new dental pulp

DENTAL PULPDENTAL PULP

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CONTENTS

INTRODUCTION EMBROLOGY ANATOMY STRUCTURAL ORGANISATION OF PULP CELLS OF PULP EXTRA CELLULAR MATRIX CIRCULATION OF PULP

METABOLISM OF PULP INNERVATION OF PULP FUNCTIONS OF PULP PULP OF DECIDUOUS TOOTH PULP CALCIFICATION AGE CHANGES CLINICAL SIGNIFICANCE CONCUSION

INTROUDCTION

• The Pulp is a soft mesenchymal connective tissue that occupies pulp cavity in the central part of the teeth.

• It is a special organ because of the unique environment

DEVELOPMENT

• During the 8th week of IUL, there is condensation of the mesenchmye under the enamel organ-Dental papilla.

• The enamel organ enlarge and enclose the dental papilla in their central portion.

• Dental papilla controls the morphology & type of tooth to be formed.

• Dental papilla shows :extensive proliferation of cellsHigh vascularity

• Following the differentiation of the IEE into ameloblasts, odontoblast differentiate from the peripheral cells of dental papilla

• Well organized capillaries are found at beginning of dentinogenesis

• Capillaries crowd around the odontoblast during active dentinogenesis

• Rim of the enamel organ (IEE & OEE) is the cervical loop.

• Root formation is carried out by the proliferation of cells at the cervical loop.

Dental Papilla

Dental papilla capped by the enamel organ

GENERAL FEATURES

• Total of 52 pulp organs 32 in the permanent and 20 in the primary teeth.

• Total pulp volume in permanent teeth is 0.38cc with mean being 0.02CC

• Each of these organs has a shape that conforms to that of the respective tooth.

• Has ability to form dentin throughout life

The pulp cavity is divided into

1. Coronal pulp

2. Radicular pulp

CORONAL PULP

• It is the pulp occupying the pulp chamber of the crown of the tooth

• In young teeth it resembles the shape of the outer dentin

• It has six surfaces : occlusal, mesial, distal, buccal, lingual and floor.

• Pulp horns are projections into the cusp• This pulp constricts at the cervical region where it

continues as the radicular pulp

RADICULAR PULP

• It is the pulp occupying the pulp canals of the root of the tooth

• In the anterior tooth it is single and in the posterior teeth it is multiple

• The radicular portions of the pulp is continuous with the periapical tissues through apical foramen

• As age advances the width of the radicular pulp is reduced, and so is the apical foramen.

APICAL FORAMEN

1. Pulp cavity terminates at root apex as small opening called apical foramen

2. Radicular pulp continuous with connective tissue of the periodontium through this foramen.

3. Diameter in an adult- maxillary teeth-0.4mm mandibular teeth-0.3mm

4. Wide open during development of root

APICAL FORAMEN

5. Undergoes changesI. Tooth may tipped from horizontal pressure cause apex to tilt in opposite direction, exert pressure on one wall of the foramen causing resorption

6. Same time cementum laid down on opposite side resulting relocation of the original foramen

7. Sometimes apical opening is found on the lateral side of the apex

8. There may be 2-3 foramina split by cementum or dentin- APICAL DELTA

Apical Foramen

Neurovascular bundle entering pulp through the foramen

ACCESSORY CANAL

• Leading laterally from the radicular pulp into the periodontal tissue.

• Present in the apical third of the root sheath cells• Formed due to premature loss of HERS or when

developing root encounters a blood vessel.• Overall occurrence is 33%• May also be present at the furcation region

Accessory Canals

Structural Organization of pulp

HISTOLOGICAL ZONES OF PULP

ODONTOBLAST LAYER

CELL-POOR ZONE

CELL-RICH ZONE

PULP PROPER

THE ODONTOBLASTIC ZONE

A layer of odontoblasts are found along the pulp periphery.

They are dentin forming cells.

CELL FREE ZONE• It is also called weil’s zone• 40 microns wide &relatively free of cells• Traversed by• blood vessels• unmyelinated nerves• cytoplasmic process of fibroblasts• This zone is found below the odontoblastic zone• Represents the space into which odontoblasts move during

tooth development.

CELL RICH ZONE

Present in subodontoblastic layerContains more proportions of fibroblast and undifferentiated mesenchymol cells.Also contains macrophages, dendritic cells and lymophocytes.Zone formed due to migration of cells from pulp properMitosis seen when dead odontoblasts are replacedAlso contain young collagen fibres during early dentiogenis.

PULP CORE

It is central region of the pulp

Contains major blood vessels and nerve of the pulp

Pulpal cells and fibroblasts are also seen

CELLS OF PULP

ODONTOBLASTS

FIBROBLASTS

UNDIFFERENTIATED CELLS

DEFENSE CELLS

ODONTOBLASTSA Peripheral area of the pulp where the

odontoblasts reside is termed odontogenic zone.Arranged in Palisading pattern cells one tall

columnar forming a layer of 3 to 5 cells in depth.Shape may vary cornal pulp- columnar

midportion - cuboidal Apical region - Flattened

These cells have large process extending into dentin

The no of odontoblasts corresponds to the number of dentinal tubules

Average no of odontoblasts estimated to 45,000 per Sq.mm of odontogenic zone.

Odontoblasts in the crown are larger than in the root.

Shape of the odontoblasts also reflect the functional activity of the cell.

During active phase, cells show increase in endoplasmic reticulum golgi appartus and secretory vesicles.

Resting (or) Non active phase cells are flattened little cytoplasm condensed chromatin and decrease no of ER

JUNCTIONAL COMPLEX

Numerous junctions such as gap junctions tight junction and desmosomes are found between odontoblasts.

Indicating exchange of ions and small molecules.

They promote cell to cell adhension and play a role in maintaining polarity of odontoblasts

JUNCTIONAL COMPLEXES

ODONTOGENIC PROCESS

Odontoblasts give off a single process that extends into dentin and housed within dentinal tubules

These process devoid of major organellesThey contain abundance of microtubular

filaments and coated vesiclesMainly composed of protein-tubulin, act in

and vimentin

FUNCTIONS OF ODONTOBLASTS

Synthesis of organic matrix

Synthesis of non collagenous substances like sialoprotein, phosphophoryn, osteocalcin, ostenoectin & osteopontin

Intracellular accumulation of calcium

Degradation of organic matrix

FIBROBALSTS

Cells that occur in greatest number in the pulp

Function is to form, maintain the matrix that consists of collages, fiber and ground substance throughout the pulp

The fibroblasts are stellate shaped cells having extensive process.

Fibroblast

H&Estain

Immunohistochemical

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Young teeth - Fibroblasts have abudant cytoplasm having

numerous cell organcells.Older pulp - Fibroblasts appear

spindle shaped posses short processes

having few cytoplasmic organelles

such cells are called fibrocytes

Dual function :

a) It has capability of ingesting and degrading the organic matrix.

b) Pathway of both synthesis and degreadation in the same cell.

UNDIFFERENTIATED MESENCHYME

These mesenchymal cells are distributed through out the pulp, frequently around the perivascular area - believed to be toti potent cell They are Polyhedral shaped with peripheral processes and large oval nuclei Difficult to differentiate from fibroblast under light microscopy Under adequate stimilus they may differentiate into odontoblast or fibroblast or macrophages. In older pulp,their number and ability to differentiate comes down

IMMUNOCOMPETENT CELLSThey play a major role local inflammation and immunity. They are recruited from blood stream and remain as transient inhabitants in pulp These cells are

1. Macrophages2. Mast cells3. Plasma cells4. Lympocytes,Neutrophils,Eosinophils

basophils and manocytes.

MACROPHAGES IN PULPDescribed as histiocytes (or) as resting wandering cellsLocated close to blood vesselHave several phenotypesMacrophages are phagocytes,function of which are engulfment and digestion of foreign materialDuring inflammation they appear in large no to aid in defense the organismIn all they constitute 8-9% of the pulpal cell population

Macrophages

Dark staining nucleus with cytoplasmic granules

PLASMA CELLSPlasma cells are seen during inflammation of the pulp

The plasma cells function in the production of antibodies.

Plasma cells may be present in coronal pulp

They have small nuclei with radiating chromatin that appears like a cast wheel.

Plasma Cell

Peripheral arrangement of chromatin in nucleus

MAST CELLS

Occur in small groups in relation to blood vessels

Present only during pulpal inflammation

Have round nucleus and contain many dark staining granules in the cytoplasm.

Their number increase during inflammation.

LYMPHOCYTES,EOSINOPHILS AND LEUCOCYTES

Usually found extravascularly in the normal pulp

During inflammation they increase in number.

Lymphocyte present along the walls of blood vessels

Involved in initial immunodefense

Usually they are not found in uninflamed pulp

Eosinophils are present in some allergic types of inflammation

In pulp.they are found in an inflammatory exudate.

LYMPHOCYTES IN PULP

Leucocytes are not found normally in the connective tissue

They are transported to such sites in response to injury and then present directly in the involved tissue as well as in blood.

They phagocyte foreign material .

EXTRACELLULAR MATRIXConnective tissue fibers

Collagen Elastin Fibronectin

Ground substance Proteoglycans Glycosaminoglycans

Basement membrane

FIBRES (COLLAGEN FIBRES)

Extra cellular structural protein,major constituent of connective tissue

Collagen fibers appear throughout the pulp

young fine fibers ranging in diameter from 10-12mm.

Pulp collagen fibers do not contribute to dentin matrix production.

After root completion pulp matures and bundles of collagen fibers increase in number

They scattered throughout the coronal or radicular pulp,or they appear in bundles.These are termed diffuse or bundle collagen

Most prevalent in root canals,especially near apical region.

Collagen Fiber

Seen in relation with fibroblasts

Type I: Present as thick striated fibrilsResponsible for pulp architecture

Type III: Thinner fibrils,mainly distributed

in cell free and cell rich zones Contributes to the elasticity of pulp

Type IV:

Present along the basement membrane of blood vessels

Type V and VI:

Seen to form dense meshwork of thin microfibrils through out the stroma

Collagen turnover is maintained by fibroblasts

During bacterial infection & inflammation,collagenolytic activity is accelerated following collagenase produced by bacteria,PMN & fibroblats

Collagen synthesis is accelerated during reparative dentin formation

ELASTIC FIBER

1. This has the ability to expand and contract like a rubber band

2. Elastic fibers are first formed in bundles of thin micro filaments called Oxytalan fibers

3. Elastin is then deposited in between oxytalan fibers.

4. Always associated with larger blood vessels

Elastic Fiber

Verhoeff's method stains the fibers black

FIBRONECTIN

It plays a role in cell-cell & cell-matrix adhesionHas a major effect on the proliferation, differentiation & organization of cells.Seen around the blood vesselsAlso found in odontoblast layer with fibers passing into predentin

Due to its close interaction with odontoblasts and extracellular fibers,fibrinoectin helps to maintain cell morphology and provide a tight seal at this site.

Fibronectin may be involved in cell migration and anchorage in the wound healing process of the connective tissue of pulp.

It regulates the migration and differentiation of secondary odontoblasts

Adherent property of fibronectin is due to cell surface glycoprotein receptors called Integrins

GROUND SUBSTANCE

It is a structureless mass,makes up the bulk of the pulp

Consists of complexes of proteins,carbohydrate and water.

Broadly classified as Glycoaminoglycans

Proteoglycans

GLYCOSAMINOGLYCANSGAG found in pulp is mainly chondroitin sulphate,dermatan sulphate & hyaluronic acid

Proteoglycans occupy larger area and they provide protection against compression.

During dentinogenesis,the ground substance show affinity for collagen and influence fibrinogenesis

They have capacity to bind with calcium and help in mineralisation

BASEMENT MEMBRANE

It is a sheet like arrangement of extra cellular protein matrix at the epithelial-mesenchymal interface

Composed of 2 layers lamina densa-electron dense lamina lucida-electrolucent

Basement membrane is a product of connective tissue and epithelium

It is composed of Collagen type IV Laminin-adhesive glycoprotein Fibronectin Heparin sulfate

Collagen IV provides binding sites for the rest of basement membrane components

Laminin binds to both cells of connective tissue and epithelium

In mature pulp,basement membrane forms interface along endothelial cells & schwann cells

FUNCTIONS

Act as sieve between epithelium and connective tissue

Helps in organisation and differentiation by enabling interactions between extra cellular molecules and cell surface receptors

Eg: Odontoblasts during tooth

development

CIRCULATION OF THE PULP

The pulp organ is extensively vascularized. They are supplied by the superior and the

inferior alveolar arteries The blood vessels gain entry into the pulp

through the apical foramen and at times through accessory foramen.

The arterioles on entering the pulp show a reduction in thickness of vessel wall musculature and therefore luman size increases.

Pulpal blood flow is more rapid than in most area of the body

So pulpal pressure is highest of body tissues The flow of blood in asterioles - 0.3 to 1mm/sec

Venules – 0.15mm/sec

Capilaries – 0.08mm/sec

Organization of Pulp Vasculature⃟ Pulp is a micro circulatory system which lacks true arteries and veins⃟ The largest vessels are arterioles & venules which regulate the local interstitial environment⃟ They enter the tooth through the apical foramen ⃟ Pulp tissue pressure is 14cm H20

Organization of pulp vasculature

H&E section showing the neurovascular bundle

ARTERIOLES:Arterioles

(50µ diameter)

Terminal arterioles

Precapillaries

Metarterioles

Capillaries (8µ)

The branching point of terminal arterioles is characterized by smooth muscle clumps that act as sphincters which are under the local cellular & neuronal control

Thus pulpal inflammation elicits a localised circulatory response restricted to the area of inflammation

Arteriolar pressure – 43mm Hg.

Apical third Middle third

PULP VASCULATURE

Microcirculatory System

Arterioles & venules

CAPILLARIES

• Function as exchange vessels regulating the transport of diffusion of substances between blood and local interstitial tissue elements

• They consists of single layer of endothelium surrounded by basement membrance

• Capillary pressure –35 mmHg• Capillary wall is 0.5µ thick & acts as

semipermeable membrane

Based on the property of semi permeability capillaries may be grouped as

Class I : Fenestrated capillaries

Class II: Continuous capillaries

(non fenestrated)

Class III : Discontinuous capillaries

Class IV : Tight junction capillaries

Class I & II are present in the dental pulp

Capillary network is organized in 3 layers

1. Terminal capillary network located in the “odontoblastic layer”

2. “Capillary network” present adjacent to the odontoblastic layer & consists of pre capillary & post capillary vessels

3. Venular network of vesselsDuring aging & decreased metabolism these layers appear as single layer

SEM shows extensive arborization of capillaries from the metarterioles

VENULESCollecting venules receive pulpal blood flow from the capillaries & transfer it to the venules

Arterio-venous anastomosis permits direct shunting from arterioles to venules

Venular pressure –19mm Hg

LYMPHATICSLymphatic vessels are formed from fine meshwork of small, thin walled lymph capillaries

Lymph capillaries coalesce to form larger lymphatic vessels with valves

They start as blind openings near Weil’s zone & odontoblastic layer

The larger lymphatic vessels run along the blood vessels & nerves

Multiple collecting lymph vessels exit though the apical foramen & drain lymph from pulp into the periodontiumRole in pulp:

They remove high molecular solutes from the interstital fluids thus maintain interstitial COP

They transport lymph to the regional lymph node before it enters into the blood vessels. This provides an immuno surveillance function.

METABOLSIMMetabolism has been studied by measuring the rate of O2 consumption & production of Coz lactic acid by pulp tissueRadiospriometry is also used to evaluate the metabolism. Pulp tissue is placed in 14C labeled substractures, such as succinate & rate of apperance of CO2 is measured.

During dentinogenesis, rate of O2 consumption is high than after crown completion.

Greatest metabolic activity is seen in the odontoblast layer.

Reduced pH of pulp causes decreases in O2 consumption as in pulp abscess.

In addition to the glycolytic pathway, the pulp has the ability to produce energy through Pentose shunt pathway, suggesting that the pulp can function under varying degrees of ischemia

Several dental materials have shown to inhibit O2 consumption Eg. ZOE , Ca(OH)2

& silver amalgam

Pulpal irritation causes increases in cycloxygenase products, which is inhibited by ZOE

As cellular composition reduces, the rate of oxygen consumption decreases.

INNERVATION Principles role is to help in conscious recognition of irritants to the pulp, which gives the opportunity to have the problem corrected before irreversible effects can occur

Nerve fibers, mylinated & unmyelinated, enter the tooth through the apical foramen

INNERVATION

Dental pulp contains sensory and motor fibers to fulfill the vasomotor and defense function

Sensory afferent fibers are branches of maxillary & mandibular division of trigeminal nerve.

After entering the foramen, they arborize. Larger fibers are present in the central zone. They divide as they proceed peripherally and coronally.

Subjacent to the cell rich zone, the nerves branch extensively forming a parietal layer of nerves-NERVE PLEXUS OF RASHKOW. This layer contains both A and C fibers.

Types of nerve fibers

Above the cell free zone, myelinated fibers begin to lose their myelin sheath.

In the cell free zone, they form a rich network responsible for pain

In the cell free zone, they form a rich network responsbile for pain.

Many of these fibers pass between the odontoblastic zone.

Nerve endings may also enter the dentinal tubules

incidence - 10-20% in cusp tips 1% at the level of CEJ

Motor nerves are supplied by the sympathetic division of autonomic nervous system.

They wrap around the arteries and terminate

in the tunica media.

They control the diameter of the vascular

lumen & therefore blood flow & volume &

ultimately the intrapulpal pressure.

Table 3.2 Classification and function of fibers in peripheral nerves

Diameter (m)

Conduction velocity (speed of impulse,

m/sec)

Function

A-alpha () A-beta()

6-20 5-12

15-80 (myelinated) 30-70

Afferent fibers for touch, pressure proprioception, vibration (mechanorecptors)

A-gamma() A-delta () B

1-5 1-3

2-30 (myelinated) 3-15 (myelinated)

Afferent fibers for pain and temperature Visceral afferent fibers preganglionic visceral efferent fibres

C 04-1.0 0.4-2(unmyelinated) Afferent fibers for pain and tempature; post ganglionic visceral efferent fibers

Neuropeptides in Pulp Neuropeptides are proteins that have been associated with central & peripheral nervous systemFollowing are the neuropeptides demonstrated in pulp :Originate from trigeminal ganglion (C fibres)

Substance PCGRPNeurokinin A

FUNCTIONS OF DENTAL PULP

INDUCTIVE

FORMATIVE

NUTRITIVE

PROTECTIVE

DEFENSE

INDUCTIVE

It induces oral epithelial differentiation into dental lamina and enamel organ

It also induces the enamel organ to differentiate into a particular type of tooth morphology

FORMATIVE

The cells of Pulp induces dentin formation

This involves formation of primary and secondary dentin.

The primary dentin is tubular and regularly arranged.Formed before root closure

Secondary dentin contain fewer tubules and is formed after root closure.

NUTRITIVE

Dental pulp maintains the vitality of dentin by providing O2 and nutrients to the

odontoblasts

Also provides continuing source of dentinal fluid

Nutrition made possible by rich peripheral capillary network.

PROTECTIVE

Pulp helps in recognition of stimuli like heat,cold,pressure,chemicals by way of sensory nerve fibres.

Vasomotor innervation controls the muscular wall of blood vessels.This regulates

the blood volume and rate of blood flow and hence the intrapulpal pressure.

DEFENSIVE (OR) REPARATIVE

Pulp as remarkable reparative abilities It responds to irritation by producing

reparative dentin and mineralizing and affected dentinal tubules.

Mild to moderate irritation results in continued peritubular dentin formation, sclerosis and intratubular calcifiction-(Tublar sclerosis)

Stimuli like operative procedures abrasion, caries can result in rapid dentin formation (Tertiary dentin)

Inflamed pulp due to bacterial infection the cells in pulp aid in the process of repair (macrophages, lymphocycts, neutrophils, monocytes, plasma , mast cells)

PULP OF DECIDUOUS TEETH• Overall dimensions smaller• Pulp chambers larger• Roots are long and slender and root canals

narrower and follow a tortuous course• Pulp horns at a higher level, especially mesial

horns of primary molars• Resorption starts soon after root completion• Root resorption and dentin deposition changes

size shape and number of root canals.

PRIMARY PULP ORGAN• Primary pulp functions for a mean of 8.3 years. This

time can be divided into three periodsPulp organ growth

Time of crown and root developmentPulp maturation (3 years, 9 months)

Time after root completion to beginning

of root resorptionPulp regression (3 Years , 6 months)

Beginning of root resorption to exfoliatin

REGRESSIVE CHANGES (AGING)Cell Changes Appearance of fewer cells in aging pulpCells are characterized by a decrease in size

and no of cytoplasmic organelles Active pulpal fibrocyte (or) fibroblast has

abundant rough-surfaced endoplasmic reticulum notable golgi complex, numerous mitochondria

Fibroblast exhibit less perinuclear cytoplasm, long thin cytoplasmic processes.

Intra cellular organelles are reduced in no and size

FIBROSIS Diffuse fibrillar components

Accumulation of both Bundles of collagen fibres

Fiber bundles may appear arranged longitudinally in the radicular pulp and more diffuse in coronal pup

Collagen accumulation also occurs in some older pulps Increase in fibers in the pulp organ is gradual and

generalized

External trauma such as dental caries (or) deep restorations cause a localized fibrosis (or) scarring effect

Increase in collages fibers decrease in the size of the pulp

Vascular changes occur in aging pulp

Pulp Fibrosis

Atherosclerotic plaques may appear in pulpal vessels.

Calcifications are found that surround vessels.

Calcification is found most often in the region near the apical foramen.

Pulp Stones(denticles)Appearing in either or both coronal and root

portions of the pulp organDevelop in teeth that appear to be normal in

other respects.Asymptomatic unless they impinge on

nerves (or)blood vesselsSeen in functional as well as embedded

unerupted teeth.

Classification

1. True denticles

2. False denticles

3. Diffuse calcifications

True denticles True denticles are similar in structure to dentinThey have dental tubules and contain processes

of the odontoblastsUsually located close to the apical foramen

Development of true denticles is caused by the inclusion of remnants of the epithelial root sheath with in the pulp

Epithelial remnants induce the cells of pulp to differentiate into odentoblasts then form the dentin mass.

True Denticle

• H&E section of true denticle

• Higher magnification

False denticles

They do not exhibit dentinal tubules They appear as concentric layers of calcified

tissue Some cases these calcification sites appear within

a bundle of collagen fibers. Some cases they appear in pulp free of collagen

accumulations

Some cases arises around vessels Center of these concentric layers of calcified

tissues there may be remnants of necrotic and calcified cells

Calcification of thrombi in blood vessels called phleholiths, may also serve as nidi for false denticles

An denticles begin as small nodules but increase in size by incremental growth

Classified as free, attached (or) embedded depending on their relation to the dentin

a) Free denticle – entirely surrounded by pulp tissue

b) Attached denticle – Partly fused with the dentin

c) Embedded denticles – Entirely surrounded by dentin

Incidence as well as the size of pulp stones increase with age.

False Denticle

False calcification seen along the walls of the blood vessel

Diffuse Calcifications Appear as irregular calcific deposits in the pulp

tissue, following collagenous fiber bundles, blood vessels,

Sometimes they develop into larger mass, persist as calcified spicules

These calcifications are usually found in the root canal and less often in coronal area

These calcification surrounds blood vessels These calcifications may be classified as

dystrophic calcification

Diffuse calcification

Diffuse calcification of the pulp, seen along with pulp fibrosis

Dystrophic Mineralization Ground substance alterations in the dental pulps occurs on aging, such charges may contribute to cellular degeneration and increase dystrophic mineralization.Circulatory disturbances may be the initiating factor Mineralizations also seen in the myelin sheaths of nerves.

Their beginnings are also found in the vessel walls as in arteriosclerosis.

Older, fibrotic pulp attract mineral salts more readily.

A mineralized pulp when extirpated, feels wooden hard.

Dystropic mineralization due to caries and periodontal disease

DM also increase as result of disease processes such as caries and periodontal diseases

Teeth whose pulps one chronically inflammed contain DM in regions of previous liquefaction necrosis.

Alkaline phosphate in odontoblasts may function as a calcium pyso phosphatus, there by stimulating ca2 uptuke in pulps.

Teeth with periodontal disease, DM increase in both cornonal and radicular pulp.

AGE CHANGES

• Formation of secondary dentin through out life, reduces the size of the pulp chamber and root canals

• Decrease in cellularity

• Odontoblast decrease in size & number, & may disappear in certain areas. Especially on pulpal floor over bifurcation & trifurca

• Increase in number & thickness in collagen fibers particularly radicular pulp

• Reduction in the nerve fibers & blood vessels

• Increase resistance of pulp against action of enzymes

• In dentin,

Increase in peritulular dentin

Dentinal sclerosis, reduces permeability

Increase in dead tracts

Factors infulencing TertiaryDentinogenesis

Reactionary Dentinogenesis:• Shallow cavity- RDT > 0.5mmRD• Deep cavity - RDT 0.25mm - RD• Very deep cavity- RDT 0.008 –0.25mm RD

Reparative Dentinogenesis:• Pulp exposure – RDT< 0.008mm- Reparative dentin

formation.

Tertiary Dentinogenesis

CLINICAL CONSIDERATIONS

1. Anatomic considerations

2. Factors to be considered during endodontic treatment.

3. Effect of Operative Procedures

4. Effect of dental materials on pulp

5. Effects subsequent to restoration

ANATOMIC CONSIDERATIONS

Pulp Chamber with stone Cervical hornswww.rxdentistry.blogspot.com

OPERATIVE PROCEDURES

Anatomic considerations

1) Shape of the pulp chamber and its extensions into the cusps pulpal horns is important.

2) Wide pulp chamber into tooth of young person will make a deep cavity preparation hazardous

3) The pulpal horns project high into the

cusps exposure of pulp can occur

4) If opening a pulp chamber for treatment its

size and variation in shape must be taken

into consideration

FACTORS TO BE CONSIDERED DURING ENTODONTIC TREATMENT

5) Age advance , the pulp chamber becomes smaller difficult to locate the root canals.

6) Shape of the apical foramen and its location may play an important part in treatment of root canals.

7) Accessory canals, and multiple canals are rarely seen in roentgenograms.

FACTORS TO BE CONSIDERED DURING OPERATIVE PROCEDURES

8) The pulp is highly responsive to stimuli, even slight stimulus cause inflammatory cell infiltration.

9) Dehydration causes pulpal damage operative procedures producing this condition should be avoided.

Filling material contain harm ful chemicals

Silicate cement - acid

Composites - monomerVital pulp is essential to good dentition.

Now vital tooth becomes brittle and is subject to fracture.

EFFECT OF DENTAL MATERIALS ON PULP

GIC – Well tolerated by pulp

Calcium hydroxide – includes dentin bridge formation.

Zine oxide – eugenol- has an anti-bacterial effect.

Formocresol – Cause chronic inflammation of the pulp.

Dentin bonding agent – can irritate the pulp causing inflammation

DETECTION OF PULP VITALITY

Electric pulp testingMore accurate than some of the tests used

to detamine pulp vitality

Heat testingThermal testing

ColdAnesthetic testing

Anesthetic testingTest cavityThis test performed when other methods of

diagnosis have failedThe test cavity is made drilling through

enamel – dentin junction of an unanaesthetized tooth

Pulse oximeter

Based on evaluating oxygen saturation of the tissue.

CONCUSION

• THE PRESEVATION OF A HEALTHY PULP DURING OPERATIVE PROCEDURES AND SUCCESSFUL MANAGEMENT IN CASES OF DISEASES ARE TWO OF MOST IMPORTANT CHALLENGE TO THE CLINICAL DENTIST.

REFERENCES

DENTAL PULP; Seltzer & bender; ORAL HISTOLOGY AND EMBROLOGY; Orban ORAL HISTOLOGY; Tencate PATHWAYS OF THE PULP; Cohen ENDODONTIC PRACTICE; Grossman ENDODONTICS;Ingle ENDODONTIC PRACTICE;Weine

new dental pulp

dental pulp

coronal pulp radicular

pulp cavity

pulp canals

pulp organs

pulp coreit

pulp chamber

pulp horns

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