It’s really boring. You’ve got to sit there, and you watch this thing slowly going in. You know, great, next. Let’s get going. It’s just the nature of you, and we have to patience. We want everything done right away, but it’s absolutely critical that you do that.
The drills that they use is very critical. We use new drills for every patient because if they’re new drills, they’re sharp. If they’re sharp, they’re going to cut efficiently. They’re not going to generate heat. So, you don’t want to get cheap and use recycled drill that’s been sterilized again because it may not be cutting as sharply as a new drill.
So, those are important parts in the atraumatic portion of the surgery and the period of healing without loading on it.
Before osseointegration became popular, which start in North America in 1984, 1985, the Swedes were very good about this. They did not, in fact, let the rest of the world know about it until they had treated patients for almost 10 years, and had a long-term success before they published any data in their literature that everybody else could read. Basically, they were being conservative. They wanted to make sure that they had a process that worked because dental implants, as I told you before, were fraught with failure.
There was no dental implant system that was predictable. Every dentist around had tried something. You can see how crazy this person must have been. This is like modern art. We can hang it up in MOA downtown. It’s job-owned. They made a casting out of chrome cobalt metal which is now being placed under the gums and teeth put on it, and these things never worked. Their 5-year success rate was less than 30%.
The people still went through and had these things done because they had no alternative, and there were about 20-30% of the patients that they worked for about 10 years but were really not successful. The downside or the reason why these different implants did not work was primarily because (a) they were not made out of titanium, (b) the surgery was not done atraumatically (it was quick), and (c) the teeth were put on it right away. It didn’t give it a chance to allow the bone to heal on the surface of the implant.
All of these failed, and if you go back historically, you can see all sorts of shapes and sizes and materials that we used. They had different names to them but were really, really unpredictable. When I started my residency in 1987, we actually spent more time treating patients where these had to be taken out than the osseointegrated implants that we were putting in there because of the problems that these created.
The other interesting thing that this group did with osseointegration was they standardize the whole process. They made standard-diameter screws. They made the system predictable. You would just go and buy it. If you look at it and say, it’s pretty crazy to have a screw fits all. It’s really not predictable for patients with different dimensions of bone and different requirements, but that’s what they started out with.
They started out with that because the patients that they were treating initially for their first 10 years were patients with no teeth at all and had trouble with their lower dentures. They almost could not wear the lower dentures, and so they said, “Let’s try and use a new technology to test it on people where we have no other option.” If it works for that group of patients, which is what happened, then these systems were modified to adapt them to other clinical scenarios like we have today.
So, these screws were basically 3.75mm in diameter, and they came in different lengths. In the early days, they were actually only in 7, 8.5, and 10. That’s all they made because they were little old ladies whose jawbones were pretty small. They resorbed a ton of weight. They’ve worn dentures for 20, 30 years, and nothing remained.
This was the first screw that was put in the jawbone, and then the second step was to connect a cylinder of some sort to the implant that then came through the gums into the mouth. The teeth were made and attached at this level. It was a pillared system. There was a screw that went into the bone. There was an intermediate component that attached this implant and brought it to the gum into the mouth, and then you made the tooth that got attached to that. That was the system that was done originally.
Now, one of the changes that modified this from us using it in patients who had no teeth at all was what was still today, and it was done in 1990. It’s called the UCLA abutment where the intermediate part was actually eliminated, and you could make a tooth by using this plastic part that you then waxed and made a tooth out of gold or porcelain that could be directly screwed to the implant like that one tooth X-ray that I showed you in the mouth. That’s what it was like, and you’ll see more of these in a bit.
Talking about clinical applications. We’re going to split this up into three categories: the edentulous patient (that means somebody who was not teeth), partially edentulous (they’ve got a few teeth), and then we also use them in our cancer patients who are missing more than just teeth and major parts of their jaw structure. This is what we’re talking about where somebody’s got a large facial tumor and has lost a lot of structure. We’re trying to use these screws to help anchor some sort of prosthesis and make them presentable in society.
When we look at the patients who have no teeth, it’s important to know what the success rates are, and if you look at these success rates that was a 15-year follow-up that was published from the original group in 1981, they claim the success in the upper jaw was 89%. The success in the lower jaw was 100%. That doesn’t make sense does it? Nothing in medicine and dentistry is 100%. It can’t be.
They have these and other numbers in parenthesis. What they were trying to tell you was that if somebody in the lower jaw was missing all their teeth and they put five screws in this person’s lower jawbone or five implants, that patient may have lost one implant, but if four remained, they were still allowed to give them the teeth which was the original objective of the treatment. So, you could provide teeth on four implants instead of five, and therefore, it was considered a success.
Am I clear to everybody about what’s going on there with the success? So, if you put 100 screws in somebody’s jawbone, only 91 of those screws really took. Nine of the screws didn’t take in the lower jaw, but because they were spread out, they were not all nine in the same patient, there were enough in one patient to allow them to give the patient teeth which is what this patient came in for.
In the upper jaw, that was not the case because in the upper jaw, only 81% of every plant that was placed was successful. So, 19 out of every 100 were lost. You could end up with a patient who put four or five in, and all five were lost in that patient and they couldn’t get a prosthesis. So, the success rate in the upper jaw was 89%.
Why does that happen? Well, two reasons. First of all, the upper jawbone is a much, much softer jawbone as compared to the lower jawbone. The lower jawbone is much denser and harder, and therefore, it provides a greater chance for the implant to be stabilized and held in place, a critical part of it.
The second part is that in the upper jawbone, we have these sinus cavities that come down, and you have your nose in the middle. When you’ve lost a lot of jawbone, there isn’t a lot of area remaining for us to put implants in. You end up with shorter jaw implants and fewer numbers. Therefore, they were not as successful.
In the lower jawbone, typically, if you were to go between where my two fingers are right now, there’s a nerve that comes right about here. It’s called the mental nerve. Between those two areas, there is no anatomical structure that’s going to limit you from putting the screw in there in majority of the patients. Therefore, you can get enough numbers of implants that would allow you to have a successful result.
What are the type of the teeth that were made for these patients who are edentulous? We break them down into three terms: a hybrid bridge—this was what traditionally done. Teeth that look like this; teeth on stilts. Titanium coming through the jawbone, and then teeth screwed on to that. A very primitive way, but that’s what was used in the early days and even today in some of the patients in the lower jaw.
This doesn’t work very well in the upper jaw because what happens when most people smile and laugh? They show their teeth. They show their upper gum. You typically don’t show your lower teeth. So, if you had a scenario like this in your upper jaw, you’d be blowing bubbles of saliva at your guest. It wouldn’t be very friendly. There would be spinach that would be stuck, and it would be showing and not so aesthetically. Therefore, we really didn’t do these kinds of prosthesis in the upper jaw.
We’ll show you what we did in most of those patients so you can understand what the differences are in the type of the prosthesis. Take you through some of the steps involved. This is the lower jaw treated in the traditional manner where there’s five implants, so five screws, that are coming in to the mouth. This is the second part already attached. Remember that pillar system that I showed you coming through the gums. We have to attach some metal pieces on there to actually make a mold so we can capture the position of these. We need to be able to generate a model of some sort because we can’t make the teeth. We can’t weld stuff in your mouth. We got to do this outside.
So, things have to be made outside so we have to accurately replicate this position on a stone model or a plaster model that we can then go make teeth on. Try them on, and then make sure that they’re successful. We first try the teeth in the mouth to make sure that the bite is correct. Based on that, we then have to make a metal structure that’s cast that fits the implants, and then, the teeth are actually bonded or attached to that metal structure.
So when you look in the mouth or an X-ray here, you see the implant part A, part B that comes through the gum into the mouth, and part C, the metal casting that which the teeth are attached. It’s quite an elaborate process which takes a lot of time to do. Typically, doing something like this is going to take seven appointments after the implants are ready to be used, and they’re about a couple of weeks apart and a lot of time and effort in the lab and expense that goes with it. When it’s finished, this is what the patient ends up looking like, and most of these patients are actually very pleased with the outcome that they end up with.
Now, I said to you that these hybrid bridges wouldn’t work very well in the upper jaw, and I also showed to you that there were five implants that were placed. What does that do? Well, it’s a number of things. Sometimes patients, medically, are not candidates for extensive surgery, or the costs of putting five implants in and making that superstructure may make that treatment something that is not realistic for them.
So, what other ways can we use the implants to provide this treatment to a larger group of patients? This is what happened in North America. We were very good, in those days, at saving one or two teeth on patients and using them to anchor a denture. So, instead of having a denture sitting and floating around the gums, if we could keep two or three roots, we would hold on to them. They were called overdentures because we were keeping some of the roots, and keeping the roots helped maintain the bones. We felt, why can’t we use that concept with implants?
