Fixed bridges are attached to your dental implants much like your natural teeth are connected to your bone. Because they are most similar to teeth, they do require some maintenance.
Most importantly is your daily routine at home. You must brush and floss your implant fixed bridge. You will also need to have regular x-rays to monitor the level of your bone. The bite needs to be checked routinely also. These are all things done during your cleaning appointments.
Overdentures are held in place by attachments that are embedded in the underside of the denture.
These clips are made of plastic and they do wear out. You will know when they wear out because the overdenture will feel much looser. They wear out about every 18 months to 2 years on average. They are easily replaced my office in about 45 minutes.
The actual teeth on an overdenture will wear out. The teeth hardly wear at all on a fixed bridge. This is strictly due to the material that the teeth are made of. Porcelain fixed teeth can chip, but generally are rarely replaced.
Overdenture teeth are made of plastic and wear out about every 5-8 years. When they wear out, they need to be replaced. If left to wear for too long, your face will begin to look older because the distance from your nose to your chin has gotten smaller.
The entire overdenture will probably need to be replaced at 10 years. Although, overdentures are great solutions, they do require replacement.
A fixed dental implant bridge requires much less maintenance than an overdenture.