Development of a device for continuous salivary pH measurement at two locations in the oral cavity

Conventional handheld pH meters have measurement limitations. Therefore, this study aimed to continuously measure the salivary pH at two intraoral locations using a newly developed sensor system.

In this pilot study, we developed custom-made intraoral mouthguards (MG) with two pH sensors in the anterior region (Channel 1: Ch1) and the buccal side of the maxillary molar (Channel 2: Ch2) to continuously monitor salivary pH at two different locations in the oral cavity.

The coefficient of determination (R²) for all MG sensor measurements was ≥0.99, with a high level of accuracy. Both sensor channels exhibited similar mean pH values for standard solutions, with small and constant variations. However, notable unstable differences in intraoral measurements were observed during rehydration owing to positional differences. Nonetheless, the MG sensors demonstrated excellent reliability with consistently high Intraclass Correlation Coefficients ranging from 0.977 to 0.999.

This pilot study provides valuable insights into salivary pH fluctuations, particularly during exercise, through continuous measurements using a sensor system for the simultaneous acquisition of real-time data from different anatomical sites. These results emphasize the potential of developing an intraoral sensor system that can detect subtle variations in salivary pH.