ENDODONTIC - PERIODONTAL LESIONS
endodontium and periodontium are closely related and diseases of one tissue
may lead to secondary diseases in the other. The differential diagnosis
of endodontic and periodontal diseases can sometimes be difficult but it
is of vital importance to make a correct diagnosis so that the appropriate
treatment can be provided.
lesions have been classified by various authors according to the primary
cause of disease. A typical classification, based on the primary disease
with a secondary effect, is as follows:
a) Primary endodontic
lesion with drainage through the periodontal ligament - a deep narrow
probing defect is noted on just one aspect of the tooth root.This is usually
a draining sinus originating from an infected root canal system.
b) Primary endodontic
lesion with secondary periodontal involvement - there is a more extensive
periodontal pocket which has occurred as a result of the drainage from
the infected canal. Long-term existence of the defect has resulted in deposits
of plaque and calculus in the pocket with subsequent advancement of the
c) Primary periodontal
lesion - the periodontal disease has gradually spread along the root
surface towards the apex. The pulp may remain vital but may show some degenerative
changes over time.
d) Primary periodontal
lesion with secondary endodontic involvement - progression of the periodontal
disease and the pocket leads to pulpal involvement via either a lateral
canal foramen or the main apical foramen. The pulp subsequently becomes
necrotic and infected.
e) Combined endodontic-periodontal
lesion - the tooth has a pulpless, infected root canal system and a
co-existing periodontal defect.
A simpler classification
would be to define any situation with both endodontic and periodontal diseases
as being a "combined endodontic-periodontal lesion". An attempt should
be made to identify the primary cause of a combined lesion but this may
not always be possible. In such cases, it is not essential to determine
which disease entity occurred first as the treatment will involve both
endodontic and periodontal management. If only one of the problems was
treated, then it would be expected that the lesion would not heal adequately.
It is generally advisable to treat both tissues concurrently in order to
create the most favourable environment for healing.
Initially a detailed
medical and dental history must be obtained from the patient. The patient's
description of any signs or symptoms will usually lead the clinician to
a provisional diagnosis. A full periodontal and endodontic examination
must then be carried out to confirm the diagnosis and to identify or exclude
any other diseases that may be present.
The clinical examination
should include inspection of the gingival and mucosal tissues, periodontal
probing, palpation, mobility testing, percussion, pulp sensibility testing,
occlusal assessment, biting tests and a radiographic examination.
is essential to identify and determine the depth of periodontal pockets
and the degree of loss of attachment. Periodontal probing should be carried
out for the entire dentition, not just the tooth involved. Any suppuration
or bleeding on probing should be noted.
Pulp testing should
be carried out with both carbon dioxide (dry ice) and an electric pulp
tester (heat testing is of limited diagnostic use unless the patient complains
of heat sensitivity). Pulp tests used in conjunction with thorough clinical
and radiographic examinations will give an indication of the clinical status
of the pulp - that is, it is usually possible to determine whether there
is a reversible pulpitis, irreversible pulpitis, necrotic pulp, or a pulpless,
infected root canal system.
Radiographs are an
essential tool to the diagnosis of any endodontic or periodontal condition.
Long-cone parallel radiographs should be taken in order to check for loss
of crestal bone, presence of periapical or lateral radiolucencies, presence
and depth of previous restorations, presence of previous root canal fillings,
root fractures, or any other pathology or abnormalities. The radiographic
examination findings should be recorded on the patient's record card.
An adequate diagnosis
should include a comment about the current status of both the endodontium
and the periodontium. A tooth showing signs of both endodontic and periodontal
diseases should be classified as having a "combined endodontic- periodontal
lesion". The primary cause of this combined lesion may be obvious in some
cases but not in others. Furthermore, in some cases, the lesions may be
unrelated and this should be also be noted.
Treatment of combined endodontic-periodontal
lesions should follow the same general principles for treatment of these
entities as though they were separate lesions. That is, the periodontal
disease should be treated by routine scaling, root planing, oral hygiene
instructions and follow-up maintenance therapy, including surgery in some
cases. Diseased pulp tissue or infected root canals should be treated by
cleaning, shaping, medicating and filling of the root canal system.
Most teeth with combined
endodontic-periodontal lesions will have an infected root canal system.
Therefore the endodontic treatment should be carried out over multiple
visits and in conjunction with the periodontal treatment. This will provide
an opportunity for antibacterial intra-canal medicaments to be placed in
order to predictably eliminate bacteria from the root canal system.
Medicaments such as
Ledermix paste and calcium hydroxide pastes have been recommended as routine
intra-canal medicaments. Ledermix paste is an ideal medicament to be used
as an initial dressing particularly if the patient presents with symptoms.
However the antibacterial spectrum of Ledermix paste, against the most
commonly found endodontic bacteria, has been reported to be somewhat limited
whereas calcium hydroxide has been reported to be the most predictable
antibacterial medicament for endodontic microbes. Therefore, calcium hydroxide
should be used in the root canals of all infected teeth at some stage prior
to the placement of the final root canal filling. Calcium hydroxide can
either be used alone as a dressing or in combination with Ledermix paste
(as a 50:50 mixture).
In teeth with previous
restorations, the pulpal disease is very likely to be associated with,
or caused by, recurrent caries or marginal microleakage and bacterial contamination
of the pulp space - these problems must be eliminated if the endodontic
treatment is to succeed. Therefore all previous restorations should be
removed prior to commencement of the endodontic treatment and the tooth
should then be assessed to determine whether it is suitable for further
restoration if the endodontic and periodontal treatment is successful.
It is important to
ensure that a tooth undergoing endodontic treatment is adequately temporised
to ensure that the coronal cavity is sealed and that there are no periodontal
consequences from the temporary restoration (such as overhangs, inadequate
contour, food packing, inability to clean, etc). In some cases it may be
necessary to place a stainless steel orthodontic band in order to stabilise
the remaining tooth structure and/or retain the temporary restoration.
The use of a reinforced glass ionomer material, such as Ketac Silver, is
ideal in these situations in posterior teeth as it will provide an adequate
long-term temporary restoration with minimal periodontal effects. A tooth-coloured
glass ionomer or composite resin can be used in anterior teeth.
The use of multiple
appointments for endodontic treatment is convenient for the treatment of
combined endodontic-periodontal lesions as it allows time for the initial
non-surgical periodontal treatment to be carried out before continuing
with the final root canal filling. The response of the patient and the
tissues can be determined and the prognosis can be reassessed before any
further treatment is contemplated. The periodontal tissues should be monitored
for at least three months prior to considering any further treatment. During
this reassessment time, the root canals can be left with either calcium
hydroxide or a calcium hydroxide/Ledermix mixture in the canals.
The placement of medicaments
in the root canals during this reassessment phase also allows adequate
time for the medicament to diffuse through the radicular dentine in order
to kill any remaining microbes - such medicaments require at least 3-4
weeks to achieve a predictable concentration within the peripheral (or
outer) layers of the dentine. There may also be sore minor beneficial effects
from the medicaments in helping to promote healing within the periodontal
ligament, as dentine and cementum have been shown to be permeable to such
If the initial phase of treatment
does not result in adequate improvement of the periodontal tissues, then
the tooth should be considered for further periodontal treatment, including
surgery. Flap surgery may be chosen in order to gain adequate access to
the entire root surface for root planing and debridement. Following this
external cleaning of the root surface, the tissues should be monitored
to determine the healing response. Again during this phase of treatment,
the root canals should be left with an intra-canal dressing for a period
of at least four to six weeks. Then, if the tissues show initial signs
of healing, the root canal filling should be completed and an adequate
coronal restoration placed. The case should then still be monitored, both
periodontally (initially at three monthly intervals), and endodontically
(initially after six months) in order to determine whether there has been
periodontal and periapical healing.
The presence of a
combined endodontic-periodontal lesion will always result in a compromised
situation following treatment. Even with apparently successful treatment,
the tooth will still be compromised as there is likely to be some gingival
recession and loss of periodontal attachment and bone support. It is of
utmost importance that the patient maintains good oral hygiene and obtains
regular professional care for this region.
Acknowledgment: Dr Paul Abbott,
Senior Lecturer in Endodontics, the University of Western Australia.
This material has been compiled
with the assistance of Dr Louise Brown, Lecturer in Periodontics at the
University of Melbourne.