This study was to prepare and screen a novel root canal sealing agent modified by polyhexamethylene biguanide (PHMB) that was in accordance with the ISO 6876:2001 standard and to study its physical and antimicrobial properties. The modified sealers were produced by mixing a certain amount of zinc oxide with eugenol containing different concentrations of PHMB (0.05, 0.1, 0.2, 0.4, 0.6 and 0.8%) at a ratio of 1:1 (w/v). The setting time, flow, film thickness, solubility and dimensional change after solidifying were assessed to screen out the modified sealing agents that the physical properties met the mentioned standards. The modified direct contact test (DCT) was used to evaluate the antimicrobial activity against Enterococcus faecalis. The results suggested that when the concentrations of PHMB were 0.05, 0.1 and 0.2%, the modified root canal sealers showed the best performance in physical and antimicrobial properties.
Keywords: Antimicrobial property; Physical properties; Polyhexamethylene biguanide; Zinc oxide eugenol.