Re-treatment of failures: from prevention to advanced guided bone regeneration on ailing dental implants

Dr. Giorgio Tabanella opens the first part of his 2-part lecture on retreatment of failures with the definition of an ailing and a failing implant. A failing implant, is an implant that needs to be removed due to suppuration, bleeding, or mobility. An ailing implant is a dental implant that is still functioning in the oral cavity. This implant is considered to be a survival implant but has some kind of issues. For example, it could be affected by mucositis, peri-implantitis, some form of mucogingival deformities, aesthetic issues, or misplacement. Such an implant is no successful, but still working in the oral cavity. Dr. Tabanella reminds us that complications and failures are unfavorable consequences of a disease, health condition or therapy. Complications and failures are part of medicine. They can even occur when a very knowledgeable and skilled clinician follows the best practice with excellent execution. In his opinion, the best clinicians are those who have fewer failures than others and can manage their own failures. He encourages us to talk about failures, as they offer the opportunity to learn form retreating them. Dr. Tabanella continues to highlight that failures are on a rise worldwide and that there might be different reasons for this. The main one might be the lack of education. Then there is also the fact, that soft and hard tissue are not properly managed. 

By showing his first patient case, Dr. Tabanella illustrates ailing and failing implants. The patient is also symptomatic, showing a poor quality of peri-implant mucosa and a misplaced implant (no.11/8). The exposed threads are showing plaque accumulation and might be exposed due to being placed in minimal bone volume initially. Additionally, failing attachment, no keratinized tissue and the age of the patient come into play. A solution for this patient needs to be found. Dr. Tabanella shares that the number of similar cases is dramatically increasing worldwide and that he sees about 80% of clinical cases in daily practice related to failures or complications. Failures can happen during any of the treatment stages. Some are also related to different types of technique. Many variables seem to correlate to failures and complications. One of them are unexperienced clinicians, although clinical residents during a post-doctoral program tend to have fewer failures compared to experienced clinicians. It is possible that this is happening because experienced clinicians are not following the protocol anymore, they feel more self-confident and maybe try to skip some important steps during the surgical and clinical procedures. The learning curve need to be considered as well when a new surgical procedure is performed, a new material or device is used. The first surgeries can be a higher risk as new procedures can be related to failures. Another influencing factor is the patient’s age in terms of compliance or regarding the capability of tissue healing and the need to keep the treatment as minimally invasive as possible. 

Every time an intervention is complex or urgent, the time for proper planning is missing, highlights Dr. Tabanella. Sometimes the increase of failures is related to the fact that a clinical treatment was urgent. Other factors can be poor communication, especially in the hospital or even clinical setting. The use of digital technology can avoid improper documentation. Other variables can be related to the work environment, inadequate assistance, a poorly designed treatment. Error of judgement is an important point, because some clinicians are focusing on one technique only. Not one technique is better than the others, Dr. Tabanella points out. We should all be able to perform different techniques and pick the best for the clinical case. Cost cutting measures can influence the risk of complications, but understandably not all facilities can provide all types of devices, especially the more expensive ones like a navigation system. According to him, complications are part of dental medicine as one deals with biology. Practitioner risk factors is the next factor as not one technique is better than the other, but one tends to perform the same procedure every day, which is not the ideal way to perform medicine, according to Dr. Tabanella. Personal factors like sleep deprivation, fatigue, depression, burnout are relatively common after the age of 40, especially in hospital settings. The clinician’s own ego influences the selection of the treatment more than we think. Some clinicians might have spent more time performing GBR every day, but in other situations block graft seems to be superior and vice versa. He reminds us that some environmental factors are related to the organization, the object of the work, the team, the work environment, and the assistants, for example. An important factor is also the behavior of the patient, which according to Dr. Tabanella has gotten worse in the last decade. Patients tend to follow the instructions less and less which may be cause by influences like stress, pandemic, or life becoming more and more complex. But this needs to be taken into consideration. 

So, what is the best approach? According to Dr. Tabanella the best approach is to learn from failures and turn something negative into something positive. Every retreatment of a failure offers a learning experience. The retreatment needs to be based on training and common sense. In case of the presented patient treatment, a provisional should be provided to ensure a good quality of life for the patient. The previous experience of such patient’s is a very complex psychological aspect that needs to be adequately handled. They are reluctant, lost trust towards the medical profession but at the same time are willing to undergo a retreatment. This leaves no error, according to Dr. Tabanella. Every retreatment is a unique journey as the protocol can completely change, he says. 

He continues his lecture with some examples of ailing and failing implants that he has been seeing at his clinic. All the shown cases have something in common, like a misplaced implant, poor management of the mucosa, or a high smile line which was not treated properly. These are case from the US, Europe, and Asia. They have also in common some sort of failure in terms of tissue management, whether with a bone reconstruction or soft tissue management. There are cases of peri-implantitis, cases of mucositis, misplacement of implants, poor pink esthetics, poor emergence profiles or symptomatic patients. This shows that complications are part of the life. Looking at literature published in 1994, an implant with an average bone loss of up to 1.5mm during the first year was a successful result. Nowadays, with the new implant surfaces and new connections, this type of bone remodeling is not seen anymore. Years ago, it was normal and physiological to see bone loss up to the first thread of the external hex implant. This parameter has changed completely, says Dr. Tabanella. An article published in 2019 by Jemt and co-workers, shows that the prevalence of peri-implantitis is increasing. Why is this so, he asks. There might be a difficult explanation, including the fact, that peri-implantitis occurs generally after the 4th year of insertion of the final restoration. But why is it increasing? With access to new technology and new materials, the risk should be reduced, but more complications seem to be occurring. One aspect could be the collaboration between specialist and general practitioners and there might be a lack of communication, as well as a lack of education. Dr. Tabanella observes that less and less colleagues are investing time in education, and he considers this to be most important part, as well as common sense. He emphasizes that soft and hard tissue manipulation is required in almost 100% of the cases. To reduce the risk of bone remodeling a thick buccal balcony is required, according to Dr. Tabanella. Also, a thick peri-implant mucosa needs to be provided. The immune system comes into play as well as most of the patients have some sort of inflammatory response correlating to the plaque index. A small percentage, ca. 5%, of patients is passive, even without good compliance and poor oral hygiene, so they do not show mucositis or peri-implantitis. Their immune system is not reacting the plaque accumulation. This situation is also reflected when looking at the occurrence of periodontal diseases. On the opposite, there is an active type of the population which also a small number, but they are experiencing an advanced peri-implant disease, even with good oral hygiene. There is no correlation between the plaque index or inflammatory index, and the amount of bone loss, which can be seen in implantology as well.  Interesting is the fact, that patient who receive implants around the age of 50, experience more failures. These patients received implants because they lost their own teeth in early phases of their treatment, for example during the first or second year after delivery of the final restoration. Dr. Tabanella highlights, that patients who received implants at a young age are more likely to have this kind of implant failure. This is also related to the immune response and the fact that some patients are at higher risk than others. He reminds us to assess the periodontal status of these patients before performing implant dentistry. By treating the patient for periodontal disease, the risk of having major issues around the neck of the implant can be reduced. 

By showing the next case, Dr. Tabanella wants to challenge us. The image shows an implant with bone loss, bone remodeling and there might be a challenge for some to differentiate bone loss from peri-implantitis. He challenges us to switch from a static mindset to a dynamic mindset. Trying to turn a negative situation in something positive, especially in terms of education. This includes trying to understand why the implant is showing the amount of bone loss, in this case about 2.5mm of vertical bone. The central and lateral incisors are missing. The initial esthetic result can be considered as good, but the patient has always been symptomatic.  Dr. Tabanella refers to a study, that was looking at predictors for peri-implant bone loss. The study was conducted with a split-model design with patients experiencing bone loss on one side of the oral cavity and no bone loss on implants places on the other side of the oral cavity. One predictor that came up was the absence of the Lamina dura, another was the presence of pockets and pain as well as the presence of three important periopathogens: Tannerella forcedia, Campylobacter species, and P micros. And as with this patient, pain is another predictor. The patient experienced pain since the placement of the implant. When clinically observing the patient, a little spot of inflammation is present. Looking at the peri-apical x-rays of the patient, advanced bone loss can be identified. The prosthetic design should be checked too, Dr. Tabanella reminds us. In this case the implant is connected to a natural tooth, and there is a bilateral distal cantilever. Could this be the reason why the implant is showing this amount of bone loss? It is known since the 1990’s that this kind of prosthetic design is a mistake as the biomechanics of the natural tooth a very different to those of the implant. Dr. Tabanella asks us whether this implant is an ailing dental implant? His answer is no, as this case is a failure in guided bone regeneration. By looking at the other pictures, this becomes clearer. He encourages us again to have a dynamic mindset to understand this. Starting to look at the implant from the occlusal point of view, one can see that the implant has been placed outside of the bony housing. This results in not having enough blood supply to maintain the augmented bone. The implant has been misplaced on the buccal side and there are no blood vessels able to support the bone out of the bone housing. 

According to Dr. Tabanella, there is no other option than to remove the implant as any kind of bone reconstruction around the exposed implant will not be successful. A misplaced implant needs to be removed as there will be no other option if a esthetically satisfying final prosthetic should be delivered. In this case, the patient shows a bone loss of 2.5 mm, additionally the central incisor, and the lateral incisor are missing. As the biology of the site is affected by the previous treatment, there is no room for errors, shares Dr. Tabanella. When it comes to complications, the majority of the complications at the oral cavity related to dental implants are biological complications, due to plaque accumulations. When it comes to bacterial contamination of the sites, there are two different types of clinical pathologies: mucositis, which is a reversible inflammatory process of the peri-implant mucosa, which affects about 50% of the implants, according to literature. Of course, in a dental practice where there is a traditional assessment of the periodontal status, where there is a good compliance of the patient, there is a good maintenance of the patient, good support therapy, these percentage cannot be seen. Mucositis is characterized by inflammation, bleeding upon probing, suppuration sometimes, but it's reversible because the bone is not affected by mucositis and it's a plaque induced disease. With the presented patient, who is sometimes symptomatic, and there is bleeding, it is easy to diagnose. When it comes to peri-implantitis, one is dealing with a plaque induced disease which is characterized by a progressive peri-implant bone loss and of course, this is not reversible. This is a bacterial type of disease, and the incidences are quite scary with 10% of the implants and about 20% of the patients. What about the clinics of peri-implantitis: inflammation, bleeding upon probing, suppuration, and progressive bone resorption. Dr. Tabanella highlights that this what it makes the difference between peri-implantitis and mucositis. In general, this is a classic sunserisation defect, a B-shaped defect or circumferential defect and this type of defect has a great potential for tissue regeneration.

Dr. Tabanella encourages us to take a step back, as we need to understand what can be done in order to prevent this type of biological complication. The mucosa seems to have a major role in that sense as the peri-implant mucosa is the first barrier to prevent bacterial ingrowth inside the oral cavity. Today, we can get a soft tissue sealing or maybe what has been defined recently with the concept of mucointegration. Adhesion can be achieved, a hemidesmosomal attachment between the connected tissue or the junction epithelium, and of course, the titanium or zirconia abutment can be achieved. He continues to show an image of human histologies, and we do see connected tissue attachment, junctional epithelium attachment. He points out that connected tissue is rich in blood vessels, but there are no vessels within the junctional epithelium. Every time that connected tissue is lost, an apical shift of the connected tissue occurs, and bone around the neck of the implant is lost. This fragile type of adhesion around the neck of the implant is so crucial to prevent bacterial ingrowth. The reason number one for having a good quality and quantity of peri-implant mucosa is to prevent bacterial ingrowth, Dr. Tabanella reminds us. It is important to avoid any kind of disruption of this very fragile and delicate adhesional connected tissue and junctional epithelium by avoiding multiple reconnections of the abutment whenever possible. Every time an abutment, titanium or zirconia, is disconnected, there is an apical shift to the connected tissue, which means that the blood vessels are going more apical and also the bone will resorb. In this case, the bone loss is not related to peri-implantitis, it is related to the fact that there is additional marginal bone absorption due to the manipulation of the site. Every time that an abutment is disconnected, we see bleeding because the adhesion between connected tissue and the abutment is disrupted and of course the bleeding is coming from the vessels of the connected tissue. 

The reason number two is to prevent bone loss. Dr. Tabanella shares that literature tells us from the literature, that every time we are dealing with a thin phenotype which is less than 2 millimeters, a bone remodeling of up to 1.2 millimeters at one year after the delivery of the final restoration can be expected. On the other side, if you're dealing with a thick phenotype, more than 2 millimeters, and the bone is stable, it is 0.2 versus 1.2 millimeters. The soft tissue is important to prevent higher plaque and bleeding scores, too. This is highly important in terms of the band of keratinized mucosa, which must be more than 2 millimeters again, according to Dr. Tabanella. The magic numbers to be remembered here is 2 millimeters, 2 millimeters of thickness, and 2 millimeters of band of keratinized mucosa. The peri-implant soft tissue is crucially important also for implant maintenance. Why is that, he asks. Because talking about compliance of the patient, only 51% of the patients are compliant after implant treatment, which is scary percentage. Dr. Tabanella closes his lecture with the outlook that every time that we have more than 2 millimeters keratinized mucosa around the neck of the implant means that we're going to have less inflammatory response, less plaque accumulation. But there will also be protective factors, as well in those patients who are erratic maintenance patients, who don't follow a supportive therapy.