Here are some sample APA Style citations, to help you get a sense of how yours should appear:
Book:
Smith, J.A. (2010). Dental materials in the twenty-first century. New York: Elsevier.
Scholarly article:
Smith, E.B. (2009). Chairside manner and dental health education: techniques and strategies. Journal of Dental Practice, 32, 204-215. doi:10.1037/0477-6670.41.22.319
Professional or popular article:
White, C.S. (2005, June). Xylitol gum: new applications for an old material. Dental Assisting Weekly, 15(6), 35-39.
Web site:
Crest whitening strips. (2010). Crest.com. Retrieved from http://www.crest.com/creststrips/