Librarians Internet Index - Websites You Can Trust http://www.lii.org/ Type in your Search Term to locate quality web sites by research subject. The home page has 13 major Subject areas to search, including a major section on Health - see Dental & Oral Health.
Martindale's Dental Center http://www.martindalecenter.com/Dental.html This extensive reference site links to journals, subject specific pages, dictionaries, teaching files and cases, conferences, you name it. Ugly, but useful.
National Center for Dental Hygiene Research http://www.usc.edu/hsc/dental/dhnet/ Provides access to searchable indexes of journals, proceedings, and clinical trials. Also covers grants, education, and consumer information.
American Dental Hygienists Association http://www.adha.org/ Email a question to a DH, purchase merchandise and publications, read consumer-bas ed oral health information. Includes membership info and a member's only job search section. Great kids section.
American Dental Association http://www.ada.org Information for the professional and the consumer. Shop, read news articles, or join the association to see the Members only section.