The participants in the mechanical instrumentation with chlorhexidine (MC) group were treated with conventional submarginal instrumentation using titanium curettes. Local anesthesia was applied before the procedure. The operator performed submarginal mechanical debridement until the implant surface was deemed adequately cleaned. Following mechanical instrumentation, the peri-implant pockets were irrigated with 0.2% chlorhexidine digluconate solution for 1 minute.

The participants in the mechanical instrumentation with ozone (MO) group were treated with conventional submarginal instrumentation using titanium curettes. Local anesthesia was applied before the procedure. The operator performed submarginal mechanical debridement until the implant surface was deemed adequately cleaned. Following mechanical instrumentation, gaseous ozone was applied to the peri-implant pockets using an ozone-generating device and a specialized glass fiber probe. The ozone gas was delivered to four sites (mesial, distal, buccal, and lingual) for 15 seconds per site, resulting in a total application time of 1 minute per implant. The device operated at a power of 3 watts and 80% oxygen concentration, as recommended by the manufacturer.

The participants in the mechanical instrumentation with glycine powder air abrasion (MA) group were treated with conventional submarginal instrumentation using titanium curettes. Local anesthesia was applied before the procedure. The operator performed submarginal mechanical debridement until the implant surface was deemed adequately cleaned. Following mechanical instrumentation, the peri-implant pockets were treated with glycine powder-based air abrasion using an air-abrasion device (AIR-FLOW® handy 3.0 PERIO HANDPIECE, EMS, Nyon, Switzerland) and a flexible Perio-Flow® nozzle. The nozzle was inserted into the pockets and guided in a circular motion from coronal to apical, parallel to the implant surface, in a non-contact mode as recommended by the manufacturer. The air-abrasion treatment was applied to four sites (mesial, distal, buccal, and lingual) for 5 seconds per site, resulting in a total application time of 20 seconds per implant.

The participants in the glycine powder air abrasion monotherapy (A) group were treated exclusively with glycine powder-based air abrasion. Local anesthesia was applied before the procedure. The peri-implant pockets were instrumented with an air-abrasion device using glycine powder and a flexible nozzle. The nozzle was inserted into the pockets and guided in a circular motion from coronal to apical, parallel to the implant surface, in a non-contact mode as recommended by the manufacturer. The air-abrasion treatment was applied to four sites (mesial, distal, buccal, and lingual) for 5 seconds per site, resulting in a total application time of 20 seconds per implant. .