Management of pulp and root canal conditions

The ultimate decision the practitioner must make is

whether to treat or not to treat the tooth, and if treat-ment is indicated, 

whether to treat the pulp or the root

canal system. The alternative management is to extract

the tooth and then to consider a prosthesis to replace it.

Accurate diagnosis and identification of the cause(s) of

the problem(s) will lead to effective management of the

offending tooth. Table 5 

summarizes the treatment strategies for the management of the various pulp

diseases.

Management strategies vary considerably for the

various pulp conditions which emphasizes the need for

an accurate diagnosis before considering any treatment.

Conditions such as a pulp with atrophy or pulp canal

calcification do not require any treatment (unless the

pulp has become necrotic and the canal has been

infected). A conservative approach should be adopted

when dealing with conditions such as pulp necrosis

without infection since pulp tests are not entirely

Examination and diagnostic procedures to assess the status of the pulp and root canals

The importance of gathering all the relevant

information for making a correct diagnosis cannot be

over-emphasized. An accurate diagnosis is imperative in

all cases so appropriate treatment can be provided in a

timely manner.

A current medical and dental health history is

important, not only for preventing health problems

during treatment but also to help reach a thorough

diagnosis.

For example, pain medication taken within

6–12 hours prior to examination may alter the

responses to pulp sensibility tests or other clinical tests.

One tablet of pain medication may be sufficient to

reduce the pulp or periapical inflammation, or the

analgesic may alter the patient’s perception of pain by

lowering the pain threshold.

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 

(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).

• A pulpless, infected root canal system with secondary

acute apical periodontitis due to breakdown of the

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

caries.

• A clinically normal pulp with pulp canal calcification

but no signs of apical periodontitis (Fig 7a).

Endodontically-treated teeth

Many teeth that are examined by dentists will have

had previous pulp therapy or endodontic treatment.

Such treatments include pulp capping, partial pulpotomy,

pulpotomy, partial pulpectomy and pulpectomy. These

teeth may or may not have signs or symptoms, and they

may or may not have apical periodontitis associated

with them. The technical standard of the previous

treatment may also vary considerably and this can only

be partly assessed by the radiographic appearance of

the material(s) placed in the pulp space or root canal(s).

Essentially, the radiographic appearance of a root

filling only indicates the radiodensity of the material

and where the material has been placed. Radiographs

do not provide any indication of whether or not the

root canal system was disinfected during the previous

treatment, how effectively the canal was sealed,

whether the seal has been maintained, whether any

bacteria survived the previous treatment and whether

any new bacteria have entered the root canal system

since the treatment was completed.

Degenerative changes

The pulp will usually respond to noxious stimuli by

becoming inflamed, but it may also respond by

degeneration which includes atrophy and fibrosis,

calcification, root resorption, or hyperplasia.

Atrophy

Atrophy is a normal physiologic process that occurs

with age and is asymptomatic. Pulp sensibility tests

responses may be normal or delayed. No significant

radiographic or clinical signs are present. As the pulp

atrophies, there will also likely be fibrosis of the pulp

tissue and the extent of this will be largely determined

by the number of irritant episodes suffered by that

particular pulp throughout its history. The size of the

pulp chamber may be reduced. No treatment is

required.

Pulpless and infected root canals

Pulpless canals will always be infected. There will be
no pain from the tooth itself when it has a pulpless
canal, although some patients may give a history of
occasional vague discomfort over a period of time.
However, pain may arise from the periradicular tissues
that become inflamed because of the presence of
bacteria in the pulp space. The only clinical sign
suggesting the condition may be the lack of response to
pulp sensibility tests. No significant changes can be
detected on the radiograph in the early stages of this
condition but within 2–10 months there will be a
radiolucency suggesting periapical involvement.

As there is the potential for erroneous pulp sensibility test
responses, corroborating the clinical findings, radio-graphs 
and patient information is necessary for a
definitive diagnosis.

Pulp necrosis

A necrotic pulp should be suspected when the tooth

does not respond to pulp sensibility tests. However, this

will not always be the case since teeth with pulp canal

calcification, previous root fillings or pulpotomies will

also not respond to pulp sensibility tests. Likewise,

some teeth or patients just do not respond to such tests

for no apparent reason. When pulp necrosis is present,

the history may reveal past trauma, previous episodes

of pain or history of restorations and caries.

Radiographically, a tooth with a necrotic pulp may

have signs (such as untreated caries, an extensive

restoration, previous pulp capping) or there may be no

such signs (e.g., following trauma). Trauma to a tooth

may cause pulp necrosis as a result of severing the

apical blood supply if the tooth has been displaced

from its normal position (e.g., luxations, avulsion) or if

there has been significant damage and inflammation to

the apical periodontal ligament (e.g., subluxation).

No significant radiographic changes are evident at

the root apex unless there is also periapical involve-ment, 

and this only occurs once the necrotic tissue

becomes infected. It is important to realize that a

necrotic pulp  per se does not cause apical periodontitis

unless it is infected.

Necrobiosis

A tooth with necrobiosis has both inflamed and

necrotic (usually infected) pulp tissue.

Many dentists use the term “partial necrosis” for this stage of the

disease process; however, “necrobiosis” was suggested

by Grossman

because it more accurately indicates the

condition – the key factor to the spread of the disease

process is the presence of bacteria within the necrotic

part of the pulp rather than the necrosis itself of part of

the pulp. The necrotic tissue may be in the coronal

portion of the pulp (e.g., pulp chamber) with the

inflamed tissue apically, or the different tissue states

may exist in different canals of a multi-canal tooth.

Teeth with this condition can be quite difficult to

diagnose since they usually present with a mixture of

the signs and symptoms of both pulpitis and necrosis

with infection. The symptoms may be mild with

Irreversible pulpitis

One of the classic symptoms of irreversible pulpitis is

lingering pain induced by thermal stimuli. Only mild

temperature changes are required to induce the pain

(e.g., tap water, breathing cold air). The initial reaction

is a very sharp pain to hot or cold stimuli and it then

lingers for minutes to hours after the stimulus is

removed. The lingering pain is usually a dull ache or a

throbbing pain. Spontaneous (unprovoked) pain, which

may wake the patient at night and may become worse

when lying down, is another hallmark feature of

irreversible pulpitis. Patients with irreversible pulpitis

often need strong analgesics and may have difficulty

locating the precise tooth that is the source of the pain.

They may even confuse the maxillary and mandibular

arches (but not the left and right sides of the mouth)

because of the extensive branching of dental nerve

axons and perhaps fewer proprioceptive fibres in the

pulp.

Reversible pulpitis

A pulp with reversible pulpitis has mild inflammation
and it is capable of healing once the irritating stimulus
has been removed. Pain is only felt when a stimulus
(usually cold or sweet foods but sometimes heat) is
applied to the tooth, and the pain ceases within a few
seconds or immediately upon removal of the stimulus.
The pain is short and sharp in nature but not
spontaneous. There are no significant radiographic
changes evident in the periapical region, and the only
radiographic findings of note may be the cause of the
problem, such as caries, a deep restoration, etc. Usually
more extreme temperatures are required to induce the
pain rather than mild changes (e.g., ice cream rather
than tap water).

Clinically normal pulp

The term “clinically normal pulp” is used to classify

a pulp that has no signs or symptoms to suggest that

any form of disease is occurring. The term “clinically”

is used since such a pulp may not be histologically

normal and/or may have some degree of fibrosis

(scarring) as a result of previous injury or stimuli.

A clinically normal pulp is asymptomatic. It

produces a mild and transient response to various

stimuli but the nature and severity of the response may

vary according to the age and state of the tooth. As

long as there has been no calcification of the coronal

pulp space, a clinically normal pulp will react to cold

stimuli with mild pain that lasts for no more than 1–2

seconds after the stimulus is removed. A clinically

normal pulp does not respond to heat stimuli.

Percussion and palpation tests will not elicit any

tenderness. Radiographic examination will demonstrate

normal appearance of the pulp chamber, root canals

and periapical tissues.

Signs and symptoms of pulp and root canal conditions

Diseases of the pulp tissues are dynamic and
progressive in nature (Fig 1). Each disease condition may
progress to other conditions if left untreated. Hence, the
signs and symptoms will vary depending on the stage of
the disease at the time the patient presents for treatment.
In addition, the reaction to and the perception of pain
will vary between individual patients and is influenced
by the individual’s emotional status and the coping
strategies used to manage the pain. Many of the signs
and symptoms overlap between the various pulp
conditions due to the dynamic interactions and the
progressive nature of the disease process. Therefore, the

A clinical classification of the status of the pulp and the root canal system

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