Pathways Of Communication Between Pulp And

Periodontium

Influence Of Pulp Pathosis On Periodontium

Influence Of Periodontal Disease On The Pulp

Clinical And Radiographic Tests

Classification And Differential Diagnosis

PATHWAYS OF COMMUNICATION

BETWEEN PULP AND PERIODONTIUM

There are several pathways that connects pulp and periodontium which includes: apical foramen, lateral canals, dentinal tubules and palatogingival grooves.

Apical foramenApical foramen is the most direct route of communica-tion between pulp and periodontium. There may be one apical foramen or multiple apcial foramina. Multiple foramina occur most frequently in mutlirooted teeth. Entrance of irritants (bacteria, toxins, etc..) through

apical foramen can cause an inflammatory responses in the periapical area which in turn leads to destruction of apical PDL, and resorption of bone, cementum, and dentin.It has been established that necrotic tooth, if left un-treated, can develop a secondary periodontal pocket.

Lateral canals (accessory canals(Lateral canals can be found anywhere in the root. However, they present more frequently in posterior teeth than in anterior teeth, and more in apical portion than coronal portion. The incidence of lateral canals in furcation area in molar ranges from 2% to 76% due to conflicting studies.Due to direct vascular communication between pulp space and periodontium through lateral canals, infec-tion can spread from pulp to periodontium and cause destruction of PDL and subsequent periodontal pock-et formation. However, spread of infection from peri-odontium to the pulp through lateral canals rarely oc-cur, due to high vascularity and defense system of vital pulp.Lateral canals are not apparent radiographically. They only shown when filled with radiopaque material such as sealer or softened obturation material.Sometimes lateral canals can be seen before that when: You see a notch on the lateral root surface. You see a localized thickening of PDL on lateral

root surface.

Endodontic-periodontal interrelationshipOsama Asadi, B.D.S, Published for Savant Dentist Blog

Pulpal and periodontal illnesses are responsible for more than 50% of tooth loss. There is an intimate in-terrelationship between pulpal and periodontal structures. The diagnosis may be difficult and challenging sometimes because pulpal diseases can mimic periodontal one, and vice versa.The primary difference between pulpal and periodontal disease is the direction of spread of the lesion. Peri-apical diseases spread apical or coronally, while periodontal diseases spreads only apically.

LECTURE OUTLINE

CHAPTER

1

Figure 1. Tooth presented with palatoginival groove (lingual

groove) and led to development of narrow pocket around the

tooth and presented with radiolucency on the radiograph. Ex-

traction was done due to hopelessness of the case

You see an isolated radiolucency on lateral root surface.

Dentinal TubulesOdontoblast cells are located at the junction between pulp and dentin on inner root surface. These cells have cytoplasmic extensions called odontoblastic processes that run horizontally from the pulp to the cementum (in root portion of the tooth) and to the enamel (in the coronal portion).Infection from the pulp can not reach the periodonium through dentinal tubules in normal conditions, because cementum and enamel work as protective barriers. However, when there is congenital loss of cementum, or presence of caries, or removal of cementum due to recent periodontal treatment, these barrier will be gone and infection can reach the periodontium.On the other hand, infection in the periodontium can not cause pulpal diseases even in the cases of denuded cementum because of the defense mechanism of vital pulp.

INFLUENCE OF PULP PATHOSIS ON

PERIODONTIUM

When pulpal pathosis occur, it lead to formation of necrotic debris, bacterial by-products, and other tox-ic irritants that may move toward the apical foramen and cause periodontal tissue degeneration. This lead to pocket formation. It has been termed Retrograde Peri-odontitis to differentiate it from the normal periodon-titis that called marginal periodontits.Also it has been suggested that high concentration of medicament used in endodontic treatment (e.g., calci-um hydroxide, corticosteriods, antibiotics) can irritate the periodontium. However, there is no sufficient evi-dence to support that claim.

INFLUENCE OF PERIODONTAL DISEASE ON

THE PULP

Theoretically, it has been suggested that periodontal in-flammation can cause pulpal irritation or even necrosis through lateral canals and dentinal tubules. However,

there is no general agreement on that. The scientific data are not sufficient to fully support this claim.It worth mentioning that root canals of teeth with peri-odontal diseases are narrower than teeth with no peri-odontal diseases. This condition has been attributed to reparative dentin formation.

CLINICAL AND RADIOGRAPHIC TESTS

This subject has been extensively discussed in previ-ous lecture. However, it will be presented here briefly.A complete patient history should be taken that include location, duration, intensity, and frequency of pain and medication used for pain relief. In general, periodontal diseases are chronic and generalized while pulpal dis-eases are localized and acute.

Visual ExaminationExamine the tooth and gingival tissue. The presence of caries, extensive restoration, discolored crown are usu-ally associated with endodontic lesion. The absence of coronal defect in the tooth in conjunction with plaque, calculus, and a generalized gingivits or periodontitis suggest a periodontal lesion.

Radiographic EexaminationPeriodontal lesion are associated with angular bone loss extending from the cervical gingiva apically. In contrast, periapical lesions cause destruction of apical periodontium that occasionally extend coronally to-ward CEJ.

Vitality TestsVitality tests are generally, but not totally, reliable. Teeth with necrotic pulp has no response to vitality tests. In contrast, teeth with periodontal diseases usu-ally response normally to vitality tests.

Palpation and PercussionPalpation of the coronal soft tissue can indicate a peri-odontal disease, while palpation of apical area can in-dicate an active periapical disease. Percussion can in-dicate inflammation of periodontal ligament, however, it can not indicate whether it is of pulpal or periodontal origin.

ProbingPeridontal defects usually have wide pocket that do not extend to the apex. However,pulpal lesions are narrow and localized to the apex or lateral canal.

2

CLASSIFICATION AND DIFFERENTIAL

DIAGNOSIS

Many authors classify endodontic-periodontal le-sions into 5 categories:

Primary Endodontic Lesion Primary Endodontic Secondary Periodontal Lesion Primary Periodontal Lesion Primary Periodontal Secondary Endodontic Lesion True Combined Lesion

See Picture above for clearification

PRIMARY ENDODONTIC LESION

Simply, it is an endodontic case that require only RCT. Its diagnosis has been discussed on previous lecture on Endodontic Diagnosis.

PRIMARY ENDODONTIC SECONDARY

PERIODONTAL LESION

In simple term: necrosis occurred then infection spread into periodontium via apical foramen, lateral canals, or dentinal tubules. So endodontic lesion occured first, which followed by periodontal lesion.These teeth present with deep caries, restoration or his-tory of trauma which led to pulpal necrosis, and the patient neglected the tooth which lead to spread of infection into periodontium and usually formation of periodontal pocket.Tooth does not response to vitality tests. It may or may not response to percussion and palpation tests. Radio-graphically, apical or lateral rediolucency can be seen and angular bony loss due to periodontal destruction. Periodontal probing show normal attachment except for one narrow area that extend to the origin of end-odontic lesion.

TreatmentThis condition require endodontic treatment. Periodon-tal lesion will resolve after proper endodontic therapy. However, if periodontal lesion is self-sustained and ex-tensive, both endodontic and periodontal treatment are required.

PRIMARY PERIODONTAL LESION

Simply put: its a periodontal pocket with angular bone loss with accumulation of plaque and calculus. It could be localized but usually generalized.Tooth usually present with mobility, and response nor-mally to vitality tests. Probing reveal wide pocket.

TreatmentPeriodontal therapy.

PRIMARY PERIODONTAL SECONDARY

ENDODONTIC LESION

This condition is exactly the same as Primary end-odontic secondary periodontal lesion except that peri-odontal lesion occur first and followed by endodontic lesion. There is no major differences between them oth-er than that.

TreatmentEndodontic therapy and periodontal treatment.

TRUE COMBINED LESION

In this condition, endodontic lesion occurred, and peri-odontal lesion occurred independently. So we have two lesions that occurred on their own. They may coalesce eventually with each other or remain separate.Unlike other conditions, tooth has wide periodontal pocket, angular bony defect, necrotic pulp and periapi-cal radiolucency, and not responsive to vitality tests.

3

TreatmentBoth endodontic and periodontal therapy.

DIFFERENTIAL DIAGNOSIS

The diagnosis of endodontic-periodontal lesion may present a difficulty for the dentist. When both endodontic and periodonal lesion are present, dentist should resist the temptation of labeling it a true combined lesion and should reach for an accurate diagnosis by means of history, clinical and radiographic tests.It should be noted that vertical root fracture can mimic endodontic-periodontal lesion and it present a diagnosis challenge.Table below will help you differentiate between pulpal and periodontal lesions:

Pulpal PeriodontalClinical

Etiology Pulp Infection Periodontal InfectionVitality Non-Vital VitalRestoration Deep Or Extensive Irrelevant Plaque/Calculus Irrelevant Primary CauseInflammation Acute ChronicPocket Single, Narrow Multiple, Wide Coronally

RadiographicallyPattern Localized GeneralizedBone Loss Wider Apically Wider CoronallyPeriapical Radiolucnet IrrelevantVertical Bone Loss No Yes

Therapy Root Canal Treatment Periodontal Treatment

4

REFERENCES

Cohens Pathways Of Pulp Endodontics Principles And Practice