I have periodontitis. everytime i eat, the food gets collected like a lump beneath the teeth, on the left side. it happens only on the left side. is it dangerous?

Could be: It is best to brush your teeth and gums after every meak and there will be no problems.

Not dangerous: But obviously locally irritating & requires evaluation by dentist so gingivitis doesn't progress to periodontitis. From my interpretation -do you have inflamed gums due to some anatomical food trap or buccally protruding bone (exostoses) that are trapping fragments of food within your buccal vestibule and alveolar bone against the teeth and causing you to have localized gingivitis?

Seek treatment: If you know you have periodontal disease you need to eliminate it. There is a direct relationship between cardiac and vascular inflammation and periodontal inflammation in addition with future bone loss you run the risk of losing teeth see a periodontist to help you.

Cure is difficult: Control is really what you want and need to do. Your dentist should evaluate and determine the best course of action. Periodontal disease is a bacterial infection that, for best results, needs to be controlled on a daily basis. I have successfully used perioprotect (non-surgical periodontal therapy) for mild to moderate periodontal treatment. For information: http://perioprotect.Com.