A Micro-Antimony Electrode Designed for Intraoral pH Measurements in Man and Small Experimental Animals

Abstract

The need for a minute strong electrode to measure the pH of small carious lesions and interproximal spaces lead to the development of a micro-antimony electrode without the usual brittle characteristics. A dental probe electrode was made by drawing into a capillary with heat 7 mm Pyrex glass tubing containing a small amount of powdered purified antimony. This electrode in conjunction with standard calomel and KC1 salt bridge was suitable for intraoral pH measurements on man and experimental animals. Some preliminary readings of interdental debris in man were from pH 7.0 to 7.8; adjacent areas on the same tooth varied widely. Carious lesions gave pH values between 6.8 and 4.7 while gingival pockets were pH 7.4-7.8. The pH of Syrian hamsters tooth surface was from 7.4-8.5. A dried carious lesion gave pH 6.7, while after application of sugar solution it fell to 5.6.