I have been a dental hygienist for 27 years and have practiced in 5 states. i am licensed in 2 states to do locat anesthesia.  I am strongly opposed to having a dental assistant do scaling of any type. There was a lot more to my training than just a month long course. This sounds like it is strictly a monetary move on the part of the dental community.  Since moving here in 2005 I have encountered several new graduates who are looking for employment. The argument that there is a dental hygiene shortage sounds unfounded.  If  you allow dental assistants to scale teeth either supra or subgingivally you will be doing a big disservice to the community.  I know that none of the patients I see would stand for substandard care.