Comparitive working length determination of non-vital teeth with immature apices : An In-Vivo Study

A primary goal in root canal treatment is to reduce intra radicular microorganisms to a level below that necessary to induce or sustain apical periodontitis. An essential prerequisite is establishment of correct working length during root canal preparation, as failure to do so may result in accidental extrusion of irrigant, dressing or filling and persistent periapical inflammation and postoperative pain.The usual cause of endodontic involvement in a tooth with an incompletely developed root is trauma. Unfortunately, traumatic injuries to young permanent teeth are not uncommon; it is said that they affect 30% of children. The majority of these incidents occurs before root formation is complete, and may result in pulpal inflammation or necrosis.  The term ‘open apex’ is used to indicate the presence of an exceptionally wide root canal at the apex. It is seen in immature teeth when root development ceases as a sequel of pulp necrosis due to trauma or caries. In mature apex extensive apical resorption, root end resection or over instrumentation may result in formation of open apex.  The most favourable landmark to terminate the WL is the apical constriction. However, it is lost in cases of immature apex. Predictable assessment of WL has been possible with the invention of EAL.4 One of the major difficulties in performing endodontic treatment in a tooth with incomplete root formation is evaluating the working length. The missing apical constriction causes a high risk of initial over instrumentation. The purpose of this study is to evaluate the usefulness of electronic apex locator and integrated apex locator that are currently available in treatment of teeth with incomplete root formation. 2 As such only 2 studies comparing working length using apex locator in open apex case is present. There are not much studies present in literature.