Distrontium Cerate as a Radiopaque Component of Hydraulic Endodontic Cement

This study aimed to synthesize distrontium cerate (2SrO·CeO(2): S(2)Ce) and evaluate its properties as an alternative component of the endodontic cement. S(2)Ce cement was prepared through calcination of strontium hydroxide and cerium carbonate. Subsequently, the crystal phase was confirmed using X-ray diffraction. S(2)Ce cement exhibited a rapid setting time (121 min) and achieved a high compressive strength (72.1 MPa) at 1 d after mixing, comparable to the compressive strength of a commercial mineral trioxide aggregate (MTA) cement (ProRoot MTA) after 28 d post mixing. However, the compressive strength decreased after 28 d of storage when the W/P ratio was 0.30–0.40 (p < 0.05). Ion dissolution test of the S(2)Ce cement showed that strontium ions were released after immersion in water (5.27 mg/mL after 1 d), whereas cerium dissolution was not detected. S(2)Ce exhibited approximately three times higher radiopacity (9.0 mm aluminum thickness equivalent) compared to the commercial MTA (p < 0.05). These findings suggest that S(2)Ce is a possible component for hydraulic endodontic cement that demonstrates a rapid setting and high radiopacity.