Summary:
Purpose: to determine the in vitro concentration of eugenol released from a zinc oxide-eugenol-based sealer at three periods of time with two different filling methods: the single-cone and the Thermafil.
•N= (10 extracted maxillary central incisors.
•Materials/Methods:
•The crown of 10 maxillary central incisors was removed, and the canal was prepared with ProFile to a size 30 under NaOCI irrigation. The patency of the apex was checked with a #8 K-file between each ProFile.
•G1: 5 roots were filled with a Thermafil #30 and 0.03 g of Sealite; G2: 5 roots were filled with a gutta-percha cone #30 and 0.07 g of Sealite
•The apical 2 mm of the roots were immersed into phosphate-buffered saline (PBS)
•The concentration of eugenol released in PBS was determined at 3 evaluation periods (immediately, after 1 day and after 1 month) by using spectrofluorimetry.
Most highlighted Results:
•The roots filled with the single-cone technique released significantly more eugenol than these filled with Thermafil immediately after sealing (p = 0.002); but after 1-day or 1-month storage, there was no difference.
•For both techniques, eugenol concentration decreased over time (p = 0.01): the immediate concentration was higher than the 1-day concentration (p = 0.04). Eugenol concentration after 1-month storage was undetectable.
•The results show that the level of eugenol released from a zinc oxide-eugenol-based sealer beyond the apex is very low and decreases over time.
Clinical significance:
Within these concentrations, eugenol has anti-inflammatory and analgesic effects that are useful after a pulpectomy and a cavity filling.

