Root canal treatment, also known as endodontic treatment, is a sequential treatment for the infected pulp of a tooth, which results in the elimination of infection and the protection of the decontaminated tooth from further microbial invasion. Root canals are physiologic hollow spaces within a tooth inhabited by the pulp, which is composed of nerve tissue, blood vessels and other cellular entities. 

Thereby defining root canal treatment as the removal of the pulp with its constituents.

Removal of the constituents is followed by the subsequent shaping, cleaning and decontamination of canals using files, reamers and irrigating solutions. This is followed by the filling of the canal with an inert filling such as gutta percha and typically a eugenol based cement, although epoxy resin is employed in some cases.

Signs that Root canal treatment is needed?

Primarily, and almost immediately, there will be relief of pain. Although, it is advised to minimize chewing from the infected side until the procedure is complete and the crown is placed.

There might be post operative inflammation the first few days after the completion of the treatment, causing a mild sensitivity in that region. This inflammation is natural and is only a matter of time until it subsides. The degree of sensitivity and inflammation depends on the pre operative inflammation and infection, and can be controlled by counter pain medications, like Ibuprofen. Most patients can return to their normal activities the next day.

Complications of root canal procedure

Complications of root canal procedure can be related to the following:

Complications related to access opening, the main challenges found are:

-incomplete removal of caries:

Complete removal of the carious lesion is the first principle of access opening even before focusing on canal orifice location. Secondary caries under the existing restoration must be checked for. Hence, the existing old restoration should be removed in total, and access re- designed accordingly. The clinician must also check the distal aspect of the tooth thoroughly for caries as any remaining carious lesion will lead to re-infection and thus failure.

-cervical perforations:

They usually occur in the form of grooves which leads to crown perforation. It is usually caused by directing the bur non-parallel to the long axis of the tooth.

-Access opening through full covered restorations.

Usually, in order to carry out endodontic treatment, any prosthesis over the tooth is removed. However, in some cases where the crown is well prepared with a good marginal seal, the clinician can consider doing the access opening with the crown in place, although it is an extremely tedious procedure.

-Inability to locate extra canals:

This could happen to various reasons, such as:

Hence, radiograph must be thoroughly read by the clinician and number of canals must be correctly assessed.

Complications related to canal shaping and cleaning.

- During the shaping and cleaning, the most common errors encountered are:

• Always using smaller sized instruments first.
• Using the instruments in a sequential order
• Using copious amounts of irrigants, ensuring the canal is wet through the cleaning and shaping.
• Disposal of instruments upon showing signs of wear and tear.

Ledge formation is an artificially created deviation of the root canal that prevents the passage of an instrument to the apex of an otherwise patent canal. Common causes of ledging are:

• Incorrect assessment of root canal curvature or length.
• Inadequate irrigation.
• Overrelying on chelating agents.
• Forcing and driving the instrument into the canal.
• Attempting to prepare a calcified canal.

    2. Deviation from normal canal atomy

• Zipping: It is the apical transfer of a curved canal caused due to improper shaping technique.
• Transportation: If the instrument remains in the confines of the canal, the elliptical preparation will produce internal transportation of the foramen. If the instrument is outside the confines of the root canal, it causes external transportation of the foramen.
• Elbow: Narrowest portion of the zipped canal.

   3.  Instrument separation in the canal

1. Under filling of gutta percha.
2. Overfilling of gutta percha.