Robert A. Horowitz is a Periodontist who maintains a private practice
limited to Periodontics and implant dentistry in Scarsdale, NY and New
York City. He is a Clinical Assistant Professor in the Department of
Implant Dentistry at the New York University College of Dentistry. Dr.
Horowitz is heavily involved in research, product development and
teaching. Our readers are also encouraged to also read a prior interview with Dr. Horowitz
in which he provided valuable information and clinical tips on
OsseoNews: Dr. Horowitz, you are a leading expert on alveolar
ridge preservation and ridge augmentation. How does this relate to
Dr. Horowitz: The most important lesson to be learned from the
literature, as well as from my own personal experience, is that when a
tooth is extracted, a bone augmentation or preservation procedure must
be instituted at the time of extraction.
OsseoNews: What happens if the tooth is extracted and no bone augmentation or ridge preservation is accomplished?
Dr. Horowitz: You can expect at least 30-60% bone loss within 6 months around the extraction socket. You can also expect at least 1mm loss of vertical bone height. These numbers are straight out of the peer-reviewed dental literature. That represents a tremendous loss of bone volume that could, if preserved, provide much needed support for implants.
OsseoNews: How serious can the loss of bone be in regard to Treatment Planning?
Dr. Horowitz: To put this in a proper perspective, let us consider a typical scenario. A patient is scheduled to have a maxillary first molar extracted and then replaced with an implant abutment and a crown. This is a situation that is commonly seen. If we extract the molar and perform a socket preservation procedure at the time of extraction, we will preserve the alveolar ridge height and width to a great extent. We may be able to place an implant and restore as planned without any further complications.
But if we extract the molar and a bone augmentation and/or ridge preservation procedure is not performed, the ridge will loose significant buccolingual bone width and vertical bone height within the next 6 months. A sinus lift or other ridge augmentation procedure may then be required to recreate adequate bone support for the implant.
Failing to accomplish bone grafting and ridge preservation at the time of extraction in the long run thus leads to a far more complicated and extensive procedure than preservation of the extraction socket volume at the time of extraction.
OsseoNews: If the Treatment Plan is for extraction to be followed by implant placement, the dentist should be prepared at the time of extraction to perform bone grafting and ridge preservation. If not, the implant site will become compromised and it will be more difficult to place the implants.
Dr. Horowitz: This is well documented in the literature and I see this all the time in my practice, as do ALL dentists who look for this. The goal is to produce the best possible circumstances for implant placement and restoration. In many cases this is as simple as performing bone grafting and ridge preservation at the time of extraction.
OsseoNews: Then it would be a serious mistake to extract teeth, let the sockets heal and then do the bone graft.
Dr. Horowitz: In many cases that would be true, depending on how long you wait after the extraction. You will often end up with a significantly compromised site for implant placement. At that point in time, the surgeon and patient are faced with more extensive and expensive procedures to replace the bone and soft tissue that have been lost.
OsseoNews: What is the best material for accomplishing bone graft and ridge preservation at the extraction visit?
Dr. Horowitz: There are a number of materials that can accomplish socket preservation. One of the best materials for this type of procedure is Cerasorb (Curasan), a tricalcium phosphate synthetic graft material. After the tooth is extracted, Cerasorb is delivered into the extraction socket and then covered with a barrier for 3-4 weeks. This is a new material which I helped to develop.
OsseoNews: How do you prepare the Cerasorb for delivery?
Dr. Horowitz: You mix the Cersorb with blood from the surgical site which is drawn up in a bulb-pipette. You can also mix the graft material with CALMATRIX (Lifecore) which is a calcium sulfate bone containing bone graft binding material. This gives the bone graft material the consistency of soft putty and makes it easy to deliver, maintain in the socket and at the same time enhancing its biologic activity with calcium sulfate.
OsseoNews: What kind of barrier do you place over the Cerasorb bone graft?
Dr. Horowitz: The selection of the barrier depends on the circumstances. Frequently I use CalForma (Lifecore), a putty-like formulation of calcium sulfate which sets even in a bloody field and sets over the graft material. In other instances, a non-expanded Teflon barrier membrane like Cytoplast (Osteogenics Biomedical) or TefGen (Lifecore) is placed over the graft. These can be easily adapted over the graft site, tucked under the periosteum and then the gingival tissues are sutured into place. These materials do not require primary closure which saves a great deal of time and effort. When you are ready to remove the barrier, you can do this without local anesthesia or a second surgical procedure. They come out more easily than removing a suture.
OsseoNews: How do you manage an infected socket? Suppose the tooth has an endodontic or periodontic lesion. Do you still place the Cersorb graft?
Dr. Horowitz: An infected extraction socket is not a problem. After extracting the tooth, the site of infection must be thoroughly debrided manually and possibly with the aid of a laser. After a thorough and vigorous debridement has been accomplished, the graft can be placed. The literature has clearly demonstrated that this can be done successfully.
OsseoNews: How long do you wait to re-enter the grafted area?
Dr. Horowitz: I wait 6 months to re-enter the grafted area. I want the graft to take and for healing to occur. Cerasorb is osteoconductive and a certain amount of time is necessary for new, vital bone to grow in the extraction socket. The grafted areas present with dense, healthy bone on re-entry. The Cerasorb material will resorb over time.
OsseoNews: Do you prescribe an anti-biotic regimen following grafting?
Dr. Horowitz: In most cases I will prescribe amoxicillin or clindamycin for 5-7 days post-operatively, beginning with the premedication dose recommended by the American Heart Association.
OsseoNews: What is the most frequent source of failure that you see with this kind of grafting procedure?
Dr. Horowitz: The most frequent error that I see is failure to isolate the surgical site. Contamination of the surgical site and graft material will likely lead to postoperative infection and failure of the socket preservation procedure. Additionally, if the surgeon who is going to place the implant fails to perform the extraction and grafting procedures, anatomic complications related to socket configuration and dehiscences/fenestrations may not be diagnosed. The areas of missing bone may delay socket healing and timing for implant placement should be adjusted accordingly.
Interview conducted by:
Gary. J. Kaplowitz, DDS, MA, M Ed, ABGD
Editor of OsseoNews.com