BY: KARISHMA ASHOK

ROLL NO: 33IV/I

ANATOMY OF PULP CAVITY

INTRODUCTION

For the success of an endodontic therapy, the knowledge of pulp anatomy cannot be ruled out. It is essential to have kbowledge about normal configuration of pulp cavity and its variations.

As the external morphology of the tooth changes, so does the internal morphology.

PULP CAVITY

The pulp cavity is the central cavity within a tooth and is entirely enclosed by dentin except at apical foramen.

It is divided into: 1. Coronal portion pulp chamber2. Radicular portion root canal

PULP CHAMBER

Occupies the coronal portion of pulp cavity.In anterior teeth, the pulp chamber gradually

merges into the root canal and the division becomes indistinct.

In multi-rooted tooth, pulp cavity consists of a single pulp chamber and usually 3 or more root canals.

ROOF OF PULP CAVITY: consists of dentin covering the pulp chamber occlussaly or incisally.

PULP HORN : Accentuation of the roof of pulp chamber directly under a cusp or developmental lobe.

FLOOR OF PULP CHAMBER: runs parallel to the roof and consists of dentin bounding the pulp chamber near cervical area of tooth, particularly dentin forming the furcation area.

CANAL ORIFICES: openings in the floor of pulp chamber leading to the root canals.

They are not separate structures but are continuous with the pulp chamber and root canals

ISTHMUS

“A narrow passage or anatomic part connecting two larger structures (root canals) “

Identified using METHYLENE BLUE DYE

Contains pulp or pulpally derived tissue and acts as store house for bacteria

Therfore should be well prepared and filed

Hsu n Kin 1997 classified isthmus as:

Type I

Type II

Type III Type IV

ROOT CANALS

“Portion of the pulp cavity from the canal orifice to the apical foramen”Parts:Apical constriction (minor diameter)Apical foramen (major diameter)Cemento-dentinal junctionAccessory canalsLateral canals

CLASSIFICATIONS

VERTUCCI’S CLASSIFICATION:

1. Type I: 1 canal extends from the pulp chamber to apex. (1)

2. Type II: 2 separate canals leave the pulp chamber and join short of apex to form 1 canal(2-1)

3. Type III: 1 canal leaves the pulp chamber and divides into 2 roots; the two then merge to exit as 1 canal. (1-2-1)

4. Type IV: 2 separate distinct canals extend from the pulp chamber to apex. (2)

5. Type V: 1 canal exits the pulp chamber and divides short of the apex into 2 separate canals with separate apical foramina. (1-2)

6. Type VI: 2 separate canals leave the pulp chamber, merge in the body of root and redivide short of apex to exit as 2 distinct canals. (2-1-2)

7. Type VII: 1 canal leaves the pulp chamber, divides and then rejoins in the body of root and finally redivides into 2 distinct canals short of the apex.

(1-2-1-2)

8. Type VIII: 3 separate distinct canals extend from pulp chamber to apex (3)

WEINE’S CLASSIFICATION

Type I:

Type II:

Type III:

Type IV:

Classification of C-shaped canals

1. Melton’s classification

I- C shaped outline without seperation

II- Semicolon (;) shaped with distinct mesial canal

III- two or more discrete canals

2. Fan’s classificationI- C shaped outline without seperationII- Semicolon (;) shaped with distinct mesial canal

(but α or β >60 )III- two or more discrete canals

(but α or β <60 )IV- only 1 oval canalV- no canal could be observed

(usually near the apex)

METHODS OF DETERMINING PULP ANATOMY

1. CLINICAL METHODSI. Anatomy studiesII. RadiographsIII. ExplorationsIV. High resolution compound tomographyV. Visualisation endogramVI. Fiberoptic endoscopeVII. Magnetic resonance imaging

2. IN VITRO METHODSi. sectioning of teethii. use of dyesiii. Contrasting mediaiv. Scanning electron microscope analysis

VARIATIONS IN INTERNAL ANATOMY

Variations in developmenti. Geminationii. Fusion iii. Concrescenceiv. Taurodontismv. Talon’s cuspvi. Dilacerationvii. Extra root canalviii. Dens invaginatusix. Dens evaginatus

In most cases, the number of root canals corresponds with the number of roots.Sometimes there may be an additional canal:1. Mesial root of mandibular 1 molar almost

always has 2 canals2. Distal root of mandibular 1 molar,

ocassionally has 2 canals3. Mesiobuccal root of maxillary 1 molar has

frequently 2 canals4. Mandibular premolar may have 2 canals

Variation in shape1. Gradual curve2. Apical curve3. C-shaped4. Bayonet shaped5. Sickle shaped

Variations because of pathology1. Pulp stones2. Internal resorption3. External resorption

Variations in apical third

A. Different position of apical foramen

B. Open apex

C. Lateral and accessory canals