Hello, I can understand your concern. If your bridge has openings in it and food gets stuck in tooth, then it is sure that the tooth is decayed because of the food stuck inside causes decay. This decay can cause pressure in the closed cavity of tooth, which can cause throbbing, pulsating pain. Most bridges fail due to involvement of the abutment (supporting) teeth in caries or decay. It is hard to tell you surely if root canal can surely solve the problem or not because it depends on the extent of the decay, but if your dentist has taken the x-ray and is sue of that root canal can solve it, then you should go for it. The correct steps of your treatment are removal of the current bridge (either intact or by breaking it in two to three pieces), root canal treatment of the carious tooth, post-root canal filling of the root canal treated tooth, cementation of the current bridge if in good condition and intact or fabrication of new bridge over the teeth. I would like to advise you to make a bridge of metal or metal fused to ceramic as bridges made by acrylic are like plastic and they wear and break easily. While metal involving bridges are little expensive, they last for years without any hindrance. I hope this information helps you. Thank you for choosing HCM. I wish you feel better soon. Best, Dr. Viraj Shah