Why It Might Seem Smart to Combine Them
There are obvious reasons why you might want to have a dental bridge supported by an implant and a natural tooth. First of all, it means that you need fewer dental implants to replace lost teeth. For example, two adjacent teeth that are lost might be replaced by a dental implant and a bridge that extends over the gap to the natural tooth on the other side. And because you know that nothing is as good as a natural tooth, you might think that using one would help the dental bridge last longer.
This might seem especially logical if you have a dental bridge fail because one of the teeth supporting it is decayed or damaged and can’t hold up its end of the bridge. It might seem like the smart thing to replace that tooth with a dental implant and continue to use the functioning tooth to support the other side of the bridge.
But, as we said, this is one of the places where the differences between your natural teeth and dental implants matters. Dental implants are affixed in the bone. Natural teeth, on the other hand, are encased in bone, but they’re actually secured by periodontal ligaments, soft but tough tissue that has a certain amount of flex to it. This acts as a cushion for the tooth under force.
So, when a dental implant and a tooth are connected via a dental bridge, the force gets distributed unevenly. Whenever force is put on the dental bridge, the natural tooth will give slightly because of the ligaments, but the dental implant won’t. This means that the dental implant will take more than its share of the bite force, and excessive bite force is one of the leading causes of dental implant failure. In addition,there is tension on the dental bridge, trying to flex the hard, inflexible material, which could cause it to break.
And it’s not just the dental implant that might be in trouble. In some situations, the tooth in question might not be up to the task of supporting its side of the bridge and it’s best to remove it and replace it with a dental implant, too.