My husband and I have had good success with plantain for toothache. Plantain is considered a "specific" for tooth pain in the herbal world. It's a drawing agent for all wounds, including pulling out splinters. And it's prominent leaf veins show it to be good for nerve pain specifically.
Here's a good reference:
From this page:
"The cooling properties of Plantain will clear toxic heat and reduce inflammation as seen in allergies, eczema and even boils and abscesses. Matthew Wood has found Plantain to be particularly helpful in infections around the teeth where there may be abscess or root canal sepsis. He says 'It is a specific here and it will almost never fail to draw out the pus and stop the infection, sometimes even saving the tooth where it was thought to be lost'."
The way to use it is to harvest a leaf or two, wash if needed, and chew them up slightly to make a wad of it. Then stuff that wad in the cheek next to the tooth in question. You can replace the wad with a new one after several hours or half a day if more treatment is needed.
My husband caught a goat horn in the cheek one day that jostled a molar and plantain completely cleared the pain and inflammation in a couple of hours. I've heard of plaintain pulling out infection after a wisdom tooth removal as well.
Best thing about it is it grows literally everywhere. It's one of a couple of plants I kept whole in the freezer for winter use "just in case".