Correlation between Coronal and Apical Microleakage for Endodontic Filling Materials

Objectives: Importance of apical or coronal leakage is well recognized but which pattern may superiorly affect the prognosis of root canal therapy is controversially and the possible correlation between them has not been investigated. Therefore, this study was aimed to investigate the presence of possible correlation between coronal and apical microleakage in canals filled with either gutta percha or Resilon filling material. Methods: Sixty freshly extracted one-canalled lower first premolars were sectioned at cemento-enamel junction. The roots were randomly divided into three equal groups. In Group I, 20 roots were obturated using Resilon/Epiphany SE sealer, Group II, roots were obturated using gutta-percha and Epiphany SE sealer, Group III, 20 roots were used as control groups; canals of 10 roots were filled with gutta-percha/Epiphany SE and other 10 canals were filled with Resilon/Epiphany SE. Half of this group (equally including both materials) was used for positive control and the other half for negative control. The coronal leakage was measured with dye penetration using Methylene blue for 7 days at 37°C. The teeth were sectioned longitudinally, and the linear extent of dye penetration was measured for apical and coronal directions and data were collected and statistically analyzed by One-Way NOVA test. Results: Negative controls revealed no dye penetration and positive controls displayed total dye penetration. Resilon revealed significantly less microleakage than gutta percha group (P < 0.05) for both apical and coronal directions. For the same material, coronal leakage was significantly more than apical leakage (P < 0.05) and the correlation between the apical and coronal leakage was not significant (p = 0.092). Conclusions: Coronal leakage was significantly more than that of apical seal and there was no correlation between the two patterns regardless the filling material used. Resilon provided better seal than gutta percha, but it failed to provide complete seal.