If you live in nearby Iowa and are planning on taking our course, check out this website for information about dental assisting in Iowa. http://www.state.ia.us/dentalboard/da.html
Basically you have to have your first employer sign a "dental assistant trainee" form saying that for 6 months he/she will be in the room whenever you're working on a patient. After this 6 months is up, you can take the Iowa State board exam to be a Registered Dental Assistant in Iowa.