8. Root Canal Obturation

The root canal must be dried with paper points prior to its obturation, as residual irrigation fluids will leave voids. The majority of dentists will use gutta percha as the primary filling material in root-canal therapy. The reason for the success of gutta percha among dentists is because it is easy to manipulate into the root canal, it is radopaque and easily seen on radiographs, and it can be removed from the canal and be replaced when necessary. Fresh Gutta percha has good handling properties, while aged Gutta percha can become brittle. Some dentists prefer to insert the gutta percha point into the canal without altering it, while other dentists like to soften the Gutta percha with heated instruments or chemicals. The softened Gutta percha can then be condensed into the canal using lateral or vertical condensation. An advantage of Gutta percha is that it is inert to the periapical tissues if it should become extruded past the root apex. Gutta-percha filling techniques use a prefitted primary point procedure, verified by a radiograph to fit the full length of the canal and to still fit tightly in the apical region of the root canal. The largest possible gutta-percha point is normally selected according to the size of the last instrument used to the full length of the prepared canal. Thin root canals or canals with an extreme curve are more difficult to obturate with standard sizes of Gutta percha points. In these situations, heated instruments or chloroform can be used to chemically soften the gutta-percha for 5 seconds so that it can be more easily into the curvature and the minimally prepared apex. The success of endodontic treatment is dependent on the obturation of the root canal with gutta percha and sealers which can seal the entire root canal, thereby preventing microleakage and the re-infection of the root canal. The sealer is evenly coated on the prepared canal surface, with the last instrument used to spread it throughout the canal length using an up and down motion. Sealers are needed to seal the gutta percha core material and prevent microleakage. The sealer fills voids and irregularities of the root canal space left unfilled by the obturation core material. Adequate sealing of the obturation material inside the root canal is important to the success of endodontic treatment, because up to 60% of endodontic treatment failures are caused by the incomplete obturation of the root canal. Root canal sealers can vary greatly in composition and contain Zinc oxide eugenol, Calcium hydroxide, Glass ionomer, Composite resin, Silipoint, Urethane Metha-crylate, Formaldehyde, and Bis-phenol A. The quality of root canal obturation can be seen in radiographs and a poor quality of obturation can increase the risk of a flare up and treatment failure