RESUMEN
Background/purpose: Tristrontium aluminate (S3A) is a hydraulic cement with setting behavior similar to that of mineral trioxide aggregate (MTA). This study examined the biological effects of S3A on mouse dental papilla cells (MDPs) in vitro and on rat exposed pulps in vivo. Materials and methods: Extracts of S3A and MTA were prepared by immersing each cement in ultrapure water. MDPs were cultured with S3A or MTA extracts, and cell proliferation was evaluated with a tetrazolium-salt assay. Attachment of MDPs on the set cements was examined with scanning electron microscopy (SEM). mRNA expression of bone morphogenic protein (Bmp2), osteocalcin (Oc) and osteopontin (Opn) in MDPs exposed to S3A or MTA extracts was determined with reverse transcription-quantitative polymerase chain reaction. Mineralized nodule formation was evaluated with Alizarin Red S staining. Simulated body fluid (SBF)-dipped S3A was examined with SEM and energy dispersive X-ray analysis (EDX). Exposed molar pulps of male Wistar rats capped with S3A or MTA were histologically examined. Results: S3A extract did not inhibit proliferation of MDPs. Set S3A and MTA exhibited attachment of MDPs on their surface. S3A extract showed significantly higher mineralized nodule formation and mRNA expression of Bmp2, Oc, and Opn than did MTA extract. SBF-dipped S3A exhibited formation of surface precipitates, which were composed of Ca, P, Sr, and Al. Direct pulp capping with S3A and with MTA induced mineralized tissue repair of the exposed pulp. Conclusion: S3A possesses biocompatibility and pro-mineralization effects comparable to those of MTA.
RESUMEN
This study aimed to synthesize distrontium cerate (2SrO·CeO2: S2Ce) and evaluate its properties as an alternative component of the endodontic cement. S2Ce cement was prepared through calcination of strontium hydroxide and cerium carbonate. Subsequently, the crystal phase was confirmed using X-ray diffraction. S2Ce 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 S2Ce cement showed that strontium ions were released after immersion in water (5.27 mg/mL after 1 d), whereas cerium dissolution was not detected. S2Ce exhibited approximately three times higher radiopacity (9.0 mm aluminum thickness equivalent) compared to the commercial MTA (p < 0.05). These findings suggest that S2Ce is a possible component for hydraulic endodontic cement that demonstrates a rapid setting and high radiopacity.
RESUMEN
This study evaluated tristrontium aluminate (S3A) and its viability as a component for tricalcium silicate (C3S) cements. The properties of S3A, C3S, and S3A/C3S mixtures were evaluated in terms of setting time, compressive strength, flowability, and radiopacity. X-ray diffraction (XRD) pattern verified the powder synthesized in the laboratory as S3A, consequently, confirming the preparation method. S3A exhibited the lowest setting time, followed by C3S and S3A/C3S mixtures. Compressive strength of C3S was significantly higher than S3A. The S3A/C3S mixture showed comparable compressive strength to C3S for 1-day post initial mixing. There was no significant difference in flowability between S3A/C3S and mineral trioxide aggregate (MTA). S3A showed comparable radiopacity to MTA, whereas that of the S3A/C3S mixture was significantly lower comparatively; however, it achieved sufficient radiopacity (3 mm aluminum thickness equivalent). Further studies are needed to improve the manufacturing process of S3A and evaluate the bioactive effect of strontium.
