May be the crown is not properly placed. Go to the nearest doctor get a deep cleaning done in that area. Do regular warm saline rinse(salt dissolve in warm water) regularly after every meals. Ask the dentist to teach you how to use interdental brush. Hope you will be relived.

ILL-FITTING CAP OR CROWN IS THE MAIN REASON FOR YOUR PROBLEM. IF YOU CAP IS UNDER WARRANTY PLEASE ASK THE DENTIST TO CHANGE IT FOR YOU.IDEALLY IF THE CAP IS DONE RECENTLY THN DENTIST SHOULD DO IT REE OF COST.

Try using an interdental brush to keep that area clean. If the cap is ill fitting you might have to get it replaced.

Hi, I guess the problem is because of ill fitting cap or decayed adjacent teeth. Visit a dentist for proper consultation

The problem that you have mentioned can have two possible causes..... one could be an improperly shaped cap or an ill-fitting cap..... the other reason could be gingival recession leading to open spaces between the teeth which is the cause of food lodgement.... in either case your first step should be to go for a proper clinical examination..... if the cap is ill fitting or improperly placed, it will require refabrication and if spaces between the teeth are due to gum loss, the dentist can advise you interdental cleaning aids for proper cleaning of those areas, where a regular toothbrush cannot reach.... Regards.....

Reason may be ill-fitting cap or while inserting cap on tooth some cementing material might goes into gums which is irritating your gums.please do visit the same dentist n get it checked again.