Duration for Apical Barrier Formation in Necrotic Immature Permanent Incisors Treated With Calcium Hydroxide Apexification Using Ultrasonic or Hand Filing

Background/Purpose: Traumatic injury usually results in pulp necrosis of immature permanent incisors in children aged 7-10 years. Calcium hydroxide apexification is the most common treatment for necrotic, immature permanent teeth. This study compared the duration for apical barrier formation in necrotic immature permanent incisors treated with calcium hydroxide apexification using ultrasonic or hand filing. Methods: Thirty-two trauma-induced necrotic immature permanent incisors with or without a periapical lesion (PL) were selected from children aged 7-10 years. They were evenly divided into four groups. Teeth in groups 1 (with PL) and 2 (without PL) were treated with ultrasonic filing, and teeth in groups 3 (with PL) and 4 (without PL) were treated with hand filing. The canals were cleaned with 0.2% chlorhexidine solution during treatment and then compactly filled with calcium hydroxide. The patients were followed up once every 1-3 weeks to change the intracanal medication and to detect when the apical barrier formed. Results: The mean duration for apical barrier formation was 11.1 +/- 1.1 weeks, 11.8 +/- 1.0 weeks, 13.3 +/- 0.9 weeks and 13.4 +/- 0.7 weeks for groups 1, 2, 3 and 4, respectively. Student's t test showed significant differences in the mean duration for apical barrier formation between groups 1 + 2 and 3 + 4 (p = 0.000), groups 1 and 3 (p = 0.000), and groups 2 and 4 (p = 0.002). These results indicated that teeth treated with ultrasonic filing required a shorter mean duration for apical barrier formation than teeth treated with hand filing, regardless of the presence of PL or not. Conclusion: Ultrasonic filing with 0.2% chlorhexidine as an irrigant is effective for disinfection of the root canal and can shorten the duration for apical barrier formation in necrotic permanent incisors treated with calcium hydroxide apexification.