Teeth are removed for several reasons, including periodontal (gum) disease, extreme decay, and for orthodontic reasons. Once a tooth is removed, the shape of the ridge (i.e., the supporting bone and gum in which the tooth was situated and retained) changes. If there has been extensive bone loss, or if the tooth needed to be surgically removed (bone had to be cut away to gain access to the area), the change will be more dramatic. The ridge shrinks, collapses into itself, and over time decreases in width and height. As more time passes after the extraction, the more change occurs.
This is an extraction site defect. Look how skinny the bone is compared to the image next to it!
The extraction site defect presents a problem when the area is to be restored with an implant.
When the ridge architecture has significantly changed, the replacement tooth will have to deviate from the ideal shape. This could easily make the area more difficult to keep clean, difficult to restore, and cosmetically quite unsightly.
Perhaps the cosmetics may not matter to you when there is a back tooth being replaced one that is not visible when you speak or smile. An extraction site defect in an area visible when you speak or smile will create a severe esthetic problem. The more the ridge has changed, the more your tooth will need to be either longer, wider, or fatter in order to fill up the extraction site. If you have a smile line that shows the tooth or gumline, the replacement tooth will be very obviously misshaped. It will never look right and will be a cosmetic failure.
Here is a dental implant on a patient from Burbank that I did:
It is clear that for the dental implant replacement tooth to have a normal appearance, the extraction site must be rebuilt. The closer it can be made to the ideal, the better the replacement tooth will appear. The site (or ridge as it is really named) can be restored through gum tissue grafting and/or bone grafting.
If the ridge needs only a small amount of augmentation, only soft tissue procedures may be needed. If there is a large defect, the underlying supporting bone will have to be replaced as well. If the site is especially visible or needs an extensive amount of rebuilding, more than one augmentation procedure may be necessary. My goal is to make the replacement tooth appear to be growing out of the extraction site, not merely lying against the gum.
If a dental implant is to be placed to act as an anchor for the replacement tooth, the extraction site must have enough bone thickness and height to properly surround the implant.
Here is an example of a 20 year old girl from Los Angeles that I had to do an onlay bone graft and gum graft to fill the major bone defect from a roller-skating accident.
After a onlay block bone graft, implant and custom Abutment. Note how there is no longer a depression of bone after the bone is built back up.
As you can see, extraction site bone or gum defects are really important. Choose the right dentist for your implant!
Ramsey Amin, DDS