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Feature Article:

Implant Paradigm Shift:
A General Dentist’s Experience

I’ve been in practice for 24 years, so it may be hard to believe that I actually “grew up” with implants. Not osseointegrated implants, but implants nonetheless. I studied dentistry at Loma Linda in the late seventies, and I was able to spend considerable time with a certain Robert James. At that time implants–blades and sub’s-- were a curiosity, at best. Many of my classmates thought our dabbling with endosseous blades was simply malpractice. After all, they all failed at some point, didn’t they? But I hated anything removable. I was quite surprised to learn during my training that we really didn’t have anything better. The blades seemed to work in mandibular free-end situations. But they were quite primitive–they had a “manageable” fibrous attachment, only had a single restorative fixture, and the bridge was usually fastened to remaining natural teeth, typically bicuspids. They were interesting, but difficult to place, and not totally predictable.

As the Swedes (read: Branemark...) invaded the States with their “commercially pure” fixtures, I was still left out on the periphery. Their classic application was the fully edentulous patient with a reasonably decent upper denture, and a poor mandibular situation...but most of my patients were fully or only partially edentulous. The Swedes demanded multiple fixtures; most of my situations were missing one or two teeth. When I did restore these implants, I found myself at the mercy of the surgeon regarding placement. To make matters worse, the implant’s restorative design was marginal–a short external hex, no retention to speak of, and total dependence on screw retention. No wonder cement retention was frowned upon–screws routinely came loose whether they were under cement or not!

I distinctly remember my first exposure to the the ITI/Straumann system. I was at a Branemark lecture. It was a fully edentulous case with the Swedish fixtures and the ITI’s were used as temporaries! That’s right, the “real” implants were the Branemarks, but there were these strange Swiss fixtures that stuck right thru the gingiva and were immediately loaded to boot! (Little did they know just how prophetic they were being). The ITI fixtures of course, were thought little of by the experts, but they seemed to be good enough for the short term. I didn’t hear much of what they were saying about the Branemarks, but I had a bundle of questions about those strange Swiss “temporary implants”.

The next time I heard much of anything about ITI’s was when our academy flew Daniel Buser out from Switzerland to talk about them. The first thing that caught my attention was that the system was originally designed for single tooth replacement(1). Finally, a system for where I lived and practiced–a system for people with just a few missing teeth! It was also much simpler to restore, and with the Morse taper taking the load, much more reliable, restoratively (no loose screws).When I discussed the system with my oral surgeon, he informed me he was already involved with five other systems and he didn’t want to get involved in a sixth. Fine, I thought, I’ll do them myself. (2)

It was late 1996, when I started studying in earnest to bring the system on board in my office. At that time, immediate placement was in it’s infancy, osteotome sinus lifts didn’t exist, and the usual routine was to extract the tooth, graft the site, wait six months, then place the implant. I still recommend that newcomers to the system start that way. When I started, I thought this would be the answer for those free-end situations and the like....I used implants when I had to....you know, when all else has failed.

What I didn’t anticipate was just how the way I think about implants was going to change. That’s what a paradigm shift is–it’s changing the way you think. How did I use to think? I was proud of the fact that I had embraced the “keep your teeth for life” so common at the time. I mean, your calling doesn’t get any higher than that does it? Until 1997, I would always encourage my patients to get the endo, get the perio surgery, get the expensive restoration because it saved the tooth. Damn the cost, we were too idealistic to even think about value.

The shift didn’t come slowly for me; rather, it ran over me like a fully loaded dental supply truck on it’s way to a convention. The first “wake up” was looking honestly at my bridge failures. I mean, hey, I wouldn’t do a partial denture, only fixed was good enough for me! But some of my fixed, even short little three unit bridges, failed. Oh, it would take a little time, but they would fail. Think about a failing lower first molar (failing for what ever reason). You take it out, prepare a bridge from second molar to second bicuspid and all is well. The second bi had a large DO amalgam, but you get enough subgingival retention on the tooth and it’s ok you think.... Then, two years later, the bi develops pulpal symptoms and you do a root canal. And you access the root canal thru the occlusal of the bridge retainer of course, to save the patient the repeat cost of the bridge. Maybe you even do a post/core thru the occlusal just for good measure....and it works...for awhile...

Three years later, at a cleaning exam, the patient casually mentions that there’s this occasional “bad taste” emanating from the second bi. You know what that means–the retainer/post (usually not just the retainer) has separated from the root. Now, if you’re really stupid, (like I was, pre-97') you would recommend removing the bridge, redoing the post, possibly redoing the root canal (assuming decay hasn’t totally wiped out the tooth )and placing a new bridge, now grabbing the first bi for a double abutment in the front. If you’re stupid, that is.

About this time, we as a profession, started doing retrospective long term studies on fixed bridgework. Or, maybe, I should say, we (3) started paying attention to these studies. At least I started paying attention. Why? Because I finally had an alternative to the bridge. When you don’t have an alternative to a given treatment, you tend to think of that treatment as the final word. Generally, three unit bridges have a 15–20% failure rate by seven years. Well, for the most part, I stopped doing bridges. Now I place an implant, and leave the other teeth alone(4). And there are many other applications besides just using an implant to replace a missing tooth.

How about using an implant, well, earlier? Think about this all to common scenario...A patient presents with a maxillary first bicuspid that is painful to bite on. There’s an MOD amalgam in the tooth, and if you look carefully after removing the amalgam, you’ll typically find some sort of crack, either going obliquely out to the lingual or buccal, or going apically down to the pulp (The diagnosis is “incomplete crown fracture”...to be official.) The tooth has symptoms, so you typically recommend a root canal, possibly a post, and a crown. You also note that the roots are quite narrow and spindly...If you decide to “save the tooth”, you end up with what I term “over-restored tooth syndrome”. These teeth, typically maxillary first bicuspids, maxillary laterals, and other small rooted teeth, are a major part of my implant practice. If you choose to keep the tooth and restore it, it will last a little while....maybe up to several years, but they will fail. The usual failure is either a split root, or the post disconnecting from the root.

Here’s another paradigm shift...why not forget the endo, post and go directly to the implant? In my office, the endo, post and crown is about $1700. And this is for a treatment that has a good chance of fracturing within the first ten years. For $2400, I can place the implant usually at the same time as the extraction, and later, place a crown. The implant at least, will probably be there when the patient is buried: a much better value for what is actually less chair time.

Now let’s go to the anterior area, and see how implants have affected our thinking...
Years ago, I remember a perio/implant lecture entitled, “It all starts with endo...” I remember thinking, boy, this is one periodontist that just can’t stand endodontics. Later, I started to agree with him...It does all start with endo...well, most of the time, is starts with an impact...

A front tooth gets hit, by a child’s head, a dog, a ball, a tool...it doesn’t matter, the tooth is hit. It loses circulation, the nerve dies, it gets an endo. If the tooth wasn’t hit too hard, a lingual resin, maybe a little incisal restoration, and the patient is “fixed”. Right. Maybe. If the tooth was broken, maybe an Ellis Class II, then it’s endo, a resin for awhile, then eventually a crown...and if there’s an endo, a post is probably placed. It lasts for years. Well, ten years, maybe fifteen, then something lets go. Usually, the post and crown stay together, but separate from the root. Now what?

The enterprising dentist may go to ortho to get some crown length, or maybe to perio for formal “crown lengthening” . Now it’s time for another paradigm shift. Crown lengthening? Doesn’t that remove bone? Don’t we want bone for implants? Yes. I mean no–no crown lengthening. We can do ortho if we need to bring bone coronally, but with our tapered implants, we often can get a good enough fit to avoid that. Now, we can extract the tooth, place the implant, and assuming we have good primary stability, place an abutment and a temporary–all in one visit. If you’re a surgically oriented general dentist, your patients will love the service–a whole new tooth–root and crown–in one visit, and in one office.

Another part of the ‘shift’. I call it the “spread-the-load” paradigm. We’ve all seen the situation of “my mouth is falling apart”. We reassure the patient this is not the case, but sometimes, it is....tell me you haven’t participated in the following scenario...

A patient fractures a tooth. It doesn’t hurt, they don’t take care of it, and they shift their chewing to some other part of their mouth. Then something else breaks, in that “other” part of their mouth. Now they see you, and before you can get them back in, another tooth breaks, but this time, even you’re surprised–it’s tooth you thought was otherwise ok, and it fractures...what’s happening? The load is concentrating. As long as the load was spread out, the oversized amalgams, the MOD resins, the endodontically treated teeth with little remaining natural tooth structure, and even the MO amalgams with distal marginal ridge cracks–they all held up well. Then one tooth broke, and the load isn’t spread anymore, and it starts to concentrate. If there’s missing teeth, the effect is magnified. And the teeth, happy when they only had to carry their own load, refuse to carry more, and they fracture. The answer? Re-spread the load with implants, get the excess load off the teeth and return the teeth to their original loading. The paradigm shift? You look at the mouth thinking about placing implants with the express purpose of getting load off teeth. The old paradigm, incidentally, did just the opposite...as teeth were lost, you’d simply use the remaining teeth to hang FPD’s and RPD’s on till you were left with a complete denture.

I’ve heard a number of implant dentists who talk about replacing teeth only from the first molars on forward, because “most people can survive nicely with first molar forward occlusion”...I emphatically disagree. God gave us second molars to spread the load. Not having second molars is like not being able to use the part of the nutcracker closest to the hinge–the best part, with the most leverage! I replace missing second molars with implants. It gets the load off the remaining teeth, and makes everything last longer. ITI has led the world with short implants–there’s nothing wrong if you can only fit an 8mm fixture back there, and most importantly, it’s way better than nothing at all.

One last application of the “shift”: deciding when to call it quits with periodontally involved teeth. In the late 1990's, new info started coming out about the relationship of periodontal disease to implants, or rather , the lack thereof. It was hard for those of us who were taught to avoid implants with advanced perio patients to “unlearn” the falsehood. I’m talking about refractory perio patients and “stable” patients who over years, slowly lose bone in furcal and other posterior interproximal areas. Here, we have what I call the “Ten millimeter Rule”.

Ten millimeters. That’s the limit. On the mandible, it’s ten millimeters from the crest of the bone to the top of the nerve. Any less than ten, and the tooth comes out, and an implant goes in. With the maxilla, it’s measured from the crest to the sinus floor. Now, I have to admit, this has been the hardest “shift” for me to make. These patients are generally asymptomatic, but we need to realize, they are continuing to loose bone, in spite of our periodontal recalls, treatments, and oral hygiene. Patients with periodontal disease that’s progressing, in spite of all your efforts, are the prime candidates. And these patients are everywhere in everyone’s practice, whether you’re a periodontist or generalist. The hard part is making the decision and “calling it a day” on a given tooth or quadrant. They’ll look asymptomatic, but when you look at the history on the perio chart, you can see it’s losing ground. And “losing ground” means losing bone. Which, for an implant dentist, is akin to losing life itself, because bone is where we live and die. I think it’s hard for me because I was raised with the belief that periodontal disease could affect implants (wrong) and I still subconsciously revert to my old ways. The fact is that bone loss ceases with implant placement. If it’s bone we’re trying to save, implants save it, and teeth (with refractory perio patients), make it melt away. That’s the facts. Believing it and acting on it is the harder part.

So let’s summarize the new implant paradigm. When teeth fail, we place implants, not bridges. We try to place them immediately–at the time of extraction-- to preserve tissue and bone. We think of implants before other options because of their incredibly high success rate and their cost effectiveness, when compared to “saving teeth at all costs”. We think of implants instead of saving teeth, when we risk “overrestoring” the tooth; the smaller the tooth, the more we think about an implant. We place implants, as many as necessary, to get loads off of natural teeth to make them last longer. Finally, we replace periodontally slipping teeth, before they’ve lost so much bone that an implant isn’t possible. We don’t wait till expensive grafting is the only way to replace the bone. It’s much, much cheaper to avoid the bigtime graft by choosing to get the tooth out when there’s still adequate bone.

A new way of thinking? Yes. As hard as it may seem, there are times, now, many times, when saving a tooth, isn’t smart. We need to relearn dental rehabilitation now that we have so much available with implants. Yes, there really are people out there with ATD(5), we just need to diagnose and treat it....

Dr. Guy Giacopuzzi, D.D.S.

Notes

• 1.  The Branemark system was “adapted” to single tooth use; it was not designed for it initially...
  
  
• 2.  Please don’t think I took implant surgery lightly. I was already accomplished with perio surgery, periodontal regeneration, minor oral surgery, and intravenous sedation. I had a pretty good understanding of bone physiology too, so the step wasn’t that big for me, especially with the back round from Bob James...
  
  
• 3.  “we”, meaning implant dentists...
  
  
• 4.  Especially if the potential abutment already has endo. Absolutely no bridges on endo’d teeth in my practice...Unless you like re-doing your dentistry....
  
  
• 5.  Acute Titanium Deficiency–a condition in which a patient has a need for an implant, but has not yet received one....