASE DESCRIPTION: A 50 years-old man sought dental assistance complaining of pain located in the mandibular left second premolar that showed a 4 mm probing depth with the presence of a foreign body in the distal gingival sulcus. Radiographic examination demonstrated a (more) slight radiopaque fragment detached from the root. The fragment was removed without a periodontal flap. Histopathological examination was performed and evidenced the presence of a cementum fragment with cementum lamellae, cementocytes, and adhered periodontal ligament fibers, confirming the diagnosis of cemental tear. CONCLUSION: After a follow-up of 2 years, the nonsurgical periodontal therapy showed satisfactory clinical and radiographic outcome. Therefore, this approach should be a suitable and predictable treatment modality for the cemental tear.

Damasceno, Leonardo Silveira; Dutra, Walderez Ornelas; Melgaço, Eder Gonçalves; Souza, Paulo Eduardo Alencar de; Zenóbio, Elton Gonçalves; Horta, Martinho Campolina Rebello

2012-01-01

286

Successful isolation, in vitro expansion and characterization of stem cells from Human Dental Pulp  

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Full Text Available BACKGROUND: Recent studies have shown that mesenchymal stem cells isolated from post natal human dental pulp, (Dental pulp stem cells-DPSCs) which is from permanent teeth and SHED (stem cells from human exfoliated deciduous teeth),the Periodontal ligament stem cells (PDLSC) and Stem cells from root Apical papilla(SCAP)have the potential to differentiate into cells of a variety of tissues including heart, muscle, cartilage, bone, nerve, salivary glands, teeth etc(1,2,3,4).This multipotential ability of DPSCs is being researched for clinical application for treating a variety of diseases like myocardial infarction, muscular dystrophy, neuro-degenerative disorders, cartilage replacement, tooth regeneration and for repair of bone defects to mention a few. Moreover, the isolation of stem cells from teeth is minimally invasive, readily accessible and the non immunogenic characteristic of dental stem cells has paved the way for efforts to store the exfoliated deciduous teeth or milk teeth which is usually discarded, for use in the future. In this study we have isolated and expanded in vitro, the cells obtained from human dental pulp. MATERIALS AND METHODS: After obtaining written informed consent, 24 teeth that were extracted for therapeutic or cosmetic reasons from 16 patients were used in this study. The specimens were transported from the clinic to NCRM lab taking 6 to 48 Hrs. For removal of the pulp tissue, the teeth were split obliquely at the Cementoenamel junction and the pulp tissue was isolated using brooches. The extracted pulp tissues were subjected to digestion using Collagenase type-I and type II at 37?C for 15- 30 minutes. The digested cells were filtered with 70µm filter and centrifuged at 1800 rpm for 10 minutes. The pellet was then suspended in Dulbecco’s modified Eagle’s medium (DMEM)/Ham’s F12 supplemented with 15% fetal bovine serum , 100 U/ml penicillin, 100 µg/ml streptomycin,2 m M L -glutamine, and 2 m M nonessential amino acids (5) .Cell counting was done by Trypan Blue dye exclusion method and the cells were seeded in 6 well culture plates. The plates with cells were incubated at 37?C with 5% CO2 for varying periods from 14 days-28 days. The cells were observed daily and media change was done every three days. RESULTS: Viable Dental Pulp tissue-cells were obtained after transportation of up to 48 hrs and the in vitro growth of cells was initially slow but colonies were identified from the 10th day onwards. The cells were harvested at different intervals of 14-28 days for each sample based on their growth and subjected to H & E staining .The H & E staining of the cultured cells of all the samples showed positive resultsCONCLUSION: We are able to transport extracted teeth and derive viable dental pulp tissue cells after enzymatic digestion and multiply them in culture after a maximum of 48 hrs after transportation. The cells could be grown in culture with a morphology resembling dental pulp stem cells while in culture expansion and in H&E studies. Further characterization of the cells is necessary to confirm their Stemness. References1.Gronthos S, Mankani M, Brahim J, Robey PG, Shi S. Postnatal human dental pulp stem cells (DPSCs) in vitro and in vivo. Proc Natl Acad Sci U S A. 20002.Nosrat IV, Widenfalk J, Olson L, Nosrat CA. Dental pulp cells produce neurotrophic factors, interact with trigeminal neurons in vitro, and rescue motoneurons after spinal cord injury. Dev Biol. 2001 Oct 3.Iohara K, Zheng L, Ito M, Tomokiyo A, Matsushita K, Nakashima M. Side population cells isolated from porcine dental pulp tissue with self-renewal and multipotency for dentinogenesis, chondrogenesis, adipogenesis, and neurogenesis. Stem Cells. 2006 Nov4.Gandia C, Armiñan A, García-Verdugo JM, Lledó E, Ruiz A, Miñana MD, Sanchez-Torrijos J, Payá R, Mirabet V, Carbonell-Uberos F, Llop M, Montero JA, Sepúlveda P. Human dental pulp stem cells improve left ventricular function, induce angiogenesis, and reduce infarct size in rats with acute myocardial infarction. Stem Cells. 2008 Mar5.Kerkis I,

Manikandhan R; Muthu MS; Sunil PM; Shalini R; Kannan TA; Manjunath S; Murugan P; Srinivasan V; Thamaraikannan P; Tholcopiyan L; Srinivasan T; Preethy SP; Abraham S

2010-01-01

287

THE IMPORTANCE OF AGGREGATIBACTER ACTINOMYCETEMCOMITANS IN ETIOLOGY OF PERIODONTAL DISEASE - MINI REVIEW  

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Full Text Available Periodontal disease is a chronic, degenerative disease of parodontium which is made of gingiva, periodontal ligament, cementum and alveolar bone. The main etiological factor for development of periodontal disease is dental plaque or oral biofilm in association with anaerobic bacteria. Aggregatibacter actinomycetemcomitans is one of the most powerful periodonthopathogens. This microorganism produces many virulent factors: leucotoxin as the most important, then bacteriocin, chemotaxis inhibiting factor, cytotoxic factors, Fc binding proteins, immunosuppressive factors, lipopolysaccharide collagenase, fibroblast inhibiting factor, antibiotic resistance determinants, adhesives, invasives and function inhibiting factor of polymorphonuclear leukocytes. The ability of Aggregatibacter actinomycetemcomitans lipopolysaccharides to stimulate macrophages to release interleukins IL-1, IL-1?, and tumor necrosis factor (TNF) is of main importance. These cytokines are able to stimulate the bone resorption. Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis represent exogenous microorganisms, based on its minor presence in healthy individuals. It has been recommended that periodontal diseases associated with periodontal pathogens represent "true infections".

Ljiljana Kesi?; Milica Petrovi?; Radmila Obradovi?; Ana Pej?i?

2009-01-01

288

Qat habit in Yemen society: a causative factor for oral periodontal diseases.  

UK PubMed Central (United Kingdom)

The effect of a common habit among Yemeni population on the periodontal status was investigated. This cross-sectional study was done on 2500 Yemenis with mean age 27.01 years (1818 males and 682 females). Among these 1528 were qat chewers and 972 were non-chewers. Detailed questionnaire and pre-designed scoring system for the periodontal status were employed for each case. Study results indicated that out of 972 non-chewers 116(12%) had periodontal pocketing and 18 (1.9%) cases had gingival recession. On the other hand, out of 1528 chewers, 468 (31.8%) had periodontal pockets and 98 (6.4%) with gum bleeding, p<0.05. These effects were found to increase with increased frequency and duration of chewing. It was concluded that habit of qat can cause damage to the periodontal ligament as pocketing and gum recession.

Ali AA

2007-09-01

289

The Relationship between Rheumatoid Arthritis and Periodontitis  

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Full Text Available Introduction: Periodontitis is an inflammatory disease of tooth supportive tissues and is characterized by destruction in periodontal ligaments and alveolar bone besides pocket formation and gingival recession. Rheumatoid arthritis is the most common chroinic inflammatory disease of the joints. The aim of this study was to survey the relationship between periodontitis and rheumatoid arthritis.Materials and Methods: In this cross-sectional-analytical study, 50 rheumatoid arthritis patients forming the case group and 50 healthy individuals as the control group were included. Mean of plaque index, percentage of bleeding sites, mean of probing depth, percentage of sites with probing depth more than 3mm, percentage of sites with attachment loss, and percentage of sites with gingival recession and the number of missing teeth were recorded in both groups. Mean values of each variable were compared between the two groups using t- test. The collected data were statistically analyzed via SPSS on a computer. (?=0/05).Results: Analyzing the data showed that there were no statistically significant differences in the mean of plaque index, percentage of bleeding sites , mean of probing depth, percentage of sites with probing depth more than 3mm, percentage of sites with attachment loss, and percentage of sites with gingival recession, between the case and the control group. The mean of attachment loss (P-value =0.04), mean of gingival recession (P-value =0.02) , and the average number of missing teeth (P-value =0.0001)were significantly higher in the rheumatoid arthritis (the case) group compared to the control group. Conclusion: periodontal disease (based on the average clinical attachment loss) was seen with a higher severity among patients with rheumatoid arthritis. Therefore, regular dental examination besides close attention to dental health in patients with rheumatoid arthritis is highly recommended. Key words: Rheumatoid Arthritis, Periodontitis, Attachment loss

P Ghaliani; V isfahanian; N sarrafan; s Pishva; H Hojati

2010-01-01

290

Modeling susceptibility to periodontitis.  

UK PubMed Central (United Kingdom)

Chronic inflammatory diseases like periodontitis have a complex pathogenesis and a multifactorial etiology, involving complex interactions between multiple genetic loci and infectious agents. We aimed to investigate the influence of genetic polymorphisms and bacteria on chronic periodontitis risk. We determined the prevalence of 12 single-nucleotide polymorphisms (SNPs) in immune response candidate genes and 7 bacterial species of potential relevance to periodontitis etiology, in chronic periodontitis patients and non-periodontitis control individuals (N = 385). Using decision tree analysis, we identified the presence of bacterial species Tannerella forsythia, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and SNPs TNF -857 and IL-1A -889 as discriminators between periodontitis and non-periodontitis. The model reached an accuracy of 80%, sensitivity of 85%, specificity of 73%, and AUC of 73%. This pilot study shows that, on the basis of 3 periodontal pathogens and SNPs, patterns may be recognized to identify patients at risk for periodontitis. Modern bioinformatics tools are valuable in modeling the multifactorial and complex nature of periodontitis.

Laine ML; Moustakis V; Koumakis L; Potamias G; Loos BG

2013-01-01

291

Modeling susceptibility to periodontitis.  

Science.gov (United States)

Chronic inflammatory diseases like periodontitis have a complex pathogenesis and a multifactorial etiology, involving complex interactions between multiple genetic loci and infectious agents. We aimed to investigate the influence of genetic polymorphisms and bacteria on chronic periodontitis risk. We determined the prevalence of 12 single-nucleotide polymorphisms (SNPs) in immune response candidate genes and 7 bacterial species of potential relevance to periodontitis etiology, in chronic periodontitis patients and non-periodontitis control individuals (N = 385). Using decision tree analysis, we identified the presence of bacterial species Tannerella forsythia, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and SNPs TNF -857 and IL-1A -889 as discriminators between periodontitis and non-periodontitis. The model reached an accuracy of 80%, sensitivity of 85%, specificity of 73%, and AUC of 73%. This pilot study shows that, on the basis of 3 periodontal pathogens and SNPs, patterns may be recognized to identify patients at risk for periodontitis. Modern bioinformatics tools are valuable in modeling the multifactorial and complex nature of periodontitis. PMID:23100272

Laine, M L; Moustakis, V; Koumakis, L; Potamias, G; Loos, B G

2012-10-25

292

Tendon and ligament imaging  

Science.gov (United States)

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.

Hodgson, R J; O'Connor, P J; Grainger, A J

2012-01-01

293

Periodontal Management of Non Healing Endodontic Lesion  

Directory of Open Access Journals (Sweden)

Full Text Available The fact that the periodontium is anatomically interrelated with the dental pulp by virtue of apical foramina and lateral canals creates pathways for exchange of noxious agents between the two tissue compartments when either or both of the tissues are diseased. Proper diagnosis of the various disorders affecting the periodontium and the pulp is important to exclude unnecessary and even detrimental treatment. This is a clinical case report of an enododontic-periodontic lesion in relation to lower left central incisor. Root canal treatment has been done with the respected tooth six months ago, but the lesion showed no sign of healing resulting in draining sinus and increasing pocket depth. Radiographic examination revealed overobturation of gutta-percha with peri-radicular pathology. Periodontal flap surgery was performed and the defect was filled with bone graft mixed with Platelet rich plasma (PRP) and covered by platelet rich fibrin (PRF). Patient reviewed for six months which showed uneventful healing and no recurrence of the lesion.

Nitin H. Dani; Shahabe A. Saquib

2011-01-01

294

The effect of Emdogain gel on periodontal healing in replanted monkeys' teeth.  

UK PubMed Central (United Kingdom)

OBJECTIVE: We sought to histologically evaluate the effect of Emdogain gel on periodontal healing in monkeys' teeth undergoing delayed replantation. Study design Mature monkey teeth simulating avulsion were endodontically treated before extraction. Negative control teeth (group N = 10 roots) underwent immediate replantation, whereas the rest were bench-dried for 1 hour and treated in one of the following ways before replantation: the positive control teeth (group P = 12 roots) had no further treatment; group C teeth (4 roots) had the periodontal ligament removed; group D teeth (10 roots) were treated with Emdogain gel; group E teeth (6 roots) had the periodontal ligament removed before the application of Emdogain gel; and group F teeth (7 roots) had the periodontal ligament removed, the root surface conditioned, and Emdogain gel applied. Periodontal healing was evaluated after 16 weeks by undertaking histomorphometric analysis. RESULTS: The Kruskal-Wallis and Mann-Whitney U tests revealed that group N teeth had a statistically higher occurrence of complete healing than did all other groups, whereas group P was not significantly different in any of the healing categories from D, E, and F, the groups in which Emdogain gel was used. Group C teeth had a significantly higher occurrence of replacement root resorption than did the teeth in groups P and F-but were not significantly different from teeth in groups D and E. CONCLUSION: Emdogain gel did not appear to significantly reduce replacement resorption in monkeys' teeth that had undergone delayed replantation.

Lam K; Sae-Lim V

2004-01-01

295

SMOKING AND PERIODONTAL DISEASE  

Directory of Open Access Journals (Sweden)

Full Text Available Periodontitis is the result of complex interrelationships between infectious agents and host factors. Environmental, acquired, and genetic risk factors modify the expression of disease and may, therefore, affect the onset or progression of periodontitis. Numerous studies of the potential mechanisms whereby smoking tobacco may predispose to periodontal disease have been conducted, and it appears that smoking may affect the vasculature, the humoral immune system, and the cellular immune and inflammatory systems, and have effects throughout the cytokine and adhesion molecule network. The aim of present review is to consider the association between smoking and periodontal diseases.

Grover Harpreet Singh; Bhardwaj Amit; Singh Yaswin

2013-01-01

296

Indirect pulp treatment in a permanent molar: case reort of 4-year follow-up  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english This case report describes the Indirect Pulp Treatment (IPT) of deep caries lesion in a permanent molar. A 16-year-old male patient reported discomfort associated with thermal stimulation on the permanent mandibular left first molar. The radiographs revealed a deep distal caries lesion, very close to the pulp, absence of radiolucencies in the periapical region, and absence of periodontal space thickening. Pulp sensitivity was confirmed by thermal pulp vitality tests. Base (more) d on the main complaint and the clinical and radiographic examinations, the treatment plan was established to preserve pulp vitality. Clinical procedures consisted of removing the infected dentin and lining the caries-affected dentin with calcium hydroxide paste. The tooth was provisionally sealed for approximately 60 days. After this period, tooth vitality was confirmed, the remaining carious dentin was removed, and the tooth was restored. At 4-year follow-up, no clinical or radiographic pathological findings were found.

Fagundes, Ticiane Cestari; Barata, Terezinha Jesus Esteves; Prakki, Anuradha; Bresciani, Eduardo; Pereira, José Carlos

2009-02-01

297

Indirect pulp treatment in a permanent molar: case reort of 4-year follow-up  

Directory of Open Access Journals (Sweden)

Full Text Available This case report describes the Indirect Pulp Treatment (IPT) of deep caries lesion in a permanent molar. A 16-year-old male patient reported discomfort associated with thermal stimulation on the permanent mandibular left first molar. The radiographs revealed a deep distal caries lesion, very close to the pulp, absence of radiolucencies in the periapical region, and absence of periodontal space thickening. Pulp sensitivity was confirmed by thermal pulp vitality tests. Based on the main complaint and the clinical and radiographic examinations, the treatment plan was established to preserve pulp vitality. Clinical procedures consisted of removing the infected dentin and lining the caries-affected dentin with calcium hydroxide paste. The tooth was provisionally sealed for approximately 60 days. After this period, tooth vitality was confirmed, the remaining carious dentin was removed, and the tooth was restored. At 4-year follow-up, no clinical or radiographic pathological findings were found.

Ticiane Cestari Fagundes; Terezinha Jesus Esteves Barata; Anuradha Prakki; Eduardo Bresciani; José Carlos Pereira

2009-01-01

298

Vital pulp therapy.  

UK PubMed Central (United Kingdom)

Vital pulp therapy is performed to preserve the health status of the tooth and its ultimate position in the arch. These procedures are performed routinely in primary and permanent teeth. This review is divided into 2 parts: the first aims to illustrate the basic biology of the pulp and the effects on the pulp due to various procedures; the second focuses on the clinical aspects of treatment and the use of various dental materials during different vital pulp therapy procedures performed in the primary and permanent teeth.

Cohenca N; Paranjpe A; Berg J

2013-01-01

299

Terapia periodontal no quirúrgica/ Nonsurgical periodontal therapy  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish INTRODUCCIÓN: en el tratamiento de las enfermedades periodontales contamos con la terapia periodontal no quirúrgica, la cual ha sido avalada científicamente mostrando su efectividad. El principal objetivo de este artículo es demostrar la efectividad de la terapia periodontal no quirúrgica evidenciada en múltiples estudios con relación a las indicaciones, aspectos microbiológicos, efectos en los tejidos y la importancia de la terapia de mantenimiento una vez finali (more) zado el tratamiento. MÉTODOS: se hizo una revisión con relación al tema en los últimos años teniendo como patrón los conceptos clave periodontales. RESULTADOS: la terapia periodontal no quirúrgica (TPNQ) no es un procedimiento que pueda y deba realizarse en un corto tiempo y en pocas citas, el tiempo para su ejecución se amplía lo necesario en especial para lograr una limpieza y regularización de las raíces lo más completa posible. CONCLUSIÓN: varios autores reportan que la reducción de la microbiota se mantuvo entre 14 y 180 días, luego de la terapia, esto justifica las citas periódicas de mantenimiento periodontal y estos señalan que el aspecto crítico de la terapia no es la escogencia entre un procedimiento quirúrgico o no quirúrgico, sino la limpieza detallada y completa por el profesional y el buen nivel de higiene bucal por parte del paciente. Abstract in english INTRODUCTION: In the treatment of periodontal diseases, we can rely on nonsurgical periodontal therapy, which has been scientifically proven as its effectiveness has been recognized. The main objective of this article is to demonstrate the usefulness of nonsurgical periodontal therapy, as evidenced in several studies that serve as guidelines, as well as microbiological aspects, effects on tissues and the importance of maintenance therapy after treatment completion. METHOD (more) S: a review was conducted in order to revise this topic considering key periodontal concepts as a guideline. RESULTS: nonsurgical periodontal therapy (NSPT) is a procedure that cannot and should not be carried out in a few sessions; the time required for its completion is extended as necessary in order to achieve cleaning and adjustment of the roots as completely as possible. CONCLUSIONS: Several authors have reported that reduction of microbiota remains between 14 and 180 days after therapy. This explains the regular periodontal maintenance appointments. They also indicate that the critical aspect of this therapy is not the choice between a surgical or a nonsurgical procedure, but a detailed and thorough cleaning by the dental professional and the good level of oral hygiene achieved by the patient.

Botero Zuluaga, Leticia; Botero Botero, Alejandro; Bedoya Trujillo, Juán Sebastián; Guzmán Zuluaga, Isabel Cristina

2012-06-01

300

Terapia periodontal no quirúrgica Nonsurgical periodontal therapy  

Directory of Open Access Journals (Sweden)

Full Text Available INTRODUCCIÓN: en el tratamiento de las enfermedades periodontales contamos con la terapia periodontal no quirúrgica, la cual ha sido avalada científicamente mostrando su efectividad. El principal objetivo de este artículo es demostrar la efectividad de la terapia periodontal no quirúrgica evidenciada en múltiples estudios con relación a las indicaciones, aspectos microbiológicos, efectos en los tejidos y la importancia de la terapia de mantenimiento una vez finalizado el tratamiento. MÉTODOS: se hizo una revisión con relación al tema en los últimos años teniendo como patrón los conceptos clave periodontales. RESULTADOS: la terapia periodontal no quirúrgica (TPNQ) no es un procedimiento que pueda y deba realizarse en un corto tiempo y en pocas citas, el tiempo para su ejecución se amplía lo necesario en especial para lograr una limpieza y regularización de las raíces lo más completa posible. CONCLUSIÓN: varios autores reportan que la reducción de la microbiota se mantuvo entre 14 y 180 días, luego de la terapia, esto justifica las citas periódicas de mantenimiento periodontal y estos señalan que el aspecto crítico de la terapia no es la escogencia entre un procedimiento quirúrgico o no quirúrgico, sino la limpieza detallada y completa por el profesional y el buen nivel de higiene bucal por parte del paciente.INTRODUCTION: In the treatment of periodontal diseases, we can rely on nonsurgical periodontal therapy, which has been scientifically proven as its effectiveness has been recognized. The main objective of this article is to demonstrate the usefulness of nonsurgical periodontal therapy, as evidenced in several studies that serve as guidelines, as well as microbiological aspects, effects on tissues and the importance of maintenance therapy after treatment completion. METHODS: a review was conducted in order to revise this topic considering key periodontal concepts as a guideline. RESULTS: nonsurgical periodontal therapy (NSPT) is a procedure that cannot and should not be carried out in a few sessions; the time required for its completion is extended as necessary in order to achieve cleaning and adjustment of the roots as completely as possible. CONCLUSIONS: Several authors have reported that reduction of microbiota remains between 14 and 180 days after therapy. This explains the regular periodontal maintenance appointments. They also indicate that the critical aspect of this therapy is not the choice between a surgical or a nonsurgical procedure, but a detailed and thorough cleaning by the dental professional and the good level of oral hygiene achieved by the patient.

Leticia Botero Zuluaga; Alejandro Botero Botero; Juán Sebastián Bedoya Trujillo; Isabel Cristina Guzmán Zuluaga

2012-01-01

 
 
 
 
301

Periodontal disease in smokers  

Directory of Open Access Journals (Sweden)

Full Text Available Tobacco contains about 4000 different toxic substances from which almost 40 are proven to be cancerogenic. Nicotine, toxic alkaloid, is the most active substance in tobacco causing major number of harmful consequences for human organism as a whole, and for periodontal tissues as well. The aim of the paper was to show harmful effects of smoking on periodontal disease development, and to point out the problems caused by smoking during and after the periodontal treatment. Periodontal disease occurs in smokers more frequently as opposed to non-smokers. Typically, smokers have lower level of gingival inflammation, more excessive and accelerated loss of alveolar bone and epithelial insertion, deeper periodontal pockets and numerous gingival recessions. Along with that, smokers are carrying a decreased immune response that is expressed through various defense mechanisms. Smoking has negative impact on the outcome of conservative and surgical periodontal therapy. Effects of smoking on periodontal therapy success rate are requiring administration of antiseptic solutions and antibiotics throughout the treatment course. Every periodontologist must influence patients to stop smoking and thus act preventively on occurrence and progress of periodontal disease.

Cerovi? Olivera; Bundalo Vera

2005-01-01

302

Characteristics of cornstalk pulping  

Energy Technology Data Exchange (ETDEWEB)

Soda and sulfate cooking of soaked corn stalks at 160 degrees gave pulp in 38-40% yield, with 0.22-0.50% rejects, 11-19 kappa no., and improved strength. The bleaching of stalk pulp by the CEH sequence gave an 81-87% yield and brightness 68-83.

Bhaumik, S.K.; Rao, V.S.; Ghosh, K.L.

1980-01-01

303

PULP dead or alive  

Directory of Open Access Journals (Sweden)

Full Text Available A pain response to hot, cold or an electric pulp tester indicates the vitality of only a tooth's pulpal sensory supply; the response does not give any idea about the state of the pulp. Although the sensitivity of these tests is high, when false-positive and falsenegative results occur, they may affect the treatment of the tooth. A tooth falsely diagnosed as nonvital with an electric pulp tester may undergo an unnecessary root canal, whereas one falsely diagnosed as vital may be left untreated, causing the necrotic tissue to destroy the supporting tissues (resorption). The vascular supply is more important to the determination of the health of the pulp than the sensory supply. Pulp death is caused by cessation of blood flow and may result in a necrotic pulp, even though the pulpal sensory supply may still be viable. The pulp can be healed only if the circulating blood flow is healthy. Although still under investigation, diagnostic devices that examine pulpal blood flow, such as the pulse oximeter and laser Doppler flowmetry, show promising results for the assessment of pulp vitality.

Pankaj Agarwal; Ashu Agarwal

2011-01-01

304

CT appearance of pulmonary ligament  

Energy Technology Data Exchange (ETDEWEB)

Pulmonary ligament consists of 2 serosal of pleura that connect the lower to the mediastinum. Author analyse and present CT appearance of pulmonary ligament of the 40 normal and abnormal patients on the basis of anatomic knowledge from the cross section of cadaver. Left pulmonary ligament is more frequency visualized than the right. The most important CT landmark in localizing pulmonary ligament is the esophagus where the ligament attaches on its lateral wall. Pitfalls in CT identification of pulmonary ligament are right phrenic nerve and right pericardiacophrenic vessels which emerge from lateral wall of the IVC and wall of the emphysematous bulla in the region of the pulmonary ligament.

Im, Jung Gi; Han, Man Chung; Chin, Soo Yil [Seoul National University College of Medicine, Seoul (Korea, Republic of)

1984-03-15

305

Secreted osteoclastogenic factor of activated T cells (SOFAT), a novel osteoclast activator, in chronic periodontitis.  

UK PubMed Central (United Kingdom)

A novel activated human T cell-secreted cytokine, referred as secreted osteoclastogenic factor of activated T cells (SOFAT), that induce osteoclastogenesis in a RANKL-independent manner was recently described. This study evaluated the role of SOFAT in periodontal tissues and periodontitis. Gingival biopsies were harvested from systemically healthy non-periodontitis (n=15) and chronic periodontitis patients (n=15). The mRNA and protein levels of SOFAT were measured by qPCR and by enzyme-linked immunosorbent assay, respectively. Moreover, RAW 264.7 cells were cultured with SOFAT or Receptor activator of nuclear factor-kB ligand (RANKL) and stained for tartrate-resistant acid phosphatase (TRAP). Also, mice received a palatal injection between the first and second upper molar of SOFAT (100 ng/ml) or saline solution (0.9%). The upper jaw was removed, histologically processed and stained with hematoxilin and eosin to observe the presence of osteoclast-like cells. The mRNA and protein levels of SOFAT were significantly higher in the gingival tissue of the periodontitis group when compared to non-periodontitis one (p<0.05). In addition, SOFAT potently induced TRAP-positive multinucleated cell formation by RAW 264.7 cells as well as induced the formation of osteoclast-like cells in the periodontal ligament in mice. The present study demonstrated that SOFAT may play an important role in periodontitis.

Jarry CR; Duarte PM; Freitas FF; de Macedo CG; Clemente-Napimoga JT; Saba-Chujfi E; Passador-Santos F; de Araújo VC; Napimoga MH

2013-07-01

306

Periodontitis in HIV patients  

Directory of Open Access Journals (Sweden)

Full Text Available The article presents the study of formation mechanisms and periodontitis course in patients with subclinical stage of HIV-infection. The examination of 45 patients has enabled the division of patients into three basic groups: patients with periodontitis and HIV-infection; patients with periodontitis; and HIV patients without periodontitis. It has been determined that the patients with periodontitis and subclinical HIV-infection have developed local inflammatory reaction with infection, activation of anti-inflammatory cytokines in parodontal recess fluid. It has been proved that the causative factor of frequent and durable relapses in parodontal pathology with clinical HIV-infection was the development of pathologic process with endotoxicosis syndrome and imbalance of lipid peroxidation and antioxidant system

Oseeva ?.?.; Soboleva L.A.; Bulkina N.V.; Shuldyakov A. A.

2011-01-01

307

Nicotine and periodontal tissues  

Directory of Open Access Journals (Sweden)

Full Text Available 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.

Malhotra Ranjan; Kapoor Anoop; Grover Vishakha; Kaushal Sumit

2010-01-01

308

An Ultrasonographic Periodontal Probe  

Science.gov (United States)

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.

Bertoncini, C. A.; Hinders, M. K.

2010-02-01

309

Tabaquismo y enfermedad periodontal  

Scientific Electronic Library Online (English)

Full Text Available Abstract in spanish Se realizó un estudio epidemiológico transversal en 96 fumadores que acudieron al examen médico y control de salud en el Hospital Militar "Comandante Manuel Fajardo Rivero" de Santa Clara, en el período comprendido de enero a junio del 2001. Para el examen de los fumadores se utilizó el índice de necesidad de tratamiento periodontal en la comunidad; los objetivos de este fueron determinar la prevalencia y gravedad de la enfermedad periodontal según la edad del paci (more) ente y los años que lleva fumando, así como las necesidades de tratamiento periodontal en los pacientes estudiados. Se pudo observar que el grupo de edad más afectado por la enfermedad fue el de 45 a 54 años, y las personas que llevan más de 40 años fumando padecen de periodontitis más severas. Los fumadores que consumen más de 10 cigarrillos o 3 tabacos diarios son los que necesitan tratamiento periodontal complejo. Abstract in english An epidemiological cross-sectional study was performed on 96 smokers who went to undergo medical examination and health control tests in "Manuel Fajardo Rivero" Military Hospital in Santa Clara from January to June, 2001. For the examination of smokers, the periodontal treatment need index in the community was used. The objectives of this paper were to determine the prevalence and seriousness of periodontal diseases according to the age of patients and years of smoking as (more) well as the needs of periodontal treatment of the studied patients. It was observed that the most affected age group was 45-54 years and people who have been smoking for over 40 years suffered from the most severe type of periodontitis. The smokers who daily smoke more than 10 cigarettes or 3 cigars need complex periodontal treatment.

Toledo Pimental, Bárbara; González Díaz, María Elena; Alfonso Tarraú, María Susana; Pérez Carrillo, Aleida; Rodríguez Linares, María Lucía

2002-06-01

310

Tabaquismo y enfermedad periodontal  

Directory of Open Access Journals (Sweden)

Full Text Available Se realizó un estudio epidemiológico transversal en 96 fumadores que acudieron al examen médico y control de salud en el Hospital Militar "Comandante Manuel Fajardo Rivero" de Santa Clara, en el período comprendido de enero a junio del 2001. Para el examen de los fumadores se utilizó el índice de necesidad de tratamiento periodontal en la comunidad; los objetivos de este fueron determinar la prevalencia y gravedad de la enfermedad periodontal según la edad del paciente y los años que lleva fumando, así como las necesidades de tratamiento periodontal en los pacientes estudiados. Se pudo observar que el grupo de edad más afectado por la enfermedad fue el de 45 a 54 años, y las personas que llevan más de 40 años fumando padecen de periodontitis más severas. Los fumadores que consumen más de 10 cigarrillos o 3 tabacos diarios son los que necesitan tratamiento periodontal complejo.An epidemiological cross-sectional study was performed on 96 smokers who went to undergo medical examination and health control tests in "Manuel Fajardo Rivero" Military Hospital in Santa Clara from January to June, 2001. For the examination of smokers, the periodontal treatment need index in the community was used. The objectives of this paper were to determine the prevalence and seriousness of periodontal diseases according to the age of patients and years of smoking as well as the needs of periodontal treatment of the studied patients. It was observed that the most affected age group was 45-54 years and people who have been smoking for over 40 years suffered from the most severe type of periodontitis. The smokers who daily smoke more than 10 cigarettes or 3 cigars need complex periodontal treatment.

Bárbara Toledo Pimental; María Elena González Díaz; María Susana Alfonso Tarraú; Aleida Pérez Carrillo; María Lucía Rodríguez Linares

2002-01-01

311

A review on endogenous regenerative technology in periodontal regenerative medicine.  

UK PubMed Central (United Kingdom)

Periodontitis is a globally prevalent inflammatory disease that causes the destruction of the tooth-supporting apparatus and potentially leads to tooth loss. Currently, the methods to reconstitute lost periodontal structures (i.e. alveolar bone, periodontal ligament, and root cementum) have relied on conventional mechanical, anti-infective modalities followed by a range of regenerative procedures such as guided tissue regeneration, the use of bone replacement grafts and exogenous growth factors (GFs), and recently developed tissue engineering technologies. However, all current or emerging paradigms have either been shown to have limited and variable outcomes or have yet to be developed for clinical use. To accelerate clinical translation, there is an ongoing need to develop therapeutics based on endogenous regenerative technology (ERT), which can stimulate latent self-repair mechanisms in patients and harness the host's innate capacity for regeneration. ERT in periodontics applies the patient's own regenerative 'tools', i.e. patient-derived GFs and fibrin scaffolds, sometimes in association with commercialized products (e.g. Emdogain and Bio-Oss), to create a material niche in an injured site where the progenitor/stem cells from neighboring tissues can be recruited for in situ periodontal regeneration. The choice of materials and the design of implantable devices influence therapeutic potential and the number and invasiveness of the associated clinical procedures. The interplay and optimization of each niche component involved in ERT are particularly important to comprehend how to make the desired cell response safe and effective for therapeutics. In this review, the emerging opportunities and challenges of ERT that avoid the ex vivo culture of autologous cells are addressed in the context of new approaches for engineering or regeneration of functional periodontal tissues by exploiting the use of platelet-rich products and its associated formulations as key endogenous resources for future clinical management of periodontal tissue defects.

Chen FM; Zhang J; Zhang M; An Y; Chen F; Wu ZF

2010-11-01

312

A review on endogenous regenerative technology in periodontal regenerative medicine.  

Science.gov (United States)

Periodontitis is a globally prevalent inflammatory disease that causes the destruction of the tooth-supporting apparatus and potentially leads to tooth loss. Currently, the methods to reconstitute lost periodontal structures (i.e. alveolar bone, periodontal ligament, and root cementum) have relied on conventional mechanical, anti-infective modalities followed by a range of regenerative procedures such as guided tissue regeneration, the use of bone replacement grafts and exogenous growth factors (GFs), and recently developed tissue engineering technologies. However, all current or emerging paradigms have either been shown to have limited and variable outcomes or have yet to be developed for clinical use. To accelerate clinical translation, there is an ongoing need to develop therapeutics based on endogenous regenerative technology (ERT), which can stimulate latent self-repair mechanisms in patients and harness the host's innate capacity for regeneration. ERT in periodontics applies the patient's own regenerative 'tools', i.e. patient-derived GFs and fibrin scaffolds, sometimes in association with commercialized products (e.g. Emdogain and Bio-Oss), to create a material niche in an injured site where the progenitor/stem cells from neighboring tissues can be recruited for in situ periodontal regeneration. The choice of materials and the design of implantable devices influence therapeutic potential and the number and invasiveness of the associated clinical procedures. The interplay and optimization of each niche component involved in ERT are particularly important to comprehend how to make the desired cell response safe and effective for therapeutics. In this review, the emerging opportunities and challenges of ERT that avoid the ex vivo culture of autologous cells are addressed in the context of new approaches for engineering or regeneration of functional periodontal tissues by exploiting the use of platelet-rich products and its associated formulations as key endogenous resources for future clinical management of periodontal tissue defects. PMID:20684986

Chen, Fa-Ming; Zhang, Jing; Zhang, Min; An, Ying; Chen, Fang; Wu, Zhi-Fen

2010-08-04

313

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

Energy Technology Data Exchange (ETDEWEB)

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.

Martin, R.R.; Naftel, S.J.; Nelson, A.J.; Edwards, M.; Mithoowani, H.; Stakiw, J. (UWO); (Saskatchewan)

2010-03-16

314

[Pathogenesis of stenosing ligamentitis  

UK PubMed Central (United Kingdom)

On the basis of complex examination of women with stenosing ligamentitis, including investigations of hormonal background in accordance with the clinical criteria, hormonal smears, radioimmunological assay of the initial vegetative tonicity, blood circulation by means of rheography, it has been concluded that the stenosing ligamentitis is the local expression of general dystrophy of the connective tissue due to hormonal shift, pathology of the vegetative nervous system and the circulatory system.

Kuznetsova NL; Gaëv AV

1991-07-01

315

Meniscotibial (coronary) ligament tears  

Energy Technology Data Exchange (ETDEWEB)

Preservation of the meniscus whenever possible is essential in maintaining knee stability and preventing premature osteoarthritis. Peripheral meniscal tears are the most amenable to surgical repair. This study evaluates the peripheral attachments of the medial meniscus and focuses on a specific tear limited to the meniscotibial ligament (coronary ligament). The diagnosis is made arthrographically when the medial meniscus floats above the tibial plateau without separating completely from the capsule. The lateral meniscus is rarely involved in this type of injury.

El-Khoury, G.Y.; Usta, H.Y.; Berger, R.A.

1984-03-01

316

Non surgical Periodontal Therapy  

Directory of Open Access Journals (Sweden)

Full Text Available Periodontal disease is the number one chronic infectious disease in the world. It is the leading cause of tooth loss, and begins as painless infection in the gums that is caused by buildup of bacterial plaque. The treatment modalities that exist for the treatment of gingivitis and Periodontitis depends on the extent and severity, but the primary objective is to restore the gingival health by removing the local factors viz plaque, calculus etc. that provoke inflammation. Non- surgical periodontal therapy or NSPT is one of the management of gingival infection with scaling, root planning, antibiotics and other non surgical means.

Rajababu P; Harinath Reddy S; Satyanarayana D; Palakuru SK

2009-01-01

317

Periodontal disease in men.  

UK PubMed Central (United Kingdom)

In relation to periodontal diseases associated with sex-steroid hormones, men have been the forgotten sex. It is not surprising that there has been less scrutiny of the effects of sex-steroid hormones in men considering the more striking changes that occur in women during different periods of their life. Despite the gingival inflammatory changes reported in women, men have been reported to have a higher prevalence of destructive periodontal diseases. The information presented in this review will provide a contemporary evaluation of male susceptibility to periodontal diseases.

Haytac MC; Ozcelik O; Mariotti A

2013-02-01

318

Periodontal disease in men.  

Science.gov (United States)

In relation to periodontal diseases associated with sex-steroid hormones, men have been the forgotten sex. It is not surprising that there has been less scrutiny of the effects of sex-steroid hormones in men considering the more striking changes that occur in women during different periods of their life. Despite the gingival inflammatory changes reported in women, men have been reported to have a higher prevalence of destructive periodontal diseases. The information presented in this review will provide a contemporary evaluation of male susceptibility to periodontal diseases. PMID:23240953

Haytac, M Cenk; Ozcelik, Onur; Mariotti, Angelo

2013-02-01

319

Ultrasound in periodontics  

Directory of Open Access Journals (Sweden)

Full Text Available Ultrasonic instruments were introduced in periodontal therapy in 1955. Approximately 50 years later, their effects on the teeth and periodontium have become much clearer. Currently, ultrasonic instruments are frequently used in daily practice. Most of these instruments work according to the magnetostrictive or reciprocal piezo-electric principle. Though, they are mainly used for routine prophylaxis, there are various other functions of these in the field of Periodontics. This article explains the principle and mechanism of action of ultrasonic instruments with their various applications in Periodontics.

Sapna N; Seetaram Kumar D; Vandana K L

2010-01-01

320

Detection of Periodontal Markers in Chronic Periodontitis  

Science.gov (United States)

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 104 bacterial cells) and 16 (53.3%) using a higher treshold (score 3 corresponding to between >105 and 106 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.

Leonhardt, Asa; Carlen, Anette; Bengtsson, Lisbeth; Dahlen, Gunnar

2011-01-01

 
 
 
 
321

Angioleiomyoma of the pulp.  

UK PubMed Central (United Kingdom)

Abstract Vascular leiomyomas or angioleiomyomas are benign solitary smooth muscular tumours that rarely occur in the distal finger. I report a 64-year-old man with uncommon clinical appearance in the pulp of the middle finger.

Ohtsuka H

2013-08-01

322

Pulp and periapical pathologies  

Directory of Open Access Journals (Sweden)

Full Text Available The pulp undergoes inflammatory or degenerative reactions when submitted to an aggressive factor. These depend on the type, frequency and intensity of the irritant as well as the patient’s immune response. If the aggressive agent is not removed, the pulp will either show calcifications or result in necrosis. This latter would occur when a pulp alteration is present and not treated. Pulp necrosis is the complete cessation of the tissue’s metabolic processes. If it is not removed, the bacterial and the tissue decomposition’s toxic products ill injure the periapical tissues, resulting in periapical alterations. The dentist must know the histological, clinical and radiographic features of these pathologies to recognize them and indicate the best treatment option.

Denise Piotto Leonardi; Allan Fernando Giovanini; Susimara Almeida; Celso Alfredo Schramm; Flares Baratto-Filho

2011-01-01

323

Periodontal disease and halitosis  

International Nuclear Information System (INIS)

Halitosis is a general term used to describe an unpleasant or offensive odor emanating from the oral cavity. It is a condition that has health and social implications in the life of those who suffer from it. The origin of halitosis is related to both systemic and oral conditions although the oral causes predominate. Volatile sulfur compound is the primary gas responsible for halitosis. They are formed as a result of gram-negative bacterial putrefaction. The major sites for oral halitosis are the dorsum of the tongue and periodontal pockets. There is a correlation between the amount of plaque on the tongue and periodontitis with the severity of halitosis. The aim of this article was to review the data and correlate periodontitis with severity of halitosis and the effect of halitosis- inducing factors on the progress of periodontal diseases. (author)

2008-01-01

324

ARTIFICIAL PERIODONTAL MEMBRANE  

UK PubMed Central (United Kingdom)

FIELD: medicine. ^ SUBSTANCE: invention refers to the area of medicine and is intended for creating an artificial periodontal membrane. The implant shall be fixed. Fractal structure nano-particles and nano-particles of metal or intermetallic compound similar to the dental implant material as well as fractal structure-oriented silver particles distributed in a strap are used as the periodontal membrane basis. The strap is a gel composition made of the patient's blood autoplasm, nano- particles of the relative metal or intermetallic compound and colloidal silver. ^ EFFECT: invention enables making an artificial periodontal membrane that would replace the missing periodontal membrane, provides for complete implant's plantation and removes the negative response of soft jaw tissues. ^ 1 dwg

BORISENKO NIKOLAJ IVANOVICH; GIZATULLIN RAMIL MIKHAJLOVICH

325

How to diagnose and treat periodontal- endodontic lesions?  

Directory of Open Access Journals (Sweden)

Full Text Available Objective: This literature review aims to assess the causes and consequences of periodontal-endodontic lesions, as well as its clinical, radiographic and microbiological aspects. Literature review: Periodontal-endodontic lesions are often changes that affect all teeth due to the close relationship between pulp and periodontium. Many authors researched about this, but there are many disagreements on the subject, starting with the different types of classification, in which many are based on the origin of the disease, the other forms of treatment, degree of pulp involvement, among others, with the purpose of helping in the correct diagnosis. The knowledge of the etiology of the disease is extremely important, because the success of the treatment depends on the rapidity of its onset, the treatment protocol adopted and medication use. Conclusion: It is necessary that the dentists know the morphology and structure of the oral cavity, as well as the knowledge of all factors that can cause the same damage, so that they differentiate the types of periodontal-endodontic lesions regarding to its origin, defining the best treatment to be followed.

Carmen Mueller Storrer; Giuliana Martina Bordin; Tarcísio Tavares Pereira

2012-01-01

326

[Stress and periodontal health  

UK PubMed Central (United Kingdom)

Periodontitis and periimplant infections are complex manifestations associated with several disease-modifying factors, such as causative pathogens and smoking. Although research into these factors has led to important progressions in the treatment of these infections in recent decades, the contribution of mental stress in the absence of pathogens or smoking is still unclear. Qualitative and quantitative assessment of mental stress might be an important instrument in periodontal and periimplant therapy.

Strooker H; de Geus E; van der Reijden WA; Laine ML; van Winkelhoff AJ

2010-01-01

327

Obesity and periodontal disease  

Directory of Open Access Journals (Sweden)

Full Text Available Obesity is characterized by the abnormal or excessive deposition of fat in the adipose tissue. Its consequences go far beyond adverse metabolic effects on health, causing an increase in oxidative stress, which leads not only to endothelial dysfunction but also to negative effects in relation to periodontitis, because of the increase in proinflammatory cytokines. Thus obesity appears to participate in the multifactorial phenomenon of causality of periodontitis through the increased production of reactive oxygen species. The possible causal relationship between obesity and periodontitis and potential underlying biological mechanisms remain to be established; however, the adipose tissue actively secretes a variety of cytokines and hormones that are involved in inflammatory processes, pointing toward similar pathways involved in the pathophysiology of obesity, periodontitis and related inflammatory diseases. So the aim of this article is to get an overview of the association between obesity and periodontitis and to review adipose-tissue - derived hormones and cytokines that are involved in inflammatory processes and their relationship to periodontitis.

Jagannathachary Sunitha; Kamaraj Dinesh

2010-01-01

328

Disruption of periodontal integrity induces expression of apin by epithelial cell rests of Malassez.  

UK PubMed Central (United Kingdom)

BACKGROUND AND OBJECTIVE: It has been suggested that epithelial cell rests of Malassez (ERM) may express enamel matrix proteins and play an important role in periodontal regeneration. Two novel proteins, apin (APIN) and amelotin (AMTN), produced by maturation-stage ameloblasts and junctional epithelium, have recently been identified. The objective of this study was to evaluate whether the ERM express APIN and AMTN under normal conditions and after periodontal challenge. MATERIAL AND METHODS: Gingivectomy and orthodontic tooth movement were carried out on the left side of the maxillae of rats. The control group included the untreated contralateral side of these animals and the maxillae of normal, untreated rats. Animals were sacrificed by intracardiac perfusion on days 3 and 5 after the experimental procedures and maxillary molars were decalcified and processed for paraffin embedding. Immunohistochemistry was used to evaluate the expression of various ameloblast products, including APIN, AMTN, ameloblastin (AMBN) and amelogenin (AMEL). RESULTS: At 3 and 5 days after periodontal challenge, ERM were more evident in the periodontal ligament along the root surface and in the root furcations. Immunodetection of APIN, but not of the other three proteins, was observed in the ERM following the disruption of periodontal integrity. No immunolabeling for APIN, AMTN, AMBN and AMEL was detected in the ERM under normal conditions. CONCLUSION: The expression of APIN at an early time-point following disruption of periodontal integrity suggests that this protein may be part of the cascade of events leading to the activation of ERM during periodontal healing and regeneration.

Nishio C; Wazen R; Kuroda S; Moffatt P; Nanci A

2010-12-01

329

Regeneration of oxytalan fibres in different types of periodontal defects: a histological study in monkeys.  

UK PubMed Central (United Kingdom)

The aim of the present study was to investigate in monkeys the regrowth of oxytalan fibres in different types of acute and chronic periodontal defects following regenerative periodontal treatment. One-wall intrabony and mandibular furcation III-defects were produced surgically in 3 monkeys (Macaca fascicularis). After a 6-wk dental plaque accumulation period the defects were exposed using a full thickness flap procedure. The granulation tissue was removed and the root surfaces were scaled and planed. Additionally, fenestration-type defects were produced at the vestibular surfaces of the maxillary and mandibular canines by surgically removing the vestibular bone plates and the root cementum. Subsequently, the defects were treated with guided tissue regeneration (GTR), enamel matrix proteins (EMP), combination of EMP and GTR or with coronally repositioned flaps. The postoperative care included tooth cleaning once a week during the experiment. After 5 months the animals were sacrificed and and the block sections were embedded in paraffin. Eight microns histological sections were cut and stained with the oxone-aldehyde-fuchsin-Halmi method. The results revealed that in all specimens where a regenerated periodontal ligament could be observed newly formed oxytalan fibers were present. They had a mainly apico-occlusal orientation and were localized closer to the cementum than to the alveolar bone. The regenerated oxytalan fibers had a similar morphological appearance than those observed in the original periodontal ligament regardless of the treatment modality by which regeneration was accomplished. Their presence was related to that of newly formed cementum suggesting a strong relationship between these 2 tissues. The neoformation of oxytalan fibres can thus be observed in some types of periodontal defects where the cementum and the periodontal ligament have been regenerated.

Sculean A; Donos N; Reich E; Karring T; Brecx M

1998-11-01

330

Posterior cruciate ligament (PCL) injury  

Science.gov (United States)

Cruciate ligament injury - posterior; PCL injury; Knee injury - posterior cruciate ligament (PCL); Hyperextended knee ... a physical examination to check for signs of PCL injury. This includes moving the knee joint in ...

331

Ankle ligament injuries  

Directory of Open Access Journals (Sweden)

Full Text Available Acute ankle ligament sprains are common injuries. The majority of these occur during athletic participation in the 15 to 35 year age range. Despite the frequency of the injury, diagnostic and treatment protocols have varied greatly. Lateral ligament complex injuries are by far the most common of the ankle sprains. Lateral ligament injuries typically occur during plantar flexion and inversion, which is the position of maximum stress on the anterotalofibular liagment (ATFL). For this reason, the ATFL is the most commonly torn ligament during an inversion injury. In more severe inversion injuries the calcaneofibular (CFL), posterotalofibular (PTFL) and subtalar ligament can also be injured. Most acute lateral ankle ligament injuries recover quickly with nonoperative management. The treatment program, called "functional treatment," includes application of the RICE principle (rest, ice, compression, and elevation) immediately after the injury, a short period of immobilization and protection with an elastic or inelastic tape or bandage, and early motion exercises followed by early weight bearing and neuromuscular ankle training. Proprioceptive training with a tilt board is commenced as soon as possible, usually after 3 to 4 weeks. The purpose is to improve the balance and neuromuscular control of the ankle. Sequelae after ankle ligament injuries are very common. As much as 10% to 30% of patients with a lateral ligament injury may have chronic symptoms. Symptoms usually include persistent synovitis or tendinitis, ankle stiffness, swelling, and pain, muscle weakness, and frequent giving-way. A well designed physical therapy program with peroneal strengthening and proprioceptive training, along with bracing and/or taping can alleviate instability problems in most patients. For cases of chronic instability that are refractory to bracing and external support, surgical treatment can be explored. If the chronic instability is associated with subtalar instability that is refractory to conservative measures and bracing as outlined above, surgical treatment must address the subtalar joint as well. Subtalar ligament injury and instability are probably more common than appreciated. Definition and diagnosis of this entity are difficult, however. Fortunately, it appears that in the majority of the acute injuries healing occurs with the same functional rehabilitation program as that for lateral ankle ligament sprains. For chronic subtalar instability an intial attempt at functional rehabilitation with ankle proprioceptive training and bracing should be attempted. If this program fails primary repair or reconstruction can be beneficial. Reconstructive procedures must address the subtalar joint. Subtalar instability often occurs in conjunction with talocrural instability, so careful diagnosis is critical in anyone with chronic ankle instability. If either is not addressed, the patient will continue to have problems. Deltoid ligament injuries most often occur in association with ankle fractures. They are rare as isolated injuries. If no fracture is evident on radiographs, particular attention must be paid to the syndesmosis to ensure there is not an associated syndesmosis disruption. True isolated deltoid injuries seem to do well with non-operative functional treatment as for lateral ankle ligament injuries. Deltoid ruptures associated with ankle fractures appear to heal well by addressing the other injuries and allowing the deltoid to heal on its own. It is vital to correct any syndesmosis injury and to obtain correct bony alignment. Syndesmosis injuries can be debilitating if not treated properly. Careful physical exam and interpretation of radiographs is necessary to obtain a correct diagnosis. Partial injuries appear to do well with functional rehabilitation. However, complete tears, if widening is not corrected, can lead to chronic ankle pain and early degenerative changes. Widening of the syndesmosis with a tear of the inferior tibiofibular ligaments is an indication for surgery to place a syndesmosis screw for reducti

Per A.F.H. Renström; Scott A. Lynch

1998-01-01

332

Ankle ligament injuries  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Acute ankle ligament sprains are common injuries. The majority of these occur during athletic participation in the 15 to 35 year age range. Despite the frequency of the injury, diagnostic and treatment protocols have varied greatly. Lateral ligament complex injuries are by far the most common of the ankle sprains. Lateral ligament injuries typically occur during plantar flexion and inversion, which is the position of maximum stress on the anterotalofibular liagment (ATFL) (more) . For this reason, the ATFL is the most commonly torn ligament during an inversion injury. In more severe inversion injuries the calcaneofibular (CFL), posterotalofibular (PTFL) and subtalar ligament can also be injured. Most acute lateral ankle ligament injuries recover quickly with nonoperative management. The treatment program, called "functional treatment," includes application of the RICE principle (rest, ice, compression, and elevation) immediately after the injury, a short period of immobilization and protection with an elastic or inelastic tape or bandage, and early motion exercises followed by early weight bearing and neuromuscular ankle training. Proprioceptive training with a tilt board is commenced as soon as possible, usually after 3 to 4 weeks. The purpose is to improve the balance and neuromuscular control of the ankle. Sequelae after ankle ligament injuries are very common. As much as 10% to 30% of patients with a lateral ligament injury may have chronic symptoms. Symptoms usually include persistent synovitis or tendinitis, ankle stiffness, swelling, and pain, muscle weakness, and frequent giving-way. A well designed physical therapy program with peroneal strengthening and proprioceptive training, along with bracing and/or taping can alleviate instability problems in most patients. For cases of chronic instability that are refractory to bracing and external support, surgical treatment can be explored. If the chronic instability is associated with subtalar instability that is refractory to conservative measures and bracing as outlined above, surgical treatment must address the subtalar joint as well. Subtalar ligament injury and instability are probably more common than appreciated. Definition and diagnosis of this entity are difficult, however. Fortunately, it appears that in the majority of the acute injuries healing occurs with the same functional rehabilitation program as that for lateral ankle ligament sprains. For chronic subtalar instability an intial attempt at functional rehabilitation with ankle proprioceptive training and bracing should be attempted. If this program fails primary repair or reconstruction can be beneficial. Reconstructive procedures must address the subtalar joint. Subtalar instability often occurs in conjunction with talocrural instability, so careful diagnosis is critical in anyone with chronic ankle instability. If either is not addressed, the patient will continue to have problems. Deltoid ligament injuries most often occur in association with ankle fractures. They are rare as isolated injuries. If no fracture is evident on radiographs, particular attention must be paid to the syndesmosis to ensure there is not an associated syndesmosis disruption. True isolated deltoid injuries seem to do well with non-operative functional treatment as for lateral ankle ligament injuries. Deltoid ruptures associated with ankle fractures appear to heal well by addressing the other injuries and allowing the deltoid to heal on its own. It is vital to correct any syndesmosis injury and to obtain correct bony alignment. Syndesmosis injuries can be debilitating if not treated properly. Careful physical exam and interpretation of radiographs is necessary to obtain a correct diagnosis. Partial injuries appear to do well with functional rehabilitation. However, complete tears, if widening is not corrected, can lead to chronic ankle pain and early degenerative changes. Widening of the syndesmosis with a tear of the inferior tibiofibular ligaments is an indication for surgery to place a s

Renström, Per A.F.H.; Lynch, Scott A.

1998-06-01

333

The relationship between periodontal disease (pd) and cardiovascular disease (cvd).  

UK PubMed Central (United Kingdom)

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.

Trevisan M; Dorn J

2010-01-01

334

THE RELATIONSHIP BETWEEN PERIODONTAL DISEASE (PD) AND CARDIOVASCULAR DISEASE (CVD).  

Directory of Open Access Journals (Sweden)

Full Text Available 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.

Maurizio Trevisan; Joan Dorn

2010-01-01

335

Effect of the interaction between periodontitis and type 1 diabetes mellitus on alveolar bone, mandibular condyle and tibia.  

UK PubMed Central (United Kingdom)

Abstract Objective. This study examined the effect of the interaction between periodontitis and type 1 diabetes mellitus on alveolar bone, mandibular condyle and tibia in animal models. Materials and methods. Rats were divided into normal, periodontitis, diabetic and diabetic with periodontitis groups. After injection of streptozotocin to induce diabetes, periodontitis was induced by ligation of both lower-side first molars for 30 days. Alveolar bone loss and trabecular bone volume fraction (BVF) of the mandibular condyle and tibia were estimated via hematoxylin and eosin staining and micro-computed tomography, respectively. Osteoclastogenesis of bone marrow cells isolated from tibia and femur was assayed using tartrate-resistant acid phosphatase staining. Results. The cemento-enamel junction to the alveolar bone crest distance and ratio of periodontal ligament area in the diabetic with periodontitis group were significantly increased compared to those of the periodontitis group. Mandibular condyle BVF did not differ among groups. The BVF of tibia in the diabetic and diabetic with periodontitis groups was lower than that of the normal and periodontitis groups. Osteoclastogenesis of bone marrow cells in the diabetic groups was higher than that in the non-diabetic groups. However, the BVF of tibia and osteoclastogenesis in the diabetic with periodontitis group were not significantly different than those in the diabetic group. Conclusions. Type 1 diabetes mellitus aggravates alveolar bone loss induced by periodontitis, but periodontitis does not alter the mandibular condyle and tibia bone loss induced by diabetes. Alveolar bone, mandibular condyle and tibia may have different responses to bone loss stimuli in the diabetic environment.

Kim JH; Lee DE; Gunawardhana KS; Choi SH; Woo GH; Cha JH; Bak EJ; Yoo YJ

2013-08-01

336

The progress of the periodontal syndrome in the rice rat  

International Nuclear Information System (INIS)

Several morphometric and cellular parameters were studied in the rice rat (Oryzomys palustris). When fed a soft, high carbohydrate diet, a severe periodontal disease occurred, with significant alterations in the morphometric and cellular endpoints observed. Weaned animals were placed on a high carbohydrate diet for periods of 6, 12 or 18 weeks. There was a linear rapid loss of bone by 18 weeks, approaching a 75% loss of original bone. Vascular spaces decreased as the remaining connective tissue became fibrotic in character. The percentage of the interdental test site which was destroyed by periodontal disease increased dramatically over the time of the experiment. The numbers of fibroblasts per mm of bone surface increased slightly at the 18 week period; osteoblasts were unchanged at any period. The numbers of osteoclast nuclei rose dramatically by 12 weeks, and these cell nuclei remained at increased levels at 18 weeks. Also, the numbers of inflammatory cells residing at the bone surface increased greatly by 18 weeks time. Finally, the numbers of 3H-TdR labeled periodontal ligament (PDL) fibroblasts increased significantly at both 12 and 18 weeks time. These cellular changes and their relation to the bone loss due to periodontal disease are discussed. (author).

1981-01-01

337

JAMA Patient Page: Periodontal Disease  

Science.gov (United States)

... Previous Article JAMA Patient Page | February 6, 2008 Periodontal Disease FREE Janet M. Torpy, MD; Alison E. ... Size: A A A Published online Article Figures Periodontal disease (unhealthy gums and teeth) often reflects serious ...

338

Bone Grafts (Periodontal Regenerative Surgery)  

Science.gov (United States)

Bone Grafts (Periodontal Regenerative Surgery) What Is It? What It's Used For Preparation How It's Done Follow-Up Risks When To ... Before your surgery, you need to have basic periodontal treatment called scaling and root planing. You also ...

339

Lateral patellofemoral ligament reconstruction.  

Science.gov (United States)

Abstract Medial dislocation of the patella is a disabling condition; there are several reports in the literature describing this condition and its association with failed lateral retinacular release. The diagnosis and treatment of medial subluxation of the patella may be difficult. Direct repair or imbrication of the lateral retinaculum provides initial stability but a noticeable increase in medial excursion usually reappears. In this article, we describe a simple and reproducible technique to reconstruct the lateral patellofemoral ligament with autogenous tissue that is based on the basic principles of all ligament reconstruction. Reconstruction of the lateral patellofemoral ligament is useful in eliminating the symptoms related to medial instability of the patella after failed lateral retinacular release; however, it must be considered a salvage procedure because it does not address the pathomechanics that led to the initial patellofemoral symptoms. PMID:15525935

Teitge, Robert A; Torga Spak, Roger

2004-11-01

340

Lateral patellofemoral ligament reconstruction.  

UK PubMed Central (United Kingdom)

Abstract Medial dislocation of the patella is a disabling condition; there are several reports in the literature describing this condition and its association with failed lateral retinacular release. The diagnosis and treatment of medial subluxation of the patella may be difficult. Direct repair or imbrication of the lateral retinaculum provides initial stability but a noticeable increase in medial excursion usually reappears. In this article, we describe a simple and reproducible technique to reconstruct the lateral patellofemoral ligament with autogenous tissue that is based on the basic principles of all ligament reconstruction. Reconstruction of the lateral patellofemoral ligament is useful in eliminating the symptoms related to medial instability of the patella after failed lateral retinacular release; however, it must be considered a salvage procedure because it does not address the pathomechanics that led to the initial patellofemoral symptoms.

Teitge RA; Torga Spak R

2004-11-01