Not all extractions need bone grafts for dental implants. A socket bone graft is done at the time of extraction to preserve the bone from shrinking. If the tooth is extracted and left alone, the bone will literally just melt away starting at just a few days after the tooth is removed. The keyword for a socket bone graft is “preservation.” This is called “bone atrophy.”
Let’s review the pros and cons of socket bone grafting:
So how do you know if you need a socket bone graft or not? The most critical zone of the mouth where socket bone grafts are extremely important are all of the front teeth to the middle “bicuspids.”This is because the bone on the outer wall of these teeth is much thinner than it is in the molar region.
Keep in mind there is massive variation from person to person on how thick the outer wall bone is. Your genetics play a huge role here. Some people have naturally thick outer walls of bone and some people have naturally thin bone which does not do well for dental implants.
Patients that have thin bone tend to have thin gums too and are easily prone to recession around their teeth and or future dental implants. Patients that have thin bone and thin gums, have to be slightly overengineered in order to have long-term success with dental implants. Bone grafting for a person with a thin bone/gum “biotype” is always necessary. The outer wall of bone has to be designed in such a way that it is more resistant to shrinkage. This can be done by various surgical techniques and by using the right bone material for your particular situation. Not all bone is the same!
When the existing outer bone plate is thin, it is almost a guarantee that the bone is going to collapse as soon as the tooth is removed. This is because the tooth root is supporting that very thin wall of bone. So once the tooth is pulled, the bone collapses in order to close the socket. This leaves you with a depression of bone in that area. Without correction or prevention of that depression in the first place, an implant would have to be placed in a non-ideal position instead of in the center.
So what about the molars… those are the teeth that are extracted the most!! On many occasions the tooth being extracted has had a root canal. It may have abscessed and is painful. When an abscess occurs bone is often naturally dissolved the way on the outer surface. If the tooth being removed too infected, and has thicker bone, a bone graft may not be necessary or advisable at the time of extraction.
Ultimately the decision to do a socket bone graft for dental implant depends on the training, judgment, and experience of performing socket preservation bone grafting on a regular basis. Not only performing the procedure is important, but evaluating its results both on 3-D scan and how the bone feels at the time of implant insertion. And most importantly, how does this bone holdup long-term? I have personal experience of seeing the results of these procedures for the last 15 years as of 2014. The techniques that I use work well and last a long time.
Look for another post coming soon on membranes as that is a common problem area.
Ramsey A. Amin, D.D.S.
Diplomate of the American Board of Oral Implantology /Implant Dentistry
Fellow-American Academy of Implant Dentistry