Chairside Saliva pH and Buffer Capacity Helped Flag Hyposalivation in Study

Edited by Dentaltown staff

Chairside measures of salivary pH and buffer capacity improved identification of patients with objectively low salivary flow beyond what age, systemic disease, and medication burden explained, according to a retrospective cross-sectional study published Oct. 13 in Clinical Oral Investigations.

Researchers reviewed 850 patients who underwent salivary flow assessment and oral evaluation at Kyung Hee University Dental Hospital in South Korea. The patients’ mean age was 60.8 years, and 77.3% were female. They were grouped by age as younger than 40, 40–64, 65–79, and 80 or older.

Unstimulated salivary flow declined with age, from 0.57 mL/min in patients younger than 40 to 0.36 mL/min in those 80 and older. Differences in stimulated flow were less pronounced, though hyposalivation defined by stimulated flow was most frequent in the oldest group, at 17.3%. After adjustment, patients 80 and older had 5.47 times the odds of stimulated-flow hyposalivation compared with those younger than 40. Female sex was associated with lower unstimulated and stimulated flow.

A higher count of high-confidence xerogenic medication classes was independently associated with stimulated-flow hyposalivation (OR, 1.63; 95% CI, 1.12–2.36).

In machine-learning models, adding salivary pH and buffer capacity produced the largest gain in discrimination. The area under the curve rose from 0.468 to 0.723 for unstimulated-flow hyposalivation and from 0.608 to 0.725 for stimulated-flow hyposalivation. Buffer capacity was the leading contributor for both outcomes.

The authors concluded that objective salivary hypofunction was not fully explained by age, systemic disease burden, or medication burden alone. They recommended a layered approach that combines chairside salivary markers with age, sex, and xerogenic medication exposure to identify patients who may need objective salivary flow assessment.

Yeon-Hee Lee of the Kyung Hee University College of Dentistry led the study with colleagues at Kyung Hee University, Seoul National University, Hanyang University, and the Korea Institute for Advanced Study. The work was funded by the National Research Foundation of Korea, and the authors reported no competing interests.

The study was retrospective and drew on a single dental hospital with a predominantly female patient population.

Sources:
Clinical Oral Investigations, “Xerogenic medications and clinical markers of salivary hypofunction,” published Oct. 13, 2026: link.springer.com/10.1007/s00784-026-07184-0