KCS theme 4- Endodontics Flashcards
What are the functions of the pulp-dentine complex ?
alert to pain whilst avoiding injury
mechanoreception and regulation of chewing force
Tubular fluid
Cellular defence
What does tubular fluid do in response to irritation ?
thickening- sclerotic dentine IgA Wet dentine- recoil for fracture toughness hydration and nutrition of engine dilution of microbial toxins
How does the pulp carry out cellular defence ?
inflamatory response
tertiary dentine
sclerotic dentine
What are the types of tertiary dentine ?
reactionary- mild insults, localised odotoblasts are up regualted
reparative- severe insults leads to death of odontoblasts an odontoblast like cells deposit dentine which is irregular and atubular
Give the histological zones of the pulp in order ?
dentine predentine odontoblasts cell free zone cell rich zone pulp core
How does the pulp get injured ?
dentinal tubules are exposed
provides a direct access to the pulp for irritants
deeper pulp tissue is more eporous
high risk of pulp injury when little dentien remains or direct pulpal exposure
How can dentinal tubules be exposed ?
caries
iatrogenic procedures
trauma
What are the classifications of pulp irritants ?
mechanical
chemical
microbial
What are microbial pulpal irritants ?
dental caries
microleakage
How does dental caries act as a pulp irritant ?
caries progresses into dentine leading to localised reversible inflammation of the pulp
production of tertiary and sclerotic dentine
can be reversed by removal of caries and sealing restoration
How can microleakage act as a pulp irritant ?
marginal invasion of restorations by bacteria
pulpal inflammation, sclerotic and tertiary dentine
How can we prevent microleakage of restorations ?
protect pulp with a cavity liner
dentine bonding agent
What are the chemical pulpal irritants?
bleaching
dental materials
How do dental materials act as a pulp irritant ?
originally thought that dental materials were toxic to the pulp
now though that the materials themselves arent toxic but the microleakage that occurs leads to pulpal injury
important to etch and bond properly to prevent microleakage
How does bleaching act as a pulpal irritant ?
Peroxide bleaching tubules diffuse down tubules into the pulp leading to reversible inflammation
bleaching also leads to increase in pulpal temperature
What are the consequences of bleaching ?
temporary tooth sensitivity
How can we prevent tooth sensitivity post bleaching ?
use desensitising agent before like potassium nitrate
What are mechanical irritants of the pulp ?
iatorgenic procedures, trauma and dentine exposure
How can the pulp be irritated iatrogenically ?
use of rotary burs exposes dentine tubules- need to use water to prevent overhating and destination
use of LA with adrenaline leads to vasoconstriction which means less regulation of pulpal temperature
more tubules exposed- more chance of pulpal injury and damage
How can trauma lead to pulpal injury ?
fracture expose dentine tubules - routes for irritants
fractures can damage blood supply- necrosis
children effected most- they also have higher pulp horns and wider dentinal tubules
How can dentine be exposed ?
cusp fracture
gingival recession - leads to cervical hypersensitivity
wear
How can dentine hypersensitivity be treated ?
desensitising agents that occlude tubules
What are the nociceptive fibres in the pulp ?
A-delta
C fibres
Describe the characteristics of A-delta fibres ?
located in the periphery and pulp horns low threshold stimulated by hot/cold/sweet mediate a short sharp transient pain well localised pain srimualted in superficial pulp inflammation
Describe the characteristics of C fibres ?
located in the core stimulated by chemical pain mediators mediate a long aching dull pain that is poorly localised exacerbated by hot/cold/sweet stimulate in deep inflammation of pulp
Describe the reaction of the pulp to an early carious lesion?
early carious lesion breaches enamel and a few dentine tubules are open
minor superficial inflammation
sensitivity to hot /cold/sweet with A-delta fibres stimulated
pulpal reaction- tertiary dentine/sclerotic dnetine
reversible inflammation- removal of caries will he’ll pulp and restore
Describe the pulp reaction to a moderate carious
lesion halfway through dentine?
more tubules are opened
sensitivity to hot/cold/sweet- a delta fibres
peripheral sensitisation- increased sensitivity to non painful stimuli - allodynia
tertiary and sclerotic dentine-
reversible if cares removed
Describe the pulp reaction to an advanced lesion within 0.2mm of pulp ?
pulp at high risk of being injured- many dentine tubules open and exposed
inflammation is now irreversible
dull, poorly localised aching pain that persists suggests irreversible inflammation and C-fibre stimulation
What was the traditional approach to managing deep caries related to the pulp ?
remove all the carious dentine as much as possible hoping to not get a pulpal exposure
What are the modern approaches to deep caries ?
not all carious dentine has to be removed as it risks a s pulpal exposure
clear the peripheries and can leave some on top of pulp if it is a symptom free tooth
use calcium hydroxide (kills bacteria and allows 3 dentine)
seal margins and restore to prevent propagation of caries
What must be remembered about caries removal ?
clear the EDJ
What are the 2 modern appraoches to deep caries management ?
indirect pulp therapy -
stepwise
What is the indirect pulp therapy management of deep caries ?
clear the EDJ
excavate most carious dentine
calcium hydroxide liner
permanently restore and sell
What is the stepwise managament technqiue to management of deep caries ?
clear the EDJ
excavate most soft dentine
calcium hydroxide
seal
leave for 6 months to allow 3 dentine
re enter and 3 dentine should be present
easier to remove the carious dentine now without risking pulpal epsure
What are the functions of pulp lining materials ?
protect the pulp from supposed cytotoxicity of material
protect against thermal/electrical changes
prevent microleakage
Allow tertairy dentien deposition
What is the most used pulp lining material ?
calcium hydroxide
gold standard and used for deep cavities
stimulate odontoblast like cells and kills microorganisms below pH 12
What are bioceramic cements like MTA/bioodentine ?
calcium silicate cements
preferred for vital pulp therapy
stimulates reparative dentine and reduces inflammation
can lead to tooth discolouration
How do glass ionomer cements work ?
they remineralsie dentine as they are gluoride releasing
also bonds with dentine- effective seal
How do resin bonding agents work ?
etch dentine
attach resin- micromechanical retention
resin meshes with collagen in engine tubules to make resin/dentine hybrid layer
follow with composite
What should we do in the case of a pulpal exposure ?
bleeding that isnt gingival indicates pulpal expsure
isolate the totoh
stop the bleeding with cotton wool and remove debris
clean the tooth with NaOCl
apply pulp liner- Calcium hydroxide
restore and seal
monitor for signs of pulp breakdown
What should be the steps used in diagnosing pulpal and periapical conditions ?
history clinical examination testing and radigraphs diagnosis treatment plan managaement monitor
What should we consider when taking a history for pulpal diagnosis ?
sympathetic questions that you let them answer in their own words open ended when did it start duration and fequency what stimulates it what eases It what makes it worse what type of pain is it previous treatment ?
Why do we need to consider a medical history ?
allergies
conditions that might effect endodontic treamtnet
affect sedation
What are the 2 components of a clinical examination ?
extraoral
intraoral
What should be observed in an extra oral examination ?
lymph nodes TMJ muscles of mastication general facial symmetry trismus maliase temeprature and pulse for systemic involvement ?
What should be considered in an intraoral examination ?
soft tissues- sinus tracts, periodontal status, swellings, plaque etc- palpate them
hard tissues- restorations, darkened teeth might be necrotic, is the tooth TTB, cracked cusps, dentine exposure ??
percussion and palpation tenderness indicate inflammation
Describe the progression of pulpal conditions ?
reversible pulpitis
irreversible pulpitis
irreversible pulpitis and symptomatic apical periodontitis
pulp necrosis and acute periapical abscess
pulp necrosis, asymptomatic apical periodontitis and chronic periapical abscess
How can hot/cold/sweet stimuli manifest as pain ?
leads to fluid movement in exposed dentinal tubules- stimulates the sensitised A-delta fibres
Why is irreverisble pulpitis poorly localised ?
C-fibre pain- poorly localsied in the core
What is referred pain ?
injury in one part of the body leads to pain in another part due to the convergence of innervation
If inflammation is limited to the pulp will tooth movement cause pain ?
no- if infection is limtied to the pulp space tooth movement should not cause pain
tooth movement causing pain is indicative of periapical involvement
What are the characteristics of reversible pulpitis ?
short sharp transient pain with hot/cold/sweer stimuli
short duration- pain goes away when stimulus is removed
no TTP
A-delta fibres
What are the characteristics of irreversible pulpitis ?
dull throbbing pain
long duration that persists after removal of the stimulus usually unprovoked but exacerbated by hot/cold/sweet
C fibres
What is the rationale behind pulp sensitivity tests ?
to assess the vitality of the tooth
to aid diagnosis
however can get exaggerated results in anxious patients- use control tooth in separate quadrant to show results
should not be used solely- but as an adjunct
What are the types of pulp sensitivity tests ?
thermal electrical test cavity preparation cusp flexure selective LA
How are cold tests conducted ?
cold- endofrost or ethyl chloride sprayed onto cotton wool and placed on tooth
the coldness causes a contraction of dnetine tubules and movement of fluid - A-delta fibres stimulated
colder temperature more accurate test
dull aching pain that lingers suggests irreversible pulpitis
How do heat tests work ?
apply a heat softned GP stick to a vaselined tooth for a max of 5 secs
What is the rationale behind electronic pulp testing ?
to assess if any vital nerve tissue is left
a total lack of response indicates a non vital tooth
How is an electronic pulp test carried out ?
isolate and dry test tooth
tip of probe covered in conductive medium like toothpaste and placed at thin enamel and pulp horns
separate tooth interproximally to prevent spread to current
when sensation is elicited remove the probe
What are the responses to an pulp electronic test ?
a healthy response will be a warm tingling - A delta fibre mediated
a dull lingering pain- C fibres
How do we carry out a test cavity prep test ?
prepare a small cavity into dentine without LA with an irrigated bur
if sensitive - indicates a vital pulp but A-delta fibres can still be present in a necrotic pulp
if no response the tooth is non vital or the pulp may have receded and wasn’t reached with the bur
Do cracks in enamel only cause pain ?
no
How does pain manifest in a crack that goes into enamel, dentine and the pulp ?
poorly loclaised pain peridoically or when biting
How can we identify cracks in teeth ?
using transillumination
How can we identify the tooth that is cracked ?
with a cusp flexure test
patient instructed to bite down on a tooth
leads to separation of fragments and symptoms are reproduced
How can selective LA be used a pulp sensitivity test ?
often patients can identify which side the pain is coming from but not if mandible or maxilla
poorly localised and referred pain
selectively anaesthetise teeth starting from the distal sulcus of the most posterior tooth and progress until pain disappears
good for pinpointing quadrant not tooth
What are the signs and smyptoms of symptomatic apical periodontitis ?
widened PDL membrnae
TTB and TTP
What are the signs and symptoms of acute apical abscess ?
very TTB
tooth elevated from socket
systemic involvement- malaise and temperature
severe pain from periapicla tissues
tooth may be necrotic
pus formation and swelling an quick onset
radiograph shows periapical radiolucency
What are the signs and symptoms of asymptomatic apical periodontitis?
necrotic tooth
no pulp response
no TTB
well define periapicla radiolucency
What are the signs and symptoms of chronic periapical abscess ?
gum boil and pus discharge from a sinus tract
painless
little or no TTB/TTP
radiolucnecy
distinguished from asymptomatic apical periodontitis as there is a sinus tract that a GP can be placed in to confirm problematic tooth
What is the sensory nerve supply to the periodontium like ?
nociceptive AND proprioceptive fibres
can localise pain properly with periapicla conditions
What is periapical pain stimulated by ?
tooh movement
What are the different periapicla diagnostic tests ?
TTP
palpation
radiographs- radiolucencies, widening of PDL, bone resorptiona nd deposition
sinus tracts
How do we manage reversible pulpitis ?
remove the cause of the irritant - usually leaky restoration
clear the EDJ
zinc oxide for pain relief
seal and resotre
allow healing to reverse the inflamamtion
What does irreversible pulpitis mean for the pulp ?
the pulp is incapable of healing and will eventually die
when it does die the breakdown products will cause severe infection - need to remove the pulp
How do we manage irreversible pulpitis ?
2 options-
extraction
pulpotemy/pulpectomy
What happens in a pulpectomy ?
full excavation of the pulp LA/rubber dam remove caries and restorations and clear EDJ access pulp and remove line with calcium hydroxide and seal return later fro RCT
What happens in a pulpotemy ?
removal of the coronal pulp only
- bit that is irreversibly inflamed- gives instant pain relief as the inflamed bit is removed
LA/rubber dam remove caries and restorations access pulp and sever the coronal pulp stop bleeding clean with odontopaste seal RCT alter
What is odontopaste ?
contain zinc oxide for pain relief
contain clindamycin- bacteriostatic to prevent further infection after endo therapy
What is problematic about irreversible inflamed pulps ?
they are hard to initially anaesthetise
How can we overcome the problem of anaesthetising irreversibly inflamed pulps?
use multiple cartrisges
use articaine instead of lidocaine
use a different LA route- intrapulpal, intraligmentous, intraoesseous i
How do we manage symptomatic apical periodontitis ?
remove the cause of the irritants to the pulp- caries or restorations
if tooth is vital consider pulpotomy ?
How do we manage acute periapical abscess ?
identify the infected tooth remove the cause of pulpal irritants pulpotemy or puplectomy drain pus antibiotics if systemic
How can we drain pus ?
incision and scalpel with LA
though tooth with file extended beyond apex with LA
What is condensing osteitis ?
in response to low grade inflammation of periapical tissues
bone deposition
more radiopaque areas at apices
What does the vitality of a tooth depend on ?
blood supply
How does a necrotic tooth present ?
discoloured
no response to tests
What is asymptomatic irreversible pulpitis ?
no clinical symptoms but obvious that the tooth wont survive
responds as a normal pulp and is vital but no symptoms even though it is inflamed
How do different pulpal conditions present with a cold test ?
normal pulp- little sensation
reversible pulpitis- sharp pain on stimulus
Irreversible pulpitis- lingering pain
pulp necrosis- no response at all
What must be done when carrying out pulpal tests ?
use opposing teeth as control to gage a normal response to compare to abnormal repsone- patient knows what normal feels like
When is electronic pulp testing contraindicated ?
cardiac pacemaker
How do normal periapical tissues present ?
they are asymptomatic and have no symptoms to TTP/TTB or percussion
