A 7-year-old boy attended the Department of Pediatric Dentistry due to a fall. Clinical and radiologic findings were diagnostic of root fracture of the right permanent central incisor (Fig. 1A). Reduction of the coronal fragment and resin wire splinting were performed (Fig. 1B). At the 2-month follow-up, diagnosed as pulp necrosis of the apical fragment, pulp extirpation, calcium hydroxide canal filling, and splint removal were performed (Fig. 1C). During this procedure, root canal treatment of the apical fragment was performed (Fig. 1D).

After 3 months, calcium hydroxide between the fragments had begun to be absorbed (Fig. 2A), therefore we tried to exchange total calcium hydroxide. Because resistance was felt at the fracture site and access to the root canal in the apical fragment was difficult, we exchanged the calcium hydroxide in the coronal fragment, and monitored the apical fragment. Subsequently, calcium hydroxide was exchanged only in the coronal fragment after 6 months (Fig. 2B). After 2 years, the coronal fragment canal was filled with Gutta-percha and the apical fragment was monitored continuously (Fig. 2C). After 4 years, calcium hydroxide in the apical fragment had been absorbed and there were no complications (Fig. 2D).

After 8 years, calcium hydroxide was completely absorbed and pulp canal obliteration was observed in the apical fragment (Fig. 3A). After 9, 10, and 11 years, pulp canal obliteration in the root-fractured teeth had continued (Fig. 3).

A 12-year-old boy with mental retardation visited our hospital due to tooth trauma. At the initial visit, an oral and radiographic examination led to diagnosis of intrusion and crown fractures without pulp exposure of the upper left and right central incisors (Fig. 4A).

On the day of visit, reduction of the intruded teeth into their original positions and wire splinting were performed (Fig. 4B). 2 weeks later, pulp extirpation was performed. After 1 month, the root canal was filled with calcium hydroxide (Fig. 4C).

After 4 months, the patient attended the hospital due to additional trauma, and a root fracture of the right permanent central incisor was observed on a periapical radiograph (Fig. 5A). Extraction and a space maintainer were considered; however, as it was unrealistic to expect co-operation from a child with mental retardation, we planned conservative treatment.

After 6 months, calcium hydroxide between the fragments had begun to be absorbed (Fig. 5B). As in the first case, because of resistance at the fracture site and difficulty accessing the apical fragment in the root, we exchanged the calcium hydroxide only in the coronal fragment, and monitored the apical fragment periodically.

After 3 years, calcium hydroxide on the coronal side of the apical fragment had begun to be absorbed (Fig. 6A). Remnant calcium hydroxide of apical fragment was completely absorbed after 4 years (Fig. 6B). After 5 years, the root fracture was healed with calcified and connective tissue, and the canal of the apical fragment was healed with bone tissue. The canal of the coronal fragment was filled with Gutta-percha, and there were no complications after 8 years (Fig. 6D).

An 8-year-old boy was referred from a local dental clinic at 2 weeks after splinting of a tooth with a root fracture. During the visit, root canal treatment and calcium hydroxide filling of the coronal fragment were performed. However, as a result of the excessive filing, a periapical radiograph showed the presence of excess calcium hydroxide in the canal of the apical fragment (Fig. 7B). As in the previous case, we exchanged the calcium hydroxide only in the coronal fragment and monitored the apical fragment at 3-month intervals.

After 3 months, calcium hydroxide in the coronal fragment was completely absorbed (Fig. 7C). After 6, 12, and 24 months, there were no complications or clinical symptoms (Fig. 8).