Antibacterial and Anti-Inflammatory Properties of Citrus aurantiifolia Essential Oil-Based Mouthwash: Potential and...

Periodontal disease is one of the most prevalent oral health problems in Indonesia. According to the 2018 National Basic Health Research (RISKESDAS), its prevalence ranges from 73.1% to 75%. The primary cause is dental plaque accumulation, which can be removed chemically using mouthwash. However, most commercial mouthwashes contain synthetic chemicals that may cause adverse effects on oral tissues when used long term. This study aimed to develop a natural-based mouthwash formulation from the essential oil of lime peel (Citrus aurantiifolia), which has been previously reported to possess antibacterial properties. Six formulations were prepared with essential oil concentrations ranging from 1%-20%. Each formulation was tested against Streptococcus mutans, S. sanguinis, S. oralis, Enterococcus faecalis, and Porphyromonas gingivalis.

The essential oil was obtained by hydrodistillation and formulated into six mouthwash preparations. The antibacterial activity was assessed using agar disc diffusion for inhibition zones, while MIC and MBC were determined using the broth microdilution method. Physicochemical properties of the mouthwash, including pH, viscosity, and specific gravity, were also analyzed. The most effective formula was further tested in vivo on the gingiva of white rats (Rattus norvegicus domestica) to assess its anti-inflammatory effect based on gingival tissue histology and polymorphonuclear (PMN) cell count. Cytotoxicity was examined using the MTT assay on normal fibroblast cells (3T3-L).

Formula IV, containing 0.8% essential oil, exhibited the strongest antibacterial activity, particularly against P. gingivalis, with a pH of 6.04, specific gravity of 1.0043 g/cm³, and viscosity of 1.738 cSt. In vivo tests demonstrated a reduction in gingival inflammation and PMN count, indicating a healing process. The MTT assay confirmed that the formulation was nontoxic to fibroblast cells.

Formula IV represents a safe and effective natural-based mouthwash for the prevention of dental caries and gingivitis.