Pulpitis may be caused by a dental caries that penetrate though the enamel and dentin to reach the pulp, or it may be a result of trauma, such as thermal insult from repeated dental procedures.
Reversible pulpitis:
Once the irritant is removed the pulp remains vital and is not unduly affected by the changes, and the tooth can be restored vital by filling.
Irreversible pulpitis:
The pulp is irreversibly damaged and necrosis will follow. Pain may not subside after removal of the irritant. Pain may be sharp or dull and throbbing. If there is any drainage, then the severity of pain is reduced.
The tooth may be endodontically treated where by the pulp is removed and replaced by gutta percha. An alternative is extraction of the tooth. This may be required if there is insufficient coronal tissue remaining for restoration once the root canal therapy has been completed.
Pulp Necrosis:
Death of pulp tissue. When the necrosis is due to ischaemia with superimposed bacterial infection, it is referred to as pulp gangrene. The tooth may show discolouration in most cases and does not respond to any pulp vitality test. Herein patient will experience hardly any pain during the RCT treatment. Patient may even walk in with no pain but will give a history of severe pain sometime in the past.
In both irreversible pulpitis and necrosis the treatment is RCT to save the followed by crown or post and core. In case of severly damaged tooth the prognosis may be not very good, hence the tooth may be extracted.