I would have suspected that myself had it been present at the time I stopped brushing with bi carb and if the dentist had seen my teeth erode from using it. I only used it twice weekly and the rest of the time I just brushed with electronic brush and water. It was only after using the Miracle-Mineral-Supplement that I started noticing what I thought was a ton of plaque on the back of some teeth. When I went back to the dentist, he told me it wasn't plaque but the silver filling standing out because the tooth enamel had eroded a lot.
Thanks for your thoughts though. It could easily have been the bi carb since I didn't clarify the situation well enough.