Junctional Epithelium (junctional + epithelium)

Distribution by Scientific Domains
Distribution within Medical Sciences


Selected Abstracts


Location of proliferating gingival cells following toothbrushing stimulation

ORAL DISEASES, Issue 1 2007
T Tomofuji
Objectives:, Mechanical stimulation by toothbrushing promotes healing of gingivitis through accelerating cell proliferation. Junctional epithelium proliferates at periodontal pocket formation. A question is arisen whether toothbrushing contributes to the repair of gingival inflammation or deterioration of pocket formation. The location of proliferating cells in gingiva stimulated mechanically by toothbrushing was investigated. Materials and methods:, A total of 24 teeth of dogs underwent daily plaque removal with a curette (plaque removal) or both plaque removal and toothbrushing (toothbrushing). Proliferative activity of gingival cells in six individual zones was evaluated by assaying expression of proliferating cell nuclear antigen (PCNA). Results:, Toothbrushing increased densities of PCNA-positive basal cells in the junctional epithelium, connective tissues adjacent to the junctional epithelium, the alveolar bone of the oral epithelial side and the oral epithelium. However, the densities of PCNA-positive cells at the apical portion of the junctional epithelium, connective tissues adjacent to the cementum and the alveolar bone of the periodontal ligament side did not increase following toothbrushing. Conclusions:, Toothbrushing promotes proliferation of gingival cells other than fibroblasts in periodontium and basal cells in the apical portion of the junctional epithelium. The repair of periodontal tissues might be promoted by toothbrushing within the limit of the direct mechanical stimulation. [source]


Keratinocyte growth factor and scatter factor expression by regionally defined oral fibroblasts

EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 1 2003
Scott Thomas William McKeown
Keratinocyte growth factor (KGF) and hepatocyte growth factor/scatter factor (SF) are two signalling molecules thought to play important roles in regulating epithelial,mesenchymal interactions. Expression of both factors by fibroblasts in subepithelial connective tissue may play a role in maintaining epithelial integrity in health and in the apical migration of junctional epithelium in periodontitis. The aims of this study were (a) to compare expression levels of KGF and SF by periodontal ligament (PDL) and gingival fibroblasts; and (ii) to determine the effects of interleukin (IL)-1,, transforming growth factor (TGF)-,1, platelet-derived growth factor (PDGF)-BB and epidermal growth factor (EGF) on KGF/SF expression by these cell populations. Three paired PDL and gingival fibroblast strains were developed. The KGF and SF protein levels were analysed by enzyme-linked immunosorbent assay. Relative levels of KGF and SF mRNA in cytokine-treated cultures were determined using semiquantitative reverse transcriptase polymerase chain reaction. No differences in the levels of KGF and SF produced by PDL and gingival (SOG) populations were found. In both cell types IL-1, stimulated KGF and SF expression, while TGF-,1 significantly inhibited expression at both the mRNA and protein levels. Epidermal growth factor and PDGF-BB induced differing effects on expression, stimulating SF protein production but inhibiting KGF output in both fibroblast populations. Differences in response to EGF and PDGF were also seen between paired PDL and gingival fibroblasts. [source]


Stability of crestal bone level at platform-switched non-submerged titanium implants: a histomorphometrical study in dogs

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 6 2009
Jürgen Becker
Abstract Objectives: To investigate the influence of platform switching on crestal bone level changes at non-submerged titanium implants over a period of 6 months. Material and Methods: Titanium implants (n=72) were placed at 0.4 mm above the alveolar crest in the lower jaws of 12 dogs and randomly assigned to either matching or non-matching (circumferential horizontal mismatch of 0.3 mm) healing abutments. At 4, 8, 12, and 24 weeks, dissected blocks were processed for histomorphometrical analysis. Measurements were made between the implant shoulder (IS) and the apical extension of the long junctional epithelium (aJE), the most coronal level of bone in contact with the implant (CLB), and the level of the alveolar bone crest (BC). Results: At 24 weeks, differences in the mean IS,aJE, IS,CLB, and IS,BC values were 0.2 ± 1.2, 0.3 ± 0.7, and 0.3 ± 0.8 mm at the buccal aspect, and 0.2 ± 0.9, 0.3 ± 0.5, and 0.3 ± 0.8 mm at the lingual aspect, respectively. Comparisons between groups revealed no significant differences at either the buccal or the lingual aspects. Conclusions: It was concluded that (i) bone remodelling was minimal in both groups and (ii) platform switching may not be of crucial importance for maintenance of the crestal bone level. [source]


Influence of platform switching on crestal bone changes at non-submerged titanium implants: a histomorphometrical study in dogs

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 12 2007
Jürgen Becker
Abstract Objectives: The aim of the present study was to investigate histomorphometrically the influence of platform switching on crestal bone changes at non-submerged wide-body titanium implants in a dog model. Material and Methods: One-stage insertion of sand-blasted and acid-etched screw-type implants with either matching (CAM) or smaller-diameter healing abutments (CPS) were randomly assigned to the lower jaws of nine beagle dogs. The animals were killed after 7, 14, and 28 days of non-submerged healing. Dissected blocks were processed for histomorphometrical analysis. Measurements were made between the implant shoulder (IS) and: , the apical extension of the long junctional epithelium (aJE), , the most coronal level of bone in contact with the implant (CLB), and , the level of the alveolar bone crest (BC). Results: At 7, 14, and 28 days, the mean IS,aJE values were significantly the lowest at CPS implants. However, after 28 days of healing, both groups revealed significantly increased mean IS,BC values at the buccal aspect of the alveolar bone. The difference in IS,CLB and IS,BC between groups was not significant. Conclusions: Within the limits of the present study, it was concluded that both CAM and CPS implants revealed crestal bone-level changes after 28 days of healing. [source]


Toothbrushing promotes gingival fibroblast proliferation more effectively than removal of dental plaque

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 9 2002
Masazumi Horiuchi
Abstract Objectives: Removal of dental plaque is an essential element of periodontal treatment. However, there have also been studies of the effects of the mechanical stimulation provided by toothbrushing on gingival host-defense mechanisms. The aim of the study was to evaluate the effects of toothbrushing on gingival fibroblast proliferation in dogs over time, compared to effects of plaque removal without brushing. Methods: The mouths of six mongrel dogs were divided into four quadrants: two for daily toothbrushing, and two for daily plaque removal with a curette. After 1, 3 and 5 weeks of treatment, histometrical analyses were performed to assess inflammatory cell infiltration, proliferating cell nuclear antigen (PCNA)-positive fibroblasts, procollagen type I-positive fibroblasts in the subepithelial connective tissue of junctional epithelium. Results: Toothbrushing increased the number of PCNA-positive fibroblasts in the first week, increased the number of type I procollagen-positive fibroblasts at the fifth week, and reduced inflammatory cell infiltration at the third week. Conclusion: These findings suggest that mechanically stimulated fibroblasts begin proliferating within a week, and this cell division results in an increased number of fibroblasts at the third week. It takes 5 weeks before differences in collagen synthesis between brushing and plaque removal areas are detectable. Zusammenfassung Die Proliferation der gingivalen Fibroblasten wird durch Zähneputzen wirkungsvoller gefördert als durch Plaqueentfernung Ziele: Die Entfernung von Zahnplaque ist ein essenzieller Bestandteil der Parodontalbehandlung. Es gibt jedoch auch Studien über die Wirkung einer durch Zähneputzen bewirkten mechanischen Stimulation der gingivalen Abwehrmechanismen. Ziel dieser Studie war es, bei Hunden die Wirkung des Zähneputzen auf die Proliferation der gingivalen Fibroblasten über eine gewisse Zeit zu untersuchen und mit der Wirkung einer Plaqueentfernung ohne Zähneputzen zu vergleichen. Methoden: Das Maul von 6 Mischlingshunden wurde in vier Quadranten unterteilt: zwei mit täglichem Zähneputzen und zwei mit täglicher Plaqueentfernung mittels Kürette. 1, 3 und 5 Wochen nach der Behandlung wurden histometrische Analysen durchgeführt um das entzündliche Zellinfiltrat, die proliferierenden Cell-Nuclear-Antigen (PCNA)-positiven Fibroblasten und die Prokollagen-I-positiven Fibroblasten des subgingivalen Bindegewebes des Saumepithels zu bestimmen. Ergebnisse: Zähneputzen erhöhte in der ersten Woche die Anzahl der PCNA-positiven Fibroblasten, erhöhte bis zur fünften Woche die Anzahl der Type-I-Prokollagen-positiven Fibroblasten und reduzierte das entzündliche Zellinfiltrat bis zur dritten Woche. Schlussfolgerung: Diese Ergebnisse lassen annehmen, dass mechanisch stimulierte Fibroblasten während einer Woche zu proliferieren beginnen und diese Zellteilung eine erhöhte Anzahl von Fibroblasten in der dritten Woche zum Ergebnis hat. Es dauert fünf Wochen bevor zwischen den Bereichen mit Zähneputzen und Plaqueentfernung Unterschiede in der Kollagensynthese nachweisbar sind. Résumé Le brossage dentaire favorise la prolifération des fibroblastes gingivaux d'une manière plus efficace que l'enlèvement de la plaque dentaire L'enlèvement de la plaque dentaire est un élément essentiel dans le traitement parodontal. Cependant, des études ont été menées sur les effets de la stimulation mécanique produit par le brossage dentaire sur les mécanismes de défense de l'hôte au niveau gingival. Le but de l'étude présente a été d'évaluer les effets du brossage dentaire sur la prolifération des fibroblastes gingivaux chez les chiens dans le temps, comparés aux effets de l'enlèvement de la plaque dentaire sans brossage. Les bouches de six chiens bâtards ont été divisés en quatre quadrants : deux pour un brossage dentaire journalier et deux pour l'enlèvement journalier de la plaque à l'aide d'une curette. Après une, trois et cinq semaines de traitement, les analyses histométriques ont été effectuées pour évaluer l'infiltration cellulaire inflammatoire, les fibroblastes positifs à l'antigène du noyau cellulaire proliférant (PCNA), les fibroblastes positifs au procollagène-I dans le tissu conjonctif sous-épithélial de l'épithélium de jonction. Le brossage dentaire augmentait le nombre de fibroblastes positifs (PCNA) durant la première semaine, augmentait le nombre de fibroblastes positifs au collagène type-1 à la cinquième semaine et réduisait l'infiltration cellulaire inflammatoire à la troisième semaine. Ces découvertes suggèrent que les fibroblastes stimulés mécaniquement commencent à proliférer en une semaine, et cette division cellulaire abouti en un nombre plus important de fibroblastes à la troisième semaine. Il faut attendre cinq semaines avant que des différences dans la synthèse du collagène entre les zones de brossage et d'enlèvement de la plaque dentaire ne soient détectables. [source]


Generalized cervical root resorption associated with periodontal disease

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 11 2001
Wouter Beertsen
Abstract Background and description of case: The etiology and pathogenesis of generalized cervical root resorptions is not well understood. In the present report, a case of severe cervical root resorption involving 24 anterior and posterior teeth is presented. The lesions developed within a period of 2 years after the patient had changed to an acid-enriched diet. They extended far into the coronal dentin and were associated with gingival inflammation and crestal bone resorption. However, no generalized clinical attachment loss had occurred. Culturing of subgingival plaque revealed the presence of several putative periodontal pathogens among which Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. Treatment consisted of mechanical debridement supported by systemic antibiotics (amoxycillin plus metronidazole) and dietary advice. Results: Within 1 year after the onset of treatment, all resorptive lesions had repaired by ingrowth of a radio-opaque mineralized tissue. The crestal areas showed radiological evidence of bone repair. 3 years after the onset of therapy, one premolar was extracted and examined histologically. It appeared that irregularly-shaped masses of woven bone-like tissue had invaded into the domain of the resorbed coronal dentin and were bordered by thin layers of acellular cementum. Conclusion: It is concluded that, in this patient, the cervical resorptions were likely the result of an osteoclastic response extending into the roots because the root-protective role of the junctional epithelium did not develop. We hypothesize that this was due to the combined effects of a periodontopathogenic microflora and a dietary confounding factor. Zusammenfassung Hintergrund und Beschreibung des Falls: Die Ätiologie und die Pathogenese der generalisierten Wurzelresorptionen ist nicht besonders bekannt. In der vorliegenden Fallpräsentation wird ein schwerer Fall von Wurzelresorption gezeigt, die 24 anteriore und posteriore Zähne einbezog. Die Läsionen entwickelten sich innerhalb einer Periode von 2 Jahren, nachdem der Patient zu einer Säure-angereicherten Diät gewechselt hatte. Die Läsionen dehnten sich in das koronale Dentin aus und waren mit gingivaler Entzündung und krestaler Knochenresorption verbunden. Jedoch wurde kein generalisierter Attachmentverlust beobachtet. Die Kultur der subgingivalen Plaque erbrachte das Vorhandensein von verschiedenen putativen parodontalen Pathogenen, unter ihnen Actinobacillus actinomycetemcomitans und Porphyromonas gingivalis. Die Behandlung bestand in der mechanischen Reinigung unterstützt mit systemischen Antibiotika (Amoxicillin und Metronidazol) und Diätanweisungen. Ergebnisse: Innerhalb eines Jahres nach dem Beginn der Therapie waren alle Resorptionsläsionen repariert durch das Einwachsen von röntgenopakem mineralisierten Gewebe. Die krestalen Regionen zeigten radiologisch nachgewiesene Knochenreparatur. 3 Jahre nach Therapiebeginn wurde ein Prämolar extrahiert und histologisch untersucht. Es schien, daß irreguläre geformte Massen von verflochtenem knochen-ähnlichen Gewebe in den Hauptteil des resorbierten koronalen Dentins hineingelangt sind und von dünnen Schichten azellulären Zementes begrenzt wurden. Zusammenfassung: Es wird geschlußfolgert, daß bei diesem Patient die zervikalen Resorptionen wahrscheinlich das Ergebnis einer osteoklastischen Reaktion waren, bis in die Wurzeln ausgedehnt, weil sich die wurzelschützende Rolle des Verbindungsepithels nich entwickelt hatte. Wir nehmen an, daß dies in der Folge eines kombinierten Effektes von parodontopathogenen Keimen und eines verwirrenden diätetischen Faktors geschah. Résumé Origine: L'étiologie et la pathogenèse des résorptions radiculaires cervicales généralisées ne sont pas suffisamment connues. Dans le rapport présent, un cas de résorption radiculaire cervicale sévère se rapportant à 24 dents antérieures et postérieures est présenté. Les lésions s'étaint développées durant les 2 années qui ont suivi le changement de régime alimentaire du patient vers un régime plus acide. Elles s'étendaient profondément dans la dentine coronaire et étaient associées à une inflammation gingivale et une résorption osseuse crestale. Cependant, aucune perte d'attache clinique généralisée n'est apparue. La culture de la plaque dentaire sous-gingivale a révélé la présence de plusieurs pathogènes parodontaux putatifs parmi lesquels l'Actinobaccilus actinomycetemcomitans et le Porphyromonas gingivalis. Le traitement a consisté en un nettoyage mécanique associéà l'utilisation d'antibiotiques par voie systémique (amoxycilline + métronidazole) et un conseil diététique. Résultats. Dans l'année qui a suivi ce traitement, toutes les lésions de résorption ont été guéries par la croissance d'un tissu minéralisé radio-opaque. Les zones crestales montraient une évidence radiologique de réparation osseuse. 3 ans après le démarrage de ce traitement, une prémolaire a été avulsée et examinée histologiquement. Il est apparu que des masses de formes irrégulières de tissus ressemblant à de l'os ouaté avaient envahi le domaine de dentine coronaire résorbé et étaient entourées par de fines couches de cément acellulaire. Conclusions: Chez ce patient, les résorptions cervicales étaient vraisemblablement dûes à une réponse ostéoclastique s'étendant dans les racines parce que le rôle de protection radiculaire de l'épithélium de jonction ne s'étaient pas développé. Cette situation était vraisemblablement dûe à des effets combinés de la microflore parodonto-pathogène et d'un facteur diététique. [source]


Treatment of intrabony defects with guided tissue regeneration and enamel-matrix-proteins

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 7 2000
An experimental study in monkeys
Abstract Background: Enamel matrix proteins (EMD) have recently been introduced in regenerative periodontal treatment. However, no histological data are yet available concerning the effect of treating intrabony periodontal defects with EMD, and no histological comparisons have been made comparing the result of treatment of intrabony defects with EMD with that of the treatment with guided tissue regeneration (GTR). Aim: Therefore, the aim of the present study was to evaluate histologically in monkeys the effect of treating intrabony defects with EMD, GTR or combined EMD and GTR. Method: Intrabony periodontal defects were produced surgically at the distal aspect of teeth 14, 11, 21, 24, 34, 31, 41 and 44 in 3 monkeys (Macaca fascicularis). In order to prevent spontaneous healing and to enhance plaque accumulation metal strips were placed into the defects. After 6 weeks the defects were exposed using a full-thickness flap procedure. The granulation tissue was removed and the root surfaces were debrided by means of hand instruments. Subsequently, the defects were treated using one of the following therapies: (i) GTR, (ii) EMD, or (iii) combination of EMD and GTR. The control defects were treated with coronally repositioned flaps. After 5 months, the animals were sacrificed and perfused with 10% buffered formalin for fixation. Specimens containing the defects and surrounding tissues were dissected free, decalcified in EDTA and embedded in paraffin. 8 ,m thick histological sections were cut and stained and subsequently examined under the light microscope. Results: In the control specimens, the healing was characterized by a long junctional epithelium and limited periodontal regeneration (i.e., new periodontal ligament, new cementum with inserting connective tissue fibers and new bone) in the bottom of the defect. The GTR-treated defects consistently presented periodontal regeneration when the membranes were not exposed whereas the sites treated only with EMD presented regeneration to a varying extent. The combined therapy did not seem to improve the results. Conclusion: It can be concluded that all 3 treatment modalities favor periodontal regeneration. [source]


Involvement of laminin and integrins in adhesion and migration of junctional epithelium cells

JOURNAL OF PERIODONTAL RESEARCH, Issue 1 2009
T. Kinumatsu
Background and Objective:, The junctional epithelium attaches to the enamel surface with hemidesmosomes (of which laminin-5 and integrin-,6,4 are the main components) in the internal basal lamina. Laminin-5 is also involved in cell motility with integrin-,3,1, although their functions have not yet been clarified. The purpose of this study was to determine the functions of those adhesive components between the tooth and the junctional epithelium during cell migration. Because an idea has been proposed that directly attached to tooth cells (DAT cells) may not contribute to cell migration, 5-bromo-2-deoxyuridine staining was performed to confirm cell migration. Material and Methods:, We investigated laminin-,2 (contained only in laminin-5), integrin-,4 (involved in cell,extracellular matrix contact) and integrin-,3 (inducing cell migration) in the junctional epithelium, oral gingival epithelium and gingival sulcus epithelium of 6-wk-old ICR mice using laser microdissection, quantitative real-time reverse transcription-polymerase chain reaction, immunofluorescence and 5-bromo-2-deoxyuridine staining. Results:, Laminin and integrins were clearly immunolocalized in the basal lamina of all epithelium. Quantitative analysis of laminin and integrin mRNAs by laser microdissection showed that they were more highly expressed in DAT cells than in basal cells in the oral gingival epithelium. In particular, a 12-fold higher expression of laminin-5 was observed in the junctional epithelium compared with the oral gingival epithelium. 5-Bromo-2-deoxyuridine staining showed rapid coronal migration of DAT cells. Conclusion:, These results suggest that the abundant expression of laminin-5 and integrin-,6,4 is involved in the attachment of DAT cells to teeth by hemidesmosomes. Abundant expression of laminin-5 and integrin-,3,1 might assist in DAT cell migration, confirmed by 5-bromo-2-deoxyuridine staining during the turnover of junctional epithelium. [source]


Expression pattern of adhesion molecules in junctional epithelium differs from that in other gingival epithelia

JOURNAL OF PERIODONTAL RESEARCH, Issue 4 2006
S. Hatakeyama
Background and Objective:, The gingival epithelium is the physiologically important interface between the bacterially colonized gingival sulcus and periodontal soft and mineralized connective tissues, requiring protection from exposure to bacteria and their products. However, of the three epithelia comprising the gingival epithelium, the junctional epithelium has much wider intercellular spaces than the sulcular epithelium and oral gingival epithelium. Hence, the aim of the present study was to characterize the cell adhesion structure in the junctional epithelium compared with the other two epithelia. Material and Methods:, Gingival epithelia excised at therapeutic flap surgery from patients with periodontitis were examined for expression of adhesion molecules by immunofluorescence. Results:, In the oral gingival epithelium and sulcular epithelium, but not in the junctional epithelium, desmoglein 1 and 2 in cell,cell contact sites were more abundant in the upper than the suprabasal layers. E-cadherin, the main transmembranous molecule of adherens junctions, was present in spinous layers of the oral gingival epithelium and sulcular epithelium, but was scarce in the junctional epithelium. In contrast, desmoglein 3 and P-cadherin were present in all layers of the junctional epithelium as well as the oral gingival epithelium and sulcular epithelium. Connexin 43 was clearly localized to spinous layers of the oral gingival epithelium, sulcular epithelium and parts of the junctional epithelium. Claudin-1 and occludin were expressed in the cell membranes of a few superficial layers of the oral gingival epithelium. Conclusion:, These findings indicated that the junctional epithelium contains only a few desmosomes, composed of only desmoglein 3; adherens junctions are probably absent because of defective E-cadherin. Thus, the anchoring junctions connecting junctional epithelium cells are lax, causing widened intercellular spaces. In contrast, the oral gingival epithelium, which has a few tight junctions, functions as a barrier. [source]


In situ detection of matrix metalloproteinase-9 (MMP-9) in gingival epithelium in human periodontal disease

JOURNAL OF PERIODONTAL RESEARCH, Issue 2 2004
Patricio C. Smith
Background and objective:, As the periodontal lesion develops, the junctional epithelium migrates apically in conjunction with the dissolution of the most coronal Sharpey's fibers. Because matrix metalloproteinase-9 (MMP-9) has been identified in migrating epithelial cells and invading tumors, we propose that this enzyme is produced by gingival keratinocytes in advanced periodontal lesions. Methods:, To test this idea, biopsies of inflamed gingival tissues were obtained from patients with advanced periodontitis. Healthy gingival tissue samples were utilized as controls. The presence and activity of MMP-9 was evaluated by combining indirect immunofluorescence of gingival tissue samples and gelatin zymography of gingival epithelium separated from connective tissue. Results and conclusions:, The staining pattern showed the presence of MMP-9 in junctional and pocket gingival epithelial cells, polymorphonuclear neutrophils (PMNs) and as a scattered deposit along connective tissues of periodontitis-affected gingival tissues. Gelatin zymography permitted the identification of pro-MMP-9 in surcular/pocket epithelium derived from inflamed gingival tissues. Lower levels of MMP-9 were detected in epithelium not exposed to inflammation. These observations suggest a role for MMP-9 in gingival epithelial response to periodontal infection. [source]


Different distribution of immunocompetent cells in the dentogingival junction during root formation in rat molars

JOURNAL OF PERIODONTAL RESEARCH, Issue 1 2003
Hiroshi Tamura
The distribution of immunocompetent cells in the dentogingival junction of rat molars during root formation was investigated by immunocytochemistry using antibodies to class II major histocompatibility complex (MHC) molecules (OX6-antibody) and monocyte/macrophage lineage cells (ED1-antibody) as well as by histochemical reaction for periodic acid,Schiff (PAS). Two portions (the junctional epithelium in the mesial gingiva of the first molar, and the interdental gingiva between the first and second molars) were selected for observations. At the eruption stage of the first molar (16,18 days after birth), OX6-positive cells, dendritic or oval in shape, were abundantly distributed in the connective tissue between the oral epithelium and tooth germ. Positive cells with slender cell processes were also found beneath the ameloblast layer. At the commencement stage of the first molar occlusion (24,28 days after birth), numerous OX6-positive cells displaying a dendritic fashion existed preferentially in the mesial gingiva, but were fewer in the interdental gingiva. In contrast, the interdental gingiva showed a denser distribution of ED1-positive cells and PAS-reactive polymorphonuclear leukocytes (PMLs) than the mesial gingiva. At the completion stage of root formation (100,120 days after birth), the OX6-immunopositive cells invaded the deeper position of the mesial gingiva with the downgrowth of the epithelium; they had a considerably higher cell density compared with those in the interdental gingiva where PAS-reactive PMLs persisted. These findings indicated that the immunocompetent cells showed a region-specific distribution and cell density by their roles in immune response. [source]


Localized antimicrobial peptide expression in human gingiva

JOURNAL OF PERIODONTAL RESEARCH, Issue 5 2001
Beverly A. Dale
The stratified epithelia of the oral cavity are continually exposed to bacterial challenge that is initially resisted by innate epithelial factors and by the recruitment of neutrophils. Antimicrobial peptides from phagocytes and epithelia contribute to this antimicrobial barrier. Using antibodies and in situ hybridization, we explored antimicrobial peptide expression in the varied epithelia of the periodontium and in cultured gingival epithelial cells. In gingival tissue, mRNA for the ,-defensins, human beta-defensin 1 (hBD-1) and human beta-defensin 2 (hBD-2) was predominately localized in suprabasal stratified epithelium and the peptides were detected in upper epithelial layers consistent with the formation of the stratified epithelial barrier. In cultured epithelial cells, both hBD-1 and -2 peptides were detected only in differentiating, involucrin-positive epithelial cells, although hBD-2 required stimulation by proinflammatory mediators or bacterial products for expression. ,-defensins were not detected in junctional epithelium (JE) that serves as the attachment to the tooth surface. In contrast, ,-defensins and cathelicidin family member LL-37 were detected in polymorphonuclear neutrophils (PMNs) that migrate through the JE, a localization that persists during inflammation, when the JE and surrounding tissue are highly infiltrated with PMNs. Thus, the undifferentiated JE contains exogenously expressed ,-defensins and LL-37, and the stratified epithelium contains endogenously expressed ,-defensins. These findings show that defensins and other antimicrobial peptides are localized in specific sites in the gingiva, are synthesized in different cell types, and are likely to serve different roles in various regions of the periodontium. [source]


Location of proliferating gingival cells following toothbrushing stimulation

ORAL DISEASES, Issue 1 2007
T Tomofuji
Objectives:, Mechanical stimulation by toothbrushing promotes healing of gingivitis through accelerating cell proliferation. Junctional epithelium proliferates at periodontal pocket formation. A question is arisen whether toothbrushing contributes to the repair of gingival inflammation or deterioration of pocket formation. The location of proliferating cells in gingiva stimulated mechanically by toothbrushing was investigated. Materials and methods:, A total of 24 teeth of dogs underwent daily plaque removal with a curette (plaque removal) or both plaque removal and toothbrushing (toothbrushing). Proliferative activity of gingival cells in six individual zones was evaluated by assaying expression of proliferating cell nuclear antigen (PCNA). Results:, Toothbrushing increased densities of PCNA-positive basal cells in the junctional epithelium, connective tissues adjacent to the junctional epithelium, the alveolar bone of the oral epithelial side and the oral epithelium. However, the densities of PCNA-positive cells at the apical portion of the junctional epithelium, connective tissues adjacent to the cementum and the alveolar bone of the periodontal ligament side did not increase following toothbrushing. Conclusions:, Toothbrushing promotes proliferation of gingival cells other than fibroblasts in periodontium and basal cells in the apical portion of the junctional epithelium. The repair of periodontal tissues might be promoted by toothbrushing within the limit of the direct mechanical stimulation. [source]


Ultrastructural study of tissues surrounding replanted teeth and dental implants

CLINICAL ORAL IMPLANTS RESEARCH, Issue 3 2009
Kazuhiro Shioya
Abstract Objectives: The aim of this study was to describe the ultrastructure of the dentogingival border at replanted teeth and implants. Material and methods: Wistar rats (8 weeks old) were divided into groups for replantation and implantation experiments. In the former, the upper right first molars were extracted and then immediately replanted. In the latter, pure titanium implants were used. All tissues were fixed, demineralized and embedded in epoxy resin for ultrastructural observations. Results: One week after replantation, the junctional epithelium was lost, and the oral sulcular epithelium covered the enamel surface. The amount of the epithelium increased in 2 weeks, and resembled the junctional epithelium, and the internal basal lamina and hemidesmosomes were formed in 4 weeks. One week after implantation, peri-implant epithelium was formed, and in 2 and 4 weeks, this epithelium with aggregated connective tissue cells were observed. In 8 weeks, the peri-implant epithelium receded, and aligned special cells with surrounding elongated fibroblasts and bundles of collagen fibers appeared to seal the implant interface. Conclusion: In replantation of the tooth, the internal basal lamina remained at the surface of the enamel of the replanted tooth, which is likely to be related to regeneration of the junctional epithelium and the attachment apparatus at the epithelium,tooth interface. Following implantation, a layer of cells with characteristics of connective tissue cells, but no junctional epithelium and attachment apparatus, was formed to seal the site of the implant. [source]