Preparation and properties of a novel polyurethane based antibacterial root canal sealer

An ideal root canal sealer should possess capacity to seal the cavity completely and has good antibacterial ability.In this paper,a novel injectable self-setting silver phosphate loaded polyurethane(Ag3PO4/PU)antibacterial root canal sealer was developed via incorporation Ag3PO4 into PU matrix by two step.The fourier transform infrared spectroscopy(FT-IR)analysis indicated that pre-polymer of polyurethane(PU)with isocyanate(—NCO)sealing side was prepared in first step and the percent conversion of the—NCO was 75.2%.The final Ag3PO4/PU root canal sealer was formed through further polymerization of the pre-polymer with other reagents and the percent conversion of the—NCO could reach 96.8%.The physicochemical properties were evaluated according to the ISO standards for root canal sealer and the results indicated that the physicochemical performance could meet requirements of the ISO standards.The antibacterial abilities of the fabricated Ag3PO4/PU root canal sealer to S.aureus were studied through inhibition zone test,anti-adhension test and bacteriostatic rate test,the results suggested that the PU/Ag3PO4had good antibacterial properties.This novel injectable self-setting antibacterial root canal sealer has a great potential to be used in clinic.