what nerve fibres does pulp sensibility test?
Integrity of A delta nerve fibres, in the dentine pup complex by briefly stimulating the outer surface of the tooth
Postitive response does not guarantee healthy pulp, only the presence of some nerve fibres to carry sensory impulses
what are myelinated A delta and A beta fibres like
- Innervate the dentine (90% are A delta)
- Low threshold
- Stimulated by movement of the dentinal fluid
Results in an acute sharp pain
what are unmyelinated c nerve fibres like
- Innervate the body of the pulp
- High threshold
- Can remain excitable even after comprised blood flow
- Results in dull burning pain, poorly localised
When activated pain can radiate
what are 4 different types of pulp sensibility testing
thermal test
electric pulp test
test cavity prep
LA test
What happen in the tooth when doing a cold test
Causes contraction of the dentinal fluid within the tubules, resulting in a rapid outward flow which results in hydrodynamic forces acting on the A delta fibres leading to a sharp sensation
Reversible= pain subsides on removal of stimulus
Irreversible= pain lingers after removal of stimulus
what can be used for cold tests
what can heat test show and what can you use
Heat tests: Activation of C fibres (dull pain of longer duration)
Hot water- isolating with rubber dam and syringing a tooth at the same time
Heated GP- excessive heat may result in pulpal damage
what occurs during a positive response to EPT
- Positive result occurs by an ionic shift in the dentinal fluid within the tubules caused by the local depolarisation and subsequent generation of an AP from an intact A delta nerve
- Intensity of the stimulus is slowly increased until the pt feels a warm of tingling sensation
- The results show that the A delta fibres are sufficiently healthy to function
where should you place the EPT machine
Incisal third for anterior teeth
tip of the MB cusp ion molar teeth
what can result in EPT false positives
- Electrode makes contact with gingiva or large amalgam
- Pt is anxious
- Liquefaction necrosis
- Tooth is not dry or well isolated
Partial necrosis (multi-rooted teeth)
- teeth with acute alveolar abscess
why may teeth with acute alveolar abscess response to EPT
Gaseous and liquified elements within the pulp can transmit electrical charges to the periapical tissues
what can give EPT false negatives
- Pt is premedicated
- Inadequate contact with enamel
- Trauma
- Canal is calcified
- Apex is immature
why may recently traumatised teeth not respond to EPT
why do teeth with immature apex not respond to EPT
how often do teeth show false-positive/ false negative for EPT
10-20%
what is test cavity prep
Test Cavity Preparation (Direct Dentine stimulation)
- Last resort
- Only when other results are inconclusive
- Drill through enamel-dentine junction of unanaesthetised tooth under rubber dam
If the pt feels pain when the dentine is reached the procedure is terminated and the cavity restored
what is LA test
what is sensitivity (stats)
what is specificity
what is laser doppler flow
what are indications for laser doppler flow
- Pulp testing in children
- Traumatised teeth
- Monitoring revascularisation of replanted teeth
- Differential diagnosis or periapical radiolucency’s
what sensitivity test is best used on immature permanent teeth with an open apex
cold test
-
Rubber Dam6
-
Pulpal and periodical pathology and microbiology18
-
indications and contraindications for root canal tx10
-
Restoring endodontically tx teeth21
-
Cores/posts26
-
Access cavities6
-
pulp sensitivity testing22
-
Instrumentation26
-
Inter-appointment disinfectant10
-
disinfection15
-
Obturation20
-
Endodontic Materials44
-
Management of Endodontic pain42
-
vital pulp tx23
-
Molar Access17
-
diagnosis10
-
Clinical Exam/follow up4
-
Retreatment procedures21
-
Diagnosis and management of complex cases28
-
Pathology and mangement of resorption18
-
Surgical Endodontics28
