Endodontic retreatment: a rational approach to non-surgical root canal therapy of immature teeth.

The specificity of retreating immature teeth involves generally a broadly wide open apex and/or an inverted root canal conicity (apical opening wider than the root canal orifice), a periapical pathology leading often to a continuous canal exudation and thin and fragile dentinal walls. Nonsurgical endodontic retreatment of immature teeth consists at first in removing coronal and root canal iatrogenic obstructions in order to regain total canal patency. Apexification is then the treatment of choice, preceding a final gutta-percha obturation. The present article outlines a step-by-step rational approach to the root canal retreatment of immature teeth, pertaining to their biomechanical and pathological specificity.