Healing of Periapical Lesions - Endodontic Success and Failure

Endodontic Success and Failure

It is possible that after conventional endodontic therapy has been completed, little to no resolution of the periapical lesion occurs over a considerable amount of time; there is a great deal of current research that discusses the possible reasons for this outcome and suggests possible treatment options. For example, it has been demonstrated that there is an association between nonresolving apical periodontitis lesions and the presence of cholesterol clefts within the periapical lesion; in fact, an incidence of up to 44% has been reported! It was shown that macrophages joined to form multinucleated giant cells and then produced a well-circumscribed area of tissue reaction, not unlike the granulomatous tissue reactions of a typical foreign body reaction, and persisted for up to 8 months. Similarly, endodontic materials as well as food debris may also be the cause of persistent periapical lesions. It was once shown that contaminated gutta percha resulted in a persistent periapical lesion for more than a decade!