Purpose: The aim of this study was to compare the effectiveness of diode laser and combined treatment protocols, applied in addition to mechanical debridement, in the treatment of peri-implantitis on clinical periodontal parameters and S100A8 levels in peri-implant sulcus fluid (PISF).

Methods: A total of 39 patients diagnosed with peri-implantitis were divided into three groups based on the treatment protocols used: Mechanical Debridement, Diode Laser, and Combined Treatment. Probing depth, clinical attachment level, modified plaque index, gingival index, and PISF volume measurements were recorded at baseline and at weeks 4 and 12. S100A8 levels in PISF samples were measured by ELISA.

This study included 39 functional implants in patients aged 30-65 diagnosed with peri-implantitis (PD ≥6 mm, no clinical mobility). Participants were assigned to three groups (n=13 per group) using simple randomization (coin toss) performed by an independent researcher: Group 1 (Mechanical debridement only), Group 2 (940 nm diode laser monotherapy), and Group 3 (Combined mechanical debridement and diode laser). Exclusion criteria consisted of systemic diseases, smoking or alcohol consumption, pregnancy/lactation, parafunctional habits, and recent use of antibiotics (within 6 months) or peri-implant treatment (within 3 months). At baseline, clinical parameters were recorded and peri-implant sulcular fluid (PISF) samples were collected. Specifically, probing depth (PD) and clinical attachment level (CAL) were measured at 6 sites per implant, while the modified plaque index (mPI) and gingival index (GI) were assessed at 4 sites per implant.

Prior to PISF sampling, supragingival plaque was removed using sterile curettes, and the area was isolated and air-dried. Samples were collected from mesial and distal sites using paper strips (Ora Flow) inserted 1 mm into the sulcus for 30 seconds; contaminated strips were discarded. PISF volume was measured in microliters using a Periotron 8000 device, and samples were stored at -80°C until analysis. Treatment protocols included: mechanical debridement with titanium curettes for Group 1; decontamination using a 940 nm diode laser (2.5 W, CP2 mode, 400 μm fiber tip) for 30 seconds for Group 2; and a sequential combination of both treatments for Group 3. Following treatment, all pockets were irrigated with 10% povidone-iodine. Clinical parameters and PISF samples were evaluated at baseline (T0), week 4 (T1), and week 12 (T2). For biochemical analysis, S100A8 levels were determined via ELISA at 450 nm and calculated as ng/mL using a standard curve.

Inclusion Criteria:

• Individuals aged 30-65 years.
• Presence of at least one functional dental implant with no clinical mobility
• Diagnosis of peri-implantitis with a probing depth (PD) of ≥ 6 mm.
• Ability to provide informed consent and attend follow-up visits.

Exclusion Criteria:

• Systemic diseases that may interfere with wound healing (e.g., uncontrolled diabetes).
• History of radiation or chemotherapy.
• Pregnancy or lactation.
• Smoking or alcohol consumption.
• Parafunctional habits (e.g., bruxism).
• Use of systemic antibiotics within the last 6 months.
• Periodontal or peri-implant treatment in the relevant area within the last 3 months.

The study population consists of systemically healthy, non-smoking individuals aged 30-65 years who have at least one functional dental implant diagnosed with peri-implantitis (probing depth ≥ 6 mm, no clinical mobility). Participants are selected from patients admitted to the Kırıkkale University Faculty of Dentistry, Department of Periodontology for routine follow-up or treatment.