There are actually quite a few homeopathic remedies that can help with various tooth problems. If it is specifically tooth decay, then Calcarea Phosphorica or Mercurius Solubilis are listed as helpful, but you can find a more complete list of homeopathic ingredients at http://www.cncahealth.com/health-notes.htm?org=cnca&ContentID=2217001
There are actually quite a few homeopathic remedies that can help with various tooth problems. If it is specifically tooth decay, then Calcarea Phosphorica or Mercurius Solubilis are listed as helpful, but you can find a more complete list of homeopathic ingredients at http://www.cncahealth.com/health-notes.htm?org=cnca&ContentID=2217001
You can also go to http://www.abchomeopathy.com/go.php?symptoms=tooth+decay&resuno=24&usethes=1 and put in all your symptoms of tooth problems for the best match (short of seeing a homeopath in person, which would be your best bet).
No possible way to rebuild decaying teeth.
not rebuild them but in the mean while until you can get proper treatment gargle mouth with some White Oak Bark.
You cannot rebuild decayed teeth.
A root canal might save the root.
Good dental hygiene is recommended to prevent losing more in the future. Flossing at least once daily, brushing after every meal, that’s the ticket.