Objective To clinically evaluate the curative effect of one- appointment root canal therapy for the crown fracture teeth caused by injury. Methods 76 teeth which fractured in the crown by injury from 68 cases were treated with one - appointment root canal therapy, and 55 teeth from 47 cases taking routine treatment in another group. In the test group, after the root canal preparation were finished, lidocaine hydrochloride added in epinephine beforehand was directly injected into the bone tissue of root apex through root canal to stop bleeding. If necessary, use cotton broach （3% hydrogen peroxide or epinephine） to press the root apex to stop bleeding. The canal was filled when there was no blood to ooze. To observe the treatment effect twelve months later. Results 76 teeth in the test group all obtained the successful treatment, while in the comparison group there was one tooth extracted because of root absorption, and 54 teeth left in this group obtained successful effect. Conclusion One- appointment root canal therapy has good clinical effect.
