Hello,
Reverse Osmosis is a cleaner system with good filtration, but be sure to check the filter as this too can become an issue. Overall, however, better than well water.
Flouride is one of the most toxic chemicals that we put into our bodies, and unfortunately, willingly. Just read the label... it is poisonous! Flouride competes with calcium for binding sites on your teeth, actually stripping calcium from your bones (teeth), this is called flourosis. The research that supports flouride is outdated and full of holes, yet dentists are offering flouride treatments. Apparently, no one has told them how harmful this is to your child and yourself! Please do the research.
What to do then... buy organic toothpaste.
There are a lot of good products to choose from with antibacterial benefits. A good website to look at is www.icpa4kids.org and put in flouride into the search engine. You will get a lot of information on the harmful effects of flouride.