Evaluation of Halitosis, Salivary Flow Rate, and Whole-Saliva pH Across Menstrual Cycle Phases in Healthy Female Dental Students: A Clinical Observational Study.

BACKGROUND: Hormonal fluctuations during the menstrual cycle may influence oral conditions, including halitosis and whole-saliva pH characteristics. However, the relationship between menstrual cycle phases, halitosis, salivary flow rate, and salivary pH has not been fully elucidated. METHODS AND MATERIALS: This prospective observational study included 32 systemically healthy female dental students aged 18-25 years with regular menstrual cycles. Measurements were performed during three phases of the menstrual cycle: menstrual (days 1-4), follicular (days 7-11), and luteal (days 24-27). Halitosis was assessed using both organoleptic evaluation and a portable device (Breath Checker®). Salivary flow rate was measured using the spitting method, and whole-saliva pH was determined with a digital pH meter. Clinical oral parameters, including plaque-positive surfaces (%) and bleeding on probing, were also recorded. Data were analysed using the Friedman test and Spearman's correlation analysis. RESULTS: No statistically significant differences were observed in halitosis scores, salivary flow rate, plaque-positive surfaces (%), or bleeding on probing across menstrual cycle phases (p > 0.05). Whole-saliva pH showed a significant difference among phases (p = 0.017), with higher values in the menstrual phase compared to the luteal phase (p = 0.006). A significant positive correlation was found between salivary flow rate and salivary pH (rho = 0.511, p 0.001). CONCLUSION: Menstrual cycle phases did not significantly affect halitosis or salivary flow rate in systemically healthy women. However, whole-saliva pH varied significantly, suggesting that hormonal fluctuations may influence the biochemical properties of saliva rather than its quantity. These findings highlight the importance of considering hormonal effects when interpreting salivary parameters in clinical practice.