Reformulated mineral trioxide aggregate components and the assessments for use as future dental regenerative cements

Abstract

Mineral trioxide aggregate, which comprises three major inorganic components, namely, tricalcium silicate (C3S), dicalcium silicate (C2S), and tricalcium aluminate (C3A), is promising regenerative cement for dentistry. While mineral trioxide aggregate has been successfully applied in retrograde filling, the exact role of each component in the mineral trioxide aggregate system is largely unexplored. In this study, we individually synthesized the three components, namely, C3S, C2A, and C3A, and then mixed them to achieve various compositions (a total of 14 compositions including those similar to mineral trioxide aggregate). All powders were fabricated to obtain high purity. The setting reaction of all cement compositions was within 40 min, which is shorter than for commercial mineral trioxide aggregate (~150 min). Over time, the pH of the composed cements initially showed an abrupt increase and then plateaued (pH 10–12), which is a typical behavior of mineral trioxide aggregate. The compression and tensile strength of the composed cements increased (2–4 times the initial values) with time for up to 21 days in an aqueous medium, the degree to which largely depended on the composition. The cell viability test with rat mesenchymal stem cells revealed no toxicity for any composition except C3A, which contained aluminum. To confirm the in vivo biological response, cement was retro-filled into an extracted rat tooth and the complex was re-implanted. Four weeks post-operation, histological assessments revealed that C3A caused significant tissue toxicity, while good tissue compatibility was observed with the other compositions. Taken together, these results reveal that of the three major constituents of mineral trioxide aggregate, C3A generated significant toxicity in vitro and in vivo, although it accelerated setting time. This study highlights the need for careful consideration with regard to the composition of mineral trioxide aggregate, and if possible (when other properties are satisfactory), the C3A component should be avoided, which can be achieved by the mixture of individual components.

Comparative Cytocompatibility and Mineralization Potential of Bio-C Sealer and TotalFill BC Sealer

“…Conversely, hydraulic cements exhibited cells that were well attached and proliferated on the set surface, which means that they would be more advantageous to cell biocompatibility even in direct contact conditions than epoxy resin-based sealers. Thus, it may be speculated that the biological properties and differentiation of the materials are influenced by their composition [34,35].…”

Physical Properties and Biofunctionalities of Bioactive Root Canal Sealers In Vitro

“…When sealers or their toxic components in extraction are exposed to the surrounding tissues outside the root canal (periapical lesion) [ 17 , 18 ], inflammation of the periapical tissue can be affected and delayed wound healing can result [ 17 , 19 , 20 ]. Calcium silicate powders are known to have excellent bioactivity, and possibly released components, such as calcium and silicate ions, have been known to accelerate the healing process, along with additional antibacterial effects by alkaline pH [ 21 , 22 , 23 , 24 ]. In particular, calcium and silicate ions can accelerate osteoinduction and angiogenesis, respectively, all of which are major biological properties that boost the periapical healing process [ 25 , 26 , 27 , 28 , 29 ].…”

Initial Cytotoxicity of Mineral Trioxide Aggregate (MTA) during Setting on Human Mesenchymal Stem Cells

“…However, all of them are still suboptimal as root-end filling materials due to their bioinert property or less bioactivity [14]. erefore, mineral trioxide aggregate (MTA) has been developed and widely utilized in clinics for perforation repair, pulpotomy, direct/indirect pulp capping, and apexification due to its good sealing ability, osteogenesis/odontogenesis, biocompatibility, and antibacterial activity and bioactive property [15,16].…”