I definately say  no to allowing a dental assistant do any type of scaling at all.  What happens to the standard of care?  The dental code of ethics?  Each patient deserves the quality of care that only a dental hygienist can provide for him or her.  An assistant cannot make a comprehensive diagnosis, will be unable to detect disease, and this throws preventive care out of the window.  Putting a patient's oral health in jeopardy is not the answer.  I, along with every other hygienist worked very hard to get our credentials that allow us to do the job we do.  Assistants should be encouraged to further their education, go to an accredited dental hygiene school, take the state boards, and get a dental hygiene license.  Quantity means nothing when the quality isn't there.  With that being said, I again say NO to allowing an assistant scale.