As a patient I would NOT feel comfortable with a DAII scaling.  Personally, I value the extensive training that my RDH has received.  There is much more to a RDH's job than just a cleaning,  a pts. medical issues have to be addressed, such as medical histories & prescription drugs that can affect dental conditions.  Is the DAII trained to deal with those factors?  A question occured to me, if a DAII was to do the scaling would the patient be informed of that or would they be under the assumption that the DAII was an RDH?   It does make a difference....I think the scaling should be left to the TRAINED, REAL PROFESSIONALS,  our RDHs.