抄録
Electrode potentials of non precious alloy crowns in the mouth were measured in a clinical situation using a pH-meter in conjunction with a platinum micro-probe and a saturated calomel electrode. Nine patients who participated in the study were restorated with crowns which were prepared from commercial dental alloys of Co-Cr, Ni-Zn-Cu and Ni-Cr. During a period of three months after the cementation of the crowns the electrode potentials of the crowns were in the range of -0.21 V (SCE) for Co-Cr crowns, -0.10--0.20 V (SCE) for Ni-Zn-Cu crowns and -0.13--0.21 V (SCE) for Ni-Cr crowns and were roughly the same for all non precious alloy crowns examined. The measurements of electrode potential in vitro showed that the potentials of the alloys in 0.1 N sodium chloride solutions were close to the potentials in the mouth. In acid solutions, however, the electrode potentials of the alloys were noble to those in neutral or alkaline solutions.
