I personally used powerful magnets to stop toothe pains.
The cracked tooth is hard to help, especially after bacteria has entered and set up house.
The Tooth/Gum powder packed around the tooth is the best thing I know of and with this, a 21 day Fast. If the pain does not go away, most likely the nerve is infected. Continued fasting should work, unless you have other dental work in the mouth.
When the Blood is clean, the toothe ache should go away. Will the toothe mend? Maybe, it is tuff and may take time.