I underwent RCT with crown for my premolar tooth on lower jaw on august 2014. I have swelling on the gum below the RCT tooth since november 2015 which is not painful to touch but when pressed hard it pains a little. My dentist asked me to get X ray done, which according to him is that the RCT is fine but there is a gap between the RCT tooth and the next molar tooth which is causing the swelling due to accumulation of food. Now my dentist is asking me to get the crown removed and place a new crown to fill the gap. Whether my dentist is right? Whether there is any other alternative? Is it a serious problem?