Length of Education. A dentist can advance his specific training into specific fields such as endodontics, periodontics, oral surgery, orthodontics and pedodontics. An ms is generally added after the dds. The ms means that the doctor has specialized in this area of dentistry. A general dentist can also advance his training without getting an ms degree. You might see fagd or another added ending after the dds.
Tough to answer. Any dental specialist is a higher specialty than a general dentist, but we really don't like to think of it in that way. A general dentist can go into practice right after dental school. A specialist chooses to advance their education in a particular field of dentistry and that education may take 2-7 years.