Handpiece is flushed for 3 minutes at the beginning of the day.. to get rid of which kind of bacteria

At the beginning of the Operation day in the clinic, you should start the water/air spray for Three minutes in order to get rid of which type of microorganisms:

OR

At the start for our clinic day, why do we spray for 3 minutes:

OR

Handpiece is flushed for 3 minutes at the beginning of the day

to get rid of which kind of bacteria:

1. Pseudomonas aeruginosa*****

2. Actinomyces

3. spirochete

4. Streptococcus sanguis