care of the pulp Flashcards
what is the pulp
- tissue that lies n the middle of the tooth
what cells are in the oulp
- odontoblasts
what nerves are in the pulp
- plexus of Raschow
- alpha fibres = myelinated
- c-fibres = unmyelinated
how do you know the pulp is a vital tissue
- it has a blood supply
- means it responds to stimuli
- has regernative potential
what is the pulp-dentine complex
- if doing something to the dentine, you are causing an effect on the pulp too
- close relationship between pulp and dentine
what are the functions of the pulp
- nutrition
- sensory = temperature, pressure, pain
- protective = tertiary dentine formation
- formative = stimulates production of secondary dentine
what do we need to know the reaction of the pulp to
- caries
- operative manipulations
- trauma
- periodontal disease
what are some injuries to the pulp
- caries
- cavity preparations
- trauma
- restorations
- toothwear
- periodontal pathology
- orthodontic treatment = lots of forces applied to tooth
- radiation therapy
- cavity crown prep = heat generation damages pulp (need water as coolant)
- dehydration of dentine = from air and water during prep
- cutting odontoblast process
- direct injury
- remaining dentine thickness important = more means less affect to pulp
- restoration material = toxicity, water absorption, heat of reaction, poor marginal adaptation/seal, cementation of restoration
what is the dentine permeability
- dentine tubules increase in number and diameter as you get closer to pulp
- increase in permeability
what are some bacterial substances
- enzymes
- peptides
- exotoxins
- endotoxins
what is dental pain typically
- short sharp pain by alpha fibres
- stimulated by EPT
what pain do c-fibres cause
- dull ache
- stimulated by increase in pulp blood flow which increases pressure but there is nowhere for pulp to expands so creates pain
what are some examples of pulp pathology
- reversible pulpitis
- irreversible pulpitis = a/symptomatic
- necrotic pulp
- ## previously treated pulp
why do you also give a periapical diagnosis
- periapical tissues have a close relationship with pulp
- can be normal/healthy
- or can be:
= periapical periodontitis = a/symptomatic
= acute apical abscess
= chronic apical abscess
= condensing osteitis
what is a healthy pulp like
- no symptoms
- vital = free of inflammation
in what situations may a healthy pulp need removed
- elective or prosthetic purposes
- traumatic pulp exposure = if not treated within 24 hours it will need removed
what is reversible pulpitis
- vital = can bounce back
- inflamed pulp
- if you treat causative agent then pulp will return to normal
- has regular response to sensibility tests
what is irreversible pulpitis
- symptomatic or asymptomatic
- vital = still vital but slowly dying off
- inflamed
- treatment options = pulpectomy then RCT, or extraction
- is not going to heal
what’s the difference between reversible and irreversible pulpitis
- reversible
= pain to cold things, lasts a short time
= alpha fibres invovled
= no change in pulp blood flow
- irreversible = spontaneous pain, intermittent, sleep disturbance = negative to cold stimuli, pain to hot = c fibres involved = increase in pulp blood flow
what is a necrotic pulp
- non-vital
- partial or total = in mulitrooted teeth can have partial
- treatment options:
= for immature teeth = pulpotomy, pulpectomy, extraction
= for mature teeth = RCT, extraction
what is normal periodical tissues like
- not sensitive to percussion or palpation
- radiographically = lamina dura intact, PDL space is uniform
what is symptomatic periapical periodontitis
- inflammation of apical periodontium
- pain = on biting, percussion, palpation
- may have periapical radiolucency
- no way to resolve other than extraction or RCT
what is asymptomatic periapical periodontitis
- inflammation and destruction of apical perioodntium
- appears as apical radiolucency
- no clinical symptoms = no pain
what is an acute apical abscess
- inflammtory reaction to pulpal infection and necrosis
- rapid onset
- spontaneous pain
- pus formation
- swelling
- may be no radiographic signs of destruction
- fever
- lymphadenopathy
- treatment = drain abscess, do RCT or extraction
what is chronic apical abscess
- gradual onset
- little or no discomfort
- found way to drain itself so not as much pressure so not as much pain
- intermittent discharge of pus through sinus tract
- bad taste
- periapical/periradicular radiolucency
- place GP cone into sinus tract to get x-ray which will point to where infection is coming from then RCT or extraction
what is condensing osteitis
- diffuse radiopaque lesion
- localised bony reaction to a low grade inflammatory stimulus
- usually seen at apex of tooth
what are the signs of non-vital teeth
- discolouration = yellow (obliteration of dentine), grey (dead tissue), pink (sign of resorption of tooth)
- sinus = grey ring around apex of tooth
- gross caries
- large restoration
- radiographic evidence = periapical radiolucency, periradicular radiolucency
what is the primary function of sensibility tests
- differentiate vital from non-vital pulp
when doing sensibility tests why do you need to test the contralateral tooth
- patient responses can be very subjective
what are some sensibility tests
- EPT
- thermal test = ethyl chloride or hot GP
- test drilling
what are the problems of sensibility tests
- tests stimulate nerve fibres = not blood supply
- don’t indicate blood supply
- vitality is the blood supply = need laser doppler test
- difficulties in testing multi-rooted teeth
what is the EPT
- electric pulp test
- current passes through tooth = alpha delta fibres stimulated
- stimulate nerves at pulp dentine junction
what is the procedure of EPT
- teeth thoroughly dried
- isolate tooth
- conducting medium needed = toothpaste, fluoride gel placed on tip of EPT probe
- EPT placed on incisal edge or cusp tip adjacent to pulp horn
- patient completes circuit by holding EPT
- current slowly increased and patient indicates when they feel tingling sensation
- number increases to 80 = closer to 80 means more non-vital
what does a positive EPT result mean
- vital pulp tissue in coronal aspect of pulp chamber
- no indication of reversibility of inflammation - healing
- no correlation between pain threshold and pulp condition
what does a negative EPT result mean
- reliable indicator for pulpectomy procedure in 97.7& cases
- EPT of young pulps or recently traumatise teeth is unreliable
how many readings are usually taken for EPT
- usually 3 taken and test the contralateral tooth as well
how do thermal tests work
- believed to work by hydrodynamic forces
- fluid movement in dentinal tubules which activate pulps sensory nerve receptor units in pulp
how are cold tests carried out
- frozen sticks of CO2 or ice =not reliable
- cotton pellet/roll sprayed with ethyl chloride or endo ice of difluorodichloromethane
- teeth carefully dried and isolated
- place cold object close to pulp horn
how are hot tests carried out
- careful = too much heat can cause pulpal necrosis
- initial stimulation of alpha fibres = sharp pain
- continued stimulation of c fibres = dull pain
- place vaseline on tooth
- apply hot GP/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
- when full coverage restorations are present
- renders other forms of testing impossible
- no LA is given
- cut into tooth
- diagnosis = patient either reports extreme pain or no pain, if there is pain then tooth is vital
what are some clinical factors than can affect pulp
- carious pulp exposure
- age
how does carious pulp exposure affect pulp
- pulp exposed to bacteria
- vital treatment of carious exposures less than 50%
- therefore RCT required
- if in immature teeth can just remove necrotic parts (poulpotomy)
how does age affect pulp
- continued dentine formation = reduced pulp size and volume
- increased = firbous components, calcification
- decreased = cellular components, number of blood vessels and nerves
- overall = pulp less likely to reverse an inflammatory response, pulp less likely to recover in older patients
how can periodontal disease affect pulp
- moderate to severe PD
- result in prematurely ages pulp
- pulp in a periodontally involved tooth is less resistant to inflammation than healthy pulp
what can previous pulpal insult cause
- premature ageing of pulp
- tubule occlusion = reparative dentine formation
how can you prevent pulp damage
- know tooth anatomy = pre-assessment radiographs
- avoid drilling into pulp = caries can be left over pulp floor in some cases
- use cavity sealers if close to pulp = indirect pulp cap
- if cavity goes into pulp then use direct pulp cap
what do cavity sealers do
- protect pulp from bacteria and toxic affects from materials
- material must adhere to dentine rather than restorative material, be thin and not dissolve in biological fluids
what are some types of cavity sealers
- varnishes
- liners
- base materials
what are cavity base/liners
- thicker sealant = thermal protection
- examples = zinc phosphate, zinc oxide eugenol, calcium hydroxide (Dycal), resin modified glass ionomers (RMGI) (vitrebond)
what are the benefits of calcium hydroxide
- bactericidal/bacteriostatic = high pH which stimulates odontoblasts to make reparative dentine
- stimulates decalcification of demineralised dentine
- neutralises low pH from acidic restorative materials
what are the problems with calcium hydroxide
- cytotoxic = can kill pulpal teeth
- weak cement
- very soluble if not protected
what are dentine bonding agents
- dentine primers with/without adhesives
- tolerated by pulp
- marked reception in micro leakage demonstrated by these
- BUT use is very technique sensitive
