Wednesday, November 5, 2014

Periapical diseases

A discussion about pulp diseases would be
incomplete without discussing the periapical tissues and
their disease processes since periapical diseases are
usually a direct result of pulp diseases. It is beyond the
scope of this paper to discuss periapical diseases in
detail and such diseases have been fully discussed in
other publications.

Unfortunately, there is also
considerable confusion amongst authors and clinicians
regarding the classifications and terminology used for
periapical conditions.

However, Abbott has 
outlined a classification for periapical diseases that is
based on the same principles as the above classification
for pulp diseases and root canal conditions and
therefore the two classifications can be used
concurrently.

When a tooth is being examined for pulp disease, the
condition of the periapical tissues must also be
assessed, and vice versa, since apical periodontitis is
usually associated with inflammatory conditions of the
pulp (i.e., reversible and irreversible pulpitis), or
infection of the pulp space following necrosis of the
pulp or after previous endodontic treatment. That is,
periapical diseases are usually a direct consequence of,
and/or a sequel to, interaction with the root canal
system.
Examples of some typical diagnoses are:
• Acute irreversible pulpitis with primary acute apical
periodontitis due to caries.
• Acute irreversible pulpitis with primary acute apical
periodontitis due to breakdown of a restoration 
Periapical diseases
(Fig 3).
• Necrotic and infected pulp with primary acute apical
periodontitis due to caries and restoration break-down.
• Pulpless, infected root canal system with secondary
acute apical periodontitis due to breakdown of the
restoration.
• Pulpless, infected root canal system with a chronic
apical abscess due to breakdown of the restoration
(Fig 5).
Periapical diseases
• A pulpless, infected root canal system with secondary
acute apical periodontitis due to breakdown of the
Periapical diseases
restoration (Fig 6).

• A root-filled tooth with an infected root canal system
and chronic apical periodontitis due to breakdown
of the restoration (Fig 6).
• Pulpless, infected root canal system with chronic
apical periodontitis due to a crack in the tooth and
Periapical diseases
caries.

• A clinically normal pulp with pulp canal calcification
but no signs of apical periodontitis (Fig 7a).