Diminished leakage along root canals filled with gutta-percha without sealer over time: a laboratory study

Aim The aim of this study was to investigate the long-term seal of gutta-pe rcha (GP) without sealer. Methodology Extracted human maxillary central incisors were prepared and ob turated using heat- or chloroform-softened GP only, or GP in combination wi th a root canal sealer. Leakage along root fillings was measured at 48 h an d after a period of 6 months using a fluid transport model. Results At 48 h the GP-filled roots without sealer leaked more than the con trol roots filled with GP and sealer (P < 0.0001). At 6 months a significan t reduction in leakage was found in the GP-only groups (P < 0.05 for both h eat- and chloroform-softened GP). After 4 months, roots filled by vertical condensation of GP-only had similar leakage as vertically condensed GP with a sealer (P > 0.05). Conclusions The long-term seal of root fillings is affected by the volume c hange of both GP and sealer. Leakage reduction due to expansion of GP may c ompensate to a certain extent for leakage that may occur from sealer dissol ution.