An aching pain in or around a tooth is unpleasant but common. It may have various origins such as cavities, abscesses, inflammation, trauma and even food stuck in-between the teeth and gums. To avoid worsening the dental condition, action has to be taken quickly.
To rule out food impaction, the mouth should be rinsed with lukewarm water in order to dislodge any food debris. Using dental floss is also strongly recommended. The application of analgesics or aspirin on the gums is contraindicated since it could damage the tissues instead of healing them.
Then, call your dentist. A sharp and sudden pain is of bad omen; in most cases, it is a fracture or an infection. If the pain is the result of an impact or injury, immediate care is needed. If you believe that the pain is an aftereffect of a previous dental treatment (teeth whitening, tooth extraction, etc.), contact your dentist as soon as possible.
Healthy eating habits combined with exemplary oral hygiene and regular visits to the dentist will help prevent a toothache.