treatments for dental decalcification?!

You cannot replace enamel that has been lost due to acid erosion. Using a treatment such as MI Paste or MI Paste Plus (ask your DDS, it's only available through a dentist) may help to replenish some of your "soft spots" or white spots that you see on your teeth. Next time you go to the dentist for a cleaning, request a fluoride varnish instead of a foam or gel fluoride treatment. Also using Pronamel toothpaste from Sensodyne may help to prevent further acid erosion. Whitening may not be a good idea because of your advanced decalcification. It will make your teeth more sensitive and will not get rid of any decalcification, it will only cover it up. Chances are it will be uncomfortable as well. I'd say for now, stick to a Pronamel toothpaste and talk to your DDS about starting at-home fluoride treatments.