Bismuth-doped injectable calcium phosphate cement with improved radiopacity and potent antimicrobial activity for root canal filling

A bismuth-doped injectable calcium phosphate cement (BD-ICPC) with improved radiopacity, potent antimicrobial activity and sealability was developed by introducing bismuth salicylate basic (BSB) into the powder phase of the calcium phosphate cement (CPC). The results showed that the radiopacity and sealability of BD-ICPC were improved compared with pure ICPC. Although BSB had a retarding effect on the setting rate of the cement, the addition of BSB reduced the viscosity and yield stress of BD-ICPC, thus enhanced its injectability. It was noteworthy that BD-ICPC had a potent antimicrobial activity with improved sealability. In addition, BD-ICPC afforded a uniform and tight adaptation to the root canal wall. These results indicate that BD-ICPC possesses a combination of good in vitro radiopacity, high injectability, potent antimicrobial activity, improved sealability and tight adaptation to the root canal. It is expected to be used as a novel root canal filling material.