Dear patient as u r telling that specific 2 teeth have turned black means u have had a traumatic injury to ur teeth sometime in the past,and because of that injury blood supply to that particular teeth has strangulated and because of the same it has got an infection now which needs to be cleared of,
Next Steps
Visit ur dentist and get the intraoral x ray done,Now charges will depend upon many factors like complexity of the treatment,materials used ,techniques and Instruments used etc.