More and more people have dental implants, and that number keeps growing. But is it always the best option for patients? To reveal why some implants are problematic, Kirk Behrendt brings back Dr. Bill Robbins, co-founder of the Global Diagnosis Study Club, to make a case against some of the most commonly placed implants in “younger” patients. It’s the way we’ve always done it, but there’s a better way! To unlearn what you’ve been taught about implants, listen to Episode 616 of The Best Practices Show!
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Links Mentioned in This Episode:
Learn more about Global Diagnosis Education
Register for the Global Diagnosis Education Symposium (September 7-9, 2023)
Sign up for Dr. Robbins’s lecture “My Failures and Lessons Learned”
Don’t get stuck in the “that’s the way we’ve always done it” mindset.
Understand why certain implants will inevitably fail faster.
In some cases, implants should be the last option.
There are better options than implants.
Treatment plan for the long term.
“Dentistry can be a fairly dogmatic discipline. I’ve seen that through my 50 years, that people learn some piece of dogmatic information, and they learned it maybe in dental school, and they’ve continued to believe it, repeat it, and do it dogmatically — and they’ll fall on their swords for it. That’s true, especially with younger dentists. They come out of dental school. They believe that they had a great dental education, and really wonderful faculty, and because their faculty taught them that, it’s got to be true. And it may not be true, or it might be partially true. But they live with that partial truth for the rest of their lives, and they never really are open to asking the question, ‘Is this really true? Is this really the best way to do it?’” (5:32—6:23)
“Implants have been available to us in our profession for about 40 years. As we all know, they’ve been incredibly successful. It has become the go-to way to replace missing teeth all over the mouth, and certainly in the anterior maxilla. Through my many years of being involved in the placement of implants in the anterior maxilla, I have become more and more reticent to place them in the anterior maxilla, for reasons we’re going to talk about. In the last five or six years, my statement has become this: I do not treatment plan single implants in the anterior maxilla in the young adult.” (7:08—7:56)
“I’m still fairly active in my practice, and I get referrals commonly from a patient or a dentist who has told this patient, generally an orthodontist, that, ‘We’re going to align your teeth to your implants. When you get to be 18 or 19, you’ll go see Dr. Robbins. He’ll put an implant in, and that will replace your upper missing lateral incisor.’ That’s what I did for many years. And then, I started looking at some of the long-term results of my implants in the anterior maxilla. About ten years ago, I started developing a concern about this. And, by the way, I’m not unique in this. We’re starting to hear more and more from the podium speakers saying, ‘We need to take a closer look at implants. They’re not doing as well as we thought they might be doing long term. We need to be a little bit more analytical about the placement.’ So, I’m not the only one that’s saying this. I’m just one of the ones that’s carrying the banner right now.” (8:03—9:06)
“I started making the transition away from replacing especially maxillary lateral incisors. It’s a very common tooth to be lost for two reasons. First of all, it’s the second-most common tooth to be missing, genetically. It’s just not there. The other is trauma. It’s a very common tooth to be avulsed and lost during those formative years between the years of, say, eight to 14. I used to replace those lateral incisors routinely with an implant. I had concerns about it, but we didn’t have a good solution to the problem until a number of years ago. For me, it was about six or seven, and that is the bonded bridge . . . The bonded bridge has become my go-to replacement for the maxillary lateral incisor.” (9:07—10:07)
“We were traditionally taught that using either wrist films or serial cephalometric X-rays that are overlaid over each other, starting at about age 18, you could tell whether or not a person’s growth was complete. Once you can confirm that their growth is complete, then you can feel comfortable placing an implant. Generally, that was in the range of age 18 for females, and around age 21 for males. Those were the common ages that we were given. And so, we were told you can do these wrist films or cephalometric X-rays that are overlaid to determine if it’s now finally the time to place the implant. Well, it turns out that neither of those are predictors of whether or not growth is complete.” (11:30—12:17)
“This is a lovely young woman in my practice that was 20 years old. We confirmed that her growth was complete, so we placed an implant in the number seven site replacing a lateral. She was missing a lateral and a canine on the other side, so we placed an implant in the canine site and put a pontic off the canine. So, two implants replacing three teeth, 2004. I saw her back on recall through the years, but didn’t pay really close attention up until 2019, which is a 15-year post-op on her. It looked like, to me, things were changing. And so, I took a photograph of the way she looked in 2019. I had a wonderful photograph, exactly the same magnification that was taken in 2004. When I put those two photographs up next to each other, there had been tremendous changes in this young woman in 15 years.” (12:25—13:24)
“What happens [with single-tooth implants] is if a patient grows, the maxilla grows down vertically, and the teeth move with the maxilla as it grows vertically — but the implants don’t. They are like an ankylosed tooth that stays in the same space as the other teeth continue to grow. In this period of 15 years, her other teeth, adjacent to the implants, had grown vertically more than two millimeters, compared to the implant. It was becoming obvious now that her implants were no longer in the correct positions in her face because her maxilla had grown vertically and brought teeth down with it, but the implants didn’t move with the maxilla. So, the implants are high. The edges of the implants are three millimeters apical to the edges of the adjacent teeth. The gingiva is also in the wrong place because the implant holds the gingiva up. So, this was a seminal turning point for me when I finally came to the conclusion that it made no sense to use implants to replace missing single anterior teeth in a young adult.” (13:25—14:38)
“Now, let me make a caveat here. I’m not talking about a patient that’s missing a bunch of front teeth either due to trauma or agenesis. We don’t have a good solution for those people other than implants. So, I’m talking about the single tooth that’s missing in the anterior maxilla. I no longer believe in the young adult — and when I say young adult, I’m talking about 20, 30, 40. I don’t think we should be putting single implants in until other ways have failed. That’s my whole point today. If things that are available to us have failed, then we can move to the implant as the last treatment option. But the implant is, by far, the most aggressive way to replace a tooth. We have much more conservative ways. That’s my belief system today.” (14:38—15:31)
“The second thing that happens to implants, long term, is the tissue tends to thin over the implants with time. As it thins, the color of the implant and the abutment starts to show through, and now you can see the grayness or blueness under the tissue. It’s a giveaway that this is not a natural tooth. The other problem is that as we age, the maxilla moves back in this direction. If the implants are here, and the maxilla is moving more centrally over 20, 30, 40, 50, 60 years, the implants are no longer in the correct position. They’re facial to the rest of the bony housing. So, I think the important question we have to ask is, when we replace a missing maxillary lateral incisor with an implant when the patient is 20 years old, how long does this have to last? Assuming that the person we place it in doesn’t have a major illness by the time they’re age 70, there’s a very high probability they’ll live to be at least 100. So, we’re expecting this implant that we’re putting in on a 20-year-old to serve them successfully for another 80 years. My question is, what are the chances? And we don’t have the data. We clearly don’t have any 80-year data on implants. But I think our hearts tell us what the answer is. And the answer is, in a lot of circumstances, this implant has not a chance to be successful for the next 80 years, first of all, because of growth. Secondly, because of tissue thinning.” (15:32—17:17)
“I had another seminal patient recently in my practice. This patient, we placed implants in number nine and number 11, and did a three-unit bridge when he was 80 years old. Eighty years old, two implants in the central and the canine, a three-unit bridge. I recently saw him on a 15-year post-op. This gentleman is now 95. He’s still a really cool guy, a wonderful person to be around. The edges of his implants were up here, and the edges of his natural teeth were down here. So, not only do we not know who is going to have late growth, because it doesn’t happen to everybody, but we don’t know how long it’s going to occur. This gentleman had vertical growth of his maxilla from age 80 to age 95. And so, these patients that I’m taking a close look at are making me very nervous about not only my patients, but the whole world of dentistry that are putting in tens of thousands of implants in the anterior maxilla every year with really no thought of the long view. We have to do our dentistry with the long view.” (17:18—18:31)
“When I first started [my lecture, “Failures and Lessons Learned”], it made me a little nervous because I’m standing in front of a group of dentists that are the referrals of the surgical specialists, and I’m saying, ‘I absolutely believe we should stop placing implants in the anterior maxilla in young adults.’ But here’s what I found very interesting. Over the last four years, I’ve probably presented this lecture 50 times. Never have I gotten pushback from the surgical specialists. And my case is a really strong one. It’s a very strong case when I go through the literature of the point I’m trying to make. So, there may be some that are not willing to argue the case because I’ve made a strong case. But most of the surgical specialists say, ‘I absolutely agree.’ So, it’s interesting. Even though they have all continued to put implants in the anterior maxilla, especially the lateral spot, when I bring it up as a subject to be discussed, I almost never get any disagreement from the surgical specialist. And so, I really believe the profession is open to hear this. I believe that it has become an automatic response to a missing lateral incisor. You put an implant in when the patient is 18 or 21. It’s “just the way we’ve always done it.” So, it’s not necessarily that everybody believes it’s the best. It’s just the way we’ve always done it. And the other problem is, our profession is not really up on the alternative treatments. And, of course, you can’t just talk about the problem. You’ve got to talk about the solutions.” (20:16—21:58)
“Another problem is mechanical failure of the implants. Everybody that has done implants has dealt with broken screws and broken implants, and there are more and more of those issues to deal with because we have more implants in the head now. It’s the worst call ever, as a restorative dentist, when you get a call and your front office person comes and says, ‘Mrs. Jones just called, and her implant crown is loose.’ Ugh, that’s the worst because you don’t know if the implant is loose, or if the screw is broken. The majority of the time, it’s not the implant, it’s the screw. And as a restorative dentist, you don’t know how long it’s going to take to retrieve that screw, or whether you’re going to be able to retrieve it at all.” (22:05—22:48)
“Here’s one practice management trick. When you have a patient in to deal with a broken screw in an implant, it should always be the last patient of the day. You don’t want to get them in at 1:00 or 1:30 and get into it, because once you get into it, you can’t quit. It’s an anterior tooth. You can’t send the patient home without some replacement. So, you may be diddling with this all afternoon, and you don’t want to foul up your afternoon. It must be the last patient of the day when you start to try to retrieve a screw.” (22:49—23:22)
“The fourth problem is an interesting one, and it’s a new one to the profession. In the last six or eight years, we’ve been starting to talk a lot about maxillary palatal expansion in adult patients. In the old days, the only way we could do that was with orthognathic surgery, SARPE, Surgically-Assisted Rapid Palatal Expansion, where you would have an adult patient with sleep apnea, a very narrow arch, all those issues we deal with every day. In the past, the only way we could widen the arch to make more tongue space and a larger oral airway was to do a complicated oral-maxillofacial surgery. Well, today we’ve got the ability, more and more, to do this palatal split more conservatively with many implant-assisted rapid palatal expansion devices. Up until recently, we could only do that in maybe up to 20-year-old males and 40-year-old females. But now, they’re making custom appliances that go into the palate. And they don’t have just four implants holding the appliance — they have six or eight. They’re custom made for the patient. And there’s getting to be a lot of reports now that we can do the palatal expansion on older males, which is very exciting. But the problem is, if the older male has an implant in the anterior maxilla, one of the four incisors, and the palatal split is done, the orthodontist can’t redistribute the space to make it all work at the end because you can’t move the implant. So, once we put an implant in the anterior maxilla, that inhibits the ability of our profession to ever do a palatal expansion on that patient. And as we get better at that and pay more attention to it, we’re going to be doing a lot of palatal expansions on adults as we become more influenced by the airway part of dentistry. That wasn’t a problem ten years ago. It’s a new problem. It’s going to be, I think, a giant problem because anybody that’s got an implant in the anterior maxilla, we cannot do a palatal expansion on.” (23:25—25:41)
“As I start looking at the literature now in terms of problems with implants, I started looking at medications. It turns out that there are a significant number of medications that at least have a correlation with implant failure. I’m not proposing that it’s a cause and effect. The data is not really strong on a lot of these medications. But there’s a bunch of medications that appear to have a negative impact on long-term success of implants. For instance, SSRI, Lexapro, Prozac — all the mood elevator drugs. There is a relationship between implant failure and those drugs. There is also a relationship to vitamin D deficiency. There is also a relationship to proton-pump inhibitors. That is, omeprazole, Nexium. How many people in the world are taking large doses of Nexium? Well, there’s a relationship between that and implant failure. Another one is allergy to penicillin. Who would have ever guessed that there would be a relationship between penicillin allergy and implant failure? But it turns out that it may not really be related to the penicillin allergy because many clinicians that place implants put the patient on a short course of antibiotics before the implants are placed. Amoxicillin is the antibiotic of choice. But if a patient is amoxicillin/penicillin allergic, then commonly, the next choice was clindamycin. It turns out that clindamycin is a very poor choice as an antibiotic prior to placement of implants, and there is a relationship between using clindamycin prior to implant placement and an increased risk of failure. And after having said all of that, then you’ve got genetic factors. There are clearly some genetic factors that lead to implant failure also. So, when you put all that together it becomes, I think, an anxiety-producing procedure, especially in the anterior maxilla. I’m much more comfortable placing an implant in the posterior maxilla or the mandible because the results of a failure are commonly hidden from view. But in the anterior maxilla, you can’t hide it. That’s the problem. There is no good way to hide it. And once the failure occurs, sometimes it’s very, very difficult to recover from that failure.” (25:47—28:30)
“The final and most common reason that implants fail is periimplantitis. When we look at the literature, we can assume that of all the implants that we place across the world, somewhere between 25% and 50% of those implants will suffer periimplantitis. So, there are a lot of reasons for our profession to have anxiety about the placement of implants. And I think we should be more thoughtful in the future about where and when we place implants, especially in the replacement of missing anterior teeth.” (28:35—29:18)
“Implants aren’t going away. We’re going to be replacing missing teeth with implants forever because they’re such a wonderful adjunct to what we do. But I’m talking about a much more specific circumstance, and that is single teeth in the anterior maxilla. I would hope that the implant companies would be open to the idea that we need to look at that. And if, in fact, replacing a maxillary lateral incisor with an implant isn’t the best idea, then let’s not recommend it there. Let’s recommend other options and let’s put implants in places where they’re going to function the best. Now, I don’t know if that’s the way it will turn out. But I’m hoping to be one of the ones to start this dialog. I optimistically believe that implant companies, if the case could be made based on data, would be open to that — I hope.” (30:23—31:16)
“Obviously, it’s easy to talk about the problem. It’s very easy to talk about all of the reasons that we shouldn’t be doing this. But we can’t talk about the problem if we don’t have a solution. In my lecture, I talk about three primary solutions. I’m only going to talk in detail about two of them. The first is auto-transplantation. That’s the one I’m not going to talk about, but it is a legitimate play. If a child loses a maxillary central incisor, let’s say at age ten due to trauma, then it is a totally legitimate concept to take a lower second premolar and transplant it into that maxillary central site. I’ve been involved in some of these cases. My orthodontist is Dr. Tito Norris . . . He is an amazing clinician. He’s done 25 or 30 of these auto-transplantations through the years, and they’re very successful. The funny thing about it is, they’ve been doing this in Scandinavia now for more than 60 years. Andreasen, a famous Scandinavian endodontist, published data 40 years ago about how successful auto-transplantations are. But it’s not something that’s done very commonly in the United States, so that’s not my go-to.” (31:27—32:53)
“My two go-to [solutions] today are, first of all, canine substitution. When I grew up as a general dentist, I was taught that you should never move a canine into a lateral spot for two reasons. First of all, it fouls up the occlusion. Your canine is no longer the discluding tooth in lateral excursion. Secondly, it narrows the upper arch and, esthetically, it doesn’t look good. Those things were both true 30, 40 years ago. But in the hands of a talented orthodontist today, canine substitution works beautifully. And again, my orthodontist, Tito Norris, and his partner, Ray Cesar, are both really, really good at doing canine substitution. They’ve learned to move the canines into the lateral spots, but they don’t lose any arch length when they do it. So, the patients don’t look triangular-shaped. Also, the occlusion can be managed, I think, without a problem. The occlusion is not an issue for me at all.” (32:53—33:52)
“My plea to orthodontists when I’m speaking at study clubs is, please involve me in the treatment planning phase of children that are going to require restorative dentistry at the end, whether it’s peg laterals that need to be bonded or it’s missing lateral incisors, whatever the circumstance, if I’m going to be involved in the treatment of that patient at the end of ortho, please involve me in the treatment plan because I may have some ideas that might be different than the orthodontist that we need to discuss. We need a treatment plan for the long term. Not just the short haul, but for the long term.” (33:53—34:33)
“Canine substitution, I believe, today is a totally legitimate treatment. But a couple of parameters must be met with those canines. First of all, they can’t be great, big, giant canines because we have to thin them down with burs and make them look like laterals. So, first of all, the canine has to be not a giant canine. Secondly, it can’t be very dark. Some canines are dark yellow, and those aren’t good for canine substitution. But the majority of canine teeth work very nicely in canine substitution because they’re not so large that with burs we can go in and thin them down, add composite to the edges, the incisal edge, and the side to make them look like lateral incisors. I, today, have a great deal of enthusiasm for canine substitution as an option to replace a missing lateral.” (34:34—35:29)
“My primary go-to today is the bonded bridge. I first started doing bonded bridges, Maryland bridges, 40 years ago. We used metal substrate, and they worked. They really worked well. But the problem was, they were all ugly because the metal of the substrate would show through the abutment teeth and make the teeth gray. So, the pontic would look pretty, and the abutment teeth would look gray. Back in the old days, we would put a wing on both teeth. We’d put a wing on the canine and a wing on the central. And we learned back in the ‘90s we don’t need to do that. We only want to put one wing. Today, we only use one wing to replace a lateral incisor. It’s going to either be the wing on the canine or on the central, and that’s based on a number of issues, and also the belief system of the restorative dentist. But we only put one wing. So, I lost my enthusiasm for the bonded bridge because they were unesthetic.” (35:29—36:34)
“There was a number, along the years, of options that were more esthetic, but not strong enough. We had substrates that were made out of reinforced composite. They were beautiful, but they broke. We then had Impress. Beautiful, but they all broke. We now have E.max. In my opinion — and that’s all I’m giving at this point — E.max isn’t strong enough to do a bonded bridge with. Therefore, we didn’t have a good solution for the bonded bridge, both esthetic and functional, until our profession finally believed that you could bond zirconia successfully in the mouth. I remember, ten years ago, so many people standing up on the podium saying, ‘You can’t bond zirconia. It just won’t work. It just won’t work.’ They’ve been doing it in Europe for years, very successfully. Matthias Kern wrote a book about the zirconia-bonded bridge, and he’s got a lot of wonderful data showing more than ten-year success — very, very high, greater than 90% success rate over ten years bonding zirconia bridges.” (36:35—37:41)
“Once I believed, about seven years ago, that we could successfully bond zirconia in the mouth, that totally opened up that world to me to do bonded bridges that are both beautiful, because the zirconia is tooth-colored, and strong, because the zirconia has approximately the same strength as metal. That’s important. Zirconia must be 3Y zirconia. There are three generic types of zirconia: 3Y, 4Y, and 5Y. 3Y is the strongest, 1,500 megapascal flexural strength — way more than you need for the strength of a bonded bridge. 4Y is half that strength, and 5Y has the same flexural strength as E.max, essentially. It’s a little stronger, but not much. So, when a clinician orders at the lab a zirconia bridge, it’s very important to order the framework to be made out of 3Y zirconia.” (37:42—38:47)
“Now, [my partners and I] both do these bridges routinely, and we’re having a very high success rate. In fact, I’ve had two break — and that was because they were made out of 5Y zirconia. I’ve had one de-bond because I didn’t use an appropriate bonding protocol. Essentially, every one that we’ve done correctly with 3Y zirconia and an appropriate bonding protocol are all still successful — up to seven years. So, granted, seven years isn’t 80 years. And I think a very fair argument against the bonded bridge would be, ‘You’re cursing the implant because it’s not going to last 80 years. Your bonded bridge isn’t going to last 80 years either.’ I absolutely agree. It won’t last 80 years. However, the way it’s going to fail, if it’s made correctly, is it’s going to come off. And when it comes off, all we have to do is to clean up the intaglio surface, clean up the tooth, and put it back in. We don’t have to worry about bone thinning and vertical growth of the maxilla. We don’t have to worry about any of those issues related to the implant. All we have to do is to clean it up and put it back in.” (39:29—40:44)
“To repeat what I said earlier, I never treatment plan for the replacement of a missing lateral incisor in a young adult with an implant. It’s going to be either canine substitution, or it’s going to be a one-wing bonded zirconia bridge. And that’s a pretty radical statement. That means if I’m involved in the treatment planning or the placement of one lateral incisor, I never treatment plan for an implant. However, let’s say, for some reason, perhaps there’s too much space. We’ve got to deal with the reality that there’s too much space and I can’t do it with a bonded bridge. The next thing I’m going to do is to ask Tito to move the canine into the lateral spot. I’m going to ask him to move the first premolar into the canine site, and then I’m going to put the implant in the first premolar site. So, if I have to use an implant in the younger patient — and I talk about younger, 20, 30, 40 years of age — if I’m going to have to place an implant, the farther to the posterior part of the mouth I can put it, the better. I’m not going to put it in the anterior maxilla if I can figure out any other way to do it. So, what does that mean? I’ve got a 50-year-old patient that’s missing a maxillary lateral incisor. What is my primary treatment option going to be? Unless proven otherwise, for some reason, like very tight occlusion, it’s going to be a bonded bridge. It’s not going to be an implant because it’s still got to last 50 years if we put it in at age 50 and this patient gets to be 100. So, I’m not starting with the implant. The implant is for the patient where everything else failed. It’s the last option.” (40:45—42:37)
“Implants are not a replacement for teeth. Implants are a replacement for missing teeth. As long as we remember that, I would much rather have a canine in the lateral spot. I would much rather have a pontic in the lateral spot than an implant. We are in the world of minimally invasive dentistry. That is the catchword today, minimally invasive dentistry. The implant is maximally invasive dentistry. It should be the last resort when replacing a missing tooth in the anterior maxilla.” (43:06—43:45)
3:39 Why this is an important topic for dentistry.
10:07 Why implants in the anterior maxilla can be problematic.
12:25 What happens to dental implants long term?
18:33 Is there pushback from other professionals?
22:00 Mechanical failure of implants.
23:24 Implant problems with maxillary palatal expansion.
25:44 Medications and implant failure.
28:31 Failure due to periimplantitis.
29:18 The hope for dental implants in the future.
31:19 Solutions: Canine substitution.
35:30 Solutions: The bonded bridge.
36:34 Solutions: Zirconia.
40:44 Implants as the last option.
42:54 Last thoughts.
43:51 More about Global Diagnosis Education and Symposium.
Dr. Bill Robbins Bio:
Dr. J. William Robbins, D.D.S., M.A., maintains a full-time private practice and is an Adjunct Clinical Professor in the Department of Comprehensive Dentistry at the University of Texas Health Science Center at San Antonio Dental School. He graduated from the University of Tennessee Dental School in 1973. He completed a rotating internship at the Veterans Administration Hospital in Leavenworth, Kansas, and a two-year General Practice Residency at the V.A. Hospital in San Diego, California.
Dr. Robbins has published over 80 articles, abstracts, and chapters on a wide range of dental subjects and has lectured in the United States, Canada, Mexico, South America, Europe, the Middle East, and Africa. He co-authored a textbook, Fundamentals of Operative Dentistry – A Contemporary Approach, which is published by Quintessence, and is in its 4th edition. He recently co-authored a new textbook, Global Diagnosis – A New Vision of Dental Diagnosis and Treatment Planning, which is also published by Quintessence.
Dr. Robbins has won several awards, including the Presidential Teaching Award at the University of Texas Health Science Center, the 2002 Texas Dentist of the Year Award, the 2003 Honorary Thaddeus V. Weclew Fellowship Award from the Academy of General Dentistry, the 2010 Saul Schluger Award given by the Seattle Study Club, the Southwest Academy of Restorative Dentistry 2015 President’s Award, and the 2016 Academy of Operative Dentistry Award of Excellence. He is a diplomate of the American Board of General Dentistry. He is past president of the American Board of General Dentistry, the Academy of Operative Dentistry, the Southwest Academy of Restorative Dentistry, and the American Academy of Restorative Dentistry.