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Dental pulp

By :Dr. ANNUPRIYA KHANNAMDS STUDENTDEPARTMENT OF PEDODONTICSHIMACHAL DENTAL COLLEGE


DEFINITION


• Dental pulp is richly vascularised and innervated connective tissue inside the pulp cavity of a tooth.

Dorland's Medical Dictionary for Health Consumers..

• Dental pulp is a tissue derived from dental papilla responsible for the formation of dentine

oral anatomy , histology , and embryology-B.K.B BERKOVITZ G.R. HOLLAND B.J. MOXHAM

• Dental pulp is a delicate specialized connective tissue containing thin walled blood vessels, nerves& nerve endings enclosed within dentin Grossman

• The organ made up of blood vessels , nerves, and cellular elements including odontoblast , that forms dentin.

Mosby


• Pulp is of mesenchymal origin with

specialized cells, the odontoblast

• Houses a number of tissue elements.

• microcirculation system - lacks true collateral

supply

•Unique sensory organ

•Retains its ability to form dentin


Contents

• Development

• Anatomy

• Structural features

• Functions

• Primary and permanent pulp organs

• Regressive changes

• Clinical considerations


Development of the pulp The precursor of the pulp is the dental papilla

It develops as a ball of proliferating cells filling

the concavity of the cap stage of tooth

development

Histologically the dental papilla consists of

undifferentiated mesenchymal cells, moderate

ground substance and sparse delicate fibers


The dental papilla


The dental pulp is said to be existent as soon as

The first dentin is laid down

or

The papilla is surrounded by dentin


Anatomy of pulp

• General features

• Pulps of maxillary teeth

• Pulps of mandibular teeth

• Coronal pulp

• Radicular pulp

• Apical foramen

• Accesory canals


General features

• Occupies centre of each tooth and consists of soft

connective tissue

• Every person normally has 52 pulp organs

32 in permanent

20 in primary teeth

• Total volume of all permanent teeth pulp is 0.38cc

• Mean volume of single adult human pulp is 0.02cc

ORBANS ORAL HISTOLOGY AND EMBRYOLOGY (11TH EDITION)


Picture depicts anatomy of pulp in maxillary central incisor and 1st molar


Pulp organs of deciduous human teeth


Pulp organs of permanent human teeth


Coronal pulp• Located centrally in the crowns• It has six surfaces The roof or occlusal The mesial The distal The buccal The lingual The floor

• With continuous deposit of dentin, pulp becomes smaller and non uniform.

• Deposits faster on floor than roof or side walls.

ORBANS ORAL HISTOLOGY AND EMBRYOLOGY(11TH EDITION)


Radicular pulp

• Extend from cervical region of crown to root

apex.

• In anterior teeth: single

in posterior teeth: multiple

• Continuous with periapical tissue through apical

foramen.

• Tubular in shape.

ORBANS ORAL HISTOLOGY AND EMBRYOLOGY (11TH EDITION)


Coronal and radicular pulp


Apical foramen

• In anatomy the apical foramen is the opening at the apex of the root of a tooth through which the nerve and blood vessels that supply the dental pulp pass. Thus it represents the junction of the pulp and the periodontal tissue.

Textbook of Oral Anatomy, Histology, and Embryology by B. K. Berkovitz, G. R. Holland, B. J. Moxham.

• Also known as major diameter• Average size in mature permanent maxillary

teeth is 0.4mm in diameter• Average size in mature permanent mandibular

teeth is 0.3 mm ORBANS ORAL HISTOLOGY AND EMBRYOLOGY(11TH

EDITION)


•Significantly, the foramen usually does not exit at the true (anatomic) root apex" , -' but is offset approximately 0.5 mm and seldom more than 1.0 mm from the true apex

•The anatomy of the apical foramen changes with age.


•There are variations in size and shape and location of apical foramen.


Accesory canals and lateral canals

• Accessory canals are secondary canals that emanate from the main canal and travel at an angle alongside it before exiting into the periodontal ligament space.

• In contrast, lateral canals are canals that emanate from the main canals but take a perpendicular course to exit into the periodontal ligament space

Cohen S, Burns RC. Pathways of the pulp. 8th edition


Accesory canal

Cross section of tooth showing lateral canal


• Numerous in apical 3rd of root.

• Mechanism of formation

Premature loss of root sheath cell

Blood vessel may be located in place of

dentin formation area.

• Clinical Significance: can spread infection either from pulp to periodontal tissue or vice versa.


Structural features

• Intercellular substance

• Fibroblasts

• Fibers

• Undifferentiated mesenchymal cells

• Odontoblasts

• Defense cells

• Blood vessels

• Lymph vessels

• Nerves

• Nerve endings


• Central region of both radicular and coronal pulp consists of large nerve trunks and blood vessels

• Peripherally, the pulp is circumscribed by specialized odontogenic region composed of-

odontoblasts (dentin-forming cells) Cell free zone(weil’s zone) - beneath the

odontoblasts,which is prominent in the coronal pulp.

Cell rich zone- cell density is high , which again is seen easily in coronal pulp adjacent to cell free zone

Pulp core

• Principal cells of pulp are odontoblasts , fibroblasts , undiferrentiated ectomesenchymal cells, macrophages and other immunocompetent cells

Ten cate’s oral histology(6th edition)


• Outermost layer, located subjacent to predentin.

• Composed of cell bodies of odontoblast• In coronal pulp more cells per unit area than

in radicular pulp.• In coronal pulp cells are columnar, in mid

portion of radicular pulp are cuboidal , near apical portion are flattened cell layer.

Odontoblast layer

Zones of pulp


Cell Poor Zone•Narrow zone approximately 40 nm in width that is free of cells.•Traversed by blood capillaries, unmyelinated nerve fibers and slender cytoplasmic processes of fibroblast.•Subodontoblastic vascular plexus-Plexus of Raschkow


Cell Rich Zone•Contain relatively high proportion of fibroblast and undifferentiated mesenchymal cells.

•More prominent in coronal pulp than radicular pulp.


Pulp Proper

•Central mass of the pulp•Contains large blood vessels and nerves•Connective tissue cell consist of fibroblast and pulpal cells



Intercellular substance• Dense gel like in nature• Appearance varies from finely granular to

fibrillar• Composed of- Acid mucopolysaccharide Protein polysaccharides

(glycosaminoglycans and proteoglycans) Chondroitin A and chondroitin B(during

early development) Hyaluronic acid Glycoproteins


Fibroblasts • Most numerous cell type in pulp • Active in collagen synthesis. • Have typical stellate shape. In the older pulp they appear rounded or

spindle shaped with short processes . they are then termed as fibrocytes

• Have ability to synthesize and phagocytose collagen (DUAL FUNCTION)


• Apoptotic cell death of pulpal fibroblasts especially in the cell rich zone indicates that some turn over of these cells is occuring

• Desmosomes are often present between these cells


Fibrocytes (fibroblasts of older pulp)


Fibers • Principal fibrous component of dental pulp is a

combination of Type I (60%) Type II(40%) Type I collagen synthesized by odontoblast and

Type I, III, V, VII are synthesized by fibroblast • Present as fibrils 50nm in diameter grouped into

fibers thinly and irregularly scattered throughout the tissue.

• Depending on appearanceo Diffused collageno Bundle collagen (prevalent in apical

third of root )

Textbook of Oral Anatomy, Histology, and Embryology by B. K. Berkovitz, G. R. Holland, B. J. Moxham.


A-BUNDLE FIBRES B-DIFFUSE FIBRES


• In very young pulp fine fibres of small size are present (FIBRILLIN)

• Cross striations at 64nm and rage in length from 10-100nm


collagen fiber-blue

elastic fiber red


Undifferrentiated mesenchymal cells• Represent the pool from which connective

tissue cells of pulp are derived Ten cate’s oral histology(6th edition)

• primary cells in very young pulp but a few are seen in pulp after root completion

• Larger than fibroblasts

• Polyhedral in shape with peripheral processes and large oval staining nuclei

• Found along pulp vessels in cell rich zone ORBANS ORAL HISTOLOGY AND

EMBRYOLOGY(11TH EDITION)


Undifferentiated ectomesenchymal cells


Odontoblasts• An odontoblast is a biological cell of neural

crest origin that is part of the outer surface of the dental pulp, and whose biological function is dentinogenesis, which is the creation of dentin, the substance under the tooth enamel.

Matrix biology : journal of the International Society of matrix biology 19(5)

• second most prominent cells of pulp

• reside adjacent to predentin

• Also synthesize type I and II collagen fibers along with dentin sialoproteins and phosphoryns.

• Also secrete alkaline phosphate enzyme linked to mineralization


• ODONTOBLAST PROCESSES:

Also called dentinal fibers or Tomes fibers. Transverse the predentin and fills the dentin

tubule.

Low magnification histologic section showing

View of odontoblasts odontoblast processes


Defense cells• T- lymphocytes are present in small numbers in

normal dental pulp• Their number increase enormously when pulp

is injured or subjected to toxins• They are- Histiocytes/macrophages Mast cells Plasma cells Neutrophils Eosinophils Basophils Lymphocytes Monocytes


Macrophages • Macrophages are white blood cells produced

by the differentiation of monocytes in tissues.

• Irregularly shaped cells with blunt processes• Associated with small blood vessels and

capillaries• Distinguishing feature-contains

aggregates of vesicles or phagosomes which contain dense phagocytized irregular bodies


Lymphocytes and eosinophils• Lymphocyte is a type of white blood cell in

the vertebrate immune system• Eosinophils are white blood cells that are one of

the immune system components responsible for combating multicellular parasites and certain infections in vertebrates

Dorlands Medical Dictionary

• Found extravascularly in normal pulp• During infection increase enormously in number

Lymphocyte Eosinophil


Plasma cells• Seen during inflammation of pulp• Nucleus appears small and concentric in the

cytoplasm• Pushed to the periphery of the cell• The chromatin is adherent to the nuclear

membrane • Plasma cell function is production of antibodies

plasma cell



Dendritic antigen presenting cells

• An important component of normal dental pulp

• 50 μm long and have three or more main dendritic processes which branch

• Stimulate activity and division of naïve T- lymphocytes

Antigen presenting cells

Textbook of Oral Anatomy, Histology, and Embryology by B. K. Berkovitz, G. R. Holland, B. J. Moxham


Blood vessels• Microcirculation system.

Primary function of microcirculation is to maintain physiology of the tissue.

Architecture of microvascular networko Major vessels are arterioles, capillaries and

the venules.o True microvascular subdivision are

arterioles.o Arterioles : 50 µm in diameter

• Blood vessels arise from inferior or superior alveolar artery and drains into the same veins in both mandibular and the maxillary region

• Small arteries and arterioles enter the apical canal and pursue a direct route to the coronal pulp.

Textbook of Oral Anatomy, Histology, and Embryology by B.

K. Berkovitz, G. R. Holland, B. J. Moxham.


•The largest diameter of arteries in pulp is 50-100μm

•The blood vessel has three layers.-Tunica intima - squamous or cuboid epithelial cells surrounded by a closely associated basal laminaTunica media –approx 5μm thick and consist of three layers of smooth muscle cellsTunica adventitia- outermost layer . made up of few collagen fibers forming a loose network around large arteries


• Among oral tissue pulp has highest blood flow rate but substantially lower than major visceral organs

• Blood flow rate in coronal pulp is twice that in radicular pulp

In arterioles-0.3mm per sec

Venules-0.15mm per sec

Capillaries-0.08mm per sec


Fenestrated capillaries• Fenestrated capillaries have pores in the

endothelial cells (60-80 nm in diameter) that are spanned by a diaphragm of radially oriented fibrils and allow small molecules and limited amounts of protein to diffuse.

Functional Ultrastructure: An Atlas of Tissue Biology and Pathology.

• 4-5% in pulp• More permeable and play imp role in rapid

supply of substrate to synthesizing cells


Lymph vessels • Second circulatory system

• Primary function is recirculation interstitial fluid to the blood stream.

• Presence of lymphatic in dental pulp is a controversy because of close resemblance of

lymphatic vessels to veins and capillaries.• Anterior teeth drain into - submental lymph nodes

• Posterior teeth - submandibular and deep cevical lymph nodes.



Clinical correlationsA. Local Anesthetics:

• Vasoconstrictor added to prolong anesthetic effect.

• Epinephrine being the commonest.

• Lidocaine with 5µg to 20 µg epinephrine decreases blood flow by 30 %

• Dose of epinephrine above 10-8 M pulp vessels collapse due to total ischemia.

• Reduce vasoconstriction effect of epinephrine as a result of vasodilation effect of some anesthetic.

(Scott et al,1976)


B. Ligament Injection:

Anesthetic solution must contain epinephrine to make it effective for ligament ingestion.

Pulpal blood flow decreases by 85% in comparison to control (plane L.A.)

C. General anesthesia:

G.A. effect velocity of blood flow, with G.A. blood flow falls to zero in first 30 sec. which disappears in a period of an hr.


D. Temperature changes:

Temperature Elevation:10oC to 15oC increase in pulp temperature, causes arteriole dilatation and linear increase in intrapulpal pressure by 2.5 mm Hg per oCelsius.Irreversible changes occur if pulp heated to 45oC for prolong period.

Temperature Reduction:• Intermediate application of subfreezing

temp. produce a transient fall in intrapulpal blood pressure.

• At temp. lower than – 2oC, pulp tissue exhibit immediate pulpal pathology such as vascular engorgement and necrosis.

(Van Hassel and Brown 1969).


E. Endodontic Therapy:

If only a part of pulp extirpated, profuse hemorrhage occur because of increased diameter of vessels.

Less hemorrhage if pulp extirpated closer to apex.

Excessive bleeding during instrumentation indicate pulp tissue remaining in apical 3rd .

F. Aging:Decreased circulation is due to

artheriosclerotic changes which cause narrowing of blood vessels and increase calcification.


G. Inflammation•Injured cells release chemical mediators, which excite sensory nerve fibers resulting in dilation.

•In chronic inflammation pulp pressure is low as compared to the acute inflammation..•In severe inflammation, lymphatic vessels closed, leads to increased fluid and pulp pressure result in pulp necrosis

(Bernick,1977)


Nerve supply• Abundant nerve supply in the pulp follows the

distribution of blood vessels• Two types of sensory nerve fibers Myelinated A fibers- 90% are narrow Aδ fibers ( Matthews B et al , 1994 )

10% are wider Aβ fibers

Unmyelinated C fibers• Enter pulp through apical foramen • Run coronally & divide into smaller branches until

single axons form dense network near pulp-dentin margin, the Plexus of Raschkow

• Individual axons may branch into numerous terminal filaments & enter the dentinal tubules

• Almost all afferent impulses from pulp result in pain


TYPE OF NERVE FIBRE

SIZE VELOCITY OF

CONDUCTION

FUNCTION

A α( Myelinated )

12-20 µm

70-120 m/sec proprioception.

A β( Myelinated )

5-12 µm 30-70 m/sec transmission of touch and pressure.

A γ( Myelinated )

3-6 µm 15-30 m/s ec for motor function to the spinal nerves

A δ( Myelinated )

2-5 µm 12-30 m/sec transmission of pain, temperature, and touch.

B( Myelinated )

1-3 µm 3-15 m/sec preganglionic autonomic function

C( Non- Myelinated )

0.2-2 µm 0.5-2 m/sec postganglionic sympathetic pain and possibly heat, cold, and pressure


•Trigeminal nerve – sensory impulses from teeth to CNS

•Maxillary division – upper teeth

•Mandibular nerve – lower teeth

•Sympathetic innervation – superior cervical ganglion


Plexus of raschkow Nerves in radicular pulp

Myelinated and unmyelinated nerve fibres


Clinical consideration:

•Electric pulp tester delivers current sufficient to overcome the resistance of enamel and dentin, Stimulates sensory A fibers. C fibers don’t respond as significant more current is needed.

•Cold test using CO2 snow and Heat test using gutta percha activates hydrodynamic forces in dentinal tubules which in turn excite intradental A fibers. C fibers are not activated by these cells unless they produce injury to the pulp.


Nerve endings• Nerve terminals• Round and oval enlargements of terminal

filaments• Contain microvesicles , small dark granular

bodies and mitochondria• Nerve terminals are very close to the

odontoblastic plasma membrane gap of 20µm

• substanceP 5-hydroxytryptamine ,vasoactive intestinal peptide,somatostatin prostaglandins acetylcholine nor epinephrine have been found throughout the pulp.

• These transmitters have been shown to affect the vascular tone and modify the excitability of nerve endings


Terminal nerve endings located among odontoblasts


Functions • INDUCTIVE: Induces oral epithelial

differentiation into dental lamina & enamel organ. Enamel organ to differentiate into a particular type of tooth morphology

• FORMATIVE: pulpal odontoblasts produce dentin which surrounds & protects it

• NUTRITIVE: nourishes dentin through odontoblast by means of blood vascular system of pulp

• PROTECTIVE: recognizes stimuli like heat, cold, pressure, chemicals through sensory nerve fibers. Vasomotor innervation controls muscular wall of blood vessels. Regulates blood volume & rate of blood flow & hence intrapulpal pressure.

• DEFENSE OR REPARATIVE: responds to irritation by producing reparative dentin and mineralizing any affected dentinal tubules.



PRIMARY PULPFunction for a shorter period of time than do the permanent pulpAverage length of time primary pulp functions in oral cavity is 8.3 yrs

This amount of time is divided into 3 time periods:

•PULP ORGAN GROWTH: CROWN AND ROOT ARE DEVELOPING (ABOUT 1 YR)

•PULP MATURATION: ROOT COMPLETION TO BEGINNING OF ROOT RESORPTION (3YRS 9 MONTHS)

•PULP REGRESSION: BEGINNING OF ROOT RESORPTION TO EXFOLIATION (3YRS 6 MONTHS)


PERMANENT PULPCrown completion, formation and calcification – 5yrs 5 months.

Crown completion to eruption – 3yrs 6 months.

Eruption to root completion – 3 yrs 11months.

Thus the pulp of permanent teeth undergo development for about 12 years 4 months (time from beginning prenatal crown calcification to root completion).

This is in contrast to 4yrs 2months it takes in primary teeth.


DifferencePrimary teeth

Permanent teethPulp chamber

Large in relation to crown. Smaller in relation to crown.

OutlinePulpal outline follows DEJ more closely.

Pulpal outline follows DEJ less closely.

Pulpal horn

They are closer to outer surface. Mesial pulp horn extends to a closer approximation to surface than does the distal horn.

The pulp horns are comparatively away from the outer surface.


Primary teeth Permanent teeth

Cellularity

High degree of cellularity & vascularity in tissue.

Comparatively less degree of cellularity & vascularity in tissue.

Potential of repair

High Low

Shape of root canalRoot canals are

ribbon shaped. The radicular pulp follows a thin branching path.

Root canals are well defined with less branching.


Primary teeth Permanent teethApical

foramenRoots have enlarged apical foramen.Thus abundant blood supply demonstrates a more typical inflammatory response

Foramens are restricted .Thus reduced blood supply favours calcific response & healing by calcific scarring.

Pulp nerve fibersIt passes to odontoblastic area where they terminate as free nerve endings

They terminate mainly among the odontoblast & even beyond the predentin

Density of innervations of nerve fibersIt is less so teeth are less sensitive to operative procedure.

Density of innervations is more.


Floor of pulp chamber

Primary teeth Permanent teeth

It is thin, tortuous & branching path canals which leads directly to inter radicular furcation.

It does not have have any accessory canals.



Regressive changes

• Cell changes

• Fibrosis

• Pulp stones or denticles

• Diffuse calcifications


Cell changes

Appearance of fewer cells in the aging pulp.

The cells are characterized by a decrease in size and a number of cytoplasmic organelles.

Fibroblast:Reduction in number of cells, possible

because of reduced circulation.Diminish in size and in number of cytoplasmic

structure associated with fibrogenesis.Intracellular organelles such as RER and

mitochondria are smaller.With aging, decrease in oxygen uptake


Odontoblast:

Undergo degenerative changesMore of vacuoles are present.Gradually odontoblast atrophy and disappear over some area or all area of the pulp.


FIBROSIS In the aging pulp accumulation of both diffuse

fibrillar components as well as bundles of collagen fibers usually appears.

The increase in fibers in the pulp organ is gradual and is generalized throughout the organ.

Vascular changes occur in the aging pulp organ as they do in any organ.


VASCULAR CHANGES Atherosclerotic plaques may appear in

pulpal vessels. Calcifications may be seen

Blood flow decreases with age


PULP STONESDefinition -Pulp stones are nodular , calcified

masses appearing in either or both the coronal or

radicular portions of the pulp organ.

ORBANS ORAL HISTOLOGY AND EMBRYOLOGY(11TH

EDITION)

larger mineralizations

fusion of several smaller ones.

Asymptomatic, unless impinge on nerves or

blood vessels

Seen in functional / embedded unerupted teeth.

Free Powerpoint TemplatesPage 75Pulp stones (denticles)


CLASSIFICATION

Composition ( KRONFELD )

True

False

Diffuse

Relation to dentin

Free

Attached

Embedded


True Denticlesmade up of dentin and is lined by

odontoblasts.

found in the apical portion of the tooth.

Resemble dentin

Inclusion of HERS


False Denticles Concentric layer of calcified tissues

Formed from degenerating cells of the pulp

that tend to mineralize.

The mineralizing cells coalesce.

Concentrically there after layer upon layer

mineral salts are laid down.


Diffuse calcificationIrregular calcific deposits

Seen near blood vessels & collagen fibres

found more frequently in radicular pulp


Embeddedformed originally in the pulp

Surrounded completely by dentin mostly

tertiary

found most frequently in the apical portion of

the root

get dislodged and block the apex during

endodontic therapy.

AttachedAttached to the dentin & not completely

embedded.


FreeFound lying free in the pulp tissue.

present in a large percentage of teeth

present in young as well as old people


Pulp stones

Formed free in pulp and later become attached

or embedded as dentin formation progresses.

66% of teeth in persons 10 to 30yrs of age

80% in those between 30 and 50 years

90% in those over 50 years of age contain calcifications of some type.


Clinical considerations

Shape of the pulp chamber and its extensions into

the cusps pulpal horns is important.The pulpal horns

project high into the cusps exposure of pulp can

occur

With the advancing age the size of pulp chamber

decreases whereas in young age pulp horns are

wider & high.

Cavity preparation: speed, heat, pressure & coolant

may all cause pulp irritation.

Thickness & nature of remaining dentine may

affect pulp response to dental material. Remaining

dentin thickness: 2 mm


Shape of the apical foramen and its location may

play an important part in treatment of root canals.

Accessory canals & multiple canals are rarely

seen in IOPA 10-15 degree - increase in intrapulpal

pressure to 2.5 mm Hg per degree centigrade

although its transient in nature.

Irreversible changes occur at temperatures higher

than 45 degrees centigrade

It has been noticed that at a temperature lower

than -2 degrees centigrade the pulpal necrosis can

occur.


Pulp Irritants

They can be living or non living.

Various pulp irritants are

1. Microbial irritants.

2. Mechanical and Thermal irritants.

3. Chemical irritants.

4. Permanent restoration irritants.

5. Radiant irritants.

The Dental Pulp (Seltzer)


Microbial Irritants Dental caries is one of the local cause

classified as microbial irritant.

Carious dentin consist of 2 layers: Infected Dentin: irreversible

denaturation and infection. Affected Dentin: denaturation is

reversible and no infection. Microorganisms and their products impinge

the dental pulp, commonly found microorganism are streptococcus mutans , lactobacilli and actinomyces.

Defense against caries: Pulp defense by Dentinal changes. Elaborating new dentin. Inflammatory and immunological reaction.


Dentinal changes:

Dentinal tubules of primary dentin mineralize.

Sclerosis of dentin( increase in peritubular

dentin).

Reparative dentin formation.

Inflammation under Caries:

Chronic inflammatory cells increases.

Degree of inflammatory changes directly

proportional to depth of dentinal lesion.

Immunological reaction:

Formation of antibodies against antigenic

component of dental caries

Immunoglobulin formed are IgG, IgM, IgA,

complement components C3 and C4.


Dynamics of Development of Pulpitis from Dental Caries


Mechanical and Thermal Irritants

Dentistogenic ( Iatrogenic ) Pulpitis -dentist induced pulpitisFollowing factors should be kept in mind:

1. Depth of Cavity Preparation:

Cavity preparation causes increase rate of dentin collagen turnover and odontoblast cell damage

Superficial cavity preparation : mild irritation, so as regular reparative dentin produced

Degree of inflammation increases proportionally to depth of cavity preparation


2. Speed of Rotation:

Greater amount of odontoblast damage:

50,000rpm

Least amount damage at :1,50,000 to

2,50,000rpm (coolant used)

Ultra high speed used for removal of

enamel and superficial dentin.

Low speed recommended for finishing of

preparation


3. Dry Cavity Preparation:

Cause great trauma to the pulp

Prolong dehydration with air cause

odontoblast displacement and edema ,

condition which cannot be reversed

Circulation of pulp affected by elevation

of temperature, above 46oC cause

irreversible changes( stasis and

thrombosis occur ).

Intrapulpal pressure increases with

initial drop, possible due to release of

chemical mediators causing vasodilation.


4. Nature of Cutting Instrument:

Thermal damage is greater with

steel bur than carbide burs.

5. Size of wheels and burs: Larger size bur produce greater

pulp damage becausea)Peripheral speed of larger disk

is higher b)Greater area cut at a timec)Coolant can’t get to tooth bur

interface readily.

6. Hand instrument:

Damage of pulp is more because of great pressure induced


7.Coolants:

Used to eliminate heat generated Coolants used are

1. Air Spray (compressed air for 10 sec. displace odontoblast)

2. Combination of water and air3. Water Spray4. Water applied through hollow bur5. Water as a jet stream

Water coolant advantages are1. Temperature reduction 2. Improved debris removal

Quantity alone of coolant is not significant but contact at bur and dentin interface is also important


8.Traumatic Injury:

Cause hemorrhage resulting in nutritional

disturbances, hyalinization of pulp tissue,

excessive mineralization and tooth

discoloration10.Crown fracture:

Pulp not exposed in facture have chances of survival than traumatic teeth without crown fracture

11.Root fracture:Favorable fracture repair by deposition

of cementumMore apical the fracture more favorable

pulp prognosis


12.Traumatic occlusion: Excessive occlusal forces cause pulp

changes such as increased pulp stones , pulpitis , necrosis.

13.Polishing of restoration: Pulp damage due to heat produced by

friction Heat damage can cause enamel fracture Should be done on slow speed and with use

of coolant


Chemical irritants:Temporary filling materials and bases:

1. ZOE:

Of all temporary materials considered to be

safest.

Greater amount of Eugenol in mix, greater

chances of pulpal irritation.

Sedative effect of ZOE is due to Eugenol

ability to block or reduce impulse activity.

2. ZnPO4 Cement:

Severe pulpal damages because of inherent

irritating properties

Toxicity more pronounced when placed in

deep cavity preparation


3. Gutta percha:

Poor marginal seal , so fluid and bacteria move into dentin

Heat and pressure associated with insertion may cause sensitivity.

Permanent Restoration

A. Silicates : Popularity decreased due to

Relatively high solubility Color instability Produce severe damage to pulp

when used as liner When applied to dentin liquid penetrates,

liberates CO2 in pulp, results in thrombosis of vascular system of pulp.

Cause centrifugal flow of fluid in dentin, result in displacement of odontoblast


Effect on pulp influenced by depth of cavity preparation, chronic inflammation may persist for 6 months to 1 yr.

Effect on pulp is progressive, continuous (as remain in gel state)

Have persistent marginal leakage.

B. Restorative Resins:

Pulp damage due to• Marginal leakage• Monomer irritation

Cause mild irritation Cavity should be lined with Ca(OH)2 and covered

with Zn(PO4) prior to insertion of filling material. Polycarboxylate or Zn(PO4) cement have no

adverse effect on polymerization but ZOE should not be used


C. Gold inlays:

Reasons of damage are

•Thinner mix of ZnPO4 cement acts as

irritant

•Large pressure generated in sealing

inlay

•Marginal leakage due to poor adapted

margins

D. Gold Foil:

Excellent marginal sealing but pulp irritation

occur due to mechanical malleting

Recovery is rapid as malleting is cause of

inflammation.


E. Amalgam: One of the safest material even though

minor inflammatory pulp response occur. Least irritant even though liners are not

employed. Lines necessary to prevent thermal

conduction and reduce pressure during amalgam condensation

Microleakage can cause some irritation but as corrosion occur space is plugged

Marginal Leakage: Causative factor in

i.Tooth hypersensitivityii.Tooth discoloration iii.Bacterial growthiv.Recurrent cariesv.Pulp pathosis

None material exhibit perfect margin seal Greatest leakage occur around Gutta Percha

and least around ZOE. Also contributed due to difference in

coefficient of expansion of tooth and restoration- fluid movement is called Percolation


Radiant IrritantsIrradiation:

Damage to teeth depend on dose, source, and type of radiation, exposure factors and stage of tooth development at time of exposure.

During developing stage exposure causes poor formation and even fail to develop.

In pulp odontoblast are injured leading to osteodentin and dentinal niche formation.

Heavy doses cause complete failure of tooth development.

Mild doses cause•Root end distortion and Dilacerations.•Decrease in mitotic activity of pulp cells•Odontoblast produce abnormal dentin•Later stages fibrosis or atrophy may occur


Osteoradionecrosis in bone may occur

Severe root sensitivity may occur.

Reduced salivary flow along with change in organic and inorganic constituent and pH result teeth become dry and brittle and more prone to decay.

Laser:Laser:

Lasers cable of mobilizing immense heat and

pressure.

Damage to pulp depends on intensity of energy.

20 joules– slight affect after 3 days

40 joules– degenerative changes


Diseases of the pulp

ACUTE PULPITISBacterial invasion,trauma ,chemical or mechanical

injury

Severe throbbing pain , either spontaneous or on

thermal stimulation , lying down

Root canal therapy if tooth is restorable


CHRONIC PULPITISSlow , progressive carious exposure

Usually asymptomatic , pain when there is

interference with drainage


REVERSIBLE PULPITISTrauma , dehydration , amalgam occludimg with gold restoration , chemical stimulus

Sharp pain , it does not occur spontaneously , subsides after removal of stimulus

Prevention - liner , varnish , base and careful cavity preparation with proper coolant , sedative dressing.


IRREVERSIBLE PULPITIS

caries, clinical, thermal or mechanical injury, reversible pulpitis may deteriorate into irreversible.

Spontaneous pain & persists after removal of stimulus, bending or lying down, referred to other sites.


NECROSIS Noxious insult injurious to pulp such as bacteria, trauma & chemical irritation

discoloration of tooth, Dull, opaque, crown, Asymptomatic


CHRONIC HYPERPLASTIC PULPITIS { PULP POLYP}

slow, progressive carious exposure, large open cavity, young resistant pulp

Usually symptomless, pressure may cause discomfort.

Elimination of polyploid tissue extirpation of pulp, provided the tooth can be restored

INTERNAL RESORPTION

unknown, usually patients have H/O trauma.

Asymptomatic, pink spot in crown, granulation tissue showing through resorbed area of crown

RCT, obturation preferably plasticized g.p. root perforated: ca(oH)2paste is sealed in root canal & is periodically renewed until the defect is repaired.


Refrences

The Pathway of Pulp (Cohen) ORBANS ORAL HISTOLOGY AND

EMBRYOLOGY(11TH EDITION) Oral histology – Ten Cate’s Textbook of Oral Anatomy, Histology, and

Embryology by B. K. Berkovitz, G. R. Holland, B. J. Moxham.

Sturdevant’s Art & Science of operative dentistry, 4th edition

A textbook of oral pathology, Shafer 5th edition

The Dental Pulp (Seltzer)


jaya's pulp.1

Documents

free powerpoint

cell rich

periodontal

orbans oral

undifferentiated

progressive

root canal

pulp damage