Which diagnostic aid is most useful in confirming irreversible pulpitis?

Thermal stimulation is particularly useful in confirming irreversible pulpitis because it directly assesses the vitality of the pulp in response to temperature changes. In cases of irreversible pulpitis, the pulp is likely to react intensely to thermal stimuli, either by causing prolonged pain or a heightened sensitivity that does not subside quickly after the stimulus is removed.

Additionally, the pain response to thermal tests can help differentiate between reversible and irreversible pulpitis. In reversible pulpitis, the pain would generally be brief and cease after the stimulus is removed, whereas in irreversible pulpitis, the pain can be severe and lingering.

While a good medical history is important for understanding the patient’s overall health and potential risk factors, it does not specifically diagnose pulp conditions. Electric vitality tests are sometimes used to assess pulp vitality but can yield variable results based on the individual patient’s response and are less reliable in cases of pulpitis. Examining for mobility primarily assesses periodontal status rather than pulp vitality and does not provide direct information about the condition of the pulp itself. Therefore, thermal stimulation is the diagnostic aid that best confirms irreversible pulpitis based on its specific evaluation of the pulp's response to temperature changes.