Dental Hygiene research is considered one of the many allied health fields. As such, you may find some good information in the article databases that focus on areas of general medical topics and nursing topics. I recommend using terms like "Dental" but only include "Hygiene" if you are certain that your topic can only be covered by dental hygiene literature. Many books and articles focus on wider issues of dental health without using the word hygiene. You may also want to consider these search terms:
