Specific reasons why root canal treatment may fail

1. Canal branches - Root canals sometimes fork, and these divisions, which may be very minute, can be hard to detect and access. Because of this, one canal branch may be properly treated while the other is totally overlooked.

2. Hidden canals - A tooth may have more root canals than is expected. And in these cases, and especially when the unexpected canals are very tiny, the dentist may not discover them. If not, they will remain untreated and a cause of problems.

3. Root cracks - Cracks that have formed in the roots of teeth can't be treated, in the sense that they can be cleaned and sealed like root canals.

4. When performing treatment, a dentist may be unaware that a crack is present (in some cases they can be impossible to identify), or underestimate the significance of the ones they see. In other cases, the root crack that has caused the problem formed after the tooth received its treatment (see below).

5. Deterioration of the seal - Even though a tooth has been expertly treated, over time the integrity of the tooth's seal can degrade, thus allowing contaminates to reenter its nerve space.

6. An inadequate dental restoration - A defective or inadequate final restoration (placed after the competion of treatment) can allow contaminates to reenter a tooth. (The x-ray graphic above shows an example of this.)

7. This phenomenon is termed "coronal leakage" and it is a major cause of root canal failure. For a more detailed discussion, use the button to the right.

8. Lack of clinician expertise. - Research has shown that treatment provided by endodontists (root canal specialists) has a higher success rate than that provided by general dentists.

CONTROL QUESTIONS:

1. Requirements for materials for obturation of root canals.
2. Materials for making fillers. Their positive and negative properties.
3. Root canal filling techniques. Way to the central cone.
4. Sectional method of filling a root canal.
5. Multiconical ways of filling the root canal. Method of cold lateral condensation of gutta-percha.
6. Method of warm lateral condensation of gutta-percha.
7. Method of vertical condensation "heated" gutta-percha (a technique Schilder).
8. Obturation of the root canal system "Thermafil.
9. Determine on radiographs the jaw, a group of teeth and the filling to / canal of sealing mass.
10. Errors and complications during root canal obturation.

HOMEWORK:

Independent out-of-class work

To sketch the degree of root canal filling:

a) to an apex with its obturation; b) behind a root apex with the introduction of filling materials into the periapical space; c) a root apex that is not filled to the end.

Tests for self-monitoring and self-correction the original level of knowledge:

1. When you root canal treatment using lateral condensation number of gutta-percha pins is:

A. one;

B. two;

C. necessary for complete filling the of root canal;

D. four or five;

E. three.

2. Methods of filling of root canal with pastes involve:

A. the introduction of a central canal of the pin;

B. the introduction of the heated gutta-percha on the metal or polymer-based;

C. the introduction of gutta-percha into the canal a few pins, followed by side seal;

D. consecutive filling canal filling material pasty consistency;

E. impregnation into the canal medication with subsequent polymerization

3. Way to canal filling with cold lateral condensation of gutta-percha includes:

A. introduction to a central canal pin;

B. introduction of the heated gutta-percha on the metal or polymer-based;

C. introduction of gutta-percha into the canal a few pins, followed by side seal;

D. consecutive filling channel filling material pasty consistency;

E. impregnation into the canal medication with subsequent polymerization.

4. Obturation of the root canal system "Thermafil" suggests:

A. introduction of one central canal pin;

B. introduction of warmed gutta-percha on the metal or polymer-based;

C. introduction of gutta-percha into the canal a few pins, followed by side seal;

D. consecutive filling canal filling material pasty consistency;

E. impregnation into the canal medication with its following polymerization.

5. Couple pulp pins are fixed:

A. in the dentin;

B. in the enamel;

C. in the dentin-enamel compound;

D. in the pulp;

E. it is intended for drying root canals.