An Interview with Dr. Sascha Jovanovic – gIDE Institute Implant Update

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Dr. Bradley Bockhorst: Before we get started with the interview, can you share with us a little bit of background information on gIDE and about the studio where we are right now?

Dr. Sascha Jovanovic: Of course. First of all, it's a pleasure to be part of this interview. gIDE was started as a training, education and research institute in 2003 based on utilizing today's new digital technology to distribute information and knowledge efficiently and swiftly. We're kind of shrinking the world of dentists, and we are able to give continuing education to our colleagues and friends very efficiently and on their time schedules. So it's online streaming, it's digital downloads, it's utilizing learning tablets. And my favorite is the blended learning, which combines in-person training and online education.

Now, to do this – we started about eight years ago, when gIDE was founded – we needed a recording studio. We're very lucky to be here today in this building, which formerly was the studio of The Beach Boys. In this area where we are right now, one of their famous songs could have been created. So it's fun for us to be here as dentists, as educators and as clinicians because we can give a little creative juice to the education we provide.

BB: Very fun history. The first several questions I have for you are related to your thoughts and experiences with various implant and abutment designs. With that in mind, what is the influence of the implant surface on crestal bone stability?

SJ: We know today that implant surfaces can affect bone and soft tissue positively.

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BB: The next question is related to that collar design. You prefer to have it going all the way to the top of the implant?

SJ: Right. When you look at the neck of the implant, which is the next point to think about, the most important bone from a standpoint of soft tissue is the crestal bone. So that's why, when we evaluate patients over the long term, we always want to know what the crestal bone stability is. When you are evaluating an implant system, here also you want to know the crestal bone stability. In addition to surface characteristics, new research nicely shows that implants with a straight neck or a reverse-neck design are even better for crestal bone stability.

There is a tendency to move away from implants with a countersink, like the traditional Brånemark System® implants (Nobel Biocare; Yorba Linda, Calif.), in the esthetic zone – versus something that has more of a straight neck, such as NobelReplace® (Nobel Biocare), the most widely used two-piece implant system. And, currently, implant designs are being introduced with a reverse-neck design. Those, again, seem to be better on maintaining the bone. These are promising results, and that's definitely the direction the research is going.

BB: Now, on top of the implant, what abutment materials have you found to be the most biocompatible?

SJ: Abutment materials are a big topic of discussion because we have titanium, which we've had for the longest period of time.

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When we look at animal research, it's very clear that there are only two materials that are stable for soft tissue, and those are titanium and zirconia. Now, of course, we can say animal research is not the same as human clinical data, but we try to follow the information that is available to us.

In my practice, I prefer to use titanium or zirconia in a case that is well planned with good implant position. But, sometimes you have the unusually complex case, and then we can still use gold alloy, with the knowledge that we might lose some crestal bone and soft tissue. Therefore, it's better not to use this material in the esthetic zone.

BB: There have been various transgingival designs for abutments – everything from convex to straight to concave designs. Which design have you found to best support peri-implant health and esthetics?

SJ: Well, the tendency that's been more and more supported in the last few years is that platform switching, or the use of abutments with reduced width in relation to the implant diameter, promotes better soft tissue stability and improves soft tissue health. Abutments are reduced or, as you mentioned, some even have a concave design, which is something we can do today with CAD/CAM. So, for me, it's very important to use, at max, a diameter of an abutment that is the same size as the implant. I won't use those divergent ones because divergence means mechanical stress to the tissues, and mechanical stress to the soft tissues means an increased risk of recession.

BB: To make sure I understand, you prefer a straight emergence?

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SJ: This is very case dependent, as you can imagine. The best way I can explain it is: Imagine we're looking at a tulip. (I'm Dutch, so I love tulips, of course.) Like a tulip, the stem, which is the abutment, should be really nice and narrow, and once we come close to the gingival margin, that's where we can emerge out. So let's say about 0.5 mm or so below the gingival margin is where the crown goes to its full emergence.

BB: In clinical practice, there are some procedures in which you're taking abutments on and off a lot. What impact does that have on the surrounding tissues?

SJ: This is clear-cut because the research studies show that implant design is unrelated to bone loss or bone stability. As an example, if you use a two-stage or a two-piece implant versus a one-piece implant, the bone stays stable until we start to remove the abutments. So, as soon as we do impressions or some type of laboratory work or change – boom! We get a reaction. And the reaction is usually soft tissue inflammation. Soft tissue inflammation leads to inflammation in the bone, which leads to bone loss. Bone loss leads to potential risk for gingival recession.

So it's very crucial for any clinician to try to pick the final abutment as early as possible. A suggestion for clinical practice is that implant impressions be taken as early as possible. It could be at the time of implant placement or at the time of uncovering. And then we select an abutment that, if possible, is the permanent abutment for the case. Now, I realize that's not always possible. You need to be well equipped and you need to plan the case well, but that would be the ideal.

Another good clinical practice is to leave a stock abutment in for at least two to three months, so the soft tissues are stable, and then make one more abutment switch at that time.

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BB: Back to implant placement. What do you find is the ideal interproximal space between the implant and the adjacent roots?

SJ: Spacing between implants and any other anatomical structures is very important for preservation of the existing periodontal and bone tissue. We have information in the literature that suggests that between adjoining implants you need a minimum of 3 mm to 4 mm, which is a good, safe space. Between an implant and a natural tooth, you need 2 mm or more. This will support the periodontal ligament, and the more bone we have, the better.

So when you are planning a case, you probably want fewer implants in the anterior region because you want to have optimal soft tissue, and you also want to have smaller diameters. In my private practice, for example, I don't place wide-platform implants in the anterior region because it compromises the soft tissue. I select regular and sometimes even narrow implants. In addition to this, think about cases where you have to place multiple implants next to each other. Often cases are better if you bring in a pontic, so you have more bone and soft tissue to work with. So, less is better, and increase the spacing between implants.

BB: How do you handle the cases of, say you're doing a single tooth – maybe it's a narrow maxillary lateral incisor or lower incisor – and you just don't have that 2 mm on either side? How are you handling those cases?

SJ: Well, those are difficult cases. So my recommendation is: When you are dealing with difficult anatomical conditions, be very careful, because you are setting yourself up for a dangerous situation, in which tissue can be lost.

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If you have, let's say, less experience with implants, my recommendation would always be: Stay away from those cases; leave that up to colleagues who have more experience, who know what the pitfalls are. Because the worst you can do is try to do the best you can for your patient and, in the end, you get a negative result. So those are not good cases. Get enough tissue. Get enough space.

BB: What is your ideal position for the top of the implant in relation to the crest of the bone?

SJ: I published in 1997 a scientific paper describing my observations about the ideal relationship of the neck of the implant and the connection with the abutment to the soft tissue margin. And we concluded that everything is related to the biological width. The biological width around implants is approximately 3 mm, so that's the soft tissue dimension around implants and around abutments. The goal today will always be to place the implant neck no deeper than 3 mm below your optimal gingival margin. And once you know what your optimal gingival margin is, which should come from your diagnosis and models, then you count back and you place the implant about 3 mm below that.

So, now, what does that mean in many clinical situations? When the crest has bone loss, there's a part of the implant neck that is going to be exposed. And with that implant neck, now you need to make a decision. Should I do a grafting to bring that bone back, or should I maybe place the implant deeper and then accept that the crown is going to be longer and there is going to be gingival recession? This may be acceptable for some patients with a low lip line.

BB: Along the same line, if you decide you are going to do grafting, when do you determine that it is truly indicated and which procedures you should perform?

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BB: Do you have a material of choice for grafting?

SJ: The most used procedure, which is evidence-based in the literature – and we have been doing this now for 20 years – is the GBR principle, which is the Guided Bone Regeneration principle. This is basically the principle where we use bone grafts based on particulate – some of it is autogenous, which is the gold standard, and some of it could be a biomaterial – and then we cover this with a barrier membrane, which could be resorbable or nonresorbable. This will, first of all, stabilize the bone graft for regeneration purposes and, secondly, exclude the soft tissue and bacteria from invading, so we don't have a loss of that bone.

BB: Another question along the line of bone grafting: If you are going to do a delayed case – say you're going to extract a tooth and then place an implant later – would you typically graft that socket?

SJ: Yes, socket grafting is something that is more of a norm today. So I would always recommend socket grafting to any clinician and to any colleague for sure in the single-rooted teeth – which basically means everything that is toward the anterior – because it will prevent collapse of the buccal plate, it will maintain more of the soft tissue, and it will improve the stability of the soft tissue dimension.

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BB: Once you've cleaned out the socket and you've grafted, what do you typically like to cover it up with?

SJ: Socket grafting, as you know, has different options. The first option, which of course most of us will look at, is to use a barrier membrane. This can be either a nonresorbable material – today there's the dense PTFE material – or we can use a resorbable material. Then there are also some new materials. We have collagen grafts, which are thicker; they have a thickness of about 5 mm. These help us to, first of all, stabilize the soft tissue and the bone graft, and they also allow the soft tissue to creep in. And then we have a procedure that is called socket seal surgery. Socket seal surgery is a procedure that has been around for a long time. Cobi Landsberg published something on this, quite nicely, and he's using a free gingival graft to stabilize the bone graft and the soft tissue.

BB: We've talked a lot about hard tissue grafting. What's the benefit of soft tissue grafting in implant cases?

SJ: What you are focusing on, Brad, is really soft tissue esthetics and health. But you can see that there are a lot of things which are happening to soft tissue before we really get to it, when we are talking about bones, implants, abutments, etc.

Why soft tissue grafting?

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BB: Over the last couple of years, there have been a lot of lectures on connective tissue grafting, particularly in the esthetic zone. What's coming across is that labial bone loss is inevitable, no matter what you do. Have you found that to be the case? And then do you have to use connective tissue grafting basically as a cosmetic Band-Aid? Or what's been your experience as far as maintaining that labial bone?

SJ: Connective tissue grafting leads into or follows up on the question you just asked. Let me refer to a very nice study that we published in 2009, where we looked at vertical bone augmentation using the GBR principle. And what we saw there, when we did a combo – a bone graft and a connective tissue graft – is that we always had better crestal bone stability.

So, you have to think about it. Soft tissue is very delicate, so when you don't have enough soft tissue, bone has a tendency to shrink more, to lose a little bit more. What connective tissue does is it, first of all, thickens the soft tissue. It prevents bone from losing too much, so it kind of keeps it in a healthy range. And, of course, it improves again the end outcome, which is esthetics and health.

BB: Very good. Then, for a final question, is a temporary restoration required for controlling the final soft tissue esthetics?

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So I would urge every single patient, especially in the esthetic zone, to go through a temporary phase. And, again, the same thing for the clinician; we need to have something which gives us a better result. And the better result definitely is there when we first do a prototype, create the abutment correctly, create the emergence correctly, and then let the soft tissue flow in. And this soft tissue growth and stabilization around abutments and around temporaries could go for more than 12 months. So make sure that you leave the spaces in. Make sure that you have the abrasion spaces into which soft tissues can flow. And don't worry about the black triangles right then because we have the potential to regenerate soft tissues interproximally between 3 mm to 5 mm. But you have to give it time to fill in, and that's the temporary phase.

BB: To start wrapping things up, first I'd like to thank you for taking the time to talk with me. We went through a lot in a short period. If there are clinicians reading this who want to get more education and training on different types of hard and soft tissue grafting and esthetics, what would you recommend?

Well, our field is full of needs for training and education. This is a great field. I'm very passionate about it. I love this area and have been involved in it, thankfully, for more than 20 years. If you want to get more involved with this and get more training in soft tissue grafting, choose the right partners for you. It could be one mentor whom you trust, it could be an institute that you trust, it could be a university, or it could be a mix of each.

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