Design and evaluation of multifunctional antibacterial ion-doped beta-dicalcium silicate cements favorable for root canal sealing

A root canal sealer plays some important roles in accomplishing various functions including antibacteria and anti-microleakage. Meanwhile, such a sealer is also expected to readily induce apatite mineralization in damaged periapical tissues and reconstruct the surrounding alveolar bone. Taking the potent antibacterial ability of some biologically essential trace elements into account, we explore the effects of Zn or Cu doping in beta-dicalcium silicate (beta-C2Si) on the physicochemical modification and biological functions of its self-curing cement and compare with the beta-C2Si cement free of foreign ion doping. An interesting aspect of the Zn or Cu doping in beta-C2Si was the prolongation of setting time and the decrease of mechanical strength, but retardation in the degradation and improvement of anti-microleakage. Furthermore, the beta-C2Si doped with 10% Cu exhibited more excellent antibacterial properties against P. gingivalis and E. faecalis. Additionally, there was similar apatite formation ability and cell growth on the beta-C2Si cements with and without Zn-/Cu-doping within the initial 1-5 d. Totally, it is demonstrated that the physicochemical and biological performances are favorably altered with Zn or Cu doping in beta-C2Si with a consequent effect on setting time, chemical stability (ion release, degradation), anti-microleakage, and antibacterial activity. Therefore, it is indicated that the Zn or Cu-doped beta-C2Si is promising as a multifunctional root canal sealer.