Thanks for writing to us,
I would like you to know that toothache is following infection and as you are aware that in order to treat it antibiotics are a must.Ampicillin
needs a doctor's prescription, therefore I would advise you to see a dentist
Until you see a dentist, use an antibacterial mouthwash(twice/day)
And warm saline rinses(3-4times/day).
It will help relief pain and swelling.
Do not apply hot compresses on the affected area.
I hope I answered your query,
Kindly write back if you have further queries,
I wish you good health.