Methods: Fifty maxillary anterior teeth were randomly divided into 3 experimental groups of 10 samples each and 2 control groups. The experimental groups were prepared using the modified double-flared technique and obturated by lateral compaction of cold gutta-percha with Ca3SiO5/CaCl2 composite cement, ZOE（zinc oxide-eugenol-based cements） and cortisomol paste. With the leakage test device, the leakage was quantified by measuring the concentration of leaked glucose in apical reservoir at 1, 3, 5, 7, 14, 20 and 30 days with the enzymatic glucose oxidase method.
For evaluation of antibacterial activity of Ca3SiO5/CaCl2 composite cements, 10 mg of each sample were added into 1 ml bacterial suspension in a 1.5 mL eppendorf tube. Following a serial of 10-fold dilution, 100 µl suspensions were moved onto LB-agar plates followed by a overnight incubation at 37℃. The resultant colonies were counted as CFU/ml (colony forming units) and the bactericidal percentages were calculated.
Results: The glucose concentration of leakage of ZOE groups are higher than Ca3SiO5/CaCl2 composite cement groups and cortisomol groups at day 7, 14, 20 and 30 (p<0.05). No significant difference was observed between the Ca3SiO5/CaCl2composite cement groups and cortisomol groups (P>0.05).
Ca3SiO5/CaCl2 composite cement exhibited antibacterial activity against E.coli similar to calcium hydroxide cement, whereas cortisomol had little effect on E.coli.
Conclusion: Ca3SiO5/CaCl2 composite cement and Cortisomol paste had a better sealing ability than ZOE (P<0.05). In addition, Ca3SiO5/CaCl2 composite cement exhibited a strong antibacterial effect against E.coli.