Trehalose vs Glycine Air-Polishing in Peri-Implant Mucositis Treatment

Change in plaque accumulation assessed by Plaque Index (PI)

The Plaque Index (PI) will be used to assess the amount of bacterial plaque on peri-implant surfaces in patients with peri-implant mucositis. The PI will be recorded on four surfaces per implant (mesial, distal, buccal, and palatal/lingual) following application of a plaque disclosing agent. Scores will be assigned according to a standardized ordinal scale: score 0 indicates no plaque; score 1 corresponds to a thin film of plaque detectable only with a disclosing agent or upon probing; score 2 indicates a moderate accumulation of soft deposits visible to the naked eye; and score 3 reflects abundant plaque deposits on the gingival margin and adjacent implant surfaces. The PI for each implant will be calculated as the mean of the four site-specific scores. The primary endpoint is the difference in mean PI scores between the trehalose and glycine groups across all timepoints. Outcome assessors will be calibrated and blinded to group allocation.

Change in peri-implant inflammation assessed by Bleeding on Probing (BoP)

Bleeding on Probing (BoP) will be used to assess peri-implant soft tissue inflammation in patients with peri-implant mucositis. BoP will be recorded by gently probing six sites per implant (mesio-buccal, mid-buccal, disto-buccal, mesio-palatal/lingual, mid-palatal/lingual, disto-palatal/lingual) using a standardized periodontal probe. A positive BoP score is assigned if bleeding occurs within 30 seconds after probing. Each site is scored as either 0 (no bleeding) or 1 (bleeding present). The BoP percentage per implant is calculated as the number of bleeding sites divided by the total number of sites examined (×100). The outcome measure will compare the mean BoP percentages between the Trehalose and Glycine groups across all timepoints. Clinical assessments will be performed by calibrated and blinded investigators.

Change in peri-implant probing depth assessed by Probing Pocket Depth (PPD)

Probing Pocket Depth (PPD) will be used to evaluate changes in peri-implant sulcus depth, an indicator of soft tissue inflammation and healing. PPD will be measured using a standardized millimeter-graded periodontal probe at six sites per implant: mesio-buccal, mid-buccal, disto-buccal, mesio-palatal/lingual, mid-palatal/lingual, and disto-palatal/lingual. The probe is inserted parallel to the long axis of the implant, and the distance from the gingival margin to the base of the sulcus is recorded in millimeters. The mean PPD per implant will be calculated and compared between the Trehalose and Glycine groups at all study timepoints. Measurements will be performed by calibrated and blinded examiners.

Change in gingival bleeding severity assessed by Bleeding Score (BS)

The Bleeding Score (BS) quantifies the severity of bleeding upon probing in peri-implant tissues. It will be recorded at each implant site showing a positive BoP response, based on the following scale: score 1 indicates minimal bleeding (isolated point), score 2 indicates moderate bleeding (line or triangle of blood), and score 3 indicates profuse bleeding (immediate blood flow covering the implant surface). The BS per implant is calculated as the mean of all site-specific scores. The outcome compares mean BS values between the Trehalose and Glycine groups at each timepoint. All probing will be performed by calibrated, blinded clinicians using gentle pressure.

Changes in implant surface morphology assessed by Scanning Electron Microscopy (SEM)

Scanning Electron Microscopy (SEM) will be used to evaluate potential morphological changes on implant surfaces after treatment with trehalose or glycine powder. In vitro tests will be conducted using standard titanium dental implant fixtures treated separately with either trehalose or glycine powder under identical air-polishing protocols. After treatment, implants will be cleaned, fixed, and analyzed using a high-resolution desktop SEM system. Surface alterations such as scratches, loss of microstructure, or contaminant residues will be assessed qualitatively and compared descriptively between groups.