Hello Nirmal , it's a good idea to visit a dentist . Your 2teeth which had decay might have lost its crown portion but the root portion might be there with in gums in the bone . You should get them out as well because that is a source of infection and might cause problems later on. Also after the removal you should get some permanent replacement for your missing teeth
Next Steps
Visit a dentist near by for extraction of the remaining tooth structure which is accumulating food.