pulp test Flashcards
If the tooth did not respond to CO2 but did respond to EPT at a value higher than the mucosal tissue response, then a diseased pulp was possible, and further clinical and radiographic investigation was recommended.
If the tooth responded to CO2 but did not respond to EPT, then the EPT result was more likely to be faulty.
Peters et al 1994
LDF had the highest sensitivity and specificity in this study compared with the other pulp tests
Evans et al 1999
Recorded in vitro temperatures for:
• Etyle chloride- older form of refrigerant spray
• DDM chlorofluorocarbon -less popular due to damage to the ozone
• Endo Frost tetrafluoroethane
• TFE (−26◦ C)
• CO2 (−78◦C)
CO2 is not as cold when used clinically, where it has been reported to be −56◦C, similar to DDM which is known to have a temperature as low as −50◦C
Chen & Abbott 2009
Electric pulp testing (EPT) works on the premise that electrical stimuli cause an ionic change across the neural membrane, thereby inducing an action potential with a rapid hopping action at the nodes of Ranvier in myelinated nerves
A “tingling” sensation will be felt by the patient once the increasing voltage reaches the pain threshold, but this threshold level varies between patients and teeth, and is affected by factors such as individual age, pain perception, tooth surface conduction, and resistance
Electric pulp tests are known to be unreliable in many instances, producing false results in healthy immature teeth with incompletely formed roots which may be erupting since these teeth may take up to five years before the maximum number of myelinated fibres reaches the pulp-dentine border at the plexus of Rashkow.
Chen & Abbott 2009
LASER DOPPLER FLOWMETRY
Electro-optical technique uses a laser source that is aimed at the pulp, and the laser light travels to the pulp using the dentinal tubules as guides
The backscattered reflected light from circulating blood cells is Doppler-shifted and has a different frequency to the static surrounding tissues. The total backscattered light is processed to produce an output signal.
The signal is commonly recorded as the concentration and velocity (flux) of cells using an arbitrary term “perfusion units” (PU) , where 2.5 volts of blood flow is equivalent to 250 PU.
Chen & Abbott 2009
Systematic + Meta-analysis:
Laser Doppler Flowmetry and Pulse Oximetry were the most accurate diagnostic methods;
Heat Pulp Testing was the least accurate diagnostic method.
EPT showed high accuracy when testing vital teeth (specificity = 0.93) but low accuracy when assessing nonvital teeth (sensitivity = 0.72).
Cold Pulp Testing had moderate accuracy when evaluating vital (specificity = 0.84) and non- vital (sensitivity = 0.87) teeth
Mainkar & Kim 2018
