Abstract
This case report describes the effect of calcium hydroxide in the treatment of traumatized immature tooth. Calcium hydroxide is used to fill the root canal after complete chemomechanical debridement has been performed. The result demonstrated the successful use of calcium hydroxide in stimulating the epithelial cells of Hertwig's sheath and the surrounding undifferentiated progenitor cells to continue formation of the apical portion of the root. Thus, the use of calcium hydroxide stimulated apical bridge formation, as well as inducing apexogenesis.