The Prevention and Management of Peri-implantitis pt.1

In the first part of his 2-part lecture, Dr. Michael Danesh-Meyer reviews the factors influencing peri-implantitis and critical elements for the diagnosis.

Dr. Danesh-Meyer opens his lecture by emphasizing that there are a number of factors with prevention that need to be considered in detail when we're discussing peri- implant infection. Ranging from the treatment planning right from the onset, right through to the type of surgical protocols that you may be using, as well as the restorative options including both the type of restoration as well as the materials that are used as part of the restoration process. Then of course, follow-up and maintenance. He will discuss how important this is to ensure the longevity of the implant treatments provided. 

As we all know, the health and the stability of peri-implant tissues is reliant on several factors. A key here is the 3D dimensional positioning of the implant head in relation to the free gingival margin. The marginal bone width is also critical. Reductions in marginal bone width can lead to premature remodeling and therefore can affect the soft tissues around the peri-implant tissue region. According to Dr. Danesh-Meyer, the implant surface can be a factor and he will look at this in a bit more detail during his lecture. The way in which the implant connects whether it's a platform switch connection, can also have a bearing on the stability of the soft tissue. Of course, the design of the prosthesis itself and also the materials that are used to manufacture the actual prosthesis can also have an impact on the health and stability of the peri-implant tissues. The soft tissue quality and quantity is a very important aspect and something very dear to his heart, shares Dr. Danesh-Meyer, being a periodontist. This is something that we should take seriously. And of course, again, from a periodontist’s perspective, the need for maintenance and regular care or post-treatment is also critical in ensuring the long-term success of our implant treatment. The key thing here to remember is if we can address these various points prior to treatment, we can often avoid problems with peri-implant infections, he reminds us. He points out when starting off with the 3-dimensional positioning we know that if we don't get the implant in the right position, not only will this potentially put the implant at risk, but we know it will have a negative impact on, particularly, the stability of the marginal tissues. He reminds us that we have some guidelines, and most of us will be familiar with these guidelines. It is important to adhere to these guidelines during the treatment planning phase of our implant treatment, because if we don't, then we end up with this problem where we have some issues with the soft tissue stability around the abutment interface which can lead to issues with inflammation due to biofilm formation and underlying bone loss, says Dr. Danesh-Meyer. Getting the implant in the right position and ensuring it's not too far buccal is paramount. He continues asking, what about the implant itself? Is the stability of the peri-implant tissues in some way maybe related to the actual implant? He reminds us we know from studies in the literature that the change that we had a few decades ago now from machined titanium implant surfaces to moderately roughened implant surfaces has had a profound effect not only on the rate of osseointegration, but actually as you can see from a short sample of studies has also had a profound impact on marginal bone stability. We know for a fact now that the moderately roughened implant surface is advantageous from osseointegration standpoint and marginal bone stability standpoint. And therefore, most of us using implants now are obviously shifted across from the days of machined implants. However, according to Dr. Danesh-Meyer, this raises the question if the moderately roughened implant surface of the implant is within bone and covered by soft tissue, we are pretty relaxed. We know that not everything is always in an ideal world this way, in cases where we have some recession, or we have some inflammation or a period of time during the lifespan of the implant where there is some inflammation and some soft tissue loss. Of course, there is always the risk that the moderately roughened surface becomes exposed to the oral environment. And then of course we have the problems of biofilm attachment to the surface which can be a real issue and a difficult one to manage. What if we can still have the advantages of an anodized oxide surface on an implant but still, if it did become exposed into the mouth reduce the risk or at least reduce the chances of plaque biofilm formation. And therefore, improve stability of periodontal health. Recent innovations in implant design have certainly helped us in this regard as, for example, the introduction of the TiUltra surface. Here we have an ultra-hydrophilic surface it's a multi-zone implant based on the long-term success that we have in the literature from TiUnite. Essentially what this composes of is a graduated form of the anodization process whereby the surface at the coronal aspect of the implant is now a lot less likely to collect large amounts of biofilm. And, removal or cleanability of this area is improved. 

What about other impacts or how can we further enhance peri-implant tissue health and the stability, asks Dr. Danesh-Meyer. The design of the prosthesis here is also extremely important. He assumes we can consider three key points here. The biocompatibility and the handling of the abutment material, how it's manufactured and how it's processed and delivered to the patient. The actual design in terms of the emergency profile of the abutment and of course, tied directly into that, is how easy is that prosthesis going to be to maintain in terms of plaque control down the track or the cleanability. According to Dr. Danesh-Meyer, what we've seen in recent years is that a great deal of interest in not so much the osseointegration side of things, but now what we term mucointegration or the adherence of the soft tissues to the actual implant abutment. This is supported by the literature studies such as those by Lambert and Rompen, Schüpbach, that there are essentially three key materials which we know will help to support a degree of soft tissue adhesion. They are Zirconia, titanium and peek plastic. Of course, peek plastic cannot be used as a definitive material. He points out that we are usually restricted to the use of zirconia and titanium. With respects to zirconia, the material itself is biocompatible and it has demonstrated to support soft tissue adhesion. However, an important point here is the way in which it's handled in the laboratory. He emphasizes that if we consider the position of the free gingival margin on the actual restoration, the surface of the implant that is below this line needs to be a pure zirconia surface. The surface is a polished zirconia surface, not a glazed zirconia surface. This is something that the laboratory needs to solicit. A communication between the laboratory and the clinician is paramount to ensure that you are all on the same page with respect to the biology of how this soft tissue is going to hopefully adhere to the surface of the implant, emphasizes Dr. Danesh-Meyer. Another key factor is the way in which we actually restore our implants. Oftentimes this involves taking on, putting off, healing abutments, definitive abutments. These connections and disconnections, unfortunately, can result in micro trauma on the soft tissues, which can then in turn lead to problems such as recession, inflammation. It's a very delicate connection between the soft tissue and the abutment surface. He points out that minimizing the number of connections and reconnections is really an important consideration when we are restoring our implant cases. And, if possible, there is now also a trend towards placing the definitive abutment of the appropriate material at the time of implant surgery so that during that healing phase, we get a connection or we get that soft tissue adhesion to the abutment. From that point on, the abutment does actually not need to be removed so we maintain that adhesion over time. This is a trend that we're seeing more and more of, he shares. And one of the things that's helping us with that trend again are further enhancements, in this case to the titanium surface. As we know titanium will support soft tissue adhesion. But can we further enhance the ability for the soft tissues to mucointegrate to that structure, he asks. With recent advances we can see an example using Xeal, which is an anodization process on the actual titanium abutment. It creates a non-porous surface, a nanostructure that is hydrophilic and also cleansable. It is enhancing mucointegration without compromising cleanability, which is only a very positive move in the right direction. From some of the earlier studies, looking at the Xeal surface, we can see that, compared to a standard machined titanium surface, it supports cellular migration in a very positive way, more so than just straight titanium. And from early histological studies, we can also see the evidence of the actual adherence of the tissues to the Xeal surface. What about the clinical relevance of this? How does this help us in clinical practice, asks Dr. Danesh-Meyer. The early studies comparing Xeal and titanium, clearly show that there is a higher degree of keratinized mucosa on the treated titanium surface relative to the standard titanium. And interestingly also this study by Hall looked at the bacterial cultivability on the actual surfaces and noted that there was less bacterial growth on Xeal versus the standard titanium. He points out, that in terms of clinical studies, we have this study from Ana Ferro and her group where they looked at the 1-year follow-up, using TiUltra implants in combination with the Xeal multi-unit abutments and again, very positive results. 100% implant survival rate, which is not unexpected, but also very low marginal bone remodeling with 0.46 millimeter at 1 year. The key findings on this study show an increase in marginal bone height, increase keratinized tissue, and also increase marginal tissue height. Again, these early studies are showing the benefits of enhancement of the titanium surface in terms of promoting that soft tissue adhesion. 

Dr. Danesh-Meyer now to turns to the topic of the design of the actual prosthesis. We should think from a periodontal standpoint, can we clean these restorations? Showing some examples, we can see that the design has a lot to do with our ability or the patient's ability to maintain good plaque control. If they're too close together if we have a mushroom shape for a crown, if we have severe ridge lapse or undercuts, of course we can't expect our patients to keep these clean. According to Dr. Danesh-Meyer, this will have a profound effect on the stability of the peri-implant tissue health in the short to medium, even the long term. The design of the abutment, the subgingival emergence profile is also very important here. Not only from a cleanability standpoint, but also allowing their sufficient volume to support the peri-implant soft tissues around the neck of the implant. Showing a clinical case, he wants us to see a concave facial surface that is really the key here. In order to enable the soft tissues to sit in the space without being under pressure and basically remaining stable over time. If we think about a full arch reconstruction, he refers to a more complex type of treatment, a fixed hybrid bridge. We can see that it is very important to have a very high-quality finish on these restorations, which is going to be less plaque retentive and also to avoid any concave surfaces which are going to collect vast amounts of food debris and plaque. 

He continues his lecture, focusing on soft tissue. What is the significance of the attached or the keratinized gingiva around our implants? That this is also fundamental in terms of identifying potential problems with soft tissue prior to, ideally, implant placement, shares Dr. Danesh-Meyer. Because if we don't, we can set ourselves up for failure prematurely. The long-term implications of dental implants that lack keratinized gingiva unfortunately are generally not a good news story. We will have increased inflammation and increased gingival recession and there's an increased risk of marginal bone loss and patient discomfort due to the inflammatory changes that occur. He reminds us that we have to look very carefully at what's going on with the soft tissues in the areas where we are planning to place implants because this is the kind of treatment result that none of us want to see. Okay, implants that are placed into thin biotypes where there is a lack of keratinized gingival tissue, they will basically be much more likely to develop peri-implant disease. And they also have been radiographically and clinically to show increased amounts of marginal bone loss in the long term. Very important to address this, according to Dr. Danesh-Meyer, because the best way to avoid these soft tissue problems is to identify them at the treatment planning phase before the implants are placed. Once the potential issue is identified it can be dealt with as a part of the surgical process. We can enhance soft tissue biotypes by grafting soft tissue in many ways because prevention is always better than the cure, particularly when it comes to peri-implantitis, Dr. Danesh-Meyer emphasizes. Another fundamental part of maintaining good peri-implant tissue health is maintenance. Long-term stability is basically reliant on the patient's ability to maintain plaque control. It must also be accompanied by a structured and well-organized recall system for monitoring and ongoing maintenance. So not only does the patient have to do their part, but we as a professional group, also have to do our part to ensure that the long-term success of these implants is good. We should not forget, dental implant treatment represents a significant financial outlay for most patients, so it's an investment in their oral health. We need to ensure that we work as a team to ensure that is the case for the long-term, not just for a short period of time. He highlights that every patient should have their own needs in terms of the oral hygiene assessed clinically, and then a treatment plan or at least some form of guidance needs to be provided to the patient as to what is the best thing for them. Because it needs to be tailored on an individual basis. The patient requires education in this regard, it's our responsibility to educate them as to what they need. According to Dr. Danesh-Meyer, we need to be able to tell them what sort of tools they need to assist them in maintaining low levels of plaque around their restorations, and we're spoiled for choice. We have a lot of different options now, but again, we need to look at the patient, identify what specifically they need and then recommend, this is the key, tailored instruction for use. As part of that process, we also need to educate the patient on the importance of professional maintenance, and together with them, building a good, stable maintenance program. He highlights the importance of building the foundation through patient education, raising the patient's dental IQ by empowering them with knowledge. If they don't have the knowledge, they're not going to be able to know what to do, says Dr. Danesh-Meyer. He encourages us to clinically demonstrate to them in the clinic what they should be doing as how they use these various tools to maintain plaque is critical. The emphasis needs to be on long-term maintenance of the biofilm and then relating that back to what they're doing in their day-to-day activities with their brushing, their cleaning, their flossing. Reinforcing the message at each opportunity. He asks us when we see these patients for routine maintenance, to always reinforce the message, provide feedback, to let them know how are they doing, are they missing areas? Dr. Danesh-Meyer emphasizes that every time we see the patient, we should make sure that we make it a positive experience. So many times, I hear I went to see my hygienists and they growled at me, he continues to explain, they were angry with me because I wasn't doing a good job. That's a very negative way to look at it. Even if they are not doing a great job, we should focus on the positive and then point out the areas where maybe they could be doing a little bit better. It will do you a lot of good and do your patients a lot of good. 

Next, Dr. Danesh-Meyer is looking at maintenance and shares that to do things properly, we need to look at this example here. You know, a proper full mouth periodontal maintenance visit consists of a number of key elements: they are the diagnostic phase, the actual treatment, the polishing, and disinfection. We must spend motivational time with them, reinforcing the oral hygiene.  We need to have a package that we can deliver to the patient. According to Dr. Danesh-Meyer, we must let the patient perceive the value in what they're receiving each time they see their hygienist. When we're looking at maintenance, we are each time assessing the peri-implant tissue health, plaque levels, charting with probing depths, because with implants, probing depths can vary because of the position of the implant. For the soft tissue thickness, we need a baseline, and then we need to be able to measure probing depths over a period of time to determine whether or not there's a problem there. Sometimes we can use plastic probes, sometimes the contour of the implant restoration is such that if we use metal probes, it's difficult to get a decent reading. Plastic probes can be helpful because there's some flexibility in there. We must assess the biotype, again, just to check, are they are thin biotype, are they a thick biotype? That will determine the risk profile for that patient. The mobility, what's the prosthesis doing, is it creating an issue for cleaning, this will be our questions, according to Dr. Danesh-Meyer. Of course, also very important is radiographic follow-up, we are reminded. Coming back to the topic of probing, he mentioned before that probing depths around implants can vary because the attachment or the relationship of the soft tissue to the abutment versus that to a natural tooth is different. We need to understand this from a biological standpoint, and we need to basically record a baseline measurement around our implant restorations and then monitor those probing depths over time.  Of course, one of the other things we're doing is seeing whether there's inflammation present or not. Because if inflammation is persistent again, we may be developing some peri-implant mucositis, which then would require some form of management. But a radiographic follow up is also important. We have a baseline when the crown or the restoration is placed on the implant, which gives us our optimal bone level. He reminds us that if we then monitor this at maintenance appointments to ensure that there is no negative change or bone loss. If we identify some progressive loss of bone between recall visits or subsequent radiographic evaluations, we need to act, if we don't act, we have a problem. He encourages us to treat it early and aggressively. And without follow-up, we will never know whether there is a problem potentially developing. When we are building our sustainable maintenance program, it's important that we tailor the interval that we see the patients at based on their needs, based on their level of oral hygiene, the plaque levels, the biotype, all these sorts of things. How difficult the restoration, the implant restorations are to maintain themselves at home. It will be variable depending on what they need. 

With this comment, Dr. Danesh-Meyer concludes the segment on prevention and turns to the diagnosis of peri-implant tissue disease. As most of us are aware that there are essentially two main conditions in terms of disease with regards to dental implants and they can be classified as either peri- implant mucositis or peri-implantitis. He continues to have a look at mucositis in the first instance. Its key features are that we are seeing patients who present with red inflamed marginal gingiva around the implant sites. There is usually readily bleeding on probing when we examine these patients. But with his former comments saying that probing depths can still be the same as where they were at baseline, we don't necessarily have increasing probing depths other than perhaps through some inflammation or inflammatory changes which would normally be minimal. These cases of mucositis do not show signs of suppuration or purulence. Also, radiographically, there should be no evidence of any marginal bone changes relative again to the baseline. Essentially, this is peri-implant mucositis which is in a loose sort of a way akin to gingivitis around unnatural dentition. Of course, peri-implantitis is a completely different animal, according to Dr. Danesh-Meyer. The features here are in some respect comparable to what we see with mucositis. We still have bleeding, we have marginal erythema, we normally now also have increasing probing depths. We sometimes, as you can see in a case Dr. Danesh-Meyer shares, have significant recession, with increasing pocket depths. Then the other key thing here, radiographically, is that we see progressive bone loss. Peri-implantitis will result in bone loss which will potentially result in exposure of the implant surface. Most of those are moderately roughened implant surfaces, irrespective of the type of implant, and that will help to enhance the formation of a biofilm. As he mentioned earlier, dental implants represent a significant investment by the patient in both time and in money. They're expecting a long life out of this restoration because they're parted with some hard-earned money. If an issue is identified, we need to look at treating it and there are several factors that can contribute to the development of peri-implantitis. Of course, the primary thing is a biofilm, which is a bacterially driven condition. However, we have other things that can factor into this, for example, the patient's periodontal susceptibility. If they have had a history of periodontitis, there is generally an increased risk of those patients’ developing issues around their implants over time because of their increased susceptibility to biofilm. The patient's systemic health, that can change over time, he reminds us, and we know there is a relationship between general health, periodontal health, and that includes peri-implant tissue health.  He advises us to be conscious of changes in the patients’ medical history over time. Looking at the implant prosthetic design, we should ask ourselves if it is helping or hindering the patient's ability to maintain the control of the biofilm around the restoration. The quality of the hard and soft tissues, we addressed this earlier on in terms of, well, how can we assess this? Is this helping or hindering the patient's ability to control of the biofilm around the restoration. If the soft tissues are of poor quality, we need to think about how we can potentially enhance this even after the implant treatment. We can still look at using soft tissue augmentation potentially to enhance and prevent the problems from getting worse. Things like soft tissue augmentation can be done post restoration, Dr. Danesh-Meyer mentions. But ideally, we want to do that as part of the initial surgical plan, just to save the patient more hassles down the track. Mechanical fail can sometimes result in peri-implant tissue issues as well. For example, if we have a prosthesis on an implant that undergoes screw loosening, the micromovement of the restoration will result in bacterial infiltration in the marginal gap. This will result potentially in quite a significant amount of inflammation. If this is not addressed early, it can lead to marginal bone loss. Not only can it lead to that, he continues to explain, but of course that because the components, the prosthetic components are moving within each other, they can lead to premature wear of the actual implant connection which can then became a problem from a prosthetic standpoint. Unfortunately, also sometimes we see peri-implant problems developing because of iatrogenic causes. In other words, surgical errors, or operator-based errors. He reiterates the point that the correct placement of implants is very important. There are several factors that we don't have time to discuss in detail on that. The diagnosis of the mucositis, the peri-implantitis, is very important. 

Dr. Danesh-Meyer continues with the next topic of his lecture to address the topic of treatment and is going to briefly look at mucositis, afterwards he is going to look in a little bit more detail at the management of peri-implantitis. With respect to mucositis, fortunately, this problem is normally relatively straightforward to manage in most cases in an otherwise healthy patient. And the key things are the three D's: disruption of the biofilm, detoxification, and disinfection as part of the long-term or the ongoing maintenance. We have several ways of dealing with this. The treatment guidelines for mucositis: clearly the focus here is the removal of the biofilm in a non-surgical way and this should be comfortable for the patient. For example, we can use air powder prophylaxis and there are studies now to support the use of this clinical technique around implant restorations. And with use with the right powder, and we normally are talking about powders that are very fine, like erythritol-based powders or glycine-based powders, which have a very fine particulate, and will be less likely to be abrasive and they will be less likely to traumatize the soft tissue, the peri-implant soft tissues as we use it. He reminds us that if we recall the sort of relationship of the marginal peri-implant tissues around the implant abutment it is a delicate one. We don't want to be heavy handed about this and we want to be thorough, we want to remove the biofilm, but we also want to be respectful of the soft tissue and the delicate nature of that soft tissue around the implant. If we go in too hard with, whether it's scalers or air powder prophylaxis, we're going to damage that. It could potentially result in premature recession of that gingival tissue around that implant, which will then set it up for biofilm formation as we get there, marginal bone loss, and then the process starts down a path which we don't want to head down. So, oral hygiene instructions to the patient, making sure they're using antiseptics if they need to, and if they're struggling with their plaque control, this is very important, Dr. Danesh-Meyer highlights. And making sure that they're enrolled in the maintenance program, and they're being seen regularly. And all those things that we talked about initially are reinforced. One of the difficulties or one of the challenges with non-surgical instrumentation around implants, particularly in this situation where you can see some anterior implants, is gaining access subgingivally. For most part, until recent times, the instrumentation that we've had have been very large and clunky because of the materials that have been made from, for example, peek plastic. There's been limitations here and this is a relatively new innovation, which is a combination of peek plastic and carbon. This has allowed the manufacturer to create a much finer tip. This is something that we are now using in the clinic on a regular basis to assist with removal of the subgingival biofilm, shares Dr. Danesh-Meyer. He continues to ask what with respects to mucositis, can we conclude? Implant therapy must not stop at the placement of the implant and the restoration of that implant. When we discussed this with the patient, we are talking about it's in essence, placement of the implant, restoration of the implant, and then maintenance of the implant. They need to be told this from the onset, so it doesn't come as a surprise that you’re going to call them back for maintenance because they thought they'd finished their treatment. If we tell them that after the fact, it's much more difficult for them to be compliant. But if we incorporate that into the initial treatment plan from the onset, their understanding is better. So, the ability to have patients return for the long-term follow-up, and therefore long-term success is going to be higher.