Surface analysis of dental caries using a wireless pH sensor and Raman spectroscopy for chairside diagnosis

• Published in: Talanta (Oxford) Vol. 235; p. 122718
• Main Authors: Tabata, Miyuki, Ratanaporncharoen, Chindanai, Ishihara, Noboru, Masu, Kazuya, Sriyudthsak, Mana, Kitasako, Yuichi, Ikeda, Masaomi, Tagami, Junji, Miyahara, Yuji
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-12-2021
• Subjects: Chairside instrument; Dental caries; Iridium oxide; pH sensor; Wireless communication system; Chairside instrument; Dental caries; Iridium oxide; Wireless communication system; pH sensor
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2021.122718

A chairside tool for quantitative analysis of dental caries would improve clinical dental inspections. The wireless caries sensing tool with dental-explorer size has been developed comparing two sensing methods, Raman reading and pH reading for evaluating dental caries. The Raman spectra at 575 cm−1 and 960 cm−1 for in inorganic compounds, as well as 1450 cm−1 and 2940 cm−1 for organic compounds reinforced and supported the pH results. An Iridium/Iridium oxide (Ir/IrOx) pH sensing probe and wireless pH sensor (comprising an ESP8266 ESP-01 wireless module and ADS1115 analog digital converter) has been developed to quantitatively evaluate dental caries. All the operations of the wireless pH sensor were performed with a developed LabVIEW-based real-time data monitoring program. The slope and the linear fitting regression value (R2) of the wireless pH sensor using seven standards were −54.9 mV/pH and 0.999, respectively, showing high accuracy and stability for the pH measurements. The pH on the dental caries surface was measured with the wireless pH sensor, and the pH mapping results in the non-caries and caries areas were 6.9 and 5.7, respectively. The developed wireless pH sensor would be useful to understand the condition of dental caries and support dentists’ inspection to remove only the caries part while keeping the non-caries structure.
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•The surface pH of the dental caries in relation to the molecular composition of the caries areas have been evaluated.•The wireless pH sensor is developed combining with a wireless module, a pH electrode and data acquisition system.•The pH value of the non-caries and caries area were 6.9 and 5.8, which was comparable to the wired pH sensor results.