Peri-implantitis: definitions and treatments
As dental implants have grown in popularity over the past 20 years, so the incidences of peri-implantitis have also increased. Stephen Jacobs describes how to combat this difficult condition
The provision of dental implant-supported restorations has increased exponentially during the last twenty years and in particular the last ten years. During this time we have also seen the increasing prevalence of problems associated with the use of implants, one of the most common being a condition called peri-implantitis.
Before I discuss this in detail, it is important to appreciate that we are still learning about this condition and the presenting factors, together with the diagnosis and recommended treatment regimes.
Furthermore, there can be some confusion over the relevant definitions and terminology that are applied when discussing the condition among both colleagues and patients. The Academy of Osseointegration in the United States is planning a consensus conference next year – which I shall attend and where hopefully some
clarification can be given – and which I hope will result in some kind of algorithm that will give guidance to the implant clinician as to how to manage a given situation.
It is pertinent to add that it was not even ten years ago that I heard experienced clinicians and academics claiming at major meetings that the condition was either extremely rare or did not even exist!
I had the honour of chairing a one-day focus meeting on peri-implantitis last year in London, where four clinicians – Tord Berghlund, Stefan Renvert, Andrea Mombelli and Niklaus Lang, all leading researchers in this field – presented to over 400 dentists and hygienists, shedding much light on this condition.
It is also important to note that there is no implant type or brand that is immune from peri-implant disease and anyone who has placed and/or restored a significant number of implants will be familiar with the occasional presentation of inflammation and bleeding around an implant or even a discharge of fluid when palpating the peri-implant tissues over a restoration. So, for the purposes of this article, we shall refer to two main conditions, peri-implant mucositis and peri-implantitis.
Peri-implant mucositis can be defined as inflammation around the marginal tissue at the neck of an implant-supported restoration and is associated with oedema, redness and bleeding on probing.
Peri-implantitis is considered as a more advanced form of the disease and presents with a purulent discharge associated with marginal bone loss around the implant itself.
The prevalence of peri-implantitis has been shown to be as much as 29 per cent in partially dentate patients and among these, up to 56 per cent of patients had more than one implant affected. Berghlund et al showed greater than 3mm bone loss around implants at ten years in 28 per cent of patients. This, therefore, is a common disease in the implant patient.
There appears to be a link with periodontal disease in that the bacteria found in peri-implant defects are similar to those found in deeper periodontal pockets and that the risk factors are similar in that it is more common in genetically susceptible patients, with secondary factors being smoking and poor oral hygiene.
For several years, I have had much success with the following protocols for managing the disease in both a non-surgical and surgical manner for peri-implant mucositis and peri-implantitis respectively.
One of the reasons that the condition has only been widely documented over the last ten years or so appears to be because of the trend to have the textured surface roughened up to the top of the implant, as opposed to a machined surface or a hybrid design.
As stated earlier, it is characterised by oedema and profuse bleeding on gentle probing and has been shown to be related to inflammatory markers identifiable within peri-implant sulcular fluid. There may also be some horizontal bone loss and gingival recession (Figure 1).
In these cases a non-surgical approach can be applied with a combination of mechanical debridement, sub-mucosal decontamination and antimicrobial therapy. The treatment should be repeated three times within a ten to 14 day period.
Peri-implantitis tends not to be associated with recession, but with a deep peri-implant pocket that becomes colonised by anaerobic periodontal pathogens. It presents with a purulent milky exudate on palpation or probing, together with vertical and crater shaped bone defects (Figs 3, 4 and 5).
Like mucositis, it is an inflammatory mediated condition as evidenced by the presence of inflammatory markers within the sulcular fluid.
The condition is site specific rather than pathogen specific as it does not necessarily affect neighbouring implants in a similar manner. Figure two is a periapical radiograph of two implants at 11 and 21 placed four years ago into good bone and with uneventful healing. Tooth 11 shows a crater like vertical defect, whereas 21 has optimal proximal bone levels. It is relevant to note that clinically, 11 has a milky crevicular exudate on palpation, as compared with healthy marginal tissues at 21.
Historically, the macro-rough surfaces such as titanium plasma spray, hydroxyapatite and porous coatings have been implicated in a severe aggressive form of peri-implantitis which led to implant failure. In contrast, the newer micro roughened implant surface texture, popular in many current brands, shows excellent long-term data; however it is unquestionable that the very common placement of implants in the partially dentate patient is leading to higher incidences of cross infection into the peri-implant tissues.
Many treatment modalities have been advocated but most lack predictability, such as the polishing of the roughened implant surface, removing the implant threads, the use of CO2 lasers and application of various acids.
The suggested protocol in this article, and one with which I have achieved much success over the years, focuses on mechanical direct debridement coupled with systemic and local anti-microbial therapy, and I am grateful to Michael Norton who originally gave me these protocols. Tetracyclines are recommended because they chelate to hydroxyapatite within bone from where they can mediate their effect. High doses of antibiotics are recommended as the pathogens in the peri-implant biofilm form a ’protected niche’, and low doses will contribute to host resistance.
It is usual, even sometimes desirable, to expect some recession of the hard and soft tissues which exposes the implant surface, and in the same way as gingival recession following treatment of periodontitis will eliminate pockets thus aiding ongoing mechanical cleansing, this occurrence can improve the medium to long-term prognosis of the implant(s). It does however place the implants at future risk of peri-implant mucositis and as such, regular follow-up with the occasional decontamination for mucositis is to be recommended.
Further, I advise the following points should be considered:
- Always probe implants in order to determine their health
- Taking peri-apical radiographs will indicate the status of the proximal bone levels, but do not show the facial, palatal or lingual bone – these being the sites commonly affected by peri-implantitis. Figure three illustrates this point, as this is the case highlighted in the clinical images in this article
- CBCT imaging can also be unreliable due to the scatter usually seen around the metal implant, not to mention IRMER and justification issues
- Always treat peri-implant mucositis to prevent it developing into peri-implantitis, which is more difficult to treat.
The progression of implant design, from machined surfaces through to the micro-textured biologically active surfaces, has seen the survival rates of dental implants soar to levels in excess of 96 per cent, even in risk groups such as smokers. But this has to be tempered by the fact that this progress has also seen the increased prevalence of peri-implant disease.
The possibility of future remedial care of their implants must be discussed with patients prior to commencing treatment, especially those with the known risk factors such as genetic susceptibility and smoking, and all this assumes that good oral hygiene is a given.
Torsten Jemt, a member of the original Branemark Clinic team and a clinician with over 35 years of documented data, suggested somewhat controversially, at the recent ADI Congress, that if we wanted long term predictability for an implant in a young patient with a long life expectancy, free from peri-implant disease, maybe we should consider a machined surface implant! These implants are not even available for purchase nowadays!
In conclusion, in my practice, we have seen increasing numbers of cases presenting, ranging from implants that I have placed some time before, to those referred from worried colleagues. While I have traditionally treated them cautiously and conservatively, I am now intervening in a more aggressive manner because there is now undisputable evidence that peri-implant mucositis, if left untreated, will develop into peri-implantitis. Without doubt, we are going to be treating this condition with increasing regularity for the foreseeable future.
About the author
Stephen Jacobs is the principal dentist at Dental FX in Bearsden, Glasgow, where he is happy to take referrals for the management of peri-implant disease and other implant issues. Stephen is also the current President of the Association of Dental Implantology.
PROTOCOL FOR TREATING PERI-IMPLANT MUCOSITIS
1. Mechanical scaling of implant surface with plastic, titanium or carbon fibre instruments. The implant insert for the Cavitron is also useful.
2. Applying to any exposed implant surface, gauze strips soaked with chlorhexidene (0.2 per cent).
3. Sub-mucosal circumferential irrigation of the implant pocket with 5ml chlorhexidene (0.2 per cent).
4. Application of 2 per cent minocycline gel (Dentomycin, Blackwell supplies Ltd).
PROTOCOL FOR TREATING PERI-IMPLANTITIS
1. Systemic antibiotics for three days pre-operatively and five days post-operatively. Advise a combination of amoxycillin (500mg tds) and metronidazole (200mg tds).
2. Pre-operative two minute mouthwash with chlorhexidene (0.2 per cent).
3. Full thickness muco-periosteal flap extending beyond the infected site to healthy tissues.
4. Thorough debridement and curettage down to healthy bone, combined with mechanical cleaning of the implant surface with titanium or plastic tipped instruments.
5. Pack gauze strips soaked in chlorhexidene (0.2 per cent) around implant, into defect and under the flap. Leave in situ for five minutes.
6. Remove gauze and irrigate thoroughly with tetracycline solution (1g in 20ml of sterile saline).
7. If possible, graft defect with hydroxyapatite bone mineral of either allogenic or xenogenic origin, rehydrated in tetracycline solution.
8. Once again, if possible, apply a resorbable collagen barrier membrane.
9. Closure of flap and regular reviews.
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