Endodontic Procedures – Root canal therapy (RCT) is treatment of disease inside an individual tooth. The idea is to clear up the infection and then to replace the removed pulp with a tightly sealed filling so that the infection won’t reoccur. Two to three appointments typically necessary for root canal therapy of a diseased tooth. Sometimes a tooth can be abscessed and non-vital without being painful.
For a variety of reasons, Endodontic Procedures is sometimes done on vital teeth that show no signs of pulpitis. If a necessary restorative procedure requires cutting a tooth down to the pulp, root canal treatment is usually done. Sometimes the root canal of a vital tooth is needed as anchorage for a restoration, such as a post for a crown. As there is no involvement of infection in the case of a vital tooth, the entire root canal procedure can be completed in one visit on such teeth.
STEPS IN ENDODONTIC TREATMENT
The procedure of RCT can be broadly outlined as follows:
• Opening the crown of the tooth.
• Removing (extirpating) the pulp and cleaning out the root canal.
• Establishing drainage of infection through the root canal.
• Widening the canal to prepare for a filling.
• Establishing control of infection and absolute sterility of the canal.
• Filling and sealing (obturating) the canal with a sterile, tight filling.
• Permanently restoring the tooth with a permanent filling or crown.
So, the entire Root Canal Therapy can be divided into the following steps:
Once the access cavity has been prepared, the floor of the pulp chamber is explored to find the canal orifices, with the help of double-ended endodontic explorer. Exploration must be done carefully to ensure the discovery of all the canals.
The removal of pulp tissue, a process called extirpation, is accomplished with broaches, reamers, and files. The removal of the instrument carries tissue with it between the blades.
The root canal is then instrumented and prepared to give it a form so that it can be readily obturated (filled and sealed). It’s of paramount importance not to over-instrument the canal, to avoid damaging apical and periodontal tissues. The root canal walls, composed of dentin, are cut away with the blades of root canal instruments, like reamers, K-files, and Hedstrom files. The finished canal should feel smooth throughout its entire length. The final size to which the canal is enlarged is based on several factors, some of which are as follows:
• The original size of the canal.
• The degree of curvature (it is difficult to negotiate sharp curvatures with instruments above #35).
• The root that is involved (some roots are much narrower in cross-section than others;
A standardized gutta percha cone of the same size as the last reamer, is used as the master cone. Spreaders and pluggers are used to position and condense gutta percha in the root canal at the time of filling. The fitted master cone should reach exactly to the apical level of instrumentation and there should be some resistance to the removal of the cone (when it is tugged back).
A radiograph with the master cone in place is taken to assure that the cone is at the correct length. After the filling of the root canal it is sealed to avoid any entry of food particles or bacteria in the root canal. A sealer is painted on the canal walls using a reamer, paper point, or similar item. Additional pointed, non-standardized cones (accessory cones) are dipped in sealer and placed alongside the master cone in the space created utilizing the lateral condensation method.
This process is repeated until the spreader won’t penetrate the root canal beyond the cervical level. This allows complete obturation of the root canal apically (toward the root tip) as well as laterally (toward the sides). The excess gutta percha is removed from the chamber using a heated instrument.
In non-vital teeth, intracanal antimicrobial drugs are used between appointments to obtain a bacteria-free root canal. Calcium hydroxide is well suited for this purpose for the following reasons:
(I) It has a good antibacterial effect because of its high pH.
(II) It has a beneficial effect on inflammation.
(Ill) It can be used as a temporary root filling material for long periods of time (even months).
Calcium hydroxide is combined with various solutions to form a paste of a suitable consistency. The entire root canal can be filled with this paste by means of a Lentulo spiral filled. During the following appointment, the calcium hydroxide is easily removed from the canal by means of instruments and irrigation.
TEMPORARY FILLING MATERIAL
Between Endodontic Procedures, a temporary cement is used to seal the access cavity in order to prevent reinfection of the instrumented canal. It has been shown that zinc oxide mixed with eugenol gives a bacteria-tight seal, so typically this cement is used.
OTHER ENDODONTIC PROCEDURES
The treatment and filling of root canals are not the only methods of endodontic procedures. There are minor endodontic procedures that are easier and less costly than root canal therapy but can only be successfully employed on selected vital teeth.
Pulp capping is the most popular of the minor endodontic procedures. After a tooth is completely cleaned of decay, if a pulpal exposure is observed which is non-infected and may be due to mechanical preparation, pulp capping can be tried. It can either the Direct Pulp Capping, if there is clear pulp exposure; Indirect Pulp Capping if the prepared cavity is not having the clear cut pulpal exposure, but the extent of the cavity is in close proximity of the pulp and routine restorative procedure may lead to subsequent pulpal irritation.
The calcium hydroxide is the material of choice for pulp capping endodontic procedures. The treatment may extend to more than one visit. The key to treatment is the action of the calcium hydroxide, a caustic (corrosive) substance that, over a period of time, often stimulates the pulp to form secondary dentin and thus bridge the exposure.
Pulpotomy is the procedure in which the pulp is extirpated partially. If the exposed pulp is not infection-free, but however, the root canal is not yet involved, then a pulpotomy can be tried. In pulpotomy, the pulp in the pulp chamber is removed with a bur or other instrument. When carefully done, both pulp capping and pulpotomy will often deliver good results.
In the pulpotomy endodontic procedures, after the extirpation of the pulp from the pulp chamber with the help of the bur, the opening is flooded with peroxide until the bleeding is brought under control. Like in the pulp capping, calcium hydroxide preparation is used as sedative dressing followed by filling. If either pulp capping or pulpotomy fails, then root canal therapy usually still can be done.
An apicoectomy is a surgical removal of the apex of the root with the surrounding persistent infection, whether it’s an abscess, a granuloma, or a cyst. Apicectomy endodontic procedures is generally performed in cases where a root-end infection persists despite endodontic treatment.
During this endodontic procedures, the following steps are performed:
1. The gingiva is incised at the level of the root tip.
2. The thin outer layer of bone is removed, exposing the apex of the root.
3. The surrounding tissue is cleaned of infection with a surgical curette.
4. A few millimeters of the root apex are cut off.
5. The apex is sealed (Retrofilling), often with silver amalgam.
6. The area is sutured.
The root canal filling can be made either before the apicoectomy is done or at the same time.
A root resection (root amputation) endodontic procedures may be performed when an individual root is hopelessly involved with caries, internal resorption, or periodontal disease.
The only conservative treatment for avulsed (knocked out) tooth is reimplantation. It is procedure for the conservative treatment for a completely avulsed tooth, where the tooth is replaced in the socket with the object of achieving reattachment. Although reimplantation is frequently successful, the ultimate prognosis may be poor due to progressive root resorption.