Pulpal diseases
Normal pulp
Normal pulp represents vital and asymptomatic pulp tissue. Teeth with healthy pulp have no signs or any symptoms which suggests present disease. There may or may not be evidence of pulp calcifications or pulpal fibrosis, depending of the age of the tooth.
Healthy pulp responds to cold and electric stimuli and the response will not linger more than few seconds. Percussion, palpation and bite test elicit no pain and there is no radiographic evidence of present pathology. A suitable control tooth must be selected for comparison , and pulpal testing should both thermal and electric testing to determine the most probable pulpal diagnosis.
Reversible pulpitis
This diagnosis represents pulp that has mild inflammation due to pulpal irritation. This mild inflammmation has healing capacity and ability and returns to a clinically normal pulp if appropriate treatment therapy is performed.
Reversible pulpitis is a result of dental caries,traumatic injury, defective or new restorations,mechanical pulp exposures, tooth brush abrasion, cracked tooth syndrome or recent subgigival scaling and curettage. Pain caused by reversible pulpitis is usually characherised from mild to severe, always elicited by stimuli ( thermal, biting, sweet or sour stimuli).
Pain usually will resolve a few seconds after stimulus has been removed. In this type of pulpitis, 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 hypersensitivity whose etiology is due to exposed root dentine.
Irreversible pulpitis
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) Occasionally the patient may present with asymptomatic irreversible pulpitis whose onset is precipitated by previous carious exposure, caries excavation or trauma.
Pulp necrosis
Pulp necrosis is the end result of irreversible pulpitis that usually occurs over a variable period of time. On rare occasions such as trauma, the onset of necrosis may be sudden and immediate Symptoms will vary according to the stage of necrosis (partial or complete) with some patients giving a history of previous pain to those who experienced none.
Percussion sensitivity may be evident if necrosis has resulted in an infected root canal system with bacteria reaching the apical portions of the tooth and beyond. Occasionally the tooth may become discoloured as a direct result of altered translucency of the tooth or haemolysis of red blood cells during pulp decomposition.Pulp tests will demonstrate no response to both electric pulp testing and thermal stimulus in cases where complete necrosis has taken place.
In multi-rooted teeth where partial necrosis may have occurred, pulpal sensibility testing may prove positive, making diagnosis difficult in the early stages The distinction between partial necrosis and complete necrosis is important in the management of trauma and immature teeth with open apices particularly when deciding whether to perform an apexogenesis or apexifi -cation procedure.
Sterile necrosis is a histological term that can only be presumed based on continued unresponsiveness to pulp testing and the presence of no peri-apical lesion at the apex of the tooth. This is usually the case in unrestored teeth that have sustained trauma where no reliable clinical and radiographic signs or symptoms can confirm the presence of apical periodontitis.
Usually a waiting period of 3 months is advised with periodic pulp testing. In such cases, the decision to wait longer with the benefi +t of pulpal revascularisation must be weighed against the possibility of developing apical periodontitis, which statistically reduces the overall sucess rate.