A properly fitted dental bridge will last up to fifteen years. It just depends on the material you chose to create the bridge. Porcelain is your best bet, since it can also withstand bruxism. However, if you chose a different sort of material for your bridge, it may need to be replaced sooner. Sometimes, a dental bridge, like a real bridge, can become shaky or "rickety." Here is what a shaky dental bridge looks and feels like, and how dental bridge services and a good dentist can fix it.
Bridge Rocks Slightly
If your dental bridge rocks slightly from side-to-side, it means that you are about to lose that bridge. The problem may be with the dental bonding agent under the crowns of the bridge. These crowns are affixed to the existing teeth on either side of the gap created by a missing tooth. If the bonding agent has come loose, or it is so old that it is failing, your dentist will need to remove the bridge, clean up your abutment teeth, and reaffix the bridge in place. Then, the bridge should not rock from side-to-side.
Another possibility for your bridge rocking from side-to-side is that an abutment tooth has worn down, or gum disease has made the abutment tooth/teeth loose. Making some effort to clear up the gum disease with an antiseptic mouthwash and more frequent brushing should help re-cement the teeth in their gum pockets. When the gums are healthy and have firmed up again, the bridge will no longer rock.
Part of the Bridge Is Removable
Under no circumstances should you be able to remove a bridge. It adheres to two existing teeth, and it is formed in a way that it is a single unit itself. Out of your mouth, it looks like three teeth glued together. If you can remove part of your bridge, it means that the entire bridge is essentially "out of order," or broken. It will need to be replaced right away, before a lot of sugars and bacteria can attack the defenseless and enamel-less abutment teeth under the crowns of the bridge.
Even if you have a bridge that only attaches to a single abutment tooth instead of two abutment teeth, you should not be able to remove it. Something is amiss here. The bridge must be broken or loose, or the abutment tooth/teeth are loose and/or broken as well.