The electrochemical activity of the oral cavity--a new approach.

In order to develop model systems for studying and understanding corrosion phenomena in the oral cavity the electrochemical nature of the oral cavity must be known. Accordingly, the PH and oxidation potential Eh (SCE) were measured in vivo in nine patients utilizing microelectrode techniques. Three of the patients had periodontal therapy and three had received minimal dental care. Sampling was always performed at five specific sites and in periodontal pockets greater than 4 mm when available. In the five sites common to all subjects the oxidation potential ranged from -58 to +212 mV (SCE) and the pH ranged from 6.1 to 7.9. For patients undergoing periodontal therapy the pH/potential clustered around acidic pH (6.6) and an oxidation potential range of 270 mV, whereas minimal dental care revealed a pH range from 6.3 to 7.9 and a small range (57 mV) of oxidation potential. Differences in pH and oxidation potential are related to site of measurement, periodontal health of patient and nature and quantity of restorations present.