Hi..based on pic, either root canal or extraction is required. Regards

Although the pic is not clear, presumably it is the third molar(wisdom tooth), which is affected. If it is really the wisdom tooth which is affected then get it extracted based upon the loss to tooth structure. If it is the second molar which is affected then you may go for an RCT if the tooth is not grossly damaged. Any proper diagnosis and treatment plan depends on clinical examination and X-RAY of the affected area. Please visit a dentist at the earliest and get it treated because infections originating from teeth can also cause other major health issues if neglected, given the age of the above stated patient.

Very poor oral hygiene.don't underestimate the tooth pbls.both the tooth are carious.go for rct other wise it will give much pain.and plz don't take any medicine without dr consult

Wel taking painkillers & antibiotics is not the permanent solution. Pic is not clear. If the tooth is grossly carious then its better to be extracted.