National Association of Dental Laboratories

http://www.nadl.org/

American Academy of Pediatric Dentistry
http://www.aapd.org/

American Dental Association Online
http://www.ada.org/tc-cons.html

Dental ResourceNet 
http://www.dental-resources.com/

The Dental Consumer Advisor
http://www.toothinfo.com/

Dental Resources for Patients
http://www.dentalbytes.com/index1.html

The Orthodontic Information Page
http://www.bracesinfo.com/