it is recommended to prevent sensitivity or pain in future in affected tooth or teeth.
life span depends on how you handle your oral cavity. people are happy with same old crown and bridge even after 20 years also but some patients required retreatment in 5 or 10 years.
You have two fixed treatment options, 1 implants
in implants you do not need to take support of adjacent teeth whereas in bridge we need to grind the adjacent teeth to replace the missing teeth.
How long a bridge lasts depends upon what sort of a bridge it is, and how it is used and maintained. The most frequent cause of bridges failing are
1. Ceramic chipping off the metal coping in case of metal-ceramic bridges. This might happen after several years, but may happen earlier if your diet includes lot of tough, chewy, sticky foods, or, if you have a habit of grinding your teeth. 2. Decay or gum disease affecting the adjacent supporting teeth of the bridge necessitating additional treatment of those teeth, possibly extraction, and replacement of a new bridge, possibly involving more teeth than the original one. This happens usually due to poor home care, failure to maintain regular dental check ups, but the very nature of the bridge also might make it more difficult to keep the area clean, predisposing to food lodgement and damage.
Generally, given good home care, regular dental check ups, a bridge should last 10 to 15 years.