Wednesday, September 1, 2010

ADVANCED ALL ON 4 CASES

I’ve been doing the All on 4 procedure for about 15 years. Eventually it became a weekly procedure and now daily. During this time there are very few mitigating factors or complications I have not seen or treated. The biggest challenge with the All on 4 procedure is and always has been upper cases. At least 30% of the patients who come to see me can’t have it done on the upper without preparatory bone grafting.

The focus of my current studies is finding ways to make this easier and more predictable. Currently when bone grafting is required to prepare a patient for dental implants the procedure is delayed by 4 to 6 months and over 40% of all grafted sites experience less than a perfect result often times requiring some type of revision surgery and occasionally needing to be completely redone. Needless to say this adds time, expense, and inconvenience to everyone involved and better solutions are badly needed. The good news is that everyone realizes this. Regardless of what type of dental implants procedures are being done, single dental implants, full mouth individual dental implants, or the All on 4 procedure, adequate bone volume is always the limiting factor.

Tremendous resources are being dedicated to finding better solutions and indeed progress is being made. We can now synthesize proteins and stem cells in the lab that make bone substitutes almost as reliable as natural bone harvested from the patient. New and better techniques are being developed for the use of these materials almost daily. I attended a meeting in Hamburg, Germany recently and much was dedicated to this. I’m going to another one in October in Boston specifically to study new grafting techniques. All in all great progress is being made. But still, over 40% of all grafts have some level of complications. The problem with bone grafting for dental implants is not primarily with the graft materials. It is with the membrane, which looks like a sheet of paper, that the graft must be covered with prior to suturing the tissues over it. All grafts with the exception of autogenous block grafts, those taken from the patient, require this covering. There are literally dozens of different membranes on the market, each with its’ advantages and disadvantages, but they all become exposed too often. Exposure occurs when the tissue over the membrane develops an ulcer that creates an opening that will allow saliva and bacteria to penetrate into the surgical site. If this happens too early the graft is likely to fail and if it happens any time before 4 months, and it often does, the graft will be less substantial than initially desired.

The advantage of the new bone grafting materials is that they grow bone faster so the membranes don’t have to been maintained for such a long time. Though I haven’t experienced I have had colleagues tell me they have seen adequate results in some cases with only two weeks of membrane coverage. The advantage of the new bone grafting membranes is that when they do expose infection is less likely to occur and more easily controlled. I think however, that in the near term, the best solution is going to be the oldest solution simply done better; autogenous block grafts. In the past this has been a delicate procedure done by few and mastered by fewer. I did two of them today but only because I had to. In severe cases it requires both an oral surgeon and an orthopedic surgeon working together in a hospital setting. Amazing new instrumentation which allows the cutting of bone without risk to nerves or blood vessels is going to make this a very safe procedure which can be predictably performed by even the less experienced dental implantologist. The use of autogenous bone in areas where the tissues are delicate and most susceptible to ulceration and bone substitutes in areas where membranes can be placed without a high risk of exposure will provide enough bone without resorting to a hospital operating theater. And minimizing the need for membranes should dramatically reduce complications.

All things considered I see the potential for many patients to be helped who previously could not because the risk – benefit ratio was too great. And on a daily basis more autogenous block grafts will be used because new procedures and instrumentation make them simpler. I am confident that this will open the door for many patients who were previously not good candidates for the upper All on 4 prodedure as well as more routine dental implant procedures. It looks like another great year ahead with much to be learned and shared in the field of dental implantology.

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