P1-ENDO LAB-ROOT CANAL ANATOMY

length of teeth

will help determine the depth of insertion of the initial instrument into the

canal

22.5 mm

average length of max central incisor

20.7 mm

average length of man central incisor

22.0 mm

average length of max lateral incsior

21.1 mm

average length of mandi lateral incsior

26.5 mm

average length of max canine

25.6 mm

average length of man canine

20.6 mm

average length of max1st premolar

21.6 mm

average length of mandi 1st premolar

21.5 mm

average length of max 2nd premolar

22.3 mm

average length of man 2nd premolar

20.8 mm

average length of max 1st molar

21. 0 mm

average length of man 1st molar

20.0 mm

average length of max 2nd molar

19.8 mm

average length of man 2nd molar

1.0 – 1.5mm

The diameter of the root canal decreases towards the apical portion, reaching its narrowest point ___ from the apex of the root

round, oval or serrated

The shape of the narrowest portion may be .

an angle to the main canal

The direction of the canal at the apical foramen is usually at

0 and 3 mm

The apical foramen is found anywhere between ___ from the apex of the root.

Frank Weine (1982)

Who list the 4 different types variation in the configuration of root canals that may be found in one root.

Type 1

Single canal from pulp chamber to apex

Type 2

- Two separate canals leaving the pulp chamber but merging short of the apex to form only one canal

Type 3

Two separate canals leaving the pulp chamber and exiting from the root in separate apical foramina

Type 4

one canal leaving the pulp chamber but dividing short of the apex into two separate canals with separate apical

foramina

apical delta

Several branches may occur from the main canal in the apical 1.0 – 2.0 mm, forming the .

Lateral canals

occur in approximately 50% of all permanent teeth.

Lateral canals

These canals leave the main canals at right angles, and although some may be blind-ending sacs the majority communicate with the root surface.

Lateral canals

may occur anywhere along the length of the root and will vary in size from a few microns to as wide as the main canal.

channels of communication between the main canal and the periodontal tissues

The relevance of lateral canals in endodontics is as

deposition of secondary or irritation dentin

The root canal system gradually reduces in size due to the

Weine

gave a simple but a basic classification of root canal morphology.

Vertucci

found more complex pulp space system in his cleared sections and classified pulp space into eight different configurations.

Vertucci’s Classification Type I

A single canal extends from pulp chamber to apex (1)

Vertucci’s Classification Type II

Two separate canals leave the pulp chamber and join short of the apex to form one canal (2-1)

Vertucci’s Classification Type III

One canal leaves the pulp chamber and divides into two in the root: the two then merge to exit as single canal (1-2-1)

Vertucci’s Classification Type IV

Two separate, distinct canals extend from the pulp chamber to apex (2)

Vertucci’s Classification Type V

one canal leaves the pulp chamber and divides short of apex into two separate, distinct canals with separate apical foramina (1-2)

Vertucci’s Classification Type VI

two separate canals leave the pulp chamber; merge in body of the root, and redivide short of the apex and exits as two distinct canals (2-1-2)

Vertucci’s Classification Type VII

one canal leaves the pulp chamber; divides and then rejoins in the body of the root, and finally divides into two distinct canals short of the apex (1-2-1-2)

Vertucci’s Classification Type VIII

three separate distinct canals extend from the pulp chamber to apex (3)

root of the max central incsior

incisors tends to be straight

root of max lateral incicsor

frequently has a distal curve in the apical portion of the root

maxillary central and lateral incisor

The shape of the cross section of the canal is oval in both teeth but tends to become round in the apical third

Maxillary canine

The tooth is labially inclined (Fig.10). The root tends to be straight or have a distal curve near the apex. The apical few millimeters of the root may be tapered and thin allowing only small sized instruments during preparation before there is danger of perforation. The canal in the middle third is broad labiopalatally forming a bulge. Towards the apex the canal becomes round in cross section (Fig.11).

maxillary 1st premolar

62% have two roots, the remainder have one, and on rare occasions three (Fig.12, Fig.13, Fig.14). The majority of teeth have two canals (85%). The floor of the pulp chamber extends well into the roots and is wide buccopalatally.

maxillary 2nd premolar

The single root usually contains one canal which is broad buccopalatally (Fig.18). Two canals occur in 25% and two separate roots in 15%. The photos (Fig.19, Fig.20) below show two views of a root-treated second premolar. The extent of the canal buccopalatally is only evident in the second oblique view.

maxillary 1st molar

molar normally has three roots, two buccal and one palatal (Fig.21).

The distobuccal root tends to be straight and round in cross section (Fig.22). The canal opening onto the floor of the pulp chamber is not related to a cusp but lies centrally.

The mesiobuccal root is curved towards the distal and is broad buccolingually (Fig.23). It normally has a groove on both the mesial and distal aspect.

maxillary 2nd molar

It is similar to the first molar (Fig.28).

The pulp chamber is flattened mesiodistally, reflecting the shape of the crown (Fig.29).

The incidence of a second canal in the mesiobuccal root is lower than in the first molar.

man central and lateral incsiors

40% of these teeth contain two canals. Configuration is Type 1 60% (Fig.30), Type 2 – 35% (Fig.31), and Type 3 – 5%.

After the molar teeth, the incisors are the most difficult root to treat because of the complex canal anatomy.

man canine

It is is single rooted but in rare cases two roots may be present (Fig.36). Teeth with one root may have canal configurations Type 1, 2, or 3.

It is the longest tooth in the mandible but its length is also the most variable. The incidence of two canals is 18% (Fig.37)

man 1st premolar

Usually one canal is present but 27% of first premolar teeth contain two canals at some point along their length, or on rare occasions three are present (Fig.38).

The canal configuration is mainly Type 4.

When a second canal is present it will be situated lingually. The canal is wide buccolingually (Fig.39).

man 2nd premolar

has fewer variations than the first premolar (Fig.40).

The canal is wide buccolingually and Type 1 is the most common configuration. There is frequently a distal curve in the apical portion of the root.

There is a clinical impression of a high incidence of lateral canals (Fig.41).

max 1st molar

The tooth usually has two separate roots.

The mesial root (Fig.42) has two distinct canals in 87% but half of these merge to have a common apical foramen.

The direction of the mesial canals from the pulp chamber is mesial, then a gradual curve to the distal.

The mesiobuccal canal is more curved than the mesiolingual. Both canals also curve towards the midline of the root.

There are frequent communications between the mesial canals along their length (Fig.43).

If the canals are separate there are often grooves in the midline wall (Fig.44). In cross section, the canals lie nearer the distal aspect of the root increasing the possibility of perforation during preparation.

man 2nd molar

This is similar to the first molar except for a lower incidence of two canals in the distal root.

The roots tend to be closer together (Fig.51, Fig.52).

The mesial root usually contains two canals, but occasionally one is present. In these cases the canal will be broad buccolingually.

Rarely, there is one root and one canal (Fig.53).

Occasionally, a C-shaped canal occurs (Fig.54) when the distal canal extends mesially to include the mesiobuccal (Fig.55) and, more rarely, the mesiolingual canal as well.

These C-shaped canals are difficult to fill and are not visible on the preoperative radiograph.