The diagnostic information obtained from pulpal testing is then used alongside a patient's history, clinical and radiographic findings to determine a diagnosis and prognosis of the tooth.
Sensitivity tests assess the sensory response of a tooth to an external stimulus, results which may be extrapolated to indirectly determine pulpal health status.
Sensory stimuli, such as heat, cold or an electrical current, are applied to the tooth in question in order to stimulate the nocireceptors within the pulp.
Sensibility testing is based on Brännström's hydrodynamic theory, which postulates that the activation of nocireceptors is caused by fluid movement within the dentinal tubules in response to thermal, electrical, mechanical or osmotic stimuli.
[4] An electrical current can be applied to the tooth in order to generate an action potential in the Type Aδ fibres within pulp, eliciting a neurological response.
The use of electric pulp testing has been questioned in patients with traditional cardiac pacemakers despite no evidence of interferences in humans, particularly with more modern devices.
[15] Despite the insights gained from sensitivity testing, a research study found that the density of nerve fibers and blood vessels in the pulp tissue, and the degree of oxygen saturation, may play a crucial role in interpreting the results.
The presence of a higher density of nerve fibers may contribute to a lower threshold for electrical stimulation, suggesting the involvement of neural factors in pulp sensibility.
However, the findings of this study should be generalized with caution due to its small sample size and focus on healthy teeth extracted for orthodontic reasons.
[19] The viability of the vascular supply of the pulp is determined by the output signal generated by the backscattered reflected light from circulating blood cells.
[19][21] The output of laser Doppler flowmetry may be influenced by the blood flow in surrounding tissues, and therefore the test tooth must be adequately isolated to avoid inaccuracies.
[23][24] Pulse oximetry, as well as laser Doppler flowmetry vitality tests may not truly reflect the real state of health of the dental pulp.
[14] In a study from Slovenia, correlations were found between clinical tests and histological analysis of dental pulp in 26 healthy permanent premolars extracted for orthodontic reasons.
This further indicated individual variations in sensitivity, with teeth showing a higher density of nerve fibers having a lower threshold for electrical stimulation.