Some observations gained from 20 years of intense implant dentistry

I took my first Brånemark implant course in 1984 in Toronto, Canada with Dr. George Zarb and Dr. P. I. Brånemark. To say that these courses were an eye opening event in my dental career is a gross understatement. I immediately realized that I want to concentrate the remainder of my professional career in the field of dental implantology, a realization that was augmented by my then recent achievement of Board Certification in Prosthodontics. And so for the last 20 years, I have made it my mission to master all phases of implant dentistry including implant prosthodontics, implant related laboratory work and finally implant surgery. To date, I have placed, restored and fabricated almost ten thousand implant units and have achieved a success rate which approached almost 100%. During this period, I have placed or restored almost every variation in implant design that has come across the market place using most of the techniques as they have become available. But admittedly, I remain a big fan of the original Brånemark design and technique.

It is interesting for me to contemplate the various implant and implant placement techniques that have crossed through my practice. It is interesting as well to look into the various advances that have been made in implantology over the years. There have been significant techniques in such critical areas as bone grafting which have enabled me to treat more patients with dental implants. There have been interesting advancements in terms of implant staging and prosthetic options that are available. The discussions that are prominent at meetings today on immediate loading, implant micro surface, delivery systems and overall implant design are fascinating as well. The problem is that many of these discussions and so called advancements are derived out of a means to sell m ore implants, not necessarily about how to make everything work better. I think that after 20 years in this field, I should comment specifically on some of these advancements and maybe try to put them all into perspective for the profession and, for the people who benefit most from dental implants, the patients.

As I stated, I have a very high success rate with dental implants. That does not mean that I do not have failures. Sometimes, I place an implant and it does not integrate. This is always of extreme interest to me because I most want to know why implants fail. I believe that in the early years, the biggest factor for failures was the learning curve, the technique of placing and restoring dental implants. Even fighting the learning curve, implants are still a very successful modality and in the beginning, it was not always easy to figure out what went wrong with the relatively small numbers of failures. At this point, however, I am confident that I can catagorize my implant failures as follows:

1. Contaminated surfaces
2. Avascular bone
3. Inadequate bone volume
4. Under-engineering (not enough implants for the given restoration)
5.Poor placement or angulation
6. Poor patient healing (Yes, I feel that one is a cop out, but....)
7. Infection
8. Poor fit of the prosthesis
9. Inadequate patient follow-up
10. Patient dissatisfaction with result

Since I began my implant odyssey, there has been lots of variations in implant design and technique introduced to the profession. Some of these innovations have clearly been motivated to increase sales and some have been well thought out to increase the applicability of dental implants to the restorative arena. My only consideration in evaluating these variations was whether or not they improved the success of what I was trying to achieve or if it made it easier to achieve that success. To tell you the truth, I have yet to find any variations in implant design or technique that do improve my results merely by virtue of the design change and to this day, I keep saying that if someone will give me an implant design that will improve my results, I would switch to it immediately. There has been some improvements, however, in the convenience of implant placement due to design and technique alterations. What I would like to do here is to discuss some of the “hot” variations that are available and give my interpretation of their relevance to treating patients who have lost teeth.

Implant Surfaces

When NobelPharma began manufacturing their original Brånemark dental implant, they had a patent on it. The patent applied only to the surface of the dental implant which was a machined surface (the result of milling an implant from a bar of titanium). When NobelPharma sued 3I for a violation of that patent, they lost. Very few manufacturers today use a machined implant surface. Research has shown us that a better way might be to specifically texture the titanium surface to make it more attractive to fibrin and osteoblasts. I agree with the theory, but to date, there is no specific surface micro structure that I can identify as yielding a superior result for my patients.

You have to understand that the dental implant is a very first step in bio-engineering a replacement for a tooth. In a hundred years or so when we can grow teeth at will (and maybe lots of other body parts) the dental implant will seem like a primitive attempt at tooth replacement. This is why all of the research and “developments” are important, but to date, the claims for superiority are baseless. Some companies in their zeal for increasing the bioactivity of implant surfaces have actually caused situations which increased failure rates significantly.

There is one surface that has very clearly demonstrated superiority in osseointegration. That is HA (Hydroxyl Appetite). We are all well aware of the bio-integration of HA, but we are also very aware of the potential problems with HA and it should be used very sparingly at this point.

Implant Shape

The original Brånemark implants were straight sided threaded affairs. They replaced a whole host of blades and subperisoteal frameworks and demonstrated clear superiority. They met Dr. Brånemark’s criteria for immediate stabilization and from the day they were introduced, the manufacturers have been searching for something better. There have been changes in the prosthetic connection and there have been changes in the actual shape of the implant. Today, we see a lot of tapered implants on the market. Are they better than straight sided implants? Not from what I have seen. They integrate the same and provide absolutely no anatomical advantage (despite some clever, inaccurate drawings), but they do go in faster and when they are seated, you know it. A disadvantage here might be that once you start inserting the implant, you are locked into a fixed end point which is not the case with straight sided implants. As far as other design parameters such as steps or tines or things that go “click” in the night, they are all clever and people always find justifications, but they don’t do anything at all to treat more patients successfully.

Internal vs External Prosthetic Connection

This is one that I don’t want to get into. Suffice it to say, I prefer an external hex connection. I have nothing per se against internal connections and if you or your dentist wants to use an implant with an internal connection, that is fine with me. It is personal preference fueled by implant manufacturers and the strength of some of the patents around. No one has ever demonstrated to me that one really works better than the other. And yes, I also prefer screw retained restorations in most instances....

Immediate Load

There has been a lot of information and technique considerations about loading implants with restorations right away. This is all despite the birth of modern implantology occurring in the realization that implants would work if we left them in an unloaded state for a specified period of time. Let me make this clear: you can immediately load some implant situations and they will work fine. I have done it many times and today my preference for placing single anterior units is an immediate non-loaded technique. But, guess what, you will have failures. Sometimes the failures can be attributed to poor case selection and sometimes to greed. Immediate loading is not what patients are asking for. It is what dentists and manufacturers are using to lure them into specific offices. It costs more and is not for the masses.

Delivery System

The best advances that I have seen are in the delivery system for implant placement. There is nothing that I enjoy less than attaching and removing a carrier from an implant. It is tedious in most systems and actually damages the prosthetic connection. Some of the new (and some of them are really not so new being around for a dozen years or more) internal drivers for implant systems are more convenient and safer to use. Some of them have yet to be proven out as being reliable.

Computer Aided Placement

Please understand that I think that the research and development of computer aided placement of dental implants is important to the profession and the future of dentistry. I just don’t think it is ready for prime time yet. Once again, a very complicated technique is being used for promotional purposes and therefor guided by greed. As someone who places and restores dental implants every day, I can’t see much use for this technology at this point.

PRP (Platelet Rich Plasma)

I think the use of Platelet Rich Plasma is a terrific thing... It is terrific for very advanced situations where there is not a lot of available anatomy to place implants. Over the years, I have gotten to the point where I can’t really conceive of placing implants without some form of bone grafting, but what I do day to day does not require or even benefit from PRP. What some of the oral surgeons that I work with who work on very compromised patients, some with significant oral carcinomas or deformities get out of PRP is amazing... Just not applicable to every day implant dentistry at this time....

Conclusions

In treating patients with dental implants every day as I do, it sort of becomes obvious what is important in dental implant therapy. The first and foremost thing is the cost and the availability of these treatments. There are millions of patients out there who need this kind of treatment and can’t afford it or have no access to it. We have to train more dentists, specifically the general practitioners, to deliver implant dentistry and we have to make it more affordable. We have to keep the techniques as simple as possible and avoid these overblown techniques and costs which make dental implants only available to the rich and famous. We have to be more generous about training our colleagues and sharing our technologies with them. Dental implants can be used successfully and efficiently to replace teeth. They can be cost effective and eventually ubiquitous... Pretty much the way that Dr. Brånemark intended.

S. Robert Davidoff