What is peri‐implantitis?

Peri‐implantitis is a plaque‐associated pathological condition occurring in tissues around dental implants, characterized by inflammation in the peri‐implant mucosa and subsequent progressive loss of supporting bone.

What is the evidence for plaque/biofilm as a principal etiological factor for peri‐implantitis?

There is evidence from observational studies that patients exhibiting poor plaque control and not attending regular maintenance therapy are at higher risk of developing peri‐implantitis. Studies on treatment of peri‐implantitis reveal that anti‐infective treatment strategies are successful in decreasing soft tissue inflammation and in suppressing disease progression.

What are the clinical characteristics of peri‐implantitis?

Peri‐implantitis sites exhibit clinical signs of inflammation, bleeding on probing and/or suppuration, increased probing depths and/or recession of the mucosal margin in addition to radiographic bone loss compared to previous examinations. At sites presenting with peri‐implantitis, probing depth is correlated with bone loss and is, hence, an indicator for the severity of disease. It is important to recognize that rate of progression of bone loss may vary between patients.

What are the histological characteristics of peri‐implantitis?

Peri‐implantitis lesions extend apical of the junctional/pocket epithelium and contain large numbers and densities of plasma cells, macrophages and neutrophils. In addition, peri‐implantitis lesions are larger than those at peri‐implant mucositis sites.

Are there any specific microbiological and immunological characteristics of peri‐implantitis?

No specific or unique bacteria or proinflammatory cytokines have been identified.

What is the evidence for peri‐implant mucositis being the precursor of peri‐implantitis?

Peri‐implant mucositis is assumed to precede peri‐implantitis. Data indicate that patients diagnosed with peri‐implant mucositis may develop peri‐implantitis, especially in the absence of regular maintenance care. However, the features or conditions characterizing the progression from peri‐implant mucositis to peri‐implantitis in susceptible patients have not been identified.

What is known about the onset and progression pattern of peri‐implantitis?

The onset of peri‐implantitis may occur early during follow‐up as indicated by radiographic data. Peri‐implantitis, in the absence of treatment, seems to progress in a non‐linear and accelerating pattern. Data suggest that the progression of peri‐implantitis appears to be faster than that observed in periodontitis.

What are the major risk indicators for peri‐implantitis?

There is strong evidence that there is an increased risk of developing peri‐implantitis in patients who have a history of severe periodontitis, poor plaque control, and no regular maintenance care after implant therapy. Data identifying smoking and diabetes as potential risk indicators for peri‐implantitis are inconclusive.

Implants that have been placed under less than ideal circumstances are often encountered in day‐to‐day practice. As a result, there may be an increased prevalence of peri‐implantitis associated with these situations.

There is some limited evidence linking peri‐implantitis to factors such as post‐restorative presence of submucosal cement and positioning of implants that does not facilitate oral hygiene and maintenance. The role of peri‐implant keratinized mucosa, occlusal overload, titanium particles, bone compression necrosis, overheating, micromotion and biocorrosion as risk indicators for peri‐implantitis remains to be determined.

There is a high priority to conduct studies that are designed to develop diagnostic, preventive, and intervention strategies for the management of these peri‐implant issues.

Does progressive crestal bone loss around implants occur in the absence of soft tissue inflammation?

Observational studies have indicated that crestal bone level changes at implants are typically associated with clinical signs of inflammation. However, there are situations in which peri‐implant bone loss may occur due to iatrogenic factors, including malpositioning of the implant or surgical trauma.