I am now placing DynaBlast, a demineralized bone matrix paste with cancellous bone, in most extraction sites. It is too often that I carefully remove a tooth, periotomes and all, and then have collapse of the cortical bone, especially the buccal plate. For implants, this is disastrous, but even for proper pontic site design under a FPD, one must maintain good bone contour. I recently took a perio course with Dr. Jan Lindhe who stated that there is 30% vertical bone loss and 50% horizontal bone loss at the alveolar crest during the first 3-4 months post surgery in a conservative extraction site. That means that even when clinicians maintain the bony walls of an extracted tooth with careful surgical technique, the healing site will show significant bone loss when we only rely on coagulation.
Those resorption figures will continue to slowely increase as time goes in an edentulous area. This means that your lovely ovate pontics will eventually trap food and you will lose precious bone arond the top threads of your implants. So I have begun placing bone graft into my surgical sights, sometimes with a membrane and sometimes without.
Let me review graft materials:
Autogenous Bone: Originally considered the best source for grafting; the procedure of taking bone from the patient from another sight (chin, tuberosity, hip) and then placing it in the defect.
Allografts: Freeze dried cadaver bone or from living human donors
Xenografts: Bone from nonhuman species such as cows (bovine bone)
Barrier Membranes: These membranes block epithelial and connective tissue cells from entering bone voids and thus allow bone cells to properly fill in these voids.
I buy my graft material from Keystone Dental (Massachusetts; 866-902-9272; www.keystonedental.com). Their products include DynaGraft-D putty and DynaGraft-D gel. I like the gel because it comes in a preloaded and paste filled syringe. It is easily and cleanly deposited into your extraction socket and slightly overflows at the crest. The putty is excellent for buccal plate defects around an implant. Once my material is applied as needed, I then place the extracellular membrane known as DynaMatrix over the surgical site and suture it in place. This membrane is also an allograft and the manufacturer receives its donors from tissue banks. Although this membrane is strong enough to be either sutured or tacked, I will usually use silk sutures to anchor it down. I have been shying away from chromic gut because in my hands, silk is easier to manipulate and will hold the membrane snugger. The patient will return in 7 days for follow up and I will remove the stitches.
It seems that Xenografts like Bio-Oss made from cows are more in use than the Allograft that I use. I haven’t used Bio-Oss so I can not comment on which is better. I can say that when my patients return months after the graft has been placed, I see a nice wide, tall ridge, and I am happy…they usually are too with the restoration that follows.