Hello. You require an x-ray of the tooth to know the extent of spread of cavity in the tooth.
In case of superficial spread, only restoration (Filling) can be done. It is a simple painless procedure. Cavity must be restored at the earliest to avoid further spread of infection.
Incase of pulpal involvement, Root canal treatment is required.
Kindly visit a dentist for definitive diagnosis and treatment
Next Steps
Kindly visit us at Dental Galaxy Pune for consultation or treatment http://dentalgalaxy.in/