Article
The previous issue of Dental Update reviewed the recent developments in restorative dentistry reported at the IADR 2017.1 It is the aim of this article to review the clinically-relevant papers presented on dental implants at the same meeting.
Over recent years, the use of dental implants has become common practice and peri-implant disease is more frequently evident. The available literature, together with the cumulative clinical experience, suggests that we will be seeing more and more cases of peri-implant disease. In this regard, the reported prevalence of peri-implant disease in the literature is that this affects almost 30–50% of implant patients.2 This means that one out of two or three of our implant patients might present with peri-implant disease at some point after implant placement. This is an important aspect of informed consent for our patients. Another troubling issue with regards to peri-implantitis is the lack of appropriate, well-documented gold-standard treatment. There are many suggested treatment options described in case reports and case series in the literature; none of them seems to provide a predictable long-term resolution for the disease. Therefore, in order to prevent and treat peri-implant disease, there is a need to understand the nature of this disease and its risk factors.
This year a number of scientists presented their findings and novel diagnostic and treatment methods of peri-implantitis during the ‘General Meeting’ of The International Association for Dental Research in San Francisco. The results were presented either by way of research posters or 15-minute oral presentations and participants could also become familiar with more specific topics by attending symposia or workshops. Peri-implantitis was discussed on the first day of the conference at the symposium Peri-implantitis: The Disease of the Future! (Abstract 11) sponsored by the Periodontal Research Group and the Colgate-Palmolive Company. The speakers focused on causes and risk factors for peri-implant disease, ways to prevent its occurrence and the currently available treatment options for peri-implantitis. The participants of the symposium learned about: the nature of peri-implant disease and its definition and prevalence; risk factors for peri-implant disease; and prevention methods for peri-implant disease; as well as recognizing the surgical and non-surgical treatment options for peri-implant disease. The chairman of the session, Professor L Levis from University of Alberta in Canada, explained that the most essential issue to remember is how to prevent peri-implantitis disease. Various risk factors have been identified, such as smoking, diabetes and periodontal disease, but the most important risk, by almost 15-fold, is poor oral hygiene. Oral hygiene is therefore a risk that can and should be controlled. Plaque control should be perfect before placing an implant and patients' consent should involve demonstration that they can control plaque effectively over time. Otherwise, both the patients and dentists will likely have to deal with possibly increasing incidence in peri-implant disease in the future.
In order to avoid the disease, Professor Curtis, from UCSF School of Dentistry, San Francisco, CA, proposed guidelines for patients with tooth- and implant-borne removable and fixed restorations, which includes:
Details can be found in the article: ‘Clinical Practice Guidelines for Recall and Maintenance of Patients with Tooth-Borne and Implant-Borne Dental Restorations.3In this, a set of the clinical practice guidelines (CPGs) was developed for tooth-borne restorations and implant-borne restorations. These documents serve as a baseline, with the expectation of future modifications when additional evidence becomes available.
The speakers suggested that dentists should aim to limit the risks of peri-implantitis, however, there is still a question – What should they do when it happens to one of their patients? Present studies are investigating the efficacy of commonly used antimicrobial agents in decontamination of multispecies mature oral biofilm on sandblasted, large-grit and acid-etched (SLA) titanium implants.4 The authors tested the following agents: 0.9% NaCl, exposed for 2 min to tetracycline paste; 1% Chlorhexidine gel (CHX); 35% phosphoric acid gel (Etch); or a novel chemical formula (0.3% cetrimide, 0.1% CHX and 0.5% EDTA), and then rinsed again with 0.9% NaCl. The results indicated that rinsing the surfaces with 0.9% NaCl removed the majority of the biofilm. However, bacteria persisted in all specimens and none of the disinfectants was superior to the double saline rinse group. The analysis showed that CHX and Etch groups had a statistically significant reduction of viable bacteria, although small. Overall, the results show that many disinfection agents used in the clinic are ineffective in biofilm removal and leave live bacteria on the surface. In other words, the answer to the microbiological disinfection of implant sites is still not clear.
A substantial and growing number of the world's population is elderly, with the greying of the world's population being predicted to have millions of individuals with systemic medical conditions that can affect oral health and dental treatment. The planning of implant treatment of these medically compromised patients can be problematic in terms of oral complications, dental therapy, and emergency care. The symposium Peri-implant Tissue Healing/Maintenance in Systemically Compromised Scenarios (267) provided a clinical update of current clinical oral implant treatment guidelines for patients presenting systemic conditions known to disrupt peri-implant tissue healing (ie metabolic syndrome, diabetes, immunosuppression), but also explored potential treatment alternatives that can be derived from current molecular, highly translational pre-clinical and clinical evidence to devise strategies for improvement in oral implantology clinical outcomes. The symposium concluded that patients with systemic diseases have a higher risk of peri-implantitis. However, it is clear that there are gaps in the understanding of how systemic conditions affect peri-implant tissue healing and maintenance and how basic preclinical and clinical research may be used to improve oral implantology care in systemically compromised patients. In that regard, Professor Romanos, from the University of Rochester, US, asked: Can patients with diabetes be good candidates for dental implant therapy? And, how does hyperglycemia and glycemic control influence osseointegration? The selected studies5 reported that poorly controlled diabetes negatively affects implant osseointegration; however, under optimal serum glycemic control, osseointegration can successfully occur in patients with diabetes. Also, the use of antiseptic mouthrinses and oral-hygiene maintenance helps achieve a successful dental implant osseointegration in subjects with diabetes. In conclusion, a successful dental implant osseointegration can be accomplished in subjects with diabetes with good metabolic control (serum glycemic level and haemoglobin A1c in normal range) in a similar manner as in subjects without diabetes.
The message from the meeting was clear. In order to understand the mechanism of peri-implantitis and failure of implant treatment, further basic research is required. Preclinical (in vivo studies) investigations of peri-implant bone healing on systemically compromised subjects have so far been limited to small animal models. While insightful, these models present a reduced translational potential due to dental implant size restrictions and the inability to monitor disease over longer periods. It was therefore interesting to note that Professor P Coelho, from New York University, US presented preliminary results of his preclinical investigation of peri-implant bone healing in infected and non-infected sites in a medically compromised large animal model. Since obese-diabetic minipigs share substantial similarities with obese-diabetic humans, such as hyperglycemia, hyperlipidemia, insulin resistance, a pro-inflammatory status, high blood pressure and atherosclerosis, the potential significance of this project may have a broader public health impact. The project is complex and only part of the results was presented, which confirmed a relationship between high serum glycemic level and peri-implant disease.
Further interesting innovations were presented during IADR about novel surfaces of dental implant using high sodium containing bioactive glass (0508), selenium nanoparticles with anti-microbial properties (0510), platelet activating peptide (0512), polyetheretherketone implants (1513), and plant-derived nanoparticles (0304). However, as mentioned, novel implants surfaces are still under in vitro, in vivo and materials properties investigations and we will still need to wait for them to be available for clinical use.
Participants of the IADR had a chance to learn directly from experts on how to treat peri-implantitis and plan treatment in patients with Periodontitis during following events. The outcome of ‘Lunch and Learning’ varies and depends on individual interest. However, from my personal experience, this session brings the most valuable, practical knowledge, so I highly recommend joining these workshops during the next General Meeting of the IADR, which will be held in London in July 2018. For those who are interested in a challenge in the innovation in implantology research, you can submit your work until 1st December 2017 to a competition organized every year by the Academy of Osseointegration. This year, the IADR Academy of Osseointegration Innovation in Implant Science Awards 2017 was presented to Lyndon Cooper. He was selected for this award for his research entitled ‘Epithelial (dys)function in Peri-implantitis’. This study will describe the molecular pathogenesis of the chronic peri-implantitis lesion and will provide a first characterization of the junctional epithelium in healthy and diseased peri-implant tissues. The results of his work will be presented in a number of publications in the following year and during the IADR in London 2018.
In conclusion, we should attempt to preserve more and extract less, treat the disease first and establish the most favourable environment for placing an implant, and control better the known risk factors. Prevention is, and will always be, better than the treatment.