This study is a randomized, controlled, split-mouth clinical trial designed to evaluate and compare the effectiveness of four different subgingival adjuncts used along side standard Scaling and Root Planning (SRP). This protocol is designed to be a standardized therapeutic model. The subgingival adjuncts are standardized, ensuring that the results are not operator dependent and can be replicated across any dental unit. The primary goal of this study is to evaluate the clinical efficacy of three distinct adjunctive strategies: Biological (I-PRF), Antiseptic : Povidone- iodine , Diode-Laser activation, compared to a Saline Control in the initial treatment of stage 2, 3 and stage 4 of the 2018 AAP/EFP periodontal classification.

The investigators hypothesize that while all adjuncts will improve results over SRP and saline irrigation , the biological group (I-PRF) will show the most significant gains in the Smoker Subgroup due to its ability to stimulate local angiogenesis and tissue repair in a traditionally poor healing environment.

• By including smokers, this study addresses "the down to reality " challenge in dentistry. Smoking often impairs the blood supply to the gums; this trial investigates: if a biological approach like I-PRF (which introduces fresh growth factors) or a high-volume Antiseptic irrigation with Povidone-iodine, or a 980nm diode laser activation can overcome these healing barriers . The Key Research Goals: is to determine if the Biological group (I-PRF), which introduces high concentrations of growth factors and leukocytes, provides superior Probing Pocket Depth (PPD) reduction compared to an antiseptic group (Povidone-Iodine) and photobiomodulation group (diode laser activation).
• The Smoking Factor:

Investigator will explore if the regenerative properties of I-PRF can overcome the compromised healing response typically found in the Smoking Subgroup.

• Healing Quality: Investigator will identify which group shows the fastest reduction in inflammation, measured by Bleeding on Probing (BOP) and Clinical Attachment Level (CAL) gain.

Inclusion: Patients with Stage II-IV Periodontitis; at least one bleeding pocket > 4 mm minimum in every quadrant.

Exclusion: patients who:

• Pregnant /Lactating
• History of radiotherapy or chemotherapy in the head/neck region.
• Known hypersensitivity to Iodine or Methylene blue solution
• Systematic antibiotic use within the last 30 days
• Long-term use of immunosuppressants or corticosteroids (daily use)
• type 1 / 2 diabetes

identified individual participant data collected during the study will be shared, including demographic characteristics (age and sex), smoking status, baseline and follow-up periodontal measurements, including probing pocket depth (PPD), clinical attachment level (CAL), bleeding on probing (BOP), treatment allocation by quadrant, and outcome data used in the primary and secondary analyses.

Beginning 6 months after publication of the primary study results and ending 5 years after publication.

qualified researchers who provide a methodologically sound research proposal. Requests should be submitted to the principal investigator and will be reviewed in accordance with institutional policies, ethical requirements, and participant confidentiality protections.