Defense Mechanism of Gingiva

8/13/2019 Defense Mechanism of Gingiva

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DEFENSE MECHANISMS

OF GINGIVA

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1. Epithelium Degree of keratinization &turn over rate.

2. Sulcular Fluid

3. Leukocytes4. Saliva

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SULCULAR FLUID/GINGIVALCREVICULAR FLUID

Waerhaug & Brill & Krasse 1950. Brill transudate

Other exudate

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METHOD OF COLLECTION

In a strictly normal gingiva little or no GCFa. Absorbing paper strips.

b. Pre weighed twisted threadsc. Micropipettesd. Intracrevicular washing

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INTRASULCULARMETHOD

(Placed within thesulcus)

EXTRASULCULARMETHOD

(Placed at itsentrance)

BRILL TECHNIQUE INSERTS IT INTO THE POCKET:CAUSES

IRRITATION OF THE SULCULAR EPITHELIUM THAT CAN BYITSELF TRIGGER THE FLOW OF FLUID.

LOE and HOLM-PEDERSEN :PLACED FILTER PAPER JUST AT THE ENTRANCE OF THE POCKET

ABSORBING PAPER STRIPS

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PREWEIGHED TWISTED THREADS

THREADS PLACED IN THE GINGIVALCREVICE AROUND THE TOOTH ,AND

THE AMOUNT OF FLUID COLLECTED WAS ESTIMATED BY WEIGHING THESAMPLE THREAD.

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MICROPIPETTES

COLLECTION OF FLUID BY CAPILLARY

CAPILLARY TUBES OF STANDARDIZEDLENGTH AND DIAMETER ARE PLACED IN THE POCKET AND THEIR CONTENT ISLATER CENTRIFUGED AND ANALYSED

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CREVICULAR SHAVINGS STUDY GCF FROM CLINICALLY NORMALGINGIVA. METHOD 1: USES AN APPLIANCE CONSISTING

OF A HARD ACRYLIC PLATE COVERING THEMAXILLA WITH SOFT BORDERS AND AGROOVE FOLLOWING GINGIVAL MARGIN

CONNECTED TO FOUR COLLECTION TUBES

WASHINGS OBTAINED BY RINSING THECREVICULAR AREAS FROM ONE SIDE TOOTHER,USING A PERISTALTIC PUMP. 8


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MODIFICATION TWO INJECTION NEEDLES FITTED ONE WITHIN

THE ANOTHER SUCH THAT DURING SAMPLING, THE INSIDE (EJECTION) NEEDLE IS AT THEBOTTOM OF THE POCKET,AND THE OUTSIDE(COLLECTING) NEEDLE IS AT THE GINGIVALMARGIN.

THE COLLECTION NEEDLE IS DRAINED INTO ASAMPLE TUBE BY CONTINUOUS SUCTION.

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AMOUNTWetted area stained with ninhydrinElectronic method-wetness affect the flow of anelectronic current-digital read out.Strip of paper 1.5 mm wide and inserted 1mmwithin the gingival sulcus absorbs 0.1 mg of GCFin 3 minsMean crevicular fluid volume in proximal spacesfrom molar teeth ranged from 0.43 to 1.56 micro lt

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ELECTRONIC DEVICE FOR MEASURING THE AMOUNT OF FLUID COLLECTED ON

FILTER PAPER

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PLACEMENT OF FILTER STRIP IN GINGIVAL SULCUS

FOR COLLECTION OF FLUID

A: INTRASULCULAR METHODB & C: EXTRASULCULAR METHOD

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COMPOSITION Proteins, specific Ab, Ag, enzyme, cellularelements 40 compounds analyzed so far.eg glucuronidase, LDH, fibroblast, PMN,collagenases phospholipase.

CELLULAR ELEMENTS Bacterial desquamated epithelial cells,

leukocytes [PMNs,lymphocytes,monocytes]INORGANIC COMPONENTS Na,K,Ca

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ORGANIC COMPONENTS Carbohydrates and proteins

Glucose hexosamine & hexuronic acidGlucose concentration is 3-4 times

greater than in serumProtein content much less then serum

Metabolic and bacterial products

Lactic acid Urea Hydroxyproline

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ENZYMES IN GCF

ACID PHOSPHATASE ALKALINE PHOSPHATASE 1 ANTITRYPSIN ARYLSULFATASE

ASPARTATE AMINOTRANSFERASE CHONDROITAN SULFATASE CITRIC ACID CYSTATINS CYTOKINES ENDOPEPTIDASES EXOPEPTIDASES

FIBRIN FIBRONECTIN15


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COMPOUNDS AND ENZYMES OFPOSSSIBLE BACTERIAL ORIGIN

DETECTED IN GCF

ACID PHOSPHATASE ALKALINE PHOSPHATASE AMINOPEPTIDASES CHONDROITAN SULFATASE CHYMOTRYPSIN LIKE PRODUCT COLLAGENASE

DEOXYRIBONUCLEASE FIBRINOLYSIN GLUCOSIDASES HEMOLYSIN

HYALURONIDASE 16


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CELLULAR/ HUMORAL

ACTIVITY Cytokines-Interleukin-1,IL-1.IL-6 and IL-8

Interleukin 1 and IL 1 increase the binding ofPMN and monocytes/macrophages to endothelialcells,stimulate the production of PGE2 and release oflysosomal enzymes and stimulate bone resorption

Interferon :- inhibits bone resorption activity of interleukin1- .

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CLINICAL SIGNIFICANCE

G.F. increased by mastication of coarse foods,tooth brushing, gingival massage, ovulation,hormonal contraceptives and smoking

The amount of GCF is greater when inflammmationis present and is sometimes proportional to theseverity of inflammation.

GCF production not increased by trauma fromocclusion.

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CIRCADIAN PERIODICITY:-gradual increase from 6am-10pm & a decreaseafterwards.

SEX HORMONE:- female sex hormones increase flow-enhance vascularpermeability.

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PERIODONTAL THERAPY:- Increase during healing.

DRUGS:- Tetracycline excreted through GCFMetronidazole

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LEUKOCYTES IN DENTOGINGIVAL AREA

Leukocytes have been found in clinically healthgingival sulci (Neutrophils)

58% B lymphocytes24% T lymphocytes18% mononuclear phagocytesT:B :: 1:3

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Leukocytes are attracted by different plaquebacteria but can also be found in the

dentogingival region of germ free adult animals. Leukocytes in the gingival sulcus in

nonmechanically irritated(resting) healthy

gingiva,indicating that their migration may beindependent of an increase in vascularpermeability

Majority of cells are viable and have phagocyticand killing capacity.

Leukocytes constitute major protectivemechanism against extension of plaque into thein ival sulcus. 22


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SALIVA

Salivary secretions are protective because theymaintain the oral tissues in physiologic state.

Exert major influence on plaqueby mechanically cleansing the exposed oral surface by buffering acid produced by bacteria andby controlling bacterial activity

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FUNCTION SALIVARY COMPONENTS PROBABLE MECHANISM


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FUNCTION SALIVARY COMPONENTS PROBABLE MECHANISM

LUBRICATION GLYYCOPROTEINS,MUCOIDS

COATING SIMILAR TOGASTRIC MUCIN

PHYSICAL PROTECTION GLYCOPROTEINS,MUCOIDS

COATING SIMLAR TOGASTRIC MUCIN

CLEANSING PHYSICAL FLOW CLEARANCE OF DEBRIS AND BACTERIA

BUFFERING BICARBONATE ANDPHOSPHATE

ANTACIDS

TOOTH INTEGRITYMAINTENANCE

MINERALS,

GLYCOPROTEIN

PELLICLE

MATURATION,REMINERALIZATION,MECHANICAL

PROTECTION ANTIBACTERIAL ACTION IgA.

LYSOZYME,

LACTOPEROXIDASE

CONTROL OF BACTERIALCOLONIZATIONBREAKS BACTERIAL CELL

WALLS

OXIDATION OFSUSCEPTIBLE BACTERIA24


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ANTIBACTERIAL FACTORS

Contains numerous organic & inorganicfactors that influence bacteria & their products

in the oral environmentIgG maximum in GCFIgA maximum in salivaIgM also present

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INORGANIC


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INORGANICIons & gases, bicarbonates, Na, K, PO4 ,Ca, F, NH4 & CO

2ORGANIC Lysozyme , lactoferrin, Myeloperoxidas

lactoperoxidase & agglutinins such as glycoproteinmucins, beta-2 macroglobulins, fibronectin anantibodies. Lysozyme is hydrolytic enzyme, that cleaves thelinkage between structural components of theglycopeptide muramic acid containing region ofthe cell wall of certain bacteria in vitro.

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The Lactoperoxidase-thiocynatesystem: bactericidal to some strains oflactobacillus & streptococcus.

Lactoferrin :- Effective againstactinobacillus sp.

Myeloperoxidase :- Bactericidal foractinobacillus.

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SALIVARY ANTIBODIES

Appear to be synthesized locally for they reactwith strains of bacteria of mouth but not with

organisms characteristic of intestinal tract. The enzymes normally found in saliva arederived from salivary glands, bacteria,

leukocytes, oral tissues & ingested substances Major enzymes PAROTID AMYLASE.

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Proteolytic enzymes in Saliva are generatedby both the host & oral bacteria.They have been recognized as contributors tothe initiation & progression of PD diseaseTo combat these enzymes Saliva contains antiproteases. Eg TIMP (tissue inhibitors of matrix

metallo proteinases) inhibits the activity ofcollagen degrading enzyme.

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Hi h l l i h i l i


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High molecular weight mucinous glycoproteinsin saliva bind specifically to many plaqueforming bacteria.

The glycoprotein-bacteria interactions facilitatebacterial accumulation on the exposed toothsurface

The interbacterial matrix of human plaqueappears to contain polymers similar to salivaryglycoproteins---aid in maintaining integrity of

plaque. These glycoproteins selectively adsorb to the

hydroxyapatite to make up part of acquired

pellicle. 30


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Other salivary glycoproteins inhibit the sorptionof some bacteria to the tooth surface and toepithelial cells of the oral mucosa

Mucin also causes deletion of bacterial cellsfrom the oral cavity by aggregation with mucinrich films.

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SALIVARY BUFFERS &COAGULATION FACTORS

Maintenance of PH at mucosal epithelial cellsurfaces & tooth surfaces. E.g. bicarbonate

carbonic acid system.Saliva contains coagulation factorsFactors VIII, IX, X plasma thromboplastin

antecedent & hageman factor that hastenblood coagulation (PTA) & protect woundsfrom bacteria

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LEUKOCYTES

PMNS

Living PMNS in saliva -OROGRANULOCYTE & theirrate of migration in oral cavity is termed as

OROGRANULOCYTIC MIGRATORY RATE

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ROLE IN PERIODONTALPATHOLOGY

SALIVA EXERTS INFLUENCE* Plaque initiation

* Maturation*Metabolism SALIVARY FLOW & COMPOSITION

*Calculus formation*Periodontal disease*Caries

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The removal of the salivary glands inexperimental animals significantly increases theincidence of dental caries and periodontaldisease and delays wound healing

In humans,an increase in inflammatory gingivaldiseases,dental caries and rapid tooth destructionassociated with cervical or cemental caries ispartially a consequence of decreased salivarygland secretion (Xerostomia)

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Xerostomia results from:

Sialolithiasis Sarcoidosis

Sjogrens syndrome Mikuliczs disease Irradiation

Surgical removal of salivary glands

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Defense Mechanism of Gingiva