Hello If you are having pain and high sensitivity in that particular tooth area, it indicates that the decay has progressed and is no longer in initiation stage. You cannot cure it on your own. You will have to get it checked by a dentist. An x Ray would be taken to decide the treatment of tooth.

Welcome to Practo. the dental caries can be removed and Restoration can be done in the cavity, in case if the dental caries are deep ,Restoration cannot be done, for that root canal treatment can be followed, it depends on the severity of dental caries, I advise you to take an x-ray and check the condition of the teeth and then continue with the dental procedures ,consult me for further details thank you.

There are diffetent stages of tooth decay. If the decay is in 1st two layers of the tooth you can get filling done.  If decay touches the inner most layer called pulp you will need root canal treatment. So choosing root canal treatment or not  is based on which layer the decay is involved.