Care of the Pulp Flashcards
what does the pulp contain
cells
nerves
blood vessels
what nerves does the pulp contain
alpha fibres
c fibres
why is pulp being a vital tissue relevant to treatment
has regenerative potential
what does pulp being part of the dentine pulp complex mean
that if you have a procedure that treats dentine then this will also have an effect on the pulp.
what are the functions of the pulp
nutrition
sensory
protective
formative
what is a problem in diagnosis of diseases of the pulp
there is a poor correlation between clinical symptomatology (what the patient is feeling) and pulpal histopathology (what is actually going on in the tooth)
what are possible injuries to the pulp
caries cavity preparation restoration trauma toothwear orthodontic treatment radiation therapy
how does periodontal pathology effect the pulp?
pulp and PDL have close relationship, especially at apex where the pulp enters and exits tooth so anything damaging periodontal tissue has the potential to damage the pulp inside as well
how does radiation therapy injury the pulp
radiation therapy damages cells so it can damage the pulp, very relevant for those receiving radiation therapy for head and neck cancers
how can cavity/crown prep injure the pulp
heat generation from handpieces type of bur used dehydration of dentine cutting odontoblast processes direct injury to pulp restoration material
how do we prevent heat generation from hand pieces damaging the pulp
we use water as a coolant
what burs have more control
large burs while small burs tend to go right into the tooth very quickly
how do we dehydrate dentine in a cavity prep
we wash that fluid away by blowing it away with air
through the water on the handpick
what is the remaining dentine thickness
distance between pulp and base of cavity
how can the restoration material injure the pulp
some of the materials are highly chemical and can be toxic
water absorption
heat of reaction
poor marginal adaption/seal - may get micro leakage
cementation of restoration
how does dentine permeability change as you go deeper into dentine
Dentine tubules increase in diameter as they approach the pulp therefore the deeper the cavity the greater the dentine permeability.
what is dentine permeable to
bacterial substances polysaccharides antibodies immune complexes complement proteins tissue destruction products
what are the bacterial substances that the dentine is permeable to
enzymes
peptides
exotoxins
endotoxins
what is key to initiating and maintaining pulpal and perirradicular pathology
microorganisms
describe alpha fibres
myelinated
produce sharp pain
stimulated by EPT
describe C fibres
non myelinated
stimulate a dull aching pain, an increase in pulpal blood flow and an increased pulpal pressure
what are the two AAE classifications
pulpal diagnosis
periapical diagnosis
Why do we also require a periapical diagnosis
we also diagnose what is going on periapically due to the close relationship of the pulp and other tissues
what are the different pulpal diagnosis
- Healthy pulp
- Reversible pulpitis
- Irreversible pulpitis (symptomatic or asymptomatic)
- Necrotic pulp
- Previously treated
- Previously initiated therapy
describe healthy pulp
vital and free of inflammation
when would we remove a healthy pulp
elective prosthetic purposes
traumatic pulp exposure
why do we remove the pulp in some elective prosthetic treatments
in a post crown
why do we have to remove healthy pulp sometimes in traumatic exposure
o If it has been exposed for more than 24 hours then we know that the pulp is going to die off and become infected.
o If presented less than 24 hours then we can just cover the pulp and monitor the tooth and in most cases it will be fine
what is reversible pulpitis
It is a reversible state of inflammation and this is because the pulp is vital but it is inflamed
how do we reverse reversible pulpitis
We treat the cause of the inflammation which in most cases is caries so we restore the tooth and the pulp essentially settles on
what is the response to sensibility tests with reversible pulpits
regular
why is irreversible pulpits sometimes symptomatic and sometimes asymptomatic
Some patients present in pain but some patients will not complain of anything but we may pick up on the fact that the tooth has the potential of dying.
describe irreversible pulpitis
Pulp is still vital as still has a degree of blood flow and severely inflamed
what are the treatment options for irreversible pulpitis
pulpectomy required then RCT
extraction when the tooth is unrestorable or if patient prefers
what does the difference between irreversible pulpitis and reversible pulpitis depend on
clinical symptoms – importance of the patient history
How does reversible pulpitis present compared to irreversible pulpitis
- Pain to cold, lasts a short time (because of the A fibres getting stimulated)
- Hydrodynamic expression – microleakage (A-fibres)
- No change in pulp blood flow
How does irreversible pulpitis present compared to reversible pulpitis
- Spontaneous pain, intermittent sleep disturbance
- Negative to cold, pain to hot (e.g tea/coffee) (C fibres)
- Increase in pulpal blood flow
what is necrotic pulp
all nerves and blood vessels have died off resulting in a brown ‘mush’
how can necrotic pulp present
Can be partial or total necrosis – if it is a multirooted tooth it may be partial but in most cases it is total necrosis
what is the treatment options for necrotic pulp in mature teeth (closed apices)
- Root canal treatment
* Extraction
what are the treatment options for necrotic pulp in immature teeth (open apices)
- Pulpotomy
- Pulpectomy then full RCT
- Extraction
why does treatment differ for mature patients and immature patients
immature patients have better regenerative potential
what is a pulpotomy
remove some of the diseased or necrotic pulp and seal the vital pulp in the tooth
what are the different perioapical diagnoses
- Normal
- Periapical periodontitis (symptomatic or asymptomatic)
- Acute apical abscess
- Chronic apical abscess
- Condensing osteitis
describe normal periapical tissue
Not sensitive to percussion (tapping) or palpation (pressing buccally or lingually with fingers
how does normal periapical tissue present radigraphically
lamina dura intact
pdl spaces uniform
what does an intact lamina dura look like on a radiograph
clear outline around all the apices of the teeth and the periradicular side of the tooth. If there is a blurring effect then there is loss of the lamina dura
describe symptomatic periapical periodontitis
Inflammation of the apical periodontium
what are the symptoms of symptomatic periapical periodontitis
pain when:
biting
percussion
palpation
why does patient get pain when biting in periapical periodontitis
Because there is inflammation of periodontal tissue then when the patient bites down they will get pain as when we bit the tooth bounces off the PDL.
how does symptomatic periapical periodontitis present radiographically
periapical radiolucency
what does severe pain to percussion mean in symptomatic periapical periodontitis
degernating pulp meaning RCT required
what happens in asymptomatic periapical periodontitis
Inflammation and destruction of the apical periodontium (of pulpal origin)
how does asymptomatic periapical periodontitis present radiographically
apical radiolucency
what is an acute apical abscess
Inflammatory reaction to pulpal infection and necrosis
Rapid onset
Spontaneous pain
what are the symptoms of acute apical abscess
extreme tenderness to pressure pus formation swelling malaise fever lymphadenopathy
what is treatment for acute apical abscess
Treatment we usually incise and drain the pulp. Then open the tooth to remove infected pulp, dress that and then get patient back to either extract or RCT. Could extract tooth on day if patient wishes.
what is a chronic apical abscess
Inflammatory reaction to pulpal infection and necrosis
Gradual onset
what are symptoms of chronic apical abscess
Little or no discomfort
Intermittent discharge of pus through sinus tract
how chronic apical abscess present clinically
Periapical/periradicular radiolucency - dark area around the tooth and it can be difficult to know which tooth the dark area is coming from
how can the suspect tooth be identified in a chronic apical abscess
- Carefully place GP cone into sinus tract
* Take radiograph
what are the treatment options for a chronic periapical abscess
RCT or extraction
what is condensing osteitis
Represents localized bony reaction to a low grade inflammatory stimulus
Usually seen at apex of tooth
We usually just monitor the tooth in this case if the patient is asymptomatic.
Tooth is sometimes okay even if there is condensing osteitis
how does condensing osteitis appear radiographically
Diffuse radiopaque lesion
what are signs of a non-vital tooth
discoloration sinus gross caries large restoration radiographic evidence
what are the different types of discoloration in non vital teeth
yellow
grey
pink
what is a yellow non vital tooth due to
obliteration of dentine tubules and so as a result light does not pass through tooth as much
what is a grey non vital tooth due to
blood products in dentine tubules
what is a pink non vital tooth due to
a sign of resorption taking place, presents around neck of the tooth
what is the primary function of a sensibility test
Primary function is to differentiate ‘vital’ from ‘non vital’ pulp
why do we sensitivity tests on contralateral tooth too
patient response is very subjective
what are the different sensibility tests
electric pulp tests
thermal tests (cold/heat)
test drilling
what are the problems in sensibility tests
they do not indicate the state of blood supply but stimulate nerve so do not actually test vitality
periradicular inflammation occurs before pulp is totally necrotic
difficulties in testing multirooted teeth
what is needed to assess blood flow
laser doppler
what happens in an electrical pulp test
Electrical Pulp test:
Electric current is used to stimulate sensory nerves at the pulp-dentine junction
A-delta fibres are stimulated
Unmyelinated C fibres may or may not response
what is procedure for EPT
• Teeth thoroughly dried – prevents current transfer to adjacent teeth
• Isolate tooth/teeth
• Conducting medium (toothpaste/fluoride gel) required and is put on the tip of EPT probe
• EPT probe placed on incisal edge or cusp tip adjacent to pulp horn as the most sensory nerves are found here
• Patient completes circuit by holding handle of EPT
• The current is slowly increased - Occurs automatically
o The patient indicates when a tingling/heat sensation is felt by pulling the probe away from the tooth and the reading is taken.
how many readings do we take in EPT
3
what happens if EPT reading is 80
means no response
what diagnostic info does a positive response to EPT give
o Vital pulp tissue in coronal aspect of pulp chamber
o No indication of reversibility of inflammation (healing)
o No correlation between pain threshold and pulp condition (measurement of electric voltage/score is not accurate)
what diagnostic info does a negative response to EPT give
o Reliable indicator for pulpectomy procedure in 97.7% of cases
o EPT of young pulps (teeth with open apices) or recently traumatized teeth is unreliable
how does a thermal test work
Thermal tests are believed to work by hydrodynamic forces – fluid movement in dentinal tubules (due to thermal stimulus) activated pulp’s sensory nerve receptor units in pulp.
what are the different types of cold tests
frozen sticks of carbon dioxide or ice used but not reliable
cotton pellet role sprayed with ethyl chloride, difluorodichloromethane, endoice (most reliable)
what is the procedure for a cold test
- Teeth carefully dried and isolated
- Spray cotton and hold with tweezers
- Place cold object close to pulp horn
what is a negative response to a cold test mean
highly indicative of pulpal necrosis
why should caution be taken in a heat test
too much heat may cause irreversible pulpitis
what happens in in a heat test
Initial stimulation results in A delta fibres producing a sharp pain and a continued stimulation results in C fibre activation resulting in a dull radiating pain.
what is the procedure for a heat test
- Vaseline on tooth
- Apply hot gutta percha/green stick to tooth
- Ask patient if they can feel
what is a negative response for a heat test
Negative response indicative of necrotic pulp – not possible to ascertain degrees of reversibility of inflamed symptomatic pulp
what is test drilling
Used when full coverage restorations are present – renders other forms of testing impossible
No local anaesthetic given
Cut into teeth
what is the diagnosis from test drilling
- Patient reports severe pain, or no pain felt when cutting dentine
- Sensitivity-like response to dentine preparation – tooth is vital
what is the alternative to test drilling
Isolation crowned tooth with rubber dam
No local anaesthetic
Spray cold water and air
Assess patient response
what are the 4 things that can influence your decision
- Carious pulp exposure
- Age
- Periodontal disease
- Previous pulpal insult/trauma
what should we take into account when removing caries
remove caries from wall first so that if we expose the pulp cavity the caries cannot get in
how does age affect our clinical decision making
Continued dentine formation means reduced pulp size and volume so for that reason there is more leeway when drilling as the pulp will be further away in a older patient.
Increased fibrous components and calcification
Decreased cellular components and number of blood vessels and nerves meaning regenerative potential is less so if you damage pulp in a younger patient then there is more scope for them to recover
Overall pulp is less likely to reverse an inflammatory response in an older patient
how does periodontal disease effect decision making
Moderate to severe periodontal disease results in a prematurely aged pulp because it has been inflamed and had to recover from it.
Pulp in periodontically involved tooth is less resistant to inflammation than healthy pulp
how does previous pulp insult affect clinical decisions
Caries, caries removal and restorative procedures still has an effect of tooth as it still lays down tertiary dentine so pulp shrinks back from disease process rather than aging
Tertiary dentine is starting to occlude the dentinal tubules and causing the pulp to become smaller
Pulpal fibrosis occurs
Premature aging of the pulp meaning it is less likely to heal than healthy pulp
how do we prevent pulpal damage
knowing tooth anatomy
avoid drilling into pulp
use cavity sealer and an indirect pulp cap
if you expose pulp use direct pulp cap
what is a pulp cap
something you can put directly on the pulp (used for exposure) or if you have a small remaining dentine thickness then you can put an indirect pulp can to thicken the base of the cavity so that its further away from the pulp.
what is a cavity sealer
Cavity sealers protect pulp from bacteria and their products and the toxic effects during the setting phase of restorative materials
what must a cavity sealer material be
- Able to adhere to dentine rather than the restorative material because otherwise if you remove the restorative material you will rip out the sealer too
- Be thin otherwise it reduces the strength of the restorative material
- Not dissolve in biological liquids
what are the different types of cavity sealers
- Varnishes – material dissolved in organic solvents e.g ether
- Liners
- Base materials
what are cavity base liners
Thicker sealants (thicker than varnishes) provide thermal protection as there are thermal effects arising through restorative material
what are examples of cavity bases/liners
- Zinc phosphate
- Zinc oxide eugenol
- Calcium hydroxide e.g dycal
- RMGI e.g vitrebond
what are the advantages of calcium hydroxide
Bactericidal/bacteriostatic
Has a high pH which stimulates fibroblasts to produce reparative dentine which is good as remaining dentine thickness is increasing
Stimulates the recalcification of demineralized dentine by stimulating pulpal cells
Neutralizes low pH from acidic restorative material
what are the disadvantages of calcium hydroxide
Cytotoxic- can kill pulp cells (not necessarily true as it is used as a direct pulp cap)
Weak cement – difficult to place
Very soluble if not protected
can dentine bonding agents be put directly onto the pulp?
Dentine primers with/without adhesives are tolerated by the pulp – you can put this directly over the pulp
Marked reduction in microleakage demonstrated by dentine bonding agents
However, use is very technique sensitive so make sure you don’t get it wet
what is step wise excavation
leave a little bit of caries at the base, restore tooth with GI which gives time for tertiary dentine to be laid so the RDT is increased so we can go in at a later date and remove the last bit of caries.
what happens in seal in caries
drill caries away from walls and leave a bit at the base of the cavity and place a permanent restoration as bacteria cannot get access to food source.
what are the treatment options for pulp damage
- Indirect pulp cap – or stepwise excavation or seal caries in
- Direct pulp cap
- Partial pulpal removal – pulpotomy
- Full pulpal removal – pulpectomy which is the progress to root canal treatment
