First things first, you must feel comfortable with your dentist and you must know their training. Not all dentists are the same. Find someone who has proper training in root canals, someone who has proper training in general dentistry and even better in Prosthodontics or Full Mouth Reconstruction.
See the links below, to find a highly trained dentist in your area. Unfortunately, consumers are not educated to find their dentists the right way. We are taught to ask a friend or go to the one who accepts our insurance. But if you were to ask a highly trained dentist, you will see that they would find a dentist for themselves or their family in a completely different way.
If you are concerned about the quality of your dentist I would ask friends about who they go to and if they are happy with them. If they know a dentist who they think is good maybe you should try him out. As for the bridge, I would see if the tooth may be saved by root canal therapy. If it can't, there really isn't anything else to do but have it pulled. However, it is important to note that if the tooth must be extracted, you have a few options for salvaging the bridge. 1. You can have the dentist section the bridge (cut the connection between the abutment (of the tooth to be pulled) and the pontic (fake tooth inbetween the two abutments (real teeth)). This will leave you with a cantilever bridge (meaning the bridge is only held up on one side). Annother option is to have the dentist remove the whole bridge, pull the affected tooth, and have a new bridge to span 4 teeth (2 abutments and 2 pontics). Annother option is to have the tooth replaced with an implant or do 2 implants and no bridge, just one crown on the previously capped abutment tooth. Yet annother option is to get a removable partial denture to replace the missing two teeth. Really there is several options you could persue. The ones I mentioned are just a few. Getting implants depends alot on how much bone support you have and if you can afford the procedure. You could always go for a couple of consultations with different dentists, and while you are there get them to quote you prices so you can get the best deal. Hope this helps!
Seeing an endodontist is advised.