Both your X-rays reveal confirmed decay in ur second molar which has approached the nerves of ur teeth , hence u will need a root canal treatment for that tooth .
Your first molar too has a decay and does need a clinical examination to make a diagnosis and find out if u need a root canal or only a filling would suffice .
Next Steps
Plz consult ur doc
Health Tips
Do not delay your treatment . Wether or not your are in pain you must get the problem corrected as once decayed the lesion only increases with time .