I am currently on my 21st day of a 30 day MC. I have done it in the past for 21 days, and several other 10 day rounds over the last 8 years. I have always felt a bit worried about the lemons and my teeth, but this time I ran across a small sidenote in a book that was suggesting the MC as a body cleanse. It said that lemons only react badly with your tooth enamel if the water you use has minerals in it. By usidng distilled water, the acid in the lemon won't react the same and it will do no damage to your teeth. I had always used spring water in the past, but switched to distilled this time, and I feel a difference. They don't feel "stripped" and "built up" all at once (for lack of better terms) this time. Now I didnt have a dentist examine me and make assessments, just my findings. Definately seems different to me this time though.. so in my book it's worth a try! I know I will never use anything but distilled for the MC again!
Best wishes to all!