Care of the Pulp Flashcards
What’s in the pulp?
Cells
- odontoblast
Nerves (plexus of Raschkow)
- alpha fibres (myelinated)
- C fibres (unmyelinated)
Blood vessels
Vital tissues
- responds to stimuli
- regenerative potential
Part of dentine - pulp complex
- close relationship with dentine
Functions of pulp
- nutrition
- sensory for temp, pressure and pain
- tertiary dentine formation by odontoblasts -> reparative healing
- secondary dentine
Injuries to pulp
- caries
- cavity prep - heat generation; type of bur used
- microleakage due to restorative materials
- trauma
- toothwear
- periodontal pathology
- orthodontic tx
- radiation therapy
Remaining dentine thickness (RDT)
Restorative materiaal
- toxicity (amalgam)
- water absorption
- heat of reaction
- poor marginal adaptation/ seal
- cementation of restoration
Dentine permeability
- dentine tubules increase in number and diameter as they approach pulp
- the deeper the cavity, the greater dentine permeability
Dental Pain
Alpha fibres
- myelinated
- sharp pain
- stimulated by EPT
C fibres
- unmyelinated
- dull aching pain
- increase pulpal blood flow
- increase pulpal pressure
Difference between reversible and irreversible pulpitis
Reversible
- pain to cold
- lasts a short time
- hydrodynamic expression (microleakage)
- A fibres
- no change in pulpal blood flow
Irreversible
- spontaneous pain
- intermittent
- sleep disturbance
- negative to cold
- pain to hot
- C fibres
- increase in pulpal BF
Tx for necrotic pulp
Mature teeth with closed apices
- RCT
- XLA
Immature teeth with open apices
- pulpotomy
- pulpectomy then full RCT
- XLA
Non-vital tooth
- discolouration; yellow, grey, pink
- sinus
- gross caries
- large restoration
- periapical radiolucency
- periradicular radiolucencies
Primary function of sensibility testing
- test neuron/ nerve function in tooth
- this test stimulate nerve fibres
- test for nerve stimulation
- does not test blood supply- hence cannot test for vitality
How to test tooth vitality?
- laser doppler to assess blood flow
- tooth vitality is related to blood supply
Problems of sensibility tests
- periradicular inflammation occurs before pulp totally necrotic
- difficulty in multi rooted teeth
How to use EPT?
- dry and isolate tooth to prevent current transfer to adjacent tooth
- use conducting medium such as toothpaste and fluoride gel at tip of probe
- probe is then placed on incisal edge/ cusp tip adjacent to pulp horn
- most sensory nerves are found here
- pt completes circuit by holding handle of EPT
- current occurs automatically and pt can sense a tingling/ hear sensation, can pull probe away from tooth when felt
Positive response for EPT
- vital pulp tissue present at coronal aspect of pulp
- no indication of reversibility of inflammation/ healing
- no correlation between pain threshold and pulp condition
Negative response
- reliable indicator for pulpectomy in 97.7% cases
- EPT on young pulps with open apices/ traumatised teeth are unreliable
Thermal test
- work by hydrodynamic forces
- fluid movement in dentinal tubules due to thermal stimulus
Cold test
- frozen sticks of CO2 9-78degrees)
- cotton pellet with ethyl chloride/ Endo-ice (-27.2)/ Endo Frost (-50) Butane propane
- negative response highly indicative of pulpal necrosis
How to perform heat test?
- vaseline on tooth
- apply hot GP/ green stick to tooth
- initial stimulation of A delta fibres -> sharp pain
- continued stimulation of C fibres -> dull pain
Test drilling
- used when full coverage restorations present
- no LA given
- cut into tooth
- pt reports severe pain/ no pain when cutting dentine
Influence of clinical factors
- carious pulp exposure
- age
- periodontal disease
- previous pulpal insult/ trauma
Maintenance of pulp vitality
Prevention of pulpal damage
- step wise excavation
- seal in caries
Vital pulp therapy
- pulp capping
- partial/ Cvek pulpotomy
- complete pulpotomy
How to prevent pulpal damage?
- know tooth anatomy
- radiographs
- avoid drilling into pulp
- caries can be left over pulpal floor
Place temp well- sealed restoration -> step-wise excavation
- remove temp in 6-12 months
- after tertiary dentine barrier is formed
- remove remaining caries and restore definitely
Vital Pulp therapy
Protect pulp from
- bacteria and toxins
- toxic effects during setting phase of restorative material
Materials used in vital pulp therapy must be?
- adhere to dentine rather than restorative material
- thin, if not will reduce strength of restorative material
- form bacterial -tight seal
Materials for Vital Pulp therapy
- zinc phosphate
- zinc oxide eugenol
- Calcium hydroxide, ie: Dycal
- Tricalcium phosphate
- Resin; Comp
- RMGI; Vitrebond
- Bioceramics; MTA, Biodentine
Effects of Calcium hydroxide
- bacteriocidal and bacteriostatic
- high pH
- stimulates fibroblasts
- reparative dentine formation (healing)
- hard tissue barrier formation
- stimulate re-calcification of demineralised dentine by stimulating pulpal cells
- neutralise low pH from acidic restorative materials
Cons
- weak cement
- very soluble if not protected
What is MTA?
- mineral trioxide aggregate
- portland cement 75%, bismuth oxide 20%, gypsum 5%
Describe MTA
- high pH similar to calcium hydroxide
- creates bacteria tight seal
- sets hard enough to act as base for restorative material
- biocompatible
- Grey contains iron
- white does not contain iron
- prolongs setting time
- discolouration of crown if grey is used
Biodentine
- quick setting
- no discolouration
Contents: check photo
Partial/ Cvek pulpotomy
- 1-2mm coronal pulp removed initially with high speed
- additional pulp removed if bleeding excessive
- once healthy pulp is reached then stop
- rinse with 5% NaOCL
- place Calcium hydroxide/ MTA/ Biodentine over pulp tissue
- palce sealing restoration; GIC
- place restoration; Comp
Complete Pulpotomy
- same as partial pulpotomy but the whole chamber is removed
- pulp in root canals are retained
Tx options for unexposed pulp
- indirect pulp cap
- stepwise excavation
- seal caries in
Tx for Exposed pulp
- direct pulp cap
- Partial pulpotomy
- Complete pulpotomy
- Full pulpal removal - Pulpectomy
- progress to full RCT
