Care of the Pulp Flashcards
What are diagnostic indicators of pulpal necrosis?
Periapical radiolucency
Discolouration of the tooth crown- usually grey/brown
Infection-related external root resorption
No response to vitality testing
Presence of fistula (sinus tract)
TTP
Gross caries
Large restorations
What reaction occurs to cause a traumatised tooth to become grey/brown?
Accumulation of haemoglobin or other haematin molecules.
What reaction occurs to cause a non-vital tooth to become grey/brown?
Hydrogen sulphates produced bt bacteria convert iron to dark coloured iron sulphates.
What sensibility tests can be utilised?
Electric pulp test
Thermal tests- ethyl chloride, frozen carbon dioxide or hot GP.
Testing drilling- when full coverage restorations are present.
Single tooth isolation with rubber dam, spray cold water/air and determine patients response.
Laser doppler flowmetry
Pulse oximetry
What are some of the issues associated with sensibility testing?
Stimulate nerve fibres, a-delta, which does not directly correlate with pulp vitality.
Blood flow determines pulp vitality.
How are thermal sensibility tests thought to work?
Hydrodynamic forces- fluid movement in dentinal tubules due to thermal stimuli.
Activates pulp’s sensors nerve receptor units in pulp.
What happens to teeth as we get older?
Reduced pulp size due to continued dentine formation.
Increased fibrous components and calcification
Decreased cellular components, blood vessels and nerves
With age, the pulp is less likely to reverse an inflammatory response.
What occurs to teeth after a previous pulpal insult?
Occlusion of dentinal tubules- pulpal fibrosis and reparative dentine formation.
What components are found in the pulp?
Odontoblasts, fibroblasts, defence cells
Nerve fibres
Blood vessels
Lymphatics
Extracellular compnents- collagen, proteoglycans
What is the function of the dental pulp?
Nutritive- blood vessels
Dentine growth
Dentine repair
Defence
How is there a close relationship between dentine and the pulp?
Developmental- both structures develop from the dental papilla
Structural- odontoblast processes extend into dentine, as well as nerve terminals, immune cells and dentinal fluid.
Functional- formation of secondary dentine, tertiary dentine.
What is reactionary tertiary dentine?
Laid down in response to mild stimulus by primary odontoblasts.
What is reparative tertiary dentine?
In response to intense stimulus that destroys the primary odontoblasts.
Laid down by secondary odontoblasts.
What is the dentine-pulp response to injury?
Immediate- Nociceptor activation, patient feels pain
1 minute- early inflammatory response, vasodilation.
10 minutes- nociceptor sensitisation, extravasation of fluid, oedema
100 minutes- enzyme activation, nerve growth factor, monocyte presence.
1 day- nerve sorting, increased axonal transport.
1 week- tertiary dentine formation.
What is the hydrodynamic mechanism of pain?
Stimulus causes dentinal tubules to open, increase rate of dentinal fluid flow, action potential generated and causes pain sensation.
Outward fluid flow- cold, drying, decreased hydrostatic pressure.
Inward fluid flow- heating, mechanical, increased hydrostatic pressure.
