Periodontitis is a multifactorial chronic inflammatory disease characterized by the
destruction of tooth-supporting tissues, including gingiva, periodontal ligament, and
alveolar bone. It is initiated by microbial dental plaque and modulated by the host
immune response, leading to both local tissue damage and systemic inflammatory effects.

Scaling and root planing (SRP) is the gold standard for non-surgical periodontal therapy
and aims to mechanically remove plaque and calculus from root surfaces. However, due to
anatomical limitations and microbial persistence in periodontal pockets, SRP alone may
not always achieve optimal clinical outcomes. Therefore, adjunctive antimicrobial and
anti-inflammatory agents have been proposed to enhance treatment efficacy.

Chlorhexidine (CHX) is considered the gold standard antiseptic in dentistry due to its
broad-spectrum antimicrobial activity and substantivity. Zinc, on the other hand, has
been shown to possess anti-inflammatory, antioxidant, and immunomodulatory properties.
The combination of CHX and zinc may provide a synergistic effect by reducing microbial
load while simultaneously modulating the host inflammatory response.

This study is designed as a single-center, randomized, controlled, prospective clinical
trial conducted at the Department of Periodontology, Faculty of Dentistry, Ataturk
University. A total of 44 systemically healthy individuals aged between 18 and 65 years
with stage I and II periodontitis will be included.

Participants will be randomly allocated into two groups using a coin-toss method:

- Test group: SRP with chlorhexidine and zinc

- Control group: SRP with distilled water

All participants will receive standardized oral hygiene instructions prior to treatment.
SRP procedures will be performed using ultrasonic instruments. In the test group,
chlorhexidine and zinc solution will be used during the procedure, whereas distilled
water will be used in the control group.

Clinical periodontal parameters including Plaque Index (PI), Bleeding on Probing (BOP),
Probing Pocket Depth (PPD), and Clinical Attachment Level (CAL) will be recorded at
baseline, 1 month, and 3 months. In addition, blood and saliva samples will be collected
at the same time points to analyze biochemical markers including C-reactive protein
(CRP), high-sensitivity CRP (hs-CRP), Oncostatin M (OSM), and Antistreptolysin O (ASO)
using ELISA methods.

The primary objective of this study is to evaluate the clinical effectiveness of CHX and
zinc as adjuncts to SRP. The secondary objective is to assess their effects on systemic
inflammatory biomarkers.

The findings of this study are expected to contribute to the understanding of adjunctive
treatment strategies in periodontal therapy and may support the use of CHX and zinc
combination as a practical and effective approach in clinical practice.