Classification of pulp disease
There is an inconsistent correlation between clinical symptoms and histological findings in pulpal disease. Diagnoses are, therefore, usually based on patient symptoms and clinical findings. Pulpal disease may result in changes to both the soft and hard tissues.
Soft tissue changes
Reversible pulpitis is a transient condition that may be precipitated by caries, erosion, attrition, abrasion, operative procedures, scaling or mild trauma. The symptoms are usually:
• pain does not linger after the stimulus is removed
• pain is difficult to localise (as the pulp does not contain proprioceptive fibres)
• normal periradicular radiographic appearance
• teeth are not tender to percussion (unless occlusal trauma is present).
Treatment involves covering up exposed dentine, removing the stimulus or dressing the tooth as appropriate.
Reversible pulpitis may progress to an irreversible situation.
Irreversible pulpitis usually occurs as a result of more severe insults of the type listed above; typically, it may develop as a progression from a reversible state. The symptoms are, however, different:
• pain may develop spontaneously or from stimuli
• in the latter stages heat may be more significant
• response lasts from minutes to hours
• when the periodontal ligament becomes involved, the pain will be localised
• a widened periodontal ligament may be seen radiographically in the later stages.
Treatment involves either root canal therapy or extractionof the tooth.
Hyperplastic pulpitis is a form of irreversible pulpitis and is also known as a pulp polyp. It occurs as a result of proliferation of chronically inflamed young pulp tissue. Treatment involves root canal therapy or extraction.
Pulp necrosis occurs as the end result of irreversible pulpitis; treatment involves root canal therapy or extraction.
Hard tissue changes
Physiological secondary dentine is formed after tooth eruption and the completion of root development. It is deposited on the floor and ceiling of the pulp chamber rather than the walls and with time can result in occlusion of the pulp chamber. Tertiary dentine is laid down in response to environmental stimuli as reactionary or reparative dentine. Reactionary dentine is a response to a mild noxious stimulus whereas reparative dentine is deposited directly beneath the path of injured dentinal tubules as a response to strong noxious stimuli. Treatment is dependent upon the pulpal symptoms.
Occasionally, pulpal inflammation may cause changes that result in dentinoclastic activity. Such changes result in resorption of dentine; clinically, a pink spot may be seen in the later stages if the lesion is coronal. Radiographic examination reveals a punched out outline that is seen to be continuous with the rest of the pulp cavity. Root canal therapy will result in arrest of the resorptive process; however, if destruction is very advanced extraction may be required.