A preliminary report on continuous recording of salivary pH using telemetry in an edentulous patient

Purpose: This study reports on the development and evaluation of a telemetr y system for recording salivary pH. Materials and Methods: The system used an iridium-oxide pH sensor (Metoxy sensor) and was housed inside a mandibul ar complete denture. It transmitted the data using the AM band (radio frequ ency of 12.3 MHz) and had a maximum power output of approximately 1 mW with a 3-V lithium battery (capacity 190 mAh). For the clinical evaluation, a 6 9-year-old woman who was edentulous and had no systemic disease was the sub ject. Results: Under the conditions of the study, the system was able to op erate for 19 hours. The maximum error of transmitted pH data values was pH 0.15 within the range from pH 5.0 to 9.0. The evaluation of the test subjec t showed that this system operated without problems, and that the pH levels responded appropriately. Conclusion: The developed system was shown to suc cessfully record salivary pH, and it functioned as expected in a single tes t subject.