
Objective: To investigate the effect of chitosan (CH), a biocompatible polysaccharide, on the antibacterial property of polycarboxylatecements. Materials and methods: The conventional control group zinc polycarboxylatecements were manipulated in their original composition and for experimental groups, solutions of chitosan added to the commercial liquid in 0.2g/L (0.0044 wt%) concentration. Antibacterial effects against Streptococcus mutans were tested in two groups after 48 hours and the data were submitted to statistical analyses. Results: The analyses of the results revealed that the highest mean zone of inhibition was recorded in experimental group compared to control group with statistically significant (P<0.001). Conclusion: The antibacterial property can be considerably improved by the addition of a tiny amount of CH. Moreover, in the presence of CH, the release of fluoride ions is catalyzed.