Does bottled-water cause cavities?

I was reading a publication from Merck.com about human physiology and nutrition today and came across a section on the flouridation of water. Flouride is a compound made up of flourine and is added to municipal water supplies to prevent tooth decay. The question that immediately came to my mind was, "How does the preponderance of bottled water affect our teeth? Have cavities in adults increased significantly since bottled water became so popular?" At the moment I don't have any answers but check back with the CanHealth Report in the coming weeks as I investigate these questions.