Abstract: Abstract Objective: To study different concentrations of ozone solution which acc on the Hepatitis b virus (HBV) in dental unit waterlines (DUWLs) and find out the minimum ozone water concentration which can inactivate HBV in DUWLs. Methods: Culture the human 2215 cell. Under the room temperature 5℃、concussion mixed、airtight and so on conditions, prepare different concentrations of aqueous solution of ozone.Put the ozone solution into the 2215 culture flask. Different concentrations of aqueous solution of ozone act with the supernatant liquid of the human 2215 cell in different times.Extract the HBV-DNA from the 2215 cell supernatant. Fluorescence quantitative PCR amplification. Detect the contents of HVB-DNA. Results: under those conditions, the aqueous solution of ozone is stable. The concentration of ozone at 0.6mg/L in 10 minutes and the concentration of ozone at 0.5mg/L in 15minet can inactivate Hepatitis b virus at limited level. Conclusion: The concentration of ozone at 0.5~ 0.6mg/L can inactivate Hepatitis b virus in DUWLs.

Key words: dental unit waterlines, ozone, hepatitis B virus, sterilize, biofilm