ROOT CANAL TREATMENT

Dental Pulp, Root Canal, Signs and Symptoms, and The Procedure

Root Canal Treatment

Dental Pulp, Root Canal, Signs and Symptoms, and The Procedure

When bacteria enter the dental pulp and cause an infection, root canal treatment is necessary to save the tooth. The infected pulp is removed during this procedure, and the tooth canal is sealed to prevent reinfection. A restoration often follows the procedure to reinstate the function and look of the tooth.

Before starting with our discussion on Root Canal Treatment (RCT), let's see what is the dental pulp and root canal to understand the treatment more clearly.

What is Dental Pulp?

  • The dental pulp is an un-mineralized oral tissue that occupies the central pulp cavity of each tooth.
  • It is composed of soft connective tissue and vascular, lymphatic, and nervous elements.
  • The pulp cavity extends down through the tooth's root as the root canal opens into the periodontium via the apical foramen.

What is Root Canal?

The root canal is the portion of the pulp space from the canal orifice to the apical foramen. The root canal is divided into two parts.
  1. The Pulp Chamber, commonly located within the anatomic dental crown.
  2. The Root canal space is found inside the radicular portion of the tooth.

What is Root Canal Treatment?

Root canal treatment involves the elimination of bacteria from the infected root canal to prevent the reinfection of the tooth in order to save the natural tooth.

In the treatment, we completely remove the inflamed, infected, or necrosed dental pulp from the root canal cavity carefully followed by cleaning and disinfecting, then filling and sealing.

What is the biological aim of Root Canal Treatment?

The ultimate biological aim of RCT is to prevent or cure apical periodontitis or, to create adequate conditions for periradicular tissue healing.

When do we need Root Canal treatment?

Caries, microleakage around restorations, Cracked or Broken teeth, Teeth abscess, desiccation, and periodontal defects.

Signs and symptoms of an infected tooth.

  • Teeth Sensitivity to different modalities like heat, cold, pressure, etc.
  • A swelling with pus area around the tooth.
  • A swelling spread to other parts of the face.
  • Bone loss around the root tip.
  • Abscess formation around the root tip.
  • Intense, throbbing pain in the tooth or gum that may come on suddenly and gets gradually worse on stimuli.
  • Pain that spreads to your ear, jaw, and neck on the same side as the affected tooth or gum.
  • Pain that's worse when lying down may disturb sleep.
  • A tooth that hurts when pressure is applied to teeth by biting on something or sometimes even on touch.
  • Discoloration of the tooth with or without pain.
  • Discoloration of the tooth after trauma to the tooth indicates that the tooth is becoming non-vital.

When the tooth needs Root canal treatment?

  • When the infection has reached the dental pulp and has infected or inflamed the pulp tissue.
  • When the tooth has lost its vitality.
  • The pulp tissue is damaged due to Dental trauma.
  • If the pulp infection reaches the bone around the teeth and causes periapical abscess formation.

Conditions when we don’t do root canal therapy?

  • A tooth with insufficient periodontal support.
  • A non-restorable tooth.
  • A tooth with a vertical fracture.
  • A tooth with massive internal or external resorption.
  • A tooth that has a canal unsuitable for instrumentation or surgery (e.g. dentinal sclerosis, sharp dilacerations, etc.)

Steps of Root Canal Treatment

  1. Diagnosis – IOPA and RVG
  2. Access Opening
  3. BMP or Biomechanical preparation
  4. Obturation (Filling and Sealing the cleaned root canal)

Step 1: Diagnosis using Radiograph (Intraoral periapical (IOPA) radiographs or RadioVisioGraphy (RVG))

  • The diagnosis is the first step in the procedure of root canal treatment. The initial diagnosis is made with the help of the sign and symptoms of the affected tooth, and the final diagnosis is made after analyzing the radiograph of the tooth.
  • The infected region in the tooth can be detected by slight discoloration in the region from the normal and the presence of infection (abscess) in the apex of the root as a regular or irregular shape.
  • Radiographs help us determine the tooth infection, the extent of pulp lesion present, the number of Roots of a tooth, the number of pulp chambers, and any other anatomical variations in the tooth's root.
  • An intraoral periapical radiograph (IOPA) is the traditional method, and RVG is the latest innovation in taking intraoral periapical radiographs in digital radiography.

Step 2: Access Opening

Our next step is to gain access to the pulp chamber. Before access opening, the patient is anesthetized with local anesthesia (Learn more about local anesthesia by clicking here) This is done with the help of the preparation of the cavity for access opening. After accessing the canal, the canal is prepared in such a manner that it provides easy, smooth, and complete access to the pulp chamber and allows the extirpation of the pulp tissue completely.

Aims of an Ideal Access Cavity Preparation?

Straight line access allows the instruments like rotary or manual files to enter the pulp chamber in a straight line without any restriction to avoid mishappening. This improves the controlling action of the instrument, makes easy obturation, decreases the chance of error, and also helps to remove weak tooth structure.
Conservation of Tooth Structure, i.e., saving sound or a good part of tooth structure which in turn provide strength to the remaining tooth structure in bearing occlusal forces and prevent tooth fracture.
Unroof the pulp chamber and expose pulp horns - In a few instances, pulp horns (the pulp that extends up into the cusps of the tooth) are present in the crown of the tooth. Exposing it is crucial to locate the canal and also gain straight access.


Failure of gaining proper access opening or cavity will lead to

  • Incomplete removal of the infected pulp tissue.
  • Breaking of files due to lack of straight line path to access canal.
  • Weakening of the crown leads to fracture due to excessive removal of crown structure in the search of the canal.
  • Improper coronal seal.

Step 3: BMP or Biomechanical Preparation

It Involves:
  • Working length determination,
  • Irrigation,
  • Cleaning and Shaping of the canal to prepare the tooth for Final obturation.
The infected pulp tissue from the root canals is removed by inserting the endodontic files from the occlusal surface. These files are flexible to ease the procedure as the root canals are not always straight. It comes in different sizes and is used based on the width of the root canal as it varies with teeth and individual. The empty root canals are then cleaned with disinfectant irrigating solutions, to make sure that no infected tissue remains in the canal which is capable of causing the infection again.

Step 4: Obturation

The pulp tissue which was removed is now replaced with gutta-percha points. The gutta-percha points are placed into the root canal by applying cement onto them so that they are well adapted to the walls of the root canal.

The gutta-percha points are adapted with the use of pressure into the canals with the help of a plugger. These gutta-percha points are available in different sizes so as to completely fill in the root canal which was emptied. A final X-ray confirms the same. 

Now, it's time for the restoration to replace the tooth structure removed during the cavity preparation.

Filling the cavity

This is one of the most important parts of the treatment. The access cavity prepared is now filled with an ideal material (composite and amalgam) that can bear the vertical stresses of occlusion.

Restoration: Dental Crown or Onlay

  1. An onlay is used in case the left tooth structure is good and sound
  2. A complete Crown is required to increase the longevity of the tooth treated in case of loss of any wall of the treated too. There are many types of crowns available – Metal, Metal Ceramic, Zirconia, etc.

References

1. Grossman’s Endodontic Practice 14th ed.

DrDent_Notes