title: Continuous measurement of intra-oral pH and temperature: development, validation of an appliance and a pilot study.
abstract: To describe a novel approach for continuous measurement of intra-oral pH and temperature in individuals carrying out normal daily activities over 24 h. We designed, validated and constructed a custom-made appliance fitted with a pH probe and a thermocouple. Six subjects wore the appliance over a 24-h period for two non-consecutive days, while the intra-oral pH and temperature were measured continuously and recorded. Intra-oral pH and temperature were very similar across different recording days, the difference being not statistically significant (P ≥ 0.14). There was a noticeable difference in the pattern of variation of pH between day and night. During the day, the mean pH was 7.3 (±0.4) and dropped markedly only after consumption of acidic food and drinks. The intra-oral pH decreased slowly during sleep with an average pH of 6.6 (±0.4) being recorded. The difference between day and night was statistically significant (P = 0.002). The mean intra-oral temperature was 33.9 °C (±0.9) during daytime and 35·9 °C (±0·5) during sleep (P = 0.013) with minor fluctuations occurring over 24 h. The continuous and simultaneous intra-oral pH and temperature measurement system described in this report is reliable, easy to construct, able to measure variables over a sustained period and may serve as a future diagnostic tool in a number of applications.
authors: Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand.
authors: J E
authors: JE
authors: Choi
authors: Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand.
authors: C
authors: C
authors: Loke
authors: Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand.
authors: J N
authors: JN
authors: Waddell
authors: Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand.
authors: K M
authors: KM
authors: Lyons
authors: Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand.
authors: J A
authors: JA
authors: Kieser
authors: Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, Dunedin, New Zealand.
authors: M
authors: M
authors: Farella
mesh_terms: D001831:Body Temperature / Q000502:physiology*; D057906:Circadian Clocks / Q000502:physiology; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D009055:Mouth / Q000502:physiology*; D010865:Pilot Projects
keywords: circadian rhythm; dental erosion; intra-oral pH; intra-oral temperature; salivary pH