endo sheet # 3- Lama Assayed

3rd endo lec

The most important thing that we care about in endotology is the dental pulp and the pulp system, as u know part of the pulp is present in the crown called pulp chamber and part in the root called pulp canal.
So … the pulp system = pulp chamber + pulp canal
 The pulp chamber is like a room inside the crown that doesn’t contain any hard tissues it contains only soft tissues like blood vessels and nerves and it extend to the root in the form of root canal.
 The root canal configuration differs between teeth and also from person to another.
Root with a tapering canal and a single foramen is an exception to the rule,,, I mean that you used to expect that the root with its tapering end will contain inside only a single canal that ends at the apex of the root but actually this if it happened is an exception the real configuration of the root canal was studied carefully by a scientist called Vertucci, he used the clearing and sectioning technique for that and at the end he found 8 configuration for most of the teeth.
Vertucci’s canal configuration :
Type I: is a single canal that extend from the pulp chamber to the apex (1)
Type II: which are two separate canals leaving the pulp chamber but join short from the apex (2-1)
Type III: one canal leaving the pulp chamber dividing into two canals inside the root and then rejoin again to form one canal near the apex (1-2-1)
 Type I, II, III, all ends with one apical foramen 
Type IV: two separate canals extending from the pulp chamber to the apex (4)
Type V: one canal leaving the pulp chamber and divides and exit the apex as two separate canals (1-2)
Type VI: two separate canals leaving the pulp chamber then unite to form one canal then divide and exist as two canals (2-1-2).
Type VII: a single canal leaving the pulp chamber divided to two then united to one and then divided to two again it’s v. complex (1-2-1-2)
type VIII: which is three separate canals leaving the pulp chamber’s floor and exit the apex as three separate canals they don’t divide they don’t merge (3)

o Note : the pulp chamber ends at the level of the cemento-enamel junction
o Note : these are the main 8 configurations u might encounter a tooth
That doesn’t belong to this category but its v. rare


Why do we need to perform root canal treatment?!
We need to do root canal treatment if there is inflammation in the pulp, any tissue in the body have the capability for self healing if there was inflammation, but if there is inflammation in the pulp for a certain degree it cannot heal itself so in this case the inflammation will turn into irreversible one and later the pulp tissue will die forming a necrotic pulp  in this case we have to remove the pulp tissue by endodontic technique.
And the main causes for pulp inflammation are:
1. Caries: if someone has caries and he didn’t care about it, it may extend from the enamel to the dentine then to the pulp, then the pulp will undergo inflammation process if it reaches the stage of irreversible pulpits it will need endodontic treatment.
2. Trauma: whether the tooth was fractured or not trauma can cause pulp necrosis which needs endodontic treatment.

o Note: we do endodontic treatment in case of irreversible pulpits if it was reversible we do nothing to the pulp it will heal it self 

The general steps for endodontic treatment:
1. Access cavity: the procedure of going inside by drilling the tooth to reach the pulp chamber is called access cavity.
2. Cleaning and shaping of the canals: to remove the dead tissue.
3. Filling of the canals.


o The access cavity is the first and most important thing in root canal treatment because it allows you to reach all the tissue that need treatment otherwise if there still part of the infected tissue is not removed it will re-infect the pulp again.
o The aim of access cavity is to create smooth straight line path to the canal system


o Note: There are 3 objectives you need to make sure that u’ve accomplished them in Ur endodontic treatment (y3ne 2t2kd 2nk 3mlt hay 2l2shya2 2bl ma tfrje sho3’lak ll D. belmo5tbar  ).

1. Straight line access to the pulp chamber,, go straight toward the pulp not mesially nor distally ,for anterior teeth the access cavity should be in the lingual surface and for posterior teeth it should be in the occlusal surface .
2. Identify all of the canal orifices ,, for example if u r working in a molar u r expecting more than one canal but if u find only one then u need to search for the rest of them, the cavity should be bigger .
3. Conserve the tooth structure ,, u should not do any unnecessary cutting

Guideline for canal number and location:
There are some guidelines that can help u to determine the number and location of the root canal .
• First low of symmetry: applied to all teeth except the upper molars, it says that the canal orifices are at equidistant from a line joined in a meso-distal direction through the floor of the pulp chamber.

• Second low of symmetry: applied to all teeth except the upper molars ,it says that the canal orifices lie on a line perpendicular to a line draw in a meso –distal direction across the central of the chamber floor. (it means that the two orifices lie in the same line so if u find one of them I can expect the location of the other  )

• Low of color change: the pulp chamber floor is always darker in color than the walls, u need to identify the floor because u should not touch it with Ur burs otherwise u may go too deep and perforate the tooth and then u’ll need to extract the whole tooth.

• First low of orifice location: the orifices are always present at the junction between the wall and the floor of the cavity.
• Second low of orifice location: the orifices of the root canal are always located at the angles in the wall-floor junction.


General steps of access cavity
1. Removal of the caries and removal of the old filling
2. Initial external outline form on lingual or occlusal surface, this means that the shape of the cavity should be similar to the shape of the chamber...
o The location of the access cavity of the anterior teeth is at the lingual surface and for posterior teeth is at the occlusal surface
3. Penetration of pulp chamber roof (drop -in) effect


Access cavity of maxillary central incisor
 First start drilling from the lingual aspect using a high speed bur so u can break the enamel, ,start perpendicular to the long axis of the tooth, drill through the enamel above the cingulum ,keep drilling till u reach about (1-1.5) m inside the dentine ,,
 Then with the same bur drill parallel to the long axis of the tooth.
 form a triangular cavity
 keep drilling till u reach the roof of the pulp chamber then u’ll feel like falling this is what is called (drop –in )effect at this stage u entered inside the pulp chamber.
 To completely remove the roof of the chamber u need to change the burs from fissure to low speed round bur and then by swiping action u remove the tissue don’t drill more inside.
 Don’t touch the floor of the pulp chamber
 Remove the lingual shoulder , it is a bulge at the lingual side of the shoulder

o 100% of the maxillary central incisors have single canal.
o The pulp chamber is wider meso- distally than bucco – lingually.
o The shape of the pulp chamber is rounded triangle, so the shape of the cavity should be triangle too the base of the triangle is toward the incisal edge

These procedures are the same for all anterior teeth what differs is the shape of the cavity
• upper centrals triangle
• upper laterals triangle or oval , single canal, wider meso-distal than bucco- lingual
• upper canines oval, mostly single canal, wider bucco- lingual than meso- distal
• lower anterior teeth oval, one or two canals so u need to increase the size of the cavity



good luck 
3rd endo lec
For D. Mohammad Hamdan
Done by: Lama Alsayed