Hello. For my chem IA, I want to do how toothpaste (NaF) neutralizes the acid in our mouth to prevent tooth decay. My model teeth is calcium carbonate, and I was going to add HCl and different amounts of NaF powder to see how HCl and calcium titration (tooth erosion) changes. However, when HCl and NaF are added, instead of neutralizing, it creates NaCl (which is not a problem) and HF (which is an acid....) Can anyone help me? Thank you.