Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concern.... As per your complain if food is getting stuffed in between the two back teeth it is possible that there is cavity formed in any one of the two teeth over the wall of the tooth that is in contact with the other tooth and such cavities gets deeper as they are not visible and when it becomes deep then only it comes to notice when the patient experience pain or food lodgement or both.. As you have a dull pain it is possible that the cavity is deep and the infection is reaching close to pulp [pulp is a central portion of tooth that contains nerves and blood vessels] or the pulp is somewhat exposed leading to inflammation of the pulp known as Pulpitis and causing pain.. You should consult a Dentist and get evaluated and along with it get an IOPAR [X RAY] done to rule out the exact status of tooth and in case if the infection is superficial and has not reached pulp filling the tooth with a tooth coloured restorative material [filling material] can help, but in case if it is deep and approximated pulp Root Canal Treatment has to be done followed by capping of the tooth.. Another aspect can be that if there is no decay in any of the tooth then food lodgement must be happening in the pockets formed between the gums and the tooth due to gum infection and in this case Scaling followed by antibiotics, painkillers, vitamin C tablets and use of gum paint and maintenance of a good oral hygiene will relieve.. Hope this information helps.. If you find the answer helpful please give me a Five Star Review and click on found the answer helpful as a token of appreciation.. Thanks and regards.. Dr.Honey Nandwani Arora..