Local and Systemic Effects of Peri-implantitis and Its Treatment (LASSO). A Randomised Controlled Clinical Trial

Dental implants provide the gold standard treatment modality for missing teeth in most clinical situations. However, patient-related, site-related and clinician-related factors play a significant part in the management of patents with edentulous spaces. As the provision of implants increases worldwide and as patient life expectancy increases the long-term maintenance of implants and their restorative components will be essential. Similar to periodontal disease occurring in the periodontium around teeth there is an akin peri-implant disease process occurring in the peri-implant mucosa around implants. The prevalence of peri-implantitis in studies range from 1-47%, with an estimated weighted mean prevalence of 22%. Systematic analysis at implant-based and subjected-based levels shows prevalence's of peri-implantitis of 9.25% and 19.83% respectively.

Peri-implantitis is an inflammatory disease of the soft tissues around an osseointegrated dental implant accompanied by bone loss beyond normal physiological remodelling. Like periodontitis, peri-implantitis is the result of a host inflammatory response to a microbial biofilm, which results in inflammation of the peri-implant connective tissue and progressive bone loss. The current understanding, although limited, suggests that peri-implant disease is a condition that, whilst having several traits in common with periodontal disease, is unique, with distinctive features. Recent discoveries in microbiology opens a completely new perspective on the aetiology of peri-implant disease and the further development of metagenomics might open the way to new therapeutic approaches.

Systemic inflammation plays a crucial role in a number of chronic disorders including diabetes and cardiovascular diseases. There is consistent and substantial evidence proposing that inflammation plays a causative role in the onset and progression of these chronic disorders. Periodontitis is linked to systemic inflammation and effective periodontal treatment resolves this host response. It is plausible to suggest that peri-implantitis could well represent a similar inflammatory trigger for the host. Recent experimental human evidence has confirmed peri-implantitis is associated with a larger mucosal inflammatory infiltrate. This local mucosal response and possible bacterial dissemination, could be triggering a systemic inflammatory response, as assessed by elevated levels of a common inflammatory biomarkers, called C-reactive protein (CRP).

With an inflammatory pathophysiology an exploration of key inflammatory biomarkers can help in disease quantification. Whilst peri-implant crevicular fluid (PICF) will be an area to assess for inflammatory biomarkers of peri-implantitis the focus is still on the blood-borne systemic inflammatory challenge, specifically focusing on the acute-phase protein CRP. CRP is a pentameric pattern recognition molecule which is extremely sensitive to the systemic response to inflammation and regulated by key cytokines like Interleukin 6 (IL-6).

Evidence on CRP specifically within peri-implant disease is lacking. However, studies which use CRP to assist in the diagnosis of diseases around other implantable biomaterials i.e. prosthetic hip and knee joint infections are available and show benefits when combined with other diagnostic tests. Increased levels of CRP have been observed in gingivitis and periodontitis reflecting the locally stressed environment. However, CRP levels fluctuate with various confounding factors including aging, elevated triglycerides and insulin-resistance diabetes. Clinical trials have also shown that treatment for periodontal infection with intensive mechanical therapy can significantly lower the serum CRP levels.