Purpose: The aim of this study was to evaluate suppuration on palpation, used as a diagnostic test, in the detection of peri-implantitis.

Materials and methods: A total of 65 patients with 267 implants were examined. Clinical inspection was performed by two blinded examiners: The first measured suppuration on palpation, and the second conducted a complete clinical examination. A third examiner combined the previously collected information with radiographic data and diagnosed the patients according to the European Federation of Periodontology/American Academy of Periodontology (EFP/AAP) classification system. Calibration was conducted previously to the fourth examiner on a set of five patients not belonging to the study sample.

Results: When suppuration on palpation was associated with diagnosis of peri-implantitis, the specificity and negative predictive value were high (88% and 84%, respectively), meaning that an implant that was negative to suppuration on palpation had a high chance of not being affected by peri-implantitis. Conversely, the sensitivity and positive predictive value were low (45% and 54%), demonstrating that a suppurating implant will be affected by peri-implantitis in only half of the cases. Area under the curve was calculated as 60.4 (P = .012), and accuracy was found to be 78%.

Conclusion: Suppuration on palpation alone, as with any other clinical sign, does not allow a precise diagnosis of peri-implantitis. An implant without suppuration on palpation shows a high chance of being free of peri-implantitis, while an implant that suppurates upon palpation is not necessarily affected by peri-implantitis. Suppuration on palpation may be a valuable clinical sign, especially when evaluating implants that are difficult to examine via probing.