This prospective in vitro study aims to evaluate the effects of two chlorhexidine-based mouthwash formulations on the survival and function of human gingival fibroblasts (hGFs). Gingival fibroblasts obtained from discarded gingival tissue collected during routine dental procedures will be cultured and exposed to different concentrations of a conventional 0.2% chlorhexidine mouthwash and a 0.2% chlorhexidine mouthwash supplemented with N-acetylcysteine (NAC) and hyaluronic acid (HA).

Cell viability, apoptosis, migration, and gene expression will be assessed at multiple time points using Trypan Blue exclusion assay, fluorescence-activated cell sorting (FACS), scratch assay, and quantitative real-time PCR. The study is designed to investigate the concentration-dependent effects of chlorhexidine on fibroblast viability and wound-healing-related functions and to determine whether the addition of NAC and HA may improve the biological compatibility of chlorhexidine-based formulations.

Inclusion Criteria:

• Male or female adults aged 18 years or older.
• Undergoing routine dental surgical procedures (e.g., tooth extraction or gingivectomy).
• Willing and able to provide written informed consent for the use of discarded gingival tissue for research purposes.
• Systemically healthy.

Exclusion Criteria:

• Presence of systemic diseases.
• Presence of relevant medical comorbidities.
• Current smoker.
• Refusal to provide informed consent for the use of discarded biological material.

The study population consists of three healthy adult donors undergoing routine dental surgical procedures at the Dental Unit of San Raffaele Hospital. Small fragments of discarded gingival tissue obtained during procedures such as tooth extraction or gingivectomy will be collected following informed consent. Human gingival fibroblasts will be isolated from these tissues and expanded in culture for in vitro experimental analyses.