Root canal obturation involves the three-dimensional filling of the entire root canal system and is a critical step in endodontic therapy. There are two purposes to obturation: the elimination of all avenues of leakage from the oral cavity or the periradicular tissues into the root canal system; and the sealing within the root canal system of any irritants that remain after appropriate shaping and cleaning of the canals, thereby isolating these irritants. Pulpal demise and subsequent periradicular infection result from the presence of microorganisms, microbial toxins and metabolites, and the products of pulp tissue degradation. Failure to eliminate these etiologic factors and to prevent further irritation as a result of continued contamination of the root canal system are the prime reasons for failure of nonsurgical and surgical root canal therapy.Other factor that influence the ultimate success or failure of each case include the materials used and how they are used.
Criteria for obturation:
1] Teeth with signs of apical periodontitis
e.g. those tenderness to apical palpation.
2] Teeth associated with radiographic signs of apical periodontitis.
3] Teeth with excessive exudate that cannot be stopped.
4]Teeth with a purulent discharge into the canal.
5] Teeth associated with aprocedural accident e.g.perforation.
Criteria for obturation:
1] Teeth with signs of apical periodontitis
e.g. those tenderness to apical palpation.
2] Teeth associated with radiographic signs of apical periodontitis.
3] Teeth with excessive exudate that cannot be stopped.
4]Teeth with a purulent discharge into the canal.
5] Teeth associated with aprocedural accident e.g.perforation.







