Many different classification systems have been
advocated for pulp diseases. However, most of them
are based on histopathological findings rather than
clinical findings which leads to confusion since there
is little correlation between them. Most classifications
mix clinical and histological terms resulting in
misleading terminology and diagnoses. This in turn
leads to further confusion and uncertainty in clinical
practice when a rational treatment plan needs to be
established in order to manage a specific pathological
entity. A simple, yet practical classification of pulp
diseases which uses terminology related to clinical
findings is proposed. This classification will help
clinicians understand the progressive nature of the
pulp disease processes and direct them to the most
appropriate and conservative treatment strategy for
each condition. With a comprehensive knowledge of
the pathophysiology of pain and inflammation in the
pulp tissues, clinicians may accomplish this task
with confidence.
Many different classification systems (Table 1) have
been advocated for pulp diseases
although most of
them are based on histopathological findings. Many
authors and clinicians have attempted to correlate the
histological conditions of the pulp to the clinical signs
and symptoms.
These classifications mix clinical and
histological terms resulting in many misleading terms
and diagnoses for the same clinical condition (Table 1).
This in turn leads to confusion and uncertainty in
clinical practice when a rational treatment plan needs
to be established in order to target a specific
pathological entity. Confusion in diagnosis can also
arise when using a classification with a wide selection
of overlapping conditions.
One of the primary purposes of establishing a
diagnosis is to determine what clinical treatment is
required. If an incorrect diagnosis is made, then
incorrect or inappropriate treatment may be instigated
and this may result in various consequences ranging
*School of Dentistry, The University of Western Australia.
Australian Dental Journal Supplement 2007;52:(1 Suppl):S17-S31
from mild to severe. Diseases of the pulp and periapical
tissues are, in general terms, either inflammatory in
nature or due to infections. An infection will also be
associated with inflammation of the adjacent tissues.
Hence, if the condition is inflammatory then the
treatment regime adopted by the clinician should be
targeted at removing the inflammatory stimuli and
reducing the inflammation in the tissues – in such a
case, an anti-inflammatory agent would be indicated as
part of the local treatment (e.g., within a root canal
medicament) or as part of any systemic medications
used. On the other hand, an infection will require the
use of an anti-microbial agent (e.g., antibiotic or anti-septic)
within the root canal medicament or, in certain
circumstances, systemically. Infected canals cause
inflammation within the adjacent periapical tissues and
therefore an anti-inflammatory agent combined with
the anti-microbial agent in the root canal medicament
should also be considered. Hence an accurate diagnosis
is essential to ensue appropriate treatment is provided.
A further purpose of a classification of diseases is to
enable communication between teachers, students,
clinicians and researchers. Hence any classification
needs to be useful, easily understood and readily
applied to the clinical environment. The use of
terminology that is inappropriate or that cannot be
applied clinically is counter-productive to these aims.
For example, if a histological examination is required
since histological terms are used, then this is impractical
in a clinical situation where an immediate diagnosis is
required before treatment is instigated; in this scenario,
a diagnosis is required in order to dictate what
treatment regime should be followed.
A clinician’s ability to diagnose accurately is
dependent on having a thorough understanding of the
disease processes involved as well as having a thorough
understanding of the diagnostic procedures and tests
being used and their limitations (see below).
The progression of disease in the dental pulp is
similar to changes in other connective tissues. Typically,
the tissue and disease progresses through the following
stages: normal, inflammation (i.e., pulpitis), necrosis,
infection and loss of pulp tissue (i.e., pulpless canals).
Inflammatory changes may be acute, chronic, reversible
or irreversible, and chronic conditions may have acute
exacerbations at any time. The classification presented
below and in Table 2 has been proposed previously by
Abbott. It is a simple yet comprehensive clinical
diagnostic system that utilizes terminology relating to
the clinical findings (i.e., signs and symptoms) and it is
based on the progression of pulp diseases through the
various stages shown in Fig 1. It also includes “normal”
pulp tissue which is an entity that should be diagnosed
and given recognition when there are no signs of
disease.