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115 persons were studied from a body of patients referred to the Faculty of Odontology, University of Umeå, for investigation regarding any occurrence of oral galvanism. Potential and polarization of metallic restorations and dentures were recorded using a method and equipment previously described. Data regarding distribution of potential ranges with respect to number of patients and type of alloy are presented. The distribution of calculated intraoral currents in relation to number and type of metallic contacts is stated. Relevant parameters for the study of oral galvanic (bimetallic) cells are discussed.

A study was conducted to scrutinize the precision of a method for in vivo potential and polarization measurements. The variation with time of the magnitude of currents created at contacts between metallic dental restorations of varying age was also studied. The precision found indicates that the method allows for comparatively precise measurements of potentials to be taken. Studies of performed measurements of polarizations show that the precision of these measurements varies somewhat with contact conditions and the areas of restorations examined. The precision of the currents calculated was found sufficient for precise enough calculation to be made of the magnitude of currents created in the oral cavity. The study also shows a decrease with time of the magnitude of currents created at contact between metallic dental restorations of varying age.

An epidemiological study was performed in 250 persons who five years previously had been treated with extensive metallic reconstructions. To gain representative information these persons were selected at random from three Local Social Insurance Offices in different parts of Sweden. Those person, who in a questionnaire reported symptoms that could be alleged to have been caused by oral galvanic actions, were offered free clinical examination including quality evaluation and free measurements of potentials and polarizations of the metallic dental restorations. Persons from a subgroup to this study not suffering from any oral discomforts were chosen as a control group. Comparisons between the two groups were made in regard to current creation at metallic contacts, clinical quality and mucosal conditions. In none of the statistical analyses performed, differences could be shown between the groups. A tendency to higher amounts of restorative care at comparatively lower level of technical quality could, however, be noticed in the group of persons with oral symptoms which they themselves associated with oral galvanism.

Amalgam is still one of the most useful and widely used dental filling materials. On rare occasions however allergy to one of its constituents may preclude its use. In such instances confirmation is required so that an appropriate treatment plan may be formulated and submitted (if necessary) to the Dental Estimates Board (DEB) for approval.

Galvanic cells may be created when dentures made of cobalt-chromium alloys are placed on teeth with metallic restorations. The power of such cells was evaluated in an in vitro galvanic using amalgams, gold alloy, and nickel-chromium alloys. The amalgams and one of the nickel-chromium alloys revealed high corrosion currents when placed in contact with cobalt-chromium alloy, the conventional amalgam showing the highest values. The gold alloy and another nickel-chromium alloy exhibited low corrosion currents and they were noble with respect to cobalt-chromium.

The content of particulate matter and mercury vapor in dentist breathing air during removal of amalgam restorations was assessed. Mercury and silver were quantitatively assayed by nuclear chemical analysis, and the mercury vapor concentration was measured with a sniffer. When the water spray was not used, the short time threshold limit values for exposure to mercury and silver were exceeded about 10 times. With water spray the mercury content was reduced to a level considerably lower than the threshold limit value, whereas the silver concentration slightly exceeded the corresponding limit.

The galvanic currents between gold and amalgam were determined in vitro in aerated artificial saliva kept at 37 degrees C. Using conventional amalgam, the current between gold and amalgam was rapidly fluctuating, and both the magnitude of this fluctuation and the maximum current density increased with increased ratio between the gold and the amalgam surface area (G/A). The current density exhibited by the non-gamma 2 amalgam was lower, independent of G/A, and showed no fluctuations.