SqueakyClean
It depends on if you're talking about the teeth wiggling in their socket (as in, moving when your finger or tongue pushes them), or if you mean repositioning in general, as in the reverse of your orthodontic treatment.
If you're talking about loose as in wiggling, then:
Dr. Christopher's or the Barefoot Herbalist's tooth powder herbs
White oak bark in particular
http://www.proliberty.com/observer/20060703.htm
Also liked the vitamin C suggestion - heard good things about sodium ascorbate in particular for the loose teeth situation.
Read this page, including the comments below. Lots of good stuff:
http://www.newmediaexplorer.org/chris/2004/04/13/good_teeth_from_birth_to_dea...
This came from that page:
Vitamin C powder (ascorbic acid) at Trader Joes is $9.99/lb. Put 1 level tsp (4 g) in a glass, add 1/2 tsp Arm and Hammer baking soda, add 1
inch of water, let fizz, dilute to 8
oz and drink. The compound made here is fresh sodium ascorbate. This is about 1000 x as soluble as C, and is more reactive towards antibody and connective tissue construction and viral destruction. Thus the gums knit back to the teeth, avoiding any kind of oral surgery for "receding gums." Receding gums are nothing but gum pockets caused by toothpaste and especially fluoride, which severs all proteins because of its highly negative character. Fluoride is the smallest negative ion on earth, and consequently is the most intensely negative particle on earth. As such, fluoride breaks the positive hydrogen bonds, which hold the coils together, in proteins and enzymes.