Defense Mechanisms of Gingiva_9c22cf914243d272b89a7a4f54a4e350
Defense Mechanisms of the Gingiva
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OverviewProf. Burcu KARADUMANDepartment of Periodontology
Focuses on gingival tissue and its defense mechanisms.
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Gingival Tissue
Constant exposure to mechanical trauma and bacterial aggressions.
Resistance provided by saliva, epithelial surface, and inflammatory response.
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Diagram Breakdown
Components Relevant to Gingival Health:
Plaque
Saliva
Tooth
Sulcular fluid
Permeability of junctional and sulcular epithelia
Leukocytes including PMNs (Polymorphonuclear leukocytes)
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Gingival Crevicular Fluid (GCF)
Key substance associated with gingival health and disease.
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Definition of GCF
Physiological fluid in the gingival crevice; classified as an inflammatory exudate during disease or serum transudate during health.
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Historical Background
Known since the 19th century, studied by Brill and Krasse in the 1950s.
Notable experiment: use of filter paper in the sulcus of fluorescein-injected animals.
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Formation of GCF
Epithelial lining of the sulcus allows molecule passage through intercellular spaces.
Wide range of molecules can penetrate epithelial barriers.
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GCF in Health vs. Disease
Health: GCF secreted as transudate due to osmotic gradients.
Periodontal Disease: Turns into exudate due to inflammation.
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Fluid Dynamics
In healthy individuals, excess fluid generally drains through lymphatics, leading to minimal transudate.
In disease, increased fluid leaks occur beyond lymphatic capacity, forming inflammatory exudate.
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Molecules Permeable to Epithelia
Includes Albumin, Endotoxin, Histamine, and others, with molecular weight up to 1000 KD.
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Methods for Collection of GCF
Absorbing paper strips
Twisted threads
Micropipettes
Intracrevicular washings
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GCF Collection Techniques
Intrasulcular Method (Brill Technique): Paper strips placed inside sulcus.
Extrasulcular Method (Löe and Holm-Pedersen): Strips placed at sulcus entrance.
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Technique Details
Brill’s technique may irritate sulcular epithelium, inducing fluid flow.
Löe and Holm-Pedersen’s method minimizes irritation by keeping strips at the entrance.
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Comparison of Techniques
Brill's Technique: Inserting into the sulcus.
Löe and Holm-Pedersen Technique: Positioned over the sulcus without penetration.
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GCF Collection Positioning
Strips positioned across tooth, gingiva, and alveolar mucosa.
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Twisted Threads Method
Threads placed in gingival crevice and fluid collection estimated by weighing.
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Micropipettes Use
Collect fluids via capillarity and analyze post-centrifugation.
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Crevicular Washings
Technique using an appliance to rinse crevicular areas, collecting fluid through a peristaltic pump.
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Modified Crevicular Washings
Involves a two-needle system for fluid collection via continuous suction.
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Collection Techniques Illustrated
Visual representation of suction, saline flush, and GCF sampling.
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GCF Evaluation Methods
Visual Staining: Ninhydrin to evaluate wetted area on paper strips.
Electronic methods: Periotron to measure GCF.
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Periotron Measurement
Illustrates electronic measures of collected GCF.
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Linear Measurement Methods
Utilization of stained paper strips.
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GCF Volume Insights
1.5 mm wide paper absorbs only 0.1 mg in 3 minutes.
Mean GCF volume in molar teeth ranges from 0.43-1.56 µl.
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GCF Collection Issues
Contamination, small sample size, prolonged sampling effects, and evaporation leading to inaccuracies.
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Unknown Compounds in GCF
Over 40 compounds analyzed; origins unclear (hosts, bacteria-derived).
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Cellular Elements in GCF
Includes bacteria, desquamated epithelial cells, leukocytes of various types: PMNs, lymphocytes, monocytes/macrophages.
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Electrolytes Studied
Key ions (K, Na, Ca) correlate positively with inflammation levels.
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Organic Compounds in GCF
Higher GCF glucose concentration than serum by 3-4 times.
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Metabolic Products Detected
Include lactic acid, urea, endotoxins, and various cytotoxic substances.
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GCF Composition Analysis Methods
Techniques: Fluorometry, ELISA, Radioimmunoassay, HPLC, Immunodot tests.
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Cellular Activity in GCF
IL-1α and IL-1β influence leukocyte binding, stimulate PGE-2 production, and affect bone resorption.
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Interferon-α Role
Protective against IL-1β-induced bone resorption during periodontal disease.
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GCF as a Diagnostic Tool
Components indicate periodontal disease progression; includes inflammatory mediators and host-response modifiers.
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Clinical Significance of GCF
GCF correlates positively with inflammation severity; influenced by various factors like food, hygiene practices, hormonal changes.
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Circadian Rhythm of GCF
Flow increases from 6 am to 10 pm, decreases thereafter; influenced by female hormones.
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Stimulation Effects on GCF Flow
Mechanical stimulation (chewing, brushing) enhances flow; smoking increases GCF production transiently.
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Therapeutic Potential
Drugs like Tetracycline and Metronidazole are excreted through GCF, beneficial for treatment.
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Leukocytes in the Dentogingival Area
PMNs are predominant and essential defense cells in the gingival sulcus.
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Presence of Leukocytes
Found in gingival sulcus even without inflammation; PMNs make up about 91% of leukocytes.
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Mononuclear Cell Composition
B cells (58%), T cells (24%), and mononuclear phagocytes (18%).
T:B cell ratio in GCF shifts from 3:1 in blood to 1:3.
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Saliva Overview
Physiologic secretion from various salivary glands; functions include cleansing, lubrication, and antibacterial properties.
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Antibacterial Factors in Saliva
Inorganic and organic factors contribute to antibacterial activity, including ions and enzymes.
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Inorganic Antibacterial Factors
Includes various ions like Na, K, and bicarbonate, which aid in maintaining oral health.
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Organic Antibacterial Factors
Enzymes such as lysozyme, lactoperoxide, and myeloperoxidase target specific oral bacteria.
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Salivary Enzymes in Periodontal Disease
Increased in conditions like periodontal disease, include hyaluronidase and collagenase.
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Salivary Antibodies
Predominantly IgA; IgG is more abundant in GCF.
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Interactions in Immune Function
Salivary antibodies impair bacterial attachment, important for oral immune defense.
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Salivary Buffers and Coagulation
Maintain pH balance and contain coagulation factors crucial for wound protection.
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Leukocytes in Saliva
PMNs are prevalent; their numbers vary person to person.
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Orogranulocyte Migration
Refers to PMNs entering the oral cavity through the gingival sulcus.
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Physical Protection Mechanisms
Salivary components like glycoproteins provide mechanical protection and cleansing action.
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Role in Periodontal Pathology
Saliva influences plaque formation, periodontal disease, and dental caries risk.
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Effects of Reduced Salivary Flow
Conditions like Mikulicz’s disease lead to increased periodontal disease severity due to reduced saliva.