The present study included 4 patients, 3 female and 1 male (mean age of 66 ± 5 years), who attended the Implant Dentistry Department at Federal University of Santa Catarina, complaining of pain, discomfort, suppuration, and/or bleeding at implant sites. All patients revealed a history of periodontal disease, were non-smokers (100%), and reported no additional systemic diseases. The patients exhibited a total of 5 machined titanium implants with a mean loading time of 12 ± 6 years, supporting single screw-retained prostheses and were diagnosed with peri-implantitis.

Peri-implantitis was defined as the combination of bleeding on gentle probing (BOP) with or without suppuration, probing depths (PD) ≥ 6 mm, and radiographic marginal bone loss (MBL) (i.e., interproximal bone levels ≥ 3 mm apical of the most coronal portion of the intraosseous part of the implant) [2]. All implant sites were associated with an advanced bone loss (> 6 mm/> 50% of the implant length) [14] and were clinically stable (i.e., no manually detected mobility) but were scheduled for explantation due to the advanced disease progression. The study protocol no. 3437751 was approved by the Human Research Committee at Federal University of Santa Catarina-Brazil, 2016–2021, and all patients signed an informed consent according to the university ethics regulations.

The following clinical measurements were recorded using a color-coded plastic periodontal probe (PCV12PT Hu-Friedy Inc., Chicago, IL, USA): (1) BOP, evaluated as present if bleeding was evident within 30 s after probing, or absent, if no bleeding was noticed within 30 s after probing; (2) PD measured from the mucosal margin to the bottom of the pocket; (3) suppuration, evaluated as present if it was evident after probing and/or peri-implant palpation. All measurements were performed at 6 aspects per implant: mesio-vestibular (mb), mid-vestibular (b), disto-vestibular (db), mesio-oral (mo), mid-oral (o), and disto-oral (do) by one calibrated investigator (M.B.).