Supplement to your natural teeth
When a tooth is lost, it is best to replace the tooth with a non-removable replacement as promptly as possible. You are probably familiar with traditional “bridgework”, which uses natural teeth as supports for bridges that span the space where teeth have been lost. Realize that these bridges have not increased the support which was present when the tooth was there in the mouth. The artificial tooth of the bridge does not have a root. As teeth are lost, the amount of available root support in the mouth decreases. In effect, we have increased the load on each remaining tooth because there are fewer of them. This can be compared with losing fence posts in a long fence. The fence is no longer as strong as it was earlier. In the case of the fence, it is obvious that fence posts need to be added so that the amount of support will be increased, and similarly these areas in the mouth need more support (which can be provided by replacing the missing root structure with implants).
Does a removable partial denture replace the missing teeth equally as well? Partial dentures are either tooth supported or tooth and gum supported. An entirely tooth-supported partial denture will fill the space, but the supporting teeth are no stronger than they were before. In other words, the stress has been increased on the remaining teeth. With many partial dentures which are both tooth and gum supported, the number of teeth has not increased, and once again, there is the same lack of root support as there was before. The areas where teeth are missing have been filled in with gum-supported denture teeth. This denture will have to be replaced or relined periodically. If these areas are not relined, then space develops under the denture. It is not bearing its fair share of the chewing load, and the remaining natural teeth are carrying all of the chewing load. The teeth are overloaded. Under these conditions, the remaining teeth will undergo accelerated bone loss. Also, this partial denture is removable. It is not permanently fastened in the mouth as a non-removable bridge would be.
Tooth supporting bone
Nature has provided tooth supporting bone during the years when there are teeth present in the mouth. When the teeth are lost, the tooth supporting bone is also lost. Nature takes away from you what you do not use! For example, the person who is confined to bed for a long period of time loses his muscle tone. The muscles get soft and literally wither away. In the mouth, the bone under the gums “shrinks”, and around the teeth which remain. Where the teeth have been lost, many times there is excessive bone and gum shrinkage. Where implants have been placed and properly maintained, the tendency is to preserve this bone because the bone is being used somewhat in the way it was when the natural teeth were present.
Your chewing efficiency
For purposes of comparison, let us assume that the patient with all of their own natural teeth in a healthy, well-maintained, functionally accurate condition can chew at 100 percent efficiency. However, with every tooth lost efficiency decreases. How much decrease there will be is dependent upon whether or not the teeth are replaced and in what manner. Ultimately, if a person reaches the point where they have no teeth, and are using properly fitted dentures on an adequate bony ridge, a chewing efficiency of perhaps 15 to 18 percent may be achieved. If the ridges are not adequate, the percentage decreases. With implants and non-removable bridgework, or well supported tooth replacement methods, a person may get back to as high as 85 percent compared with what they had with their natural teeth, depending on the number of natural teeth present and their condition.