Is the water in air water syringes used by dentists sterile? is it cleaned to prevent biofilm?

It is safe: Dentists follow sterilization standards and use the same safety techniques as all other licensed health providers. There is NO danger in the United States.

Sometimes: Unless you use a separate syringe with sterile water or have a filter installed in your dental unit most of the water is the same as in the sink. Be more concerned about the other sterile procedures that all dentists should use such as instruments ,needles gloves and many other materials that come in contact with you.