This randomized controlled trial evaluates the efficacy of diode laser-assisted non-surgical periodontal therapy in kidney transplant recipients with periodontitis. Eighty participants will be allocated to two parallel groups: scaling and root planing (SRP) with adjunctive diode laser therapy or SRP alone. Clinical periodontal parameters, blood biomarkers, radiographic findings, and subgingival microbiome profiles will be assessed at baseline and during follow-up. The study aims to determine whether adjunctive diode laser therapy provides superior clinical and biological improvement compared with SRP alone.

• This is a prospective, parallel-group, randomized controlled clinical trial in kidney transplant recipients diagnosed with periodontitis.
• Participants will be randomized in a 1:1 ratio to receive either SRP with adjunctive diode laser therapy (intervention arm) or SRP alone (control arm).
• Follow-up visits are scheduled at baseline, 1 month, 3 months, and 6 months after treatment.
• Main clinical outcomes include clinical attachment level (CAL), probing pocket depth (PPD), plaque-related indices, gingival inflammation (GI), bleeding on probing (BOP), and oral hygiene status (OHI-S).
• Systemic laboratory outcomes include platelet count, urea, creatinine, and C-reactive protein (CRP).
• Subgingival plaque samples will undergo next-generation sequencing of 16S ribosomal RNA (16S rRNA) at baseline and 1 month after treatment to evaluate microbiome changes.
• Alveolar bone changes will be assessed radiographically according to the study imaging protocol.

Inclusion Criteria:

• Kidney transplant recipients aged 18 years or older.
• Diagnosis of periodontitis according to the study case definition.
• Medically stable and able to undergo non-surgical periodontal treatment.
• Willing and able to provide written informed consent and attend follow-up visits.

Exclusion Criteria:

• - Periodontal treatment or systemic antibiotic use within the predefined exclusion window in the protocol.
• Acute oral infection requiring urgent treatment.
• Pregnancy or lactation, if excluded by the approved protocol.
• Serious systemic condition or clinical instability judged by investigators to preclude study participation.
• Inability to comply with study procedures or follow-up schedule.

Single or double masking only if the protocol truly supports it; otherwise choose None (Open Label). Recommended: Outcomes Assessor masked, if examiner blinding is feasible.