lecture 5, disorders of dental pulp (script)

8/3/2019 Lecture 5, Disorders of Dental Pulp (Script)

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Disorders of the Dental Pulp

Today the topic is about Disorders of the dental pulp

We talked about the developmental changes of teeth, non carious tooth,

loss or changes affecting the teeth we said there is erosion, abrasion,

attrition; all of these can result in loss of the tooth structure but without

caries.

We skipped caries in your text book because caries is extensively

explained to you in Dental Caries and in conservative lectures etc.. , so

we won't talk about caries, but the caries and other trauma to the teeth can

induce pulp response.

How the connection between dentine and pulp occur, through what?

The channels between the external environment and the pulp are dentinal

tubules.

Even if there is caries in the enamel or dentine; the product of caries will

reach the pulp through the dentinal tubule; and before the pulp exposure

or the bacteria enter the pulp, [before the caries reach the pulp], the pulp

will start showing responses.

What are the types of trauma to the pulp? How can the pulp be

traumatized?

1. The first thing or the most significant cause of pulpitis or pulpresponse is Caries

2. other cause of pulp irritation, cavity preparation without cooling;without water spray we are generating heat and this heat will affect

the pulp

3. another cause is chemical restorative material when they areplaced directly on the pulp they may induce pulp response

regardless of the type of the pulp response

4. and there is another trauma to the pulp called Barotrauma[differences in the pressure] example; when divers goes a deep

inside the water and there is a big difference in the pressure thenitrogen bubbles will formed inside the pulp; and this is painful


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this will induce toothache; but later on they found that if the tooth

is not carious barotrauma will not induce pain, so barotrauma is

just exacerbating factor for pain in a previously carious tooth.

Barotrauma: is difference in pressure and its will lead to nitrogenbubbles formation

A student asked something about barotrauma and the doctor

answered:

In barotrauma the difference in pressure will induce nitrogen bubbles

formation, the nitrogen bubbles within the pulp will cause pressure on thenerve inside the pulp and because the pulp is contained within dentine

(hard tissue) there is no area to expand so it will induce not pulpitis, but

pain and when the cause is gone the tooth will come back to normal.

Where got the bubbles come from?

They are formed due to difference in atmospheric pressure like in the

diver for example or going in high altitude.

Pulpitis

From oral pathology text book

Barotrauma (aerodontalgia)

Dental pain has been described by air crew flying at high altitudes

in unpressurized aircraft, and in divers subjected to too rapid

decompression following deep-sea diving. This pain has been

attributed to the formation of nitrogen bubbles in the pulp tissues or

vessels, similar to the decompression syndrome elsewhere in thebody. However, gas bubbles are seldom found in decompressed

organs and the possibility of fat emboli from altered lipoproteins

and platelet thrombi around the fat is suggested by some

investigators. Aerodontalgia is really a marker of inadequate pulp

protection from the atmosphere and this usually means caries. It is

not a direct cause of pulpitis, rather an exacerbating factor.


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Is inflammation of the pulpal tissue regardless of the infective agent.

The types of inflammation:

1. Maybe Acute or Chronic and this classification depends on; natureof pain if it's severe pain or mild; and duration of the pain.

2. Now according pulpitis it's also classified as Reversible andIrreversible

The Reversible Vs. Irreversible Classification is more important than

Acute Vs. Chronic, Why?

Because the first ; Reversible Vs. Irreversible; you have to decide

based on it your treatment plan ;if the tooth is having reversible pulpitis

then you can do for example filling for the tooth but if the tooth is having

irreversible pulpitis maybe you have to do Root Canal Treatment [RCT]

So your treatment choice depends mainly on the diagnoses of

reversible Vs. irreversible not on acute Vs. chronic

Sometimes pulpitis occurs without symptoms; that's mean absence of

symptoms doesnt mean that the pulp normal, maybe the pulp is necrotic

but there is no symptoms.

So we have to decide if the process is reversible or irreversible so that we

can decide:

to restore the tooth , or to remove the pulp , or even to remove the entire tooth.

Causes of pulpitis

1. It is maybe Bacterial .From where the bacteria will enter or reach the pulp?

The bacteria may occur :

due to caries ,


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due to cracks in the tooth; if the tooth is fractured with cracks inthe crown the oral environment is filled with bacteria then the

bacteria may enter the pulp through cracks.

Periodontal pockets; when the bacteria enter the pulp through theperiodontal pockets there are lateral accessory canals the bacteria

may enter through them and reach the pulp directly through the

canals, or if there is a periodontal pockets reaching the apex the

bacteria may enter through the main apex not the lateral accessory

canals. so the periodontal pockets is another route for bacteria to

reach the pulp and we call it endo perio lesion

When the bacteria enters the pulp through periodontal pockets

without caries without cracks we will call it Endo perio lesion

if the tooth malformed; for example having dense invaginatus thencaries may reach the pulp through the depth of the pit " you

remember that, right !!"

** Dense invaginatus when there is a pit inside the tooth and then caries

may occur inside the pit and then the stimuli will reach the pulp.

2. Traumatic causesLike:

crown fractures ;will expose dentine and then the bacteria willenter through the fracture or the root will be exposed to the oral

environment

root fractures also the bacteria will find a way to reach the pulp Partial avulsion the tooth is going out its socket due to trauma

maybe so the bacteria will enter from the oral environment to the

apex

Bruxism and AbrasionAll of these will induce loss of tooth structure exposing dentine and

dentinal tubules. Then the irritant will reach the pulp through the expose

dentinal tubule.


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Why there is sensitivity in abrasion?

Because there is a fluid movement in the dentinal tubules affecting the

pulp.

3. Iatrogenic causes:Maybe the dentist will cause to the patient include:

heat generation like cavity preparation without coolant, deep preparation; sometimes the preparation comes very close to

the pulp even with a coolant the pulp maybe irritated

Pulp exposure during cavity preparation, the book write aboutexperiments done on the rats without bacteria exposure , there was

no pulpal inflammation ,so the factor in pulp exposure in the oral

cavity is that the entrance of bacteria

When the exposure happened if there is good isolation, the bacteria will

not enter the pulp and maybe there will be no pulpitis. But if there is lot

of bacteria in oral cavity when pulp exposure occur bacteria will enter the

pulp and will start causing inflammation

Filling materials maybe toxic to the pulp if they are placed directlyon the pulp

and toxic disinfectant or if you are using certain material it may bevery toxic to the pulp.

These are the Iatrogenic causes: "which are the causes that you induce or

you put to the patient"

And the doctor said there is a table in your book talking about these

causes !!


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Reversible pulpitis

when the patient comes to the clinic complaining of stimulated pain; pain

induce by cold or hot drinks or air for example and this pain last for few

second or short duration of time and then it will go by it is self , these arethe clinical features of reversible pulpitis.

Irreversible pulpitis

When the pain is spontaneous; pain comes by it is self; the pain doesn't

need cause (doesnt induce by cold or hot), its lasting for long duration

and sometimes disturbing sleep of the patient.

Reversible pulpitis is the mildest form of inflammatory response to

something, it may occur with severe attrition, so exposing dentine will cause

reversible pulpitis, abrasion, caries when it's not deep this is reversible

pulpitis

And what happened in reversible pulpitis is just a slight infiltrate of

lymphocyte

Let's look here there is caries or cavity within the tooth and in the pulp

we have a little bit of lymphocytic infiltrate just close to the area of

irritant.

Lymphocyte


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Somebody may ask that the caries is not reaching the pulp yet so why we

have inflammation?

The answer is that the chemicals products of caries will reach the pulp,

before the carious exposure of the pulp, through the dentinal tubule thenthe pulp will start immediately responding by a little or a small layer of

lymphocyte it's localized to the irritant area, a little bit of vasodilatation

and that's it. No necrosis, no neutrophils, no abscess formation, no

extensive involvement of the pulp with lymphocyte. It is just a local

collection of lymphocyte and a little bit of vasodilatation.

Reversible pulpitis

Here is the dentine and the dentinal tubules, here is the dark rounded

spots are mainly lymphocyte look how they are localized forming a single

layer immediately below the dentine of the affected area , blood vessels

maybe slightly dilated and congested I mean engorged with blood , slight

distribution of the odontoblast layer; sometimes the odntoblast go insidethe dentinal tubule according to stimulus or they may be pushed a little

bit forming small clusters of odontoblast so they may be disturbed but it's

still there.

Dentine

(dentinal tubule )

lymphocyt

Odontoblast layer

Dilated blood vessel


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So we can diagnose reversible pulpitis by:

Clinical pictures. Symptoms; stimulated pain last for short duration relived by its self The Histopathologic picture; where there is a focal collection oflymphocyte with a little bit of vasodilatation.

Irreversible Pulpitis

It may be acute or chronic even it clinically or microscopically, and the

treatment of irreversible pulpitis is removal of pulp, we can't remove the

caries because the pulp can't go back to normal unlike the reversiblepulpitis we can remove the caries and place restorative materials or

whatever.

Acute irreversible pulpitis

Look at the pulp response here; we have focal collection of inflammatory

cells, what are these inflammatory cells? These are acute inflammatory

cells which are neutrophils, and you know when there is collection of

neutrophils that means we have an abscess .

The definition ofabscess: focal collection of neutrophils , plus necrotic

materials and bacteria ..... etc.

Note: acute inflammation means that we have neutrophils, chronic

inflammation means that we have lymphocyte.

Carious exposure of the pulp

Neutrophils

Dilated blood

vessel


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Here (in acute pulpitis) we have focal area of acute inflammation with

caries exposure, edema formation and dilated blood vessels, after that

what will happen to the pulp?

As a result of acute inflammation there will be more vasodilatation, moreedema and fluid accumulation within the pulp which will compressed the

circulation, and when the blood supply is cut or not reach at a specific

area that will cause necrosis, the same applies in the pulp with focal

inflammation, mediators of the inflammation, exudates, fluid

accumulation then there will be compression of the circulation, why there

will be compression of the circulation here?

Because there is no space for the pulp to expand (the pulp can't expand),

where the fluid will go? It will start taking the space of the blood vessels

and compressing them and that lead to cut the blood supply, later on

necrosis will start, it starts focally and then it may expand to involve the

whole pulp.

So Acute Pulpitis:

It called acute because

1. There is rapid entrance of bacteria to the pulp, so the immediateresponse is focal accumulation of neutrophils.

This occurs mainly in children and adolescents why?

Because there is no secondary dentin formation; with age the thickness of

dentin will increase so the caries will take more time to reach the pulp,

but in children the thickness of dentin is small so the caries will reach

rapidly to the pulp.

2. Another cause of acute response is overheating due to cavitypreparation, it is fast and rapid so it is an acute cause.


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Pulp abscess :

Here we have an abscess with a core of neutrophils and the pulp start

forming granulation tissue surrounding the abscess without forming

capsule this one of the outcome of the abscess , another outcome isspreading to involve the whole pulp.

Chronic pulpitis :

It occurs in older tooth with thick layer dentin formation consist of

sclerotic dentin and reparative dentin with penetration of the pulp with

very low amount of bacteria or in slow manner.

Again acute Vs chronic isn't the important factor that determinates your

treatment plan , the factor that determinates your treatment plan is

reversible Vs irreversible.

Reversible Vs Irreversible

You can differentiate reversible and irreversible by clinical symptomsand the histopathological features .

What are the clinical symptoms for pulpitis??

Reversible Irreversible

The pain is Elicited (stimulated) ,

Sharp

The pain is Spontaneous , Dull

The pain last for 1015 minutes orless

The pain last for more than 20minutes

Unaffected by body posture Affected by body posture

The pain is Poorly Localized

What's the difference between stimulated and spontaneous?Stimulated: need stimulus to occur like cold, hot, or air.

Spontaneous: doesn't need stimulus to occur it's comes by it self.


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Sharp Vs dull pain sometimes it's not easy to differentiate betweenthem but the sharp pain is just like electric shock the patient will

tell you that ) (

In reversible pulpitis the pain last for short duration ; after youdrink cold water the pain will last only for 10 minutes may be

(actually the pain may last for second only and it will goes) but in

the irreversible the pain will last for long period it's not really 20

minutes its sometimes several hours.

Why in the irreversible pulpitis the pain is affected by bodyposture?

Sometimes when the patient sits in a certain condition he will feel

relieve of pain because in the irreversible pulpitis we have fluid we

have edema inside the pulp so when the patient moves his head to

one side the pressure will be relieved slightly or when the patient

lowers his head down sometimes the pressure increase in the pulp

so the pain will increase

So the pulpitis which is affected by the body posture is not reversible

(irreversible) because there is a fluid, edema and accumulation.

It's difficult to localized pulpitis in general but it's localized inperiapical inflammation, when the inflammation goes out of the

pulp, the pain is easily localized why? Because in the periodontal

ligaments (PDL) there are proprioceptors, there is nerve ending

that feels the pressure, and the pain can be localized this in the

periapical inflammation, but when there is pulpitis we don't have

proprioceptors within the pulp so the pain can't be localized to

which tooth.


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Finally the doctor said "The things I want you to understand are the

clinical symptoms of reversible and irreversible, how to differentiate

between them clinically, how to differentiate between them

microscopically ,the pathological out comes which is if you have a

localized abscess ether this abscess can be localized or has spread ,the

body can form granulation tissue and keep it localized ,or the amount of

bacteria entering to the pulp is very huge ,insulting to the pulp that the

pulp can't cope with it so complete necrosis may occur .

So the response of the pulp depends on the amount of bacteria entering

the pulp and the body response to this amount of bacteria

Little amount of bacteria can be handled but huge amount of bacteria may

induce complete necrosis to the pulp."

A student asked: If there is another cause for reversible pulpitis than

bacteria??

Reversible pulpitis can be induce by bacteria ,due to caries, can be induce

by air causing fluid to move in the dentinal tubules in abrasion or fracture

tooth .. suppose your tooth is fracture and there is no caries but there is

pulpitis why? because of the fluid movement in the dentinal tubule .

sometimes your fracture tooth will allowed the bacteria to enter directly

to the pulp from oral cavity from saliva without caries so caries is not the

only factors cause pulpitis ether it's reversible or irreversible

And how about the treatment ?

Method of the treatment is differing: In reversible pulpitis just remove the

caries and put filling, if the tooth is fractured repair fracture first, theimportant thing you have to cover the dentine to isolate the pulp from the

surrounding environment but if the pulpitis is irreversible there is several

way to treated ether direct pulp capping or partial remove of the pulp or

complete removal of the pulp or what ever

Reversible is treated by filling, placement, covering the dentine.

Irreversible is treated by several ways including direct or indirect

pulp capping etc.. "You will take it in Endo insha'allah "


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Now we already know the histology of the reversible and irreversible

pulpitis, Here is a comparison between the reversible and irreversible

pulpitis :

reversible pulpitis irreversible pulpitis

Inflammation cell Lymphocyte Neutrophils

Abscess formation No Yes

Exudates formation Very minimal or No yes

Necrosis No yes

Treatment Remove the caries Remove the pulp RCT

The abscess that form in the pulp may be localized or spread to the whole

pulp or even go beyond the tooth and spread surrounding tissue, but the

abscess will never be capsulated like in the skin and other region.

These are the features of the pulp that change the fate of the inflammation

compared to the other region:

1. the pulp is contained within a solid chamber and we know now theimportant of this statement ; the pulp can't expand , the fluid

doesn't have space to accumulate except by causing pressure on the

adjacent structure .

2. pulp has limited blood supply through the epical foramen , so if theblood supply is cut due to exudates pressure ,blood supply is

difficult to come to the pulp , unlike skin ; it have blood supply

coming from all around to neutralizing the toxin and inducinghealing.

The inflammation in the pulp may be destructive by ;

1. mediators of the inflammation may cause edema which meansfluid accumulation that may compressed blood supply and induce

necrosis.

2. dilated blood vessels cause pressure on the nerves .3. leakage of fluid from blood vessel leads to accumulate fluid within

the pulp , and further complicate the inflammation process .


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4. migration of the cells from the blood vessel may occur , when theneutrophils die and the enzyme will released and spread causing

further damage to the surrounding pulp .

Pulp necrosis;

Untreated irreversible pulpitis (infected with bacteria):

lose acute and chronic symptoms ; mediator of inflammation willinduce fluid accumulation .

degeneration of nerve fibers . autolysis ; when neutrophils die there will be release of their

enzyme and will start lysis of the surrounding pulp tissue , but it

called autolysis because the lysis occur due to the neutrophils fromour bodies .

Histopathology of pulp disease:

In general it is difficult to correlate pulpal finding with a symptoms,

sometime the patient have severe pain but the pulpal changes are very

minimal.

suppose that the tooth was extracted for a patient with severe pain , and

then the tooth was taken to the histolopathology. Sometime the

inflammation is very minimal compared to the symptoms but it still

inducing sever pain because of the special feature of the pulp, again any

extra amount of fluid doesn't have a space it will press on the nerves and

induce pain or it will press on the blood vessel and induce necrosis.

Bacterial entrance leads to dilate and congest blood vessel and thatcause exudates formation as a result of inflammatory mediators

coming from the inflammatory cells, this exudates formation willcompressed the blood vessel and later on the blood supply is cut

and cause ischemia followed by necrosis.

If there is low caries level the response will be very mild, and whatdid we say about the very mild response ? What is the type of

WBC's? the type of the inflammatory cell is lymphocyte , because

the type of the inflammation is reversible ,and there will be a very

minimal dilatation of blood vessel but no exudates formation .


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Chronic Hyperplastic pulpitis:

Sometimes the response of the pulp isn't abscess or autolysis or edema

formation, but it may be hyperplastic type of pulpitis (there will be

increase amount of granulation tissue formation , to extent that project(protruding) out of the cavity) , and this occur in certain circumstances

that is :

1. to have big opened cavity to allow this exuberant amount ofgranulation tissue to protrude out of it .

2. to have an opened apex so that you have very good bloodsupply for the granulation tissue to occur.

We need blood supply here; the inflammation and the granulation tissue

formation need good blood supply why? Because we need WBC's, so we

will get them and why we need WBC's? Because we need the

inflammatory mediators to induce this amount of granulation tissue

formation.

Where can we have opened apex? In which type of people?

In children!

Because they still have opened apex with good blood supply and also we

need the caries to be widely opened to have this type of response

The granulation tissue that protrude out into the oral cavity can't be

covered by epithelium and then it will bleed easily, any touch to the polyp

will induce bleeding or it may be epithelialized ,the epithelial will comefrom the surrounding gingival (from the desquamated cells in saliva) and

it will reach the surface and cover it with epithelium if it's epithelialized

then it doesn't bleed easily.

So the granulation tissue can be epithelialized or not epithelialized

according to the oral cavity condition .


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So Chronic Hyperplastic Pulpitis (pulp polyp) :

It is hyperplastic because there is increase in the amount of the pulp.

The features:

1. opened occlusal cavity .2. opened apex or good blood supply.3. the patient is usually young with young pulp capacity to regenerate

and the features of this pulp polyp is that the nerves aren't prominent so it

isn't painful to touch, and the tooth is not painful.

This projected pulp doesn't disappear by itself, and if you cut it you will

induce server excessive bleeding, so we can treat this chronic

hyperplastic pulpitis (pulp polyp) by removal the whole pulp (RCT).

Low grade caries over long period of time allowing the formation of this

big cavity.

Pulp calcification and changes of the pulp

Calcification may occur to the pulp with time

Pulp stones may form what are the pulp stones?Calcified particles within the pulp (round particles) and they may be true

or false.

The True pulp stones contain dentinal tubules but the False pulp stones

contain layer of calcified material without dentinal tubule


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Here is a pulp stone if I examine it microscopically I should find dentinal

tubules to call it True pulp stone, no dentinal tubule False pulp stone.

Here also the pulp stone is free, so it can be free or can be adherent to

anything or may be interstitial; it mean incorporated within dentine for

example lining the pulp.

So it may be: Free or, Adherent or, Interstitial (when they have become

surrounded by reactionary or secondary dentine)

True pulp stone composed of dentine and contain dentinal tubule False

pulp stone composed of calcified material but not having dentinal tubule

This is one of the features of age changes of the pulp, so the pulp stone

will start increasing in number with age

There is Dystrophic Calcification , sometimes the mineral candeposit in the pulp forming dystrophic calcification they are

irregular in the shape ,they may be just granules or linear area but

not forming something rounded (or particles)

So Pulp Stone it has a core it's rounded just like a stone, but the granules

(Granular deposit) and anything scattered are Dystrophic Calcification!!

Fig. 4.13 Dystrophic calcifications in the radicular pulp "from the text book"


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Why we call it dystrophic calcification? What is the dystrophic

calcification? What are the types of calcification?

Dystrophic Calcification can occur in the skin or in the kidney or in the

liver it can occur anywhere in the body and even in the pulp so indystrophic calcification the tissue is abnormal, there is something

abnormal in the tissue that allowed calcium minerals to deposit over it ,

there is a change in the tissue; it's may be inflammation or any generative

change; and this is abnormal tissue will allowed the calcium minerals to

precipitate in it

But in the other type of calcification (the doctor forget the name) the

calcium level is high in the blood and calcification happened everywhere

because the calcium is very high.

The End

))(())((

.!

__

Done By:SAKHA'A ALI TWAISSIDUAA WALID ABU HMAID

Please read the extra notes in the next page maybe it will help

you .. and forgive us for any mistake we really try to do our

best..

Some extra notes the doctor pointed to them in the next lecture:


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in pulpitis clinical features in the book they didn't mentionedanything about localized pain ether in reversible or irreversible

pulpitis soWe will rely in this chapter that the pain in pulpitis in general is

poorly localized

you must focus on the importance of bacteria as etiology of pulpitisthey found even if the tooth has fractured and bacteria didn't enter

the pulp pulpitis will not occur or if there was exposure with no

bacteria pulpitis will not occur so the important factor in pulpitis is

the entrance or penetrance of bacteria to the pulp

From the text book((Reactionary dentine may continue to form after the onset of

pulpitis, providing the odontoblasts and pulp have not been

irreversibly damaged, and may in time protect the pulp from

further injury by increasing the thickness of calcified tissue

between the pulp and the irritant in the dentine.))

rate of progression of pulpitis is vary from individual to individualthe severity of pulpitis depends on individual itself (individual

response) and amount of bacteria which enter the pulp sometimes

amount of bacteria that entrance the pulp is too small but cause

excessive response .

before bacteria enter the pulp pulpitis(the inflammatory response)will start and when bacteria enter the pulp abscess and exudates

formation starts

the difference between carious exposure and non carious exposureto the pulp , trauma and the fracture and the excessive force to the

tooth this non carious, may start immediately as acute excaudate

(pus), in the other hand the carious exposure start with focal

inflammation and later it's return to abscess if the bacteria enter the

pulp


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pulp stones increase with age but it's not only present in elderly itmay be present in four condition \circumstances: increasing with

age ,and as a response for operative procedure ,and in traumatic

injury to the apex ,and maybe in Dentin Dysplasia and

Dentinogenesis imperfecta

from the text book((Pulp stones increase in number and size with age and are

apparently more numerous after operative procedures on the tooth.

When large they may be recognized on radiographs. They do not

cause symptoms, although neuralgic pain has sometimes been

attributed to their presence.))

what happened to the pulp with age it will be narrower why ?Because of dentine deposition and pulp stone and calcification will

increases and vascularity and cellularity of the pulp will decrease

with age

from the text book

((The volume of the pulp gradually decreases with age due to the

continued production of secondary dentine. Decreased vascularity,

reduction in cellularity, and increase in collagen fiber content havealso been reported, and these changes may impair the response of

the tissue to injury and its healing potential))

The doctor advised us and said:

" please read your text book and rearrange the information . so you can

study easily"

lecture 5, disorders of dental pulp (script)

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