The development of Teeth-in-an-Hour

Transcription

1 The development of Teeth-in-an-Hour Interview with Daniel van Steenberghe, DDS, MD, PhD, Drhc, HFRCS (Dubl) by Christina Darle Daniel van Steenberghe Professor van Steenberghe is the President of the School of Dentistry, Oral Pathology & Maxillofacial Surgery at the Catholic University in Leuven Belgium. There he is Professor of Anatomy and of Periodontology, as well as holder of the P-I Brånemark Chair in Osseointegration. He is the past president of the European Academy of Osseointegration, of the Continental European Division of the International Association of Dental Research, of the Belgian Society of Periodontology and of the Dutch Society of Oral Biology. Professor van Steenberghe has been an invited lecturer in more than 40 countries and has published extensively, authoring or co-authoring over 250 full scientific papers and textbooks. I met him after his lecture at the Nobel Biocare World Conference in Las Vegas 2003, at which time the participants were able to view two live surgeries utilizing what is currently called the Teeth-in-an-hour concept. Professor van Steenberghe, you were the initial driving force behind what turned out to be a fantastic treatment concept. Please tell us how it all started? It is true that first now do people realize what we have developed starting some 7 years ago thanks to the Brånemark Chair and the enormous input of several partners - especially our Engineering Department. I originally thought about navigation I wanted to do something with direct, transferable imaging - but soon found that this was not practical for the time being for the oral situation. Patients are moving their jaws, which contrasts with neurosurgery where the reference points can be screwed on the skull during general anesthesia. So we moved to drilling templates and finally this. It is the merit of Dr Matts Andersson (inventor of the CAD/CAM Procera technology) to have understood that our ideas were perfectly compatible with Procera. Nobel Biocare therefore Matts Andersson became extensively involved. The story proves that progress is often unexpected, which is called serendipity. How does it work? The patient is completely treated in two visits (excluding the planning phase). First a CTscan is taken of the patient s jaw then one of the prosthesis alone. These two images are then fused together utilizing a 3D-software on a laptop computer developed here at the Leuven University. It should not be confused with some commercially available implant planning systems that are 2,5 D. 1

2 The resultant image of our software takes into account the prosthetic reconstruction as well as the bone factors. You can see in this virtual reality exactly where implants can be optimally placed and which implant lengths to use. A model is produced using the Procera technology. It is used by the local dental technician, who delivers a drill guide in which high precision sleeves fit - as well as the prosthesis in time for surgery. All surgical components are delivered on basis of the CT-scan derived 3-D planning. That means that both the surgeon and the general dentist have everything they need in time for surgery and placement of the prosthesis immediately thereafter. CAM planning images above. CAD image below where you can see the bone behind the translucent prosthesis. 2

3 Please briefly describe the surgery? After adapting the drill guide on the jaw bone in a first series of patients, we have now opted for placing it on the gums to allow "flapless" surgery. This drill guide is stabilized in a precise position using three horizontal fixation pins that are drilled in the jaw bone. A drill is then used to remove the gingiva at the implant locations. The normal drilling procedure involves the use of 2 and a 3 mm twist drills. Two implants are installed first, one on each side. The remaining implants are then installed in series. Fixture mounts are placed to prevent tissue collapse around already installed implants. The template can then be removed. This surgery takes less than an hour for a full jaw with even 8 implants. The placements of the abutments is done together with the final prosthesis - which is screwed into place using a manual torque controller that tightens to 35 Ncm. The abutments are uniquely self adjusting when they come in contact with the implant assuring perfect passive fit. These abutments invented by Izidor Brajnovic at Nobel Biocare - do not pull the bridge down toward the implant. Needless to say, the most essential aspect is the correct placement of the initial template. And as stated, the whole procedure requires two patient visits. That means the patient leaves the surgery with the final prosthesis in place? Exactly. It is truly immediate function. If a prosthesis is installed after one week - one should call it early function! Anything unusual about the prosthesis? This is not my expertise since I am a periodontologist, but it looks just like a regular Procera bridge. Yet the framework is made of fiber-reinforced carbon a material that is more rigid than steel. This is important to achieve uniform loading of the implants, which will be immediately functional. We also instruct the patient thoroughly not to exert important chewing forces during at least two months, just like we do with fracture healing of a leg. 3

4 How did it feel to watch the two live surgeries that were broadcasted to Las Vegas - performed with the Teeth-in-an-hour technique? Obviously I was a little nervous considering the participants in the audience. But I had complete faith in the surgical teams of Dr Peter Moy in Los Angeles and Dr Ingvar Ericsson in Sweden. I think people were impressed with the fact that the whole procedure took 30 minutes in Los Angeles (upper jaw) and 22 minutes in Sweden (lower jaw), the latter harboring less implants. It was important that the audience saw the patients directly after surgery. Since this was broadcasted as well - and the patients answered questions immediately - I was satisfied. It proved beyond a doubt that the treatment works extremely well. And it warmed my heart when the surgical teams received standing ovations from the audience. What did the patients say immediately after surgery? The first patient said the worst part was the drilling because he could hear it, but all in all it was no worse than a dental treatment. He even stated This is the greatest thing ever, I have teeth! Another patient who had been previously treated accepted to testify on stage. I was reluctant to do this, but when I heard how much she wanted to testify - I accepted because if done in a dignified manner, this testimony could be inspiring to many clinicians. She said she took painkillers for one day following surgery on Friday and then went to work on Monday. The second patient sat up in front of the camera after undergoing live surgery - stating it was painless, quick and easier than she had anticipated much like an extraction. She was asked why she had agreed to the immediate teeth procedure and she answered Because I wanted my teeth right away. I like to eat and enjoy life. She waved to the audience in Las Vegas. It was a great moment. What studies have been made of the concept? Well, we first started with a cadaver study to make sure the procedure worked and that the precision was sufficient. It was even better than anticipated. Then we joined together with Nobel Biocare, a company I am glad to say has the patience to wait for the clinical results. This cooperation between industry and academia has evolved into a large scale clinical study in which again Matts Andersson has been very instrumental. Then we published a prospective study 1 of 10 patients with an observation time of up to 24 months. All these patients still have perfectly functional prostheses. Since then, more than 30 patients have also been operated in Sweden, Australia, Switzerland, USA, etc. To date, we have seen no prosthetic failures. As for the implants, it is too early to say because too few bridges have been removed to assess the individual implant stability. What is the status now? If everything goes according to plan, the treatment should be sufficiently documented for large scale use by the end of this year or early next year. What do you see as the major advantages with Teeth-in-an-Hour? First of all, I do not like the name you use. The concept was called Litorim, evoking IT, stereolitography and immediate function; but I have no idea which trade name will be finally chosen by Nobel Biocare. The main advantages besides time saving are fourfold: First of all, the surgery is meticulously planned and it is prosthesis-oriented. Limiting my clinical activities to periodontal surgery, I always understood that the general dentists or 4

5 prosthodontist, like Professor Naert who heads our Department of Prosthetic Dentistry have slightly different endeavors than we surgeons. Secondly, since everything is computerized - a clinician is also able to conduct teleconsulting, i e to send the planning over a network for expert opinion. The same is true for the Procera network and the laboratory. Thirdly, the drilling templates with the sleeves are of utmost precision, which allows implant placement also in narrow bone ridges. Finally, the surgery is flapless - which means less trauma for the patient. The time saving is enormous. All in all, a classical treatment takes 9 hours, whereas the new concept (including planning and CT-scanning) takes 4 hours. Any final comments? I think one should never forget that with a staged approach, as originally developed by Professor P-I Brånemark, we obtained so far the best results, e g 99% cumulative survival rate after 15 years in the edentulous lower jaws. 2 Thus one should always have arguments, there regularly are, before choosing the immediate loading approach rather than the two-stage treatment. References Christina Darle is a freelance writer at WordPower in Mölndal, Sweden wordpower@swipnet.se 1 van Steenberghe, D, Naert, I, Andersson, M, Brajnovic I, Van Cleynenbreugel, J, Suetens, P. A custom template and definitive prosthesis allowing immediate loading in the maxilla: A clinical report. Int J Oral Max- Fac Impl 17: (2002). 2 Lindquist L, Carlsson, G, Jemt, T. A prospective 15-year follow-up study of mandibular fixed prostheses supported by osseointegrated implants. Clin Oral Implants Res 7: (1996). 5