Acute Oral Health Benefits of Chewing Plectranthus amboinicus: A Clinical Pilot Study on Salivary Pathogens, pH, and Plaque

<p> </p><p> </p><p><bold>Objective:</bold> To evaluate the acute effects of chewing fresh <italic>Plectranthus amboinicus</italic> leaves on oral health parameters, including salivary microbiology, physicochemical properties, and clinicalindices. <bold>Materials and Methods:</bold> A single-blind, randomized, controlled, crossover pilot study was conducted with 25 healthy adults. Participants underwent two interventions on separate days: chewing fresh <italic>P. amboinicus</italic> leaves (experimental) or a tasteless cellulose gum (control) for 5 minutes. Salivary levels of <italic>Streptococcus mutans</italic> and <italic>Candida albicans</italic>, pH, flow rate, total antioxidant capacity (TAC), Plaque Index (PI), Gingival Index (GI), and volatile sulfur compounds (VSCs) were measured at baseline, immediately post-intervention (T1), and at 120 minutes (T3). Acceptability was recorded via questionnaire. <bold>Results:</bold> Chewing <italic>P. amboinicus</italic> resulted in a significantly greater and sustained reduction in salivary <italic>S. mutans</italic> and <italic>C. albicans</italic> counts compared to control (p<0.001), with effects persisting at T3. It induced a significantly stronger increase in salivary pH (to 7.65 ± 0.28 at T1 vs. 7.10 ± 0.25 for control, p<0.001) and boosted TAC at T3 (p<0.001). Significant reductions in PI and VSCs (68% reduction at T1) were also observed uniquely with <italic>P. amboinicus</italic> (p<0.01). The intervention was rated as highly acceptable (92%). <bold>Conclusion:</bold> Chewing fresh <italic>Plectranthus amboinicus</italic> leaves provides immediate, multi-mechanistic oral health benefits—including antimicrobial, alkalinizing, antioxidant, anti-plaque, and anti-malodor effects—significantly surpassing mechanical chewing alone. This validates its traditional use and positions it as a promising natural adjunct for oral hygiene.</p><p> </p>