Reinforcing effect of a resin glass ionomer in the restoration of immature roots in vitro.

Fifty-six extracted maxillary central incisors were used for this study. The crown of each tooth was removed in order to obtain a standard length of 13 mm. Root canals were enlarged to simulate immature teeth after apexification. The apical 2 mm of the root canal was obturated with gutta-percha and AH26 sealer. The specimens were divided into two groups. Group A was unrestored and served as positive control. In group B, the canal walls were reinforced with a resin modified glass ionomer using a translucent curing post. All teeth were subjected to compressive force using an Instron testing machine until fracture occurred. Group B showed an increased resistance to fracture (456.02 +/- 172.47 N) compared with group A (263.46 +/- 98.00 N). The difference between groups was statistically significant (P < 0.005).