Fig. 1

Schematic drawings of dentinal sample preparation. The dentin blocks were prepared by dental handpiece and immersed into mid-phased E. faecalis suspension for 24 h to acquire infective dentin blocks. Then ultrasonic bath in the 1% sodium hypochlorite solution was applied to resolve constructed biofilms on infective dentin blocks. Thereafter CPC-chitosan or CPC-chitosan-GO paste was intruded to cover the surface of disinfected dentin blocks as a kind of sealer and the dentin samples were immersed again into mid-phased E. faecalis suspension for 24 h to investigate their antibacterial property