Many different classification systems have been proposed to describe the various states of pulpal health and disease based on either histopathological findings or clinical findings. The majority of classifications advocated are a combination of the two [1–9]. Even when the ‘gold standard’ of histological findings was correlated with pulpal clinical signs and symptoms, no direct correlation could be made, further proving this fallacy [10–12]. The clinician should be aware that we are only able to indicate the probable pulpal status of any tooth based on both clinical and radiographic findings [13–15]. Often our treatment decisions based on presumed diagnosis are only proven once treatment has been initiated. It is therefore of paramount importance that we correctly diagnose the pulpal status along the continuum of health and disease with as much confidence as possible. A starting point on this road to success is identifying and understanding correct terminology when attempting to address the endodontic health of any given tooth and eliminating terminology related to histopathology that cannot be attained in the clinical situation [16–24] (see Tables 3.1 and 3.2).

This is equivalent in meaning to a vital, asymptomatic or healthy pulp (Fig. 3.1).

Teeth with a normal pulp and peri-radicular tissues demonstrate no signs or symptoms to suggest any disease is present. Depending on the age of the tooth, there may or may not be evidence of pulp calcification and pulpal fibrosis. The pulp will generally respond to cold or electric stimuli, and the response will not linger for more than a few seconds. Percussion, palpation and bite tests elicit no pain and the radiographic appearance is normal. A suitable control tooth must be selected for comparison, and pulpal testing should include both thermal and electrical testing to determine the most probable pulpal diagnosis.

This refers to a pulp that has mild inflammation due to pulpal irritation that is capable of healing and returning to a clinically normal pulp if appropriate treatment therapy is performed. Reversible pulpitis is a result of caries, trauma, defective or new restorations, mechanical pulp exposures, tooth brush abrasion, cracked tooth syndrome or recent subgingival scaling and curettage. The pain is characterised as mild to severe elicited by stimuli (e.g. thermal, biting, sweet or sour stimuli) (Fig. 3.2 and 3.3).

The pain will resolve after a few seconds once the stimulus has been removed and there is no history of spontaneous pain. There will be no response to percussion or palpation, and the radiographic appearance is generally normal. Reversible pulpitis must be distinguished from dentine sensitivity whose aetiology is due to exposed root dentine.

A pulpal condition is usually caused by deep dental caries or restorations, previous pulp capping procedure, crack or any other pulpal irritant. Spontaneous pain may occur or be precipitated by thermal or other stimuli. The pain may last for several minutes to several hours described as a sharp or dull exaggerated painful response that lingers after the stimulus has been removed. The nature of the pain depends on the type of nerve fibre responding to the inflammation within the pulp (either A delta fibres that mediate sharp pain or C fibres responsible for dull throbbing pain). This disease entity implies that the pulpal state will not heal and if left untreated will result in pulpal necrosis followed by apical periodontitis.

The tooth may or may not be sensitive to percussion and the radiographic appearance may be unremarkable other than the aetiology (deep restoration) (Fig. 3.4