Preclinical Preclinical periodontologyperiodontology

PeriodontologyPeriodontologyBranch of Dentistry deals with the Branch of Dentistry deals with the

diseases & treatment of diseases & treatment of PeriodontiumPeriodontium

PeriodontiumPeriodontiumsupporting tissues supporting tissues

supporting teeth in the supporting teeth in the archesarches

Periodontium composed Periodontium composed from four partsfrom four parts

GingivaGingivaPeriodontal ligamentPeriodontal ligament

Cementum Cementum Alveolar boneAlveolar bone

Periodontal diseases have Periodontal diseases have afflicted humans since the afflicted humans since the dawn of history & studies dawn of history & studies showed that destructive showed that destructive periodontal diseases as periodontal diseases as evidenced by bone loss evidenced by bone loss affected ancient egyptaffected ancient egypt

Oral hygiene was practiced by Oral hygiene was practiced by sumerians as seen gold toothpicks sumerians as seen gold toothpicks

found in excavations atfound in excavations at OROR

babylonians & assyrians suffered babylonians & assyrians suffered from periodontal problems & they from periodontal problems & they

were treating them by Gingival were treating them by Gingival massage combined with various massage combined with various

herbal medicationsherbal medications

Later on, during golden age Later on, during golden age of arabic science & medicine, of arabic science & medicine,

Ibn Sina was greatest Ibn Sina was greatest physicians with his text the physicians with his text the Canon that involve Gingival Canon that involve Gingival disease as bleeding gum, disease as bleeding gum,

ulcers ,recession & ulcers ,recession & separation of gum & epulisseparation of gum & epulis

Abul Qasim described Abul Qasim described role of calculus deposit role of calculus deposit

in etiology of periodontal in etiology of periodontal disease & technique of disease & technique of

scaling the teeth using a scaling the teeth using a set of instruments that set of instruments that

he developed,he developed,he also wrote in details he also wrote in details splinting loose teeth splinting loose teeth

with gold wirewith gold wire

Histology & Anatomy of periodontium

Histology & Anatomy of periodontiumGingiva

Together with hard palate form masticatory mucosa

its part of oral mucosa that covers Alveolar process & surround the neck

of teeth

Gingiva is of three parts

attached Marginal

Interdental papillae

Marginal(Free,unattached)

terminal edge of Gingiva surrounding teeth in a collar-

like fashion

Marginal(Free,unattached)

its demarcated from Attached Gingiva by shallow linear depression known as free Gingiva groove in about 50% of

people, its positioned at a level corresponding to

level of CEJ

Pink in colorPink in color firm in consistency firm in consistency scalloped outline scalloped outline

free Gingiva rounded in free Gingiva rounded in such away that small such away that small

sulcus is formedsulcus is formed

its of 1.5-2mm in depthits of 1.5-2mm in depth& about 1mm in & about 1mm in widthwidth

InterDental InterDental papillaepapillae

its shape determine by contact its shape determine by contact relationship, relationship,

in anterior region is pyramidal in anterior region is pyramidal in molar its more flattened in BL in molar its more flattened in BL

direction & consist of 2 papillae & col direction & consist of 2 papillae & col shape( valley like depression ) connect shape( valley like depression ) connect them & conform to shape of the above them & conform to shape of the above

contact areacontact area

in absence of proximal tooth contactin absence of proximal tooth contactGingiva is firmly bound over InterdentalGingiva is firmly bound over Interdental

bonebone& & form smooth rounded surfaceform smooth rounded surface

firm & tightly bound to firm & tightly bound to underlying periosteum & underlying periosteum &

extend to movable & loose extend to movable & loose oral mucosa where its oral mucosa where its separated from it by separated from it by

Mucogingival junctionMucogingival junction

Attached GingivaAttached Gingiva

Its pink in color with Its pink in color with stippling (orange peel) in stippling (orange peel) in

40% of people due to 40% of people due to presence of minute presence of minute depression in oral depression in oral

epithelium at the collection epithelium at the collection of retepegeof retepege

Attached GingivaAttached Gingiva

Its width range between 1-9mmIts width range between 1-9mm& & gradually increase with agegradually increase with age

due to occlusal weardue to occlusal wear so teeth is slowly eruptso teeth is slowly erupt

MoreMore in maxilla in maxilla than mandible with least than mandible with least

width width in the 1in the 1stst premolar region premolar region

palatal surface in maxilla palatal surface in maxilla blends imperceptibly with blends imperceptibly with

equally firm, resilient palatal equally firm, resilient palatal mucosamucosa

Gingival contourGingival contour

marginal Gingiva envelops teeth in marginal Gingiva envelops teeth in collar like fashion & follows a collar like fashion & follows a

scalloped outline on Facial & oral scalloped outline on Facial & oral surfacessurfaces

It form a straight line along teeth It form a straight line along teeth with flat surfaceswith flat surfaces

on teeth with labial version on teeth with labial version as upper canine, the normal as upper canine, the normal

contour is accentuated & contour is accentuated & Gingiva located farther Gingiva located farther

apicallyapically

teeth with lingual version, teeth with lingual version, Gingiva becomes horizontal Gingiva becomes horizontal & thickened shelf-like that & thickened shelf-like that

its aggravated by local its aggravated by local irritation of Dental Plaqueirritation of Dental Plaque

Microscopical Microscopical AnatomyAnatomy

Epithelium covers Free Epithelium covers Free Gingiva is differentiated intoGingiva is differentiated into Oral Epithelium facing oral Oral Epithelium facing oral

cavity & covers free & cavity & covers free & Attached Gingiva,Attached Gingiva,

sulcular epithelium lining sulcular epithelium lining the sulcus & the sulcus &

Junctional Epithelium Junctional Epithelium bringing Gingiva in contact bringing Gingiva in contact

with toothwith tooth

Oral Epithelium are Oral Epithelium are keratinized stratified keratinized stratified squamous cells with squamous cells with

retepeges while Sulcular & retepeges while Sulcular & Junctional are not Junctional are not

keratinized ,keratinized ,only Sulcular one of them only Sulcular one of them

has retepegeshas retepeges

Epithelium composed Epithelium composed ofof

1- basal cells layer faces 1- basal cells layer faces basement membrane & its basement membrane & its

mitotic activity induces new cells mitotic activity induces new cells that migrate to surfacethat migrate to surface2- spinous cells layer 2- spinous cells layer 3- granular cells layer3- granular cells layer

4- keratinized cells layer;4- keratinized cells layer;keratine filled flattened cell, keratine filled flattened cell,

deprived of energy production deprived of energy production & its of 2 types,& its of 2 types,

Orthokeratine without Orthokeratine without nucli & parakeratine with nucli & parakeratine with

nuclinucli

Epithelium composed Epithelium composed ofof

Oral Epithelium also hasOral Epithelium also has melanocytes, melanocytes, langerhans & langerhans &

non-specific cells that are non-specific cells that are stellate cellsstellate cells

MelanocytesMelanocytes

pigment containing cells ,pigment containing cells ,they synthesize melanin,they synthesize melanin,

melanin granules that phagocytosed & melanin granules that phagocytosed & contained within other cells of contained within other cells of

epithelium & connective tissue called epithelium & connective tissue called melanophagesmelanophages or or melanophoresmelanophores

LangerhanseLangerhanse

immune cells that react with Ag, its immune cells that react with Ag, its belong to mononuclear phagocyte belong to mononuclear phagocyte

system (reticuloendothelial system) system (reticuloendothelial system) as modified monocyte derived from as modified monocyte derived from

bone marrowbone marrow

Merkel cellsMerkel cells

located in deeper layer of epithelium located in deeper layer of epithelium harbor nerve ending & connected to harbor nerve ending & connected to

adjacent cells by desmosoms,adjacent cells by desmosoms,its identified as tactile perceptorsits identified as tactile perceptors

HemidesmosomHemidesmosom

Cell membrane of epithelial cells that Cell membrane of epithelial cells that face Basement Membrane has a no. face Basement Membrane has a no.

of electron dense thicker zones of electron dense thicker zones appearing at various intervals along appearing at various intervals along

cell membrane, tonofilament of cell membrane, tonofilament of cytoplasm converge toward these cytoplasm converge toward these

structurestructure It involves in attachment of epithelial It involves in attachment of epithelial

cells to Basement Memranecells to Basement Memrane

Pair of adjacent Pair of adjacent Hemidesmosom formHemidesmosom form Desmosom Desmosom among among

adjacent cellsadjacent cells

Junctional Junctional EpitheliumEpithelium

Its formed by joining of Reduced Its formed by joining of Reduced Enamel Epithelium (ameloblast + Enamel Epithelium (ameloblast + outer Enamel epithelium) & Oral outer Enamel epithelium) & Oral

EpitheliumEpithelium

Its 0.25-1.35mm in Its 0.25-1.35mm in coronoapical dimension & coronoapical dimension &

about 0.15mm wideabout 0.15mm wide

Larger cells, wider Larger cells, wider intercellular space & less intercellular space & less

desmosomsdesmosoms

Junctional Junctional EpitheliumEpithelium

The junctional epithelium is attached to the tooth

surface (epithelial attachment) by mean of an internal basal lamina

and to the gingival connective tissue by anexternal basal lamina that has the same

structure as other epithelial-connective tissue attachments elsewhere

in the body.

The internal basal lamina consists of a

lamina densa adjacent to the enamel

and a lamina lucida to which hemidesmosomes are attached Organic strands from the enamel

appear to extend into the lamina densa

The junctional epithelium attaches to afibrillar

cementum present on the crown

(usually restricted to an area

within 1 mm of the cementoenamel junction) and root cementum in a

similar manner

The attachment of the junctional epithelium to

the tooth is reinforced by the gingival fibers,

which brace the marginal gingiva

against the tooth surface

For this reason, the junctional epithelium

and the gingival fibers are considered

a functional unit, referred to as

the dentogingival unit

Connective tissues of Gingiva

Composed of Collagen fibers (60%),

fibroblast(5%),vessels, nerves & matrix (35%)

with mast cells, macrophage, lymphocyte, neutrophil, plasma cells

Connective tissue fibers are produced by fibroblast &

divided into collagen , reticulin & elastic fibers

Collagen fibers are predomanent one & their

synthesis is started inside fibroblasts that produce

tropocollagen molecules composed of 3 chains of polypeptide then they are secreted outside to start polymerization where they are

aggregated longitudinally to produce protofibril that aggregated laterally to

collagen fibrils which bundle together to form

Collagen fibers

Reticular fibersReticular fibers

occur in loose connective tissue surrounding occur in loose connective tissue surrounding blood vesselsblood vessels

& adjacent to Basement membrane& adjacent to Basement membrane

Elastic fibers systemElastic fibers system

composed of oxytalan, elaunin composed of oxytalan, elaunin & elastin fibers destributing & elastin fibers destributing

among collagen fibersamong collagen fibers

Collagen fibers arrange in groups of Collagen fibers arrange in groups of bundles with destinct oreintationbundles with destinct oreintation; ;

1- 1- CircularCircular; in free Gingiva; in free Gingiva2- 2- DentogingivalDentogingival from root to free Gingiva from root to free Gingiva3- 3- DentopereostealDentopereosteal to attached Gingiva to attached Gingiva ( both groups called ( both groups called GingivodentalGingivodental ) )4- 4- Transeptal Transeptal to the root of neighboring

tooth across interdental septum

FFunctionunction? ? 1-Give1-Give Gingiva its resiliency &Gingiva its resiliency &

2- attached it to tooth 2- attached it to tooth 3-provide rigidity to resist force of 3-provide rigidity to resist force of mastication without being deflected mastication without being deflected

away from toothaway from tooth4- unite the free Gingiva with 4- unite the free Gingiva with cementum & adjacent Attached cementum & adjacent Attached

GingivaGingiva

MatrixMatrixground substanceground substance

derived mostly from fibroblast & some from derived mostly from fibroblast & some from mast cell & bloodmast cell & blood,,

composed from watercomposed from water,,Glyco- Protein like FibronectinGlyco- Protein like Fibronectin, ,

Polysaccharide MoleculesPolysaccharide Molecules,,proteoglycans mainly Hyaluronic Acid & proteoglycans mainly Hyaluronic Acid &

Chondroitin SulphateChondroitin Sulphate,,

Matrix (ground substance)Matrix (ground substance)

it transports water, Electrolyte it transports water, Electrolyte & Nutrient to & from cells& Nutrient to & from cells, , also this Macromoleculs also this Macromoleculs

important for resiliency of important for resiliency of GingivaGingiva