It has long been recognized that an intimate relationship
exists between the pulp of a tooth and the surrounding
The periodontium communicates with pulp tissues through
many channels or pathways.
Thus, lesions of the periodontal ligament and adjacent
periodontium or tissues of the dental pulp.
The simultaneous existence of endodontic and
inflammatory periodontal lesions can complicate
Sequence of treatment
Pulpal and periodontal inter-relationship
The pulp and periodontium have
Functional inter- relationships
They are ectomesenchymal in origin
connections which remain throughout the life of the tooth.
The apical foramen decreases in size as the proliferation of
the Sheath of Hertwig continues. It remains patent and serves
as the communication on which the pulpal tissues rely for
nutrition and nervous innervation
incorporated, either due to dentine formation around existing
blood vessels or breaks in the continuity of the Sheath of
Hertwig, to become accessory or lateral canals
Tubular communication between the pulp and periodontium
may occur when dentinal tubules become exposed to the
periodontium by the absence of overlying cementum
These are the pathways that may provide a means by which
pathological agents pass between the pulp and periodontium,
thereby creating the perio-endo lesion
Pathways for the communication of the Dental Pulp
with the Periodontium
PATHWAYS OF DEVELOPMENTAL ORIGIN [ANATOMIC]
ACCESORY CANALS/ LATERAL CANALS
CONGENITAL ABSENCE OF CEMENTUM EXPOSING DENTINAL
PERMEABILITY OF CEMENTUM.
DEVELOPMENTAL ANOMALIES SUCH AS ENAMEL PROJECTIONS
AND ENAMEL PEARL.
PATHWAYS OF PATHOLOGICAL ORIGIN
ROOT FRACTURES FOLLOWING TRAUMA
EMPTY SPACES ON ROOT CREATED BY DESTROYED SHARPEY’S
FIBRES [ ESPECIALLY AFTER REIMPLANTATION OF AVULSED
IDIOPATHIC RESORPTION – INTERNAL AND EXTERNAL.
LOSS OF CEMENTUM DUE TO EXTERNAL IRRITANTS [PLAQUE
OR CALCULUS ACCUMULATION]
PATHWAYS OF IATROGENIC ORIGIN
EXPOSURE OF DENTINAL TUBULES FOLLOWING ROOT PLANING.
ACCIDENTAL PERFORATIONS OF THE ROOT DURING ENDODONTIC
FRACTURED/ DEFECTIVE RESTORATIONS OF ENDODONTICALLY
Effects of Pulpal Disease and Endodontic Procedures on
Pulp inflammation or necrosis may lead to an inflammatory
response in the periodontal ligament at the apical foramina or
at the site of a lateral or accessory canal.
The resulting inflammatory lesion can be
extensive destruction of the periodontal ligament, tooth
socket, and surrounding bone
A lesion related to pulpal necrosis may also result in a
draining sinus tract that drains through
the gingival sulcus of the involved tooth or
through the gingival sulcus of an adjacent tooth
1. Technical procedures involved in root canal treatment, irrigants,
medicaments, dressings, sealers, and filling materials have the
potential to cause an inflammatory response in the periodontium.
2. An inflammatory response resulting from commonly used root
canal treatment methods and materials, however, is usually
transient in nature and resolves quickly if filling materials are
confined within the canal space
Procedural errors during root canal treatment
destructive inflammatory processes in the periodontium.
Breakdown of the attachment resulting in a periodontal
defect may occur after procedural errors such as
access perforations in the floor of a pulp chamber
perforations on the root surface apical to the gingival
strip perforations or root perforations related to cleaning and
shaping procedures, and
vertical root fractures
Effects of Periodontal Disease and Procedures on the Pulp
1. Periodontal disease must extend all the way to the apical
foramen or an opening of the lateral/ accessory canals to
cause significant pulp involvement.
2. Bacterial & inflammatory products of periodontitis could
gain access to the pulp via accessory canals, apical
foramina or dentinal tubules.
3. This process , the reverse of effects of necrotic pulp on the
periodontal ligament , has been referred to as Retrograde
All treatment modalities for periodontal disease have the
potential to adversely affect the pulp.
Increased hypersensitivity is one of the common sequelae
of nonsurgical and surgical periodontal therapy.
removal of cementum and the subsequent exposure of
dentinal tubules to the oral environment.
Periodontal surgery affects the pulp to the extent that it is
dentinal tubules, or in extreme cases the apical foramen
Primary endodontic lesions
• An acute exacerbation of a chronic apical lesion on a tooth
with a necrotic pulp may drain coronally through the
periodontal ligament into the gingival sulcus.
• This condition may mimic clinically the presence of
periodontal abscess. In reality, it is a sinus tract from pulpal
origin that opens through the periodontal ligament area
Insert a gutta-percha cone into the sinus tract and take one
or more radiographs to determine the origin of the lesion.
When the pocket is probed, it is narrow and lacks width.
A similar situation occurs where drainage from the apex of
a molar tooth extends coronally into the furcation area. This
may also occur in the presence of lateral canals extending
from a necrotic pulp into the furcation area.
No noticeable changes in the early stages
As the disease continues → widening of PDL → periapical
radiolucency → bony lesion
Primary endodontic diseases usually heal following root
Primary periodontal lesions
In most cases, pulp tests indicate a clinically normal
There is frequently an accumulation of
calculus and the pockets are wider
Show angular bone loss extending from the cervical
regions of the tooth.
The prognosis depends upon the stage of periodontal
disease and the efficacy of periodontal treatment
Treatment : periodontal therapy
If after a period of time a suppurating primary endodontic
disease remains untreated, it may become secondarily
involved with periodontal breakdown.
Plaque forms at the gingival margin of the sinus tract and
leads to plaque-induced periodontitis in the area.
When plaque or calculus is detected, the treatment and
prognosis of the tooth are different than those of teeth
involved with only primary endodontic disease.
Probing may show a solitary but wider pocket
The tooth now requires both endodontic and periodontal
involvement may also occur as a result of root perforation
during root canal treatment, or where pins or posts have been
misplaced during coronal restoration.
Symptoms may be acute, with periodontal abscess formation
formation, and tooth mobility.
A more chronic response may sometimes occur without
pain, and involves the appearance of
bleeding on probing or exudation of pus.
a pocket with
Primary periodontal lesions with secondary endodontic
The apical progression of a periodontal pocket may continue
until the apical tissues are involved.
The pulp may become necrotic as a result of infection
entering via lateral canals or the apical foramen.
In single-rooted teeth the prognosis is usually poor.
In molar teeth the prognosis may be better. Since not all the
roots may suffer the same loss of supporting tissues, root
resection can be considered as a treatment alternative
The treatment of
periodontal disease can also lead to
secondary endodontic involvement.
Lateral canals and dentinal
tubules may be opened to the
oral environment by scaling and root planing or surgical flap
It is possible for a blood vessel within a lateral canal to be
severed by a curette and for microorganisms to be pushed
into the area during treatment, resulting in pulp inflammation
Pulp tests may show an abnormal response or complete
absence of any response.
Treatment : Endodontic therapy + periodontal therapy
[ root resections if indicated]
True combined lesions
A true combined lesion is said to be present when an endodontic
lesion extends and communicates with a pre-existing periodontal
frequently than other endodontic–periodontal problems. It is
formed when an endodontic disease progressing coronally joins
with an infected periodontal pocket progressing apically
The degree of attachment loss in this type of lesion is
particularly true in single-rooted teeth.
In molar teeth, root resection can be considered as a
treatment alternative if not all roots are severely involved
combined periodontal-endodontic lesions can
management depends on careful clinical evaluation, accurate
diagnosis, and a structured approach to treatment planning for
both the endodontic and periodontic components.