The Washtenaw District Dental Society is a component of both the Michigan Dental Association (MDA ) and the American Dental Association (ADA). The ADA was established in 1859. Today the ADA has more than 155,000 dentist members. As the words largest and oldest national dental association, the ADA is the oral health authority committed to both the public and the dental profession. The MDA has more than 6,000 dentist and student members and is Michigan's official source for oral health care. Be sure to visit both sites for answers to many of your dental questions by clicking the Oral Health A-Z links. Also, be sure to check out the WDDS Find a Dentist link to the left to locate a member dentist in the Washtenaw County area.