Prevalence of Peri-implantitis; the Influence of Different Levels of Criteria

Today several measurements are combined to define presence of peri-implant infection. Different thresholds are used in determining disease. Aim: To assess the impact differences in thresholds have on the reported prevalence of peri-implantitis.

Methods:

164 subjects with dental implants inserted at the Institute of Clinical Odontology, University of Oslo between 1990 and 2005, were invited to join the project. 109 subjects attended the examination (mean age 43.8 years, range: 18-80). Mean functional loading time was 7.4 years (SD 4.7). The participants were examined clinically and radiographically. The participants had not been recalled or maintained by the institute as part of a clinical routine.

The study was a cross sectional, clinical study approved by the Regional Committee for Research Ethics. All subjects gave written, informed consent.

Different thresholds were set in order to define peri-implantitis:

• Presence of BOP at PPD ≥ 4mm or ≥ 6mm

• Radiographic peri-implant bone loss was assessed at three different thresholds 2.0 mm, 2.5 mm and 3.0 mm

• Combining these thresholds yielded six levels of peri-implantitis

Results:

Peri-implantitis was diagnosed in 12 to 21 subjects (11.3 – 20.4%) depending on the definition. At implant level, peri-implantitis was diagnosed at 19 to 37 implants (5.4 – 11.4%).

Conclusion:

Peri-implant inflammation was a frequent finding, both with and without peri-implant bone loss. Small changes of clinical and/or radiographic thresholds determining peri-implantitis had a major effect on the prevalence of the disease.