Care of The Pulp Flashcards
what are the 3 components of pulp?
- cells
- nerves
- blood vessels
what cells are in pulp?
odontoblasts
what is the nerve plexus in pulp called?
plexus of Raschkow
what types of nerves are in pulp?
- Alpha fibre (myelinated)
- C-fibres (unmyelinated)
is pulp a vital tissue?
yes has a blood supply
what is pulp apart of?
dentine-pulp complex
- closely related
procedures in dentine will have effect of treatment of pulp and dentine
- don’t consider in isolation
what are the 4 main functions of pulp?
- nutrition
- sensory (temperature, pressure, pain)
- protective (tertiary dentine formation)
- formative
why is it hard to diagnose pulp issues?
poor correlation between clinical symptomatology and pulpal histopathology
- due to misaligned symptoms and histopathology to what is happening in the tooth
more negative tests mean….
more likely a disease process
possible injuries to pulp
- caries
- cavity/crown preparation
- dehydration of dentine
- cutting odontoblast processes
- direct injury to pulp
- remaining dentine thickness too small
- restorations
- trauma
- tooth-wear
- periodontal pathology
- orthodontic treatment
- radiation therapy
how can cavity/crown prep injure the pulp?
- Heat generation- use coolant!
- Type of bur used (Size, speed, sharpness, force, vibration)
how can dehydration of dentine injure pulp?
air or water infiltrating???
how can cutting odontoblast processes injure the pulp?
Odontoblast trail through tooth leaving trail of cell – cut them will damage the pulp
why is it important to keep in mind remaining dentine thickness?
Keep in mind potential remaining dentine thickness RDT (top of pulp to base of cavity)
- larger = less chance of pulp damage
how can restorations damage the pulp?
Restoration materials can be highly chemical and toxic • Toxicity • Water absorption • Heat of reaction • Poor marginal adaptation/ seal • Cementation of restoration • Microleakage etch
how can trauma lead to pulp injury
teeth are in vulnerable area of body
- exposed to external onslaught
how can periodontal pathology lead to pulp injury?
close relationship to perio tissue around the pulp
microtubules that go through dentine to periodontal ligament
how can radiation injure the pulp?
X rays can kill pulp cells
describe dentine permeability
Dentine tubules increase in number and diameter as they approach the pulp
- Tubules more numerous and wider the deeper in dentine
- Easier for substance to enter and exit pulp
therefore, the deeper the cavity the greater the dentine permeability
what bacteria substances can enter the pulp via the dentine?
- enzymes
- peptides
- exotoxins
- endotoxins (e.g. LPS)
what substances can enter the pulp via the dentine?
- bacterial substances
- polysaccharides
- antibodies
- immune complexes
- complement proteins
- tissue destruction products
what are a key factor in causing pulp problems?
micro-organisms
- causes inflammatory process
- manifests as clinical pain in patient
what are the fibres responsible for the 2 types of pain/
Alpha fibres
- sharp
C fibres
- dull/aching
are alpha fibres myelinated?
yes
are C fibre myelinated?
no
what is the effect of C fibres stimulation/
- increased pulpal blood flow
- increased pulpal pressure
- can’t expand pulp chamber so increase in pressure results in crushing pain (dull/ache)
what fibres are stimulated by Electric Pulp Tester (EPT)?
Alpha fibres
how to determine and diagnose pulpal health?
SOCRATES history taking acronym
Diagnose pulp and periapical together – due to close relationship
AAE classification
- 2 parts: a pulpal diagnosis and a periapical diagnosis
4 types of pulpal diagnosis
- healthy pulp
- reversible pulpitis
- irreversible pulpitis
- necrotic pulp
what is health pulp diagnosis?
Vital
- free of inflammation
- No symptoms
Removed if endodontic treatment indicated for:
- Elective or prosthetic purposes
- Traumatic pulp exposure
Ideally treat exposure within 24 hours, but if not – RCT required
- Sometimes still worthwhile doing endodontic treatment – extreme tooth wear as pulp had time to lay done tertiary dentine, no tooth tissue to restore tooth so need to put in post into pulp and so need to carry out root treatment first to get rid of pulp as healthy pulp would be sore if inserted
- Traumatic mouth exposure – pulp exposed, don’t go dentist for 24hours so pulp died off, if before 24 hours can cover pulp and potentially cure
See paediatric dentistry lectures
what is reversible pulpitis diagnosis?
Vital
Inflamed pulp
- Reversible state of inflammation – if remaining vital can go back from inflamed state
Treat cause of inflammation e.g. caries
Investigations suggest:
- Can reverse to health if adequate vital pulp therapy performed
Many diagnostic mistakes made
- Most difficult to diagnose – need good history and tests (if don’t think it is can carry out unnecessary root treatment)
Regular response to sensibility tests
what is irreversible pulpitis diagnosis?
Vital
Inflamed
- Still has blood supply but in dying process
Investigations suggest:
- Pulpal inflammation can not heal
Treatment options:
- Pulpectomy required then RCT
- Extraction (Unrestorable tooth - Caries spread beyond crestal bone or Patient preference)
what is necrotic pulp diagnosis?
Non-vital pulp
- Partial or total necrosis
- Brown mush in tooth
Can have necrotic tissue in some canals but others vital especially in multi-rooted tooth
Treatment options:
- Mature teeth (closed apices, adults): Root canal treatment or Extraction
- Immature teeth with open apices (children): Pulpotomy; Pulpectomy then full RCT or Extraction
(open apices so more regenerative potential, seal remaining vital pulp and remove necrotic tissue )
reversible Vs irreversible pulpitis
Difference between reversible or irreversible pulpitis depends on clinical symptoms
- Mainly from history
Reversible pulpitis:
- Pain to cold, lasts a short time
- Hydrodynamic expression- microleakage (A-fibres)
- No change in pulp blood flow
Irreversible pulpitis:
- Spontaneous pain, intermittent, sleep disturbance
- Negative to cold, pain to hot (e.g. tea/ coffee) (C-fibres)
- Increase in pulpal blood flow
reversible pulpitis charavteristics
- Pain to cold, lasts a short time
- Hydrodynamic expression- microleakage (A-fibres)
- No change in pulp blood flow
irreversible pulpitis characteristics
- Spontaneous pain, intermittent, sleep disturbance
- Negative to cold, pain to hot (e.g. tea/ coffee) (C-fibres)
- Increase in pulpal blood flow
5 types of periapical diagnosis
- normal
- periapical periodontitis (symptomatic or asymptomatic)
- acute apical abscess
- chronic apical abscess
- condensing osteitis
what is normal periapical diagnosis?
Not sensitive to percussion or palpation
Radiographically,: - Lamina dura intact - PDL space uniform. See clear outline round all apices (Blurring effect is loss of lamina dura)
what is symptomatic periaplical periodontitis diagnosis?
Inflammation of the apical periodontium (Inflammation gone through all pulp to periodontal ligament and tissue)
- PDL is like a hammock round tooth – spongey around when bite, inflammation causes this to hurt
Pain:
- Biting
- Percussion and/or
- Palpation
May have periapical radiolucency (dark shadow)
Severe pain to percussion and/or palpation highly indicative of degenerating pulp
RCT required
what is asympotamtics periaplical periodontitis diagnosis?
Inflammation and destruction of the apical periodontium (of pulpal origin)
Appears as an apical radiolucency
- No present clinical symptoms
- No pain on percussion
- No pain on palpation
- No problems
get X rays for other reasons and notice big dark shadow – chance finding
what is acute apical abscess diagnosis?
Inflammatory reaction to pulpal infection and necrosis
- Emergency clinics often
- Rapid onset
- Long manifestation time, lot of pus formation and increase in pressure
Spontaneous pain Extreme tenderness to pressure Pus formation Poor taste May be no radiographic signs of destruction Malaise Fever Unable to sleep Lymphadenopathy (Inflammation in lymph nodes – trying to fight back)
Treatment
- drain abscess numb tooth and incision, pus removed, open tooth to removed infected pulp, dressing and come back to extract/RCT
Can cause a huge facial swelling – requires additional treatment (max fax)
what is chronic apical abscess diagnosis?
Inflammatory reaction to pulpal infection and necrosis
- Pus slowly finds a way through mucosa and present buccally or labially
Intermittent discharge of pus through sinus tract.
- Draining itself – so less pressure build up, so less constant pain compared to other
Gradual onset
Little or no discomfort
Periapical/periradicular radiolucency.
Suspect tooth can be identified:
- Carefully place GP cone into sinus tract
- Take radiograph
(Sinus is trapped where pus draining into. Put GP point into sinus and take X-ray and will point to source of infection )
what is condensing osteitis diagnosis?
Diffuse radiopaque lesion
Represents localised bony reaction to a low-grade inflammatory stimulus
- Usually seen at apex of tooth
(White area on X ray)
Monitor tooth if asymptomatic
how can dehydration of dentine injure pulp?
taking away natural dentinal fluid
5 signs of non-vital teeth
- discolouration
- sinus
- gross caries
- large restorations
- radiographic evidence
what discolouration can occur in non-vital teeth?
yellow
grey
pink
what are yellow non-vital teeth a sign of?
obliteration of dentine tubules, less light passes through
what are grey non-vital teeth a sign of?
blood products in dentine tissue
what are pink non-vital teeth a sign of?
sign of resorption, eating away at itself, tends to be round the cervical of the tooth
what is the sinus sign for non-vital teeth?
presentation of sinus = dead tooth
how can gross caries cause a non-vital tooth?
enters pulp
how can a large restoration cause a non-vital tooth?
encroached on pulp by error, can lead to slow death
what radiographic evidence shows a non-vital tooth?
- periapical radiolucency
- periradicular radiolucency
what is the old term for sensibility tests?
vitality tests
what do sensibility tests test for?
Primary function is to differentiate “vital” from “non-vital” pulp
- nerve supply (not blood supply, tooth vitality is blood supply dependent but these are for nerve stimulation)
Patient response very subjective
- Compare patient’s response with a contralateral tooth then re-examine same tooth
3 types of sensibility tests
Electric pulp tests (Electric Pulp Tester (EPT))
Thermal tests:
- Cold tests (Ethyl chloride)
- Heat tests (Hot gutta percha (GP))
Test drilling
some issues that can occur in sensibility tests
TEST NERVE SUPPLY AND SENSIBILITY, NOT BLOOD FLOW
periradicular inflammation occurs before pulp totally necrotic
- so partially necrotic but still response as alive
Difficulties in testing multi-rooted teeth
what does an electric pulp test do?
stimulates nerves at pulp-dentine junction
mainly Alpha fibres
unmyelinated C fibres may not respond
procedure for electric pulp test
Teeth thoroughly dried with air or cotton wool
- Prevents current transfer to adjacent teeth
Isolate tooth/teeth
Conducting medium (toothpaste/ fluoride gel) required
- Place on Tip of EPT probe
- Allows current to pass through
EPT probe placed on incisal edge or cusp tip adjacent to pulp horn
- Most sensory nerves found here
Patient completes circuit by holding handle of EPT
Current slowly increased from 0 to 80
- Occurs automatically
Patient indicates when a tingling/ heat sensation is felt
- Can pull probe away from tooth and number will stop
Specific number ranges for different teeth – guide on EPT
take 3 readings from tooth – patient’s response can be different
Always test the contralateral tooth (upper left second incisor test upper right second incisor)
what must you always do when carrying out an electric pulp test?
Always test the contralateral tooth (upper left second incisor test upper right second incisor)
positive response to electric pulp test
Vital pulp tissue in coronal aspect of pulp chamber
No indication of reversibility of inflammation (healing)
No correlation between pain threshold and pulp condition (measurement of electric voltage/ score is not accurate)
close to reading
negative response to electric pulp test
Reliable indicator for pulpectomy procedure in 97.7% cases
EPT of young pulps (teeth with open apices) or recently traumatised teeth
- unreliable
above reading
how is thermal tests believed to work?
hydrodynamic forces
fluid movement in dentinal tubules (due to thermal stimulus
- when apply a thermal stimulus on the tooth the fluid wants to move towards the stimulus
- jars the odontoblast processes
Activates pulp’s sensory nerve receptor units in pulp
what are the types of thermal tests?
cold tests (most typical, ethyl chloride used in clinic, endo ice is better)
heat tests
cold test procedure
Teeth carefully dried and isolated
Place cold object close to pulp horn (spray cotton wool with chemical)
Ask if they feel the cold stimulus
- Yes – positive result
- No – negative result
Negative response highly indicative of pulpal necrosis
types of chemical used for cold tests
- ethyl chloride – (not reliable)
- Difluorodichloromethane – -500 degrees C
- Endo-Ice (-27.2 degrees C)
what should be remembered when carrying out a heat test?
rare
need caution
- Too much heat may cause irreversible pulpitis!
Initial stimulation of A-delta fibres
- Sharp pain
Continued stimulation results in C-fibre activation
- Dull radiating pain
procedure for heat test
Vaseline on tooth
Apply hot gutta percha (used in RCT)/ green stick to tooth
- Negative response indicative of necrotic pulp
Not possible to ascertain degrees of reversibility of inflamed symptomatic pulp
when is test drilling used as a sensibility test?
Used when full coverage restorations present
- Renders other forms of testing impossible
- Really unsure – inconclusive results and history
what is the procedure for test drilling?
No local anaesthetic given
Cut into tooth
Diagnosis
- Patient reports severe pain or no pain felt when cutting dentine
- Sensitivity-like response to dentine preparation – tooth is vital
what is an alternative to test drilling if inconclusive pulp diagnosis from other test sand history?
Isolation crowned tooth with rubber dam (No LA)
Bombard with spray of cold water and air
Assess patient response
what 4 clinical factors can influence pulp health
- carious pulp exposure
- age
- periodontal disease
- previous pulpal insult
carious pulp exposure impact on pulp health
Pulp exposed to caries and bacteria
Vital treatment of carious exposures less than 50% successful
- Therefore, RCT required
However – not in all cases
- E.g. Immature teeth with incomplete root development – Consider removal of necrotic parts of pulp only (Pulpotomy)
Want to remove caries from wall of cavity first rather than base
- as if accidentally drill into pulp and still have caries, flakes of caries can enter and cause infection
age impact on pulp health
Continued dentine formation (secondary dentine)
- Reduced pulp size and volume
- More leeway when drilling as less likely to encroach
Increased:
- Fibrous components
- Calcification
Decreased:
- Cellular components
- Number of blood vessels and nerves
Overall, pulp is less likely to reverse an inflammatory response
what are the changed characteristics of older pulp?
Increased:
- Fibrous components
- Calcification
Decreased:
- Cellular components
- Number of blood vessels and nerves
Overall, pulp is less likely to reverse an inflammatory response
periodontal disease impact on pulp health
Moderate to severe periodontal disease, Result: “prematurely aged” pulp
- increased fibrous component of periodontal disease
- less resistant to inflammation than healthy pulp
- Close relationship between pulp and periodontal tissues
- Can prematurely age pulp
previous pulpal insult effect on pulp health
Caries, caries removal and restorative procedures
- Close to pulp in caries treatment, pulp responds - shrink back as part of disease process as tertiary dentine is laying done
Tubule occlusion
- Reparative dentine formation
- Pulpal fibrosis
“Premature aging” of pulp
- Less likely to heal than healthy pulp
what are the 2 maintenance techniques of pulp health?
- prevention of pulpal damage
- treatment of pulpal damage
prevention better than care
what are 4 points of prevention of pulpal damage?
- know tooth anatomy
- avoid drilling into pulp
- cavity close to pulp
- cavity into pulp (exposure)
why knowledge of tooth anatomy is important in pulpal prevention?
Size, location and proximity of pulp (canals related to pulp horns)
Pre-assessment
- Radiographs
why is avoiding drilling into pulp important in pulpal prevention?
Stop if close to pulp
Caries can be left over pulpal floor in some cases
- Placement of well-sealed restoration
Deep cavity drill maybe stop and place lining, step wise excavation, sealing caries and restoring tooth
what should be done if a cavity is close to the pulp to aid pulpal prevention?
Use of cavity sealers
Indirect pulp cap
- Or small remaining thickness of dentine place to thicken
what should be done is pulp exposure has occurred to aid pulpal prevention?
Direct pulp cap
- material over pulp directly
what do cavity sealers protect pulp from?
- bacteria and their products
- toxic effects during setting phase of restorative material
Whole exposed pulpal dentine must be covered
what are the 3 key characteristics for cavity sealers?
adhere to dentine rather than restorative material
- don’t want sealer to be removed if need to remove the restoration in furture
be thin
- Otherwise – reduces strength of restorative material (requires a certain thickness or will fracture and fail)
Not dissolve in biological liquids
what are 3 types of cavity sealers?
- varnishes (rare)
- liners
- base materials
why are liners and bases used more than varnishes as cavity sealers?
thicker so greater thermal protection from external things and restorative materials
examples of cavity bases/liners
- Zinc phosphate
- Zinc oxide eugenol
- Calcium hydroxide e.g. Dycal (most)
- Resin modified glass ionomers (RMGI) e.g. Vitrebond
positive properties of calcium hydroxide
High pH (alkaline) – Stimulates fibroblasts - reparative dentine formation (tertiary/healing)
Stimulates recalcification of demineralised dentine
- by stimulating pulpal cells
Neutralises low pH from acidic restorative materials
bacteriostatic
negative properties of calcium hydroxide
Cytotoxic
- Can kill pulp cells
Weak cement – so hard to place
Very soluble if not protected– tiny bit moist from saliva, it will dissolve
what are dentine bonding agents?
Dentine primers with/ without adhesives
- tolerated by the pulp
- can be placed directly over pulp without killing it off
Marked reduction in microleakage demonstrated by dentine bonding agents
However
- Use is VERY “technique sensitive”
4 treatment options for pulp damage
Treatment of pulpal damage
- Indirect pulp cap
- Or stepwise excavation or seal caries in
Direct pulp cap
Partial pulpal removal – Pulpotomy
Full pulpal removal – Pulpectomy
- Progress to RCT
step wise excavation
- Leave a bit of caries at base restore with glass ionomer buys time for tertiary dentine being laid down
- Don’t expose pulp
- Restore permanent – encase bacteria in tooth – no food source access no more caries
what is the change in theory behind new treatment options for caries?
remove one of the 4 caries elements
- without one cannot occur
e.g. Cut off bacteria from substrate can arrest caries, if scared to expose the pulp
bacteriostatic
biological or chemical agent that stops bacteria from reproducing, while not necessarily killing them otherwise
bactericidal
is a substance that kills bacteria
