Diagnosis of peri-implantitis in the absence of baseline data: A diagnostic accuracy study

The aim of the present study was to evaluate the diagnostic accuracy of clinical and radiographic evaluations made at a single time point during follow-up in identifying (a) a history of peri-implant bone loss and (b) the presence of peri-implantitis.

427 patients provided with implant-supported reconstructions 9 years earlier were evaluated clinically by Probing Pocket Depth, Bleeding or Suppuration on Probing (PPD, BoP & SoP) and radiographically. Bone levels were assessed relative to the most coronal point of the intra-osseous part of the implant. A history of bone loss and diagnosis of peri-implantitis was confirmed through baseline documentation (direct evidence). Diagnostic accuracy of radiographic bone levels at 9 years and clinical findings (indirect evidence/secondary case definition) in identifying a history of bone loss and peri-implantitis were evaluated through correlation and multilevel regression analyses as well as receiver operating characteristic curves. Results were expressed as sensitivity/specificity and area under the curve (AUC).

Bone levels observed at 9 years were highly accurate in identifying pronounced bone loss (>2 mm; AUC = 0.96; 95% CI 0.95-0.98). In the absence of baseline documentation, a secondary case definition based on the presence of BoP/SoP & bone level ≥ 1 mm (indirect evidence) provided the overall best diagnostic accuracy (AUC = 0.80; 95% CI 0.77-0.82) in identifying peri-implantitis cases (direct evidence: BoP/SoP & bone loss > 0.5 mm). Moderate/severe peri-implantitis (BoP/SoP & bone loss > 2 mm) was most accurately identified by the combination of BoP/SoP & bone level ≥ 2 mm (AUC = 0.93; 95% CI 0.91-0.96). Sensitivity of the secondary case definition suggested by the 2017 World Workshop of Periodontology (WWP) (BoP/SoP ≥ 1 site & bone level ≥ 3 mm & PPD ≥ 6 mm) was low.

The present results underline the importance of baseline documentation for the correct diagnosis of peri-implantitis, especially in its early/incipient forms. The secondary case definition of peri-implantitis suggested at the 2017 WWP demonstrated a high level of specificity but low sensitivity. Moderate/severe peri-implantitis was most accurately identified by the combination of BoP/SoP & bone level ≥ 2 mm.