Digital and strip-based salivary pH measurements assessed for caries risk in 66 school-aged children

Dental caries is a multifactorial disease influenced by biological, behavioral, and preventive factors. Salivary pH has been proposed as a non-invasive biomarker for caries risk assessment, however, its independent clinical relevance within structured digital risk models remains unclear. This study school-aged pediatric cohort using the Cariogram platform as a structured, multifactorial caries risk assessment tool, and to evaluate the role of digitally measured salivary pH in relation to caries risk stratification and clinical caries indicators within this framework. A total of 66 children aged 6–12 years were included. Unstimulated salivary pH was measured using both a digital pH meter and colorimetric strips. Caries risk was assessed using the Cariogram platform. Agreement between pH measurement methods was evaluated using Bland–Altman analysis. Associations between salivary pH, dietary intake frequency, and caries risk were explored using Spearman's rank correlation. A multivariable linear regression model was constructed using the Cariogram-derived chance to avoid new caries (%) as the dependent variable, including mean digitally measured salivary pH, dietary intake frequency, oral hygiene status, fluoride toothpaste use, age, gender, and saliva collection timing as predictors. Digital salivary pH values ranged from 6.1 to 7.2, with a peak between 6.6 and 6.8. Strip-based measurements systematically underestimated pH, with a mean bias of approximately 0.24 pH units. Salivary pH showed weak or negligible associations with Cariogram risk categories. In the multivariable model, dietary intake frequency, oral hygiene status, fluoride toothpaste use, and saliva collection timing were significant predictors of caries risk, whereas salivary pH was not independently associated after adjustment for behavioral and preventive factors. Salivary pH is a biologically relevant but insufficient standalone marker of caries risk in children. Its clinical value emerges when measured reliably and interpreted within a multifactorial, caries risk-assessment framework supported by digital tools, particularly the Cariogram platform and digital pH measurement.