Methods and Materials: Pulpectomies were performed on 105 extracted human singlecanal mandibular incisors. The teeth were then randomly divided into 2 groups: 1 was obturated with gutta-percha and the other with R/E. Obturation was performed using the lateral condensation technique. The teeth were then incubated for 10 days, 1 month or 3 months in a heated water bath solution with dye to simulate conditions in the human oral cavity. Teeth were sectioned and examined under dissecting and scanning electron microscopes to assess dye penetration, seal and bonding.

Results: Resilon as the main obturation material consistently resulted in less microleakage than gutta-percha at all 3 time intervals.

Conclusion: The R/E system provides a new material for root canal treatment. R/E creates a chemical bond with the internal tooth structure over the entire root area that is maintained over time, thus representing a better option than gutta-percha. Further studies on R/E will help validate its use and determine its long-term success rates in vivo.