Please advise what is the best cure for toothache?

Proper diagnosis. A toothache can be caused by a number of things. The best cure is to have the proper diagnosis of the cause and then the proper treatment by a qualified dentist.
Treatment. The best "cure" for a toothache is to visit your dentist and have the tooth evaluated and restored. In the meantime, take otc pain meds until you can get an appointment.
See a dentist ASAP. Toothache is merely a symptom of being sick. It can cause sore throat, swelling of the gums, neck glands and muscle pains. Abscess can further spread to other parts of the body like jaw bones and heart. It can result in systemic infection. See a dentist ASAP.
The telephone. You need to call your Dentist immediately. Pain indicates a spreading infection, which can do harm to other organ systems.