and its adverse affects on the human body

Citations from literature


Edited and translated by

Mats Hanson


Additional references by Mike Williams

More links to Galvanism in the mouth


# ... it is evident that metallic contacts between gold fillings and silver amalgam fillings must be considered malpractice since under such conditions a direct local element is formed with corresponding voltages and corrosive conditions (Reply from Bundesgesundheitsamt 14.02.1980 to an inquiry from the consumer organization Arbeitsgemeinschaft der Verbraucher, Bonn)


#This amalgam is destructive to gold fillings and plate. The strong affinity of gold for mercury, renders this amalgam destructive to gold fillings or plate. I have seen in several instances the teeth which were clasped to secure the plate, filled with mercurial paste, and in each instance the clasp was literally eaten off at this point. To demonstrate this effect, we need only rub a piece of gold with the amalgam, when the surface will immediately become white to the extent that the amalgam of gold is formed. This amalgam like that of silver is oxydable and easily removed; gold plugs and plate are not only subject to this destructive process, from actual contact of the amalgam in its primitive form, but several salts formed from the oxydation of these cement fillings, and which are held in solution by the saliva, are also destructive to gold. Westcott: Report on Mineral Paste, The American Journal of Dental Science vol IV, 1844, 175-193


#Occasionally, a gold inlay is placed in contact with an adjacent proximal amalgam restoration, or an amalgam filling is placed in an opposing tooth, or perhaps a gold clasp touches an amalgam restoration. All such procedures are almost sure to cause a corrosion of of the amalgam, since an electrocouple with considerable elevtromotive force is produced between the gold alloy and the amalgam (approximately 500 millivolts). Mercury is sometimes found in the gold alloy, which is thereby weakened. Such a condition is always a hazard to the health of the patient. When couples of this nature are studied under laboratory conditions, the amalgam corrodes, regardless of a polished surface or a protective tarnish film. (The Science of Dental Materials, E.W. Skinner, 3:e ed. 1948, W.B. Saunders Co, Phil. & Lond.) (Changed in the next edition to: such conditions should be avoided)


#...older man, who besides many amalgam fillings, had a gold crown in his mouth, something dentistry considers not allowable because of the possible galvanic processes, but dentists often ignore in practice. 11,2 µg Hg in 780 cm3 urine (14,4 µg/l). He had had stomatitis for several years and also other symptoms indicating mercury poisoning. (Stock A & Cucuel F der Quecksilberhalt der menschlichen Ausscheidungen und des menschlichen Blutes. Zeitschr angew. Chemie 47, 1934, 641-7)


#Amalgam and gold close together is, because of the then occurring electrolytic degradation process in the mouth, especially dangerous and should be avoided. (Stock A. Die Gefährlichkeit des Quecksilberdampfes und der Amalgame, Zeitschr angew. Chemie 39, 1926, 984-989)


#One should especially avoid placing amalgam plombs in the vicinity of metals (genuine gold fillings, gold bridges and bridges and plates of false gold). In such cases electrolytic currents will occur, which also degrade the deeper parts of the amalgam fillings and can cause the evaporation of larger amounts of mercury. (F. Gradewitz, (dentist) Zeitschr angew. Chemie 39, 1926 788-9)


#The erratic variation of current that we found when we plotted the Evans diagrams of gold alloy coupled with an amalgam alloy also can be explained as a succession of deterioration and reconstruction of the corrosion film. Our conclusion is that a clinical amalgam restoration in contact with a gold crown, could corrode continously at a high rate. (Study of the electrochemical behavior of gold dental alloys. Brugirard J, Bargain R, Dupuy JC, Mazille H & Monnier G Study of the electrochemical behavior of gold dental alloys J. Dent. Res 52, 1973, 828-836)


#Cracks in gold crowns cemented on amalgam.... explanation can be mercury diffusing into the grain boundaries in regions where there was contact between amalgam and gold. In this study corrosion products derived from amalgam were identified in the main cracks.... The small area of amalgam exposed to the oral cavity through the cracks will give a small anode and a big cathode, and this will cause accelerated corrosion of the amalgam. The corrosion causes the release of metallic ions, which can cause problems for some individuals. In this case the gold crowns were obtained from patients with symptoms such as a metallic taste from the teeth before extraction. It is not known how common cracks in gold crowns are, but we believe that many cracks have not been detected simply because no one has looked for them. (Ode'n A & Tullberg M, Cracks in gold crowns cemented on amalgam restorations Acta Odont Scand 43 1985 15-17)


#Gold and amalgam placed in contact in the oral cavity will cause galvanic currents and increased corrosion of the amalgam, with release of metal ions. The corrosion of the amalgam may reduce its strength and cause increased marginal breakdown of the filling. The electric currents and possibly also the release of metal ions may cause oral discomfort in certain individuals.... In clinical use, an amalgam restoration may come into contact with a crown or a bridge several times larger, which must be regarded as particularly unfavorable. (Holland, R.I. Galvanic currents between gold and amalgam Scand. J. Dent. Res. 88, 1989 269-272).

# Contact between two different alloys thus enhance corrosion. Under such circumstances a galvanic element in the mouth is formed where the two metals constitute the poles and the saliva the electrolyte. Galvanism, electrocorrosion are different names for the same phenomenon. A gold restoration, repaired with amalgam, causes considerable corrosion, especially of the amalgam and produces noticable changes in the amalgam and also in the gold. An amalgam post under a gold crown also leads to corrosion. Thus, amalgam should not be used to fill cavities in the presence of gold at the cavity margin or occlusally afte endodontic treatment through a gold crown. If it should be necessary to use amalgam for this purpose because of difficulties to introduce some othe material, (e.g. composites), it should be non-gamma2-amalgam, since this corrodes slightly less than other amalgams. If there is a contact between two different amalgam types, a non-gamm2 and one of another type, the older type corrodes extensively. I a gold crown is prepared on an amalgam core, changes on the inner surface can be recognized with the naked eyes. Mixing different types of metals in the same oral cavity should, if possible, be avoided. (Söremark, R. Biological aspects of dental  materials, Compendium, inst. Prostetics, Dept of Dent, Karolinska Inst. Sth).

# In the laboratory and clinically we study the proneness to corrode when commonly used dental alloys are combined. The results show very large differences in corrosion rate between different combinations. The conclusion is that certain dental alloys should not be combined in the same mouth (Söremark, R. Oral Galvanism - vad är det?, KI-Journalen (Karolinska Inst.) no.1 1982 17-17)

# Two or more metals, in the same environment, may cause electrochemical processes such as galvanic cell corrosion and currents. Several investigations have shown that the use of different metals as restorative materials in the same mouth can cause not only symptoms of 'galvanic pain' and patological lesions on the soft tissue, but also deterioration of the used materials and distribution of corrosion products into the tissues.

Cast gold alloy and amalgam are often used for dental restorations in the same mouth. Galvanic corrosion resulting from contact between amalgam and gold has been studied by several workers. Schoonover & Souder reported that gold tarnished and amalgam corroded, when they were placed in contact and kept in a sodium cloride solution for six months.

 ..In spite of these established facts and the oral symptoms caused by electrochemical effects, it is still common practise to mix different alloys as restorative materials in the same mouth and even in the same tooth. (Arvidson K., In vitro corrosion studies of a dental gold alloy in contact with cohesive gold and amalgam Swed. Dent J. 68 1975 41-45).

# Mixing different restorative alloys may give rise to electrochemical processes, such as currents and galvanic corrosion, causing more or less pronounced destruction of the alloys, and pathologic changes in the surrounding soft tissues. As a consequence, restorations of gold and amalgam, in contact with each other, have been contraindicated. (Arvidson, K. Corrosion studies of a dental gold alloy in contact with amalgam under different conditions Swed Dent J 68 1975 135-139).


#Although dissimilar metals not in contact have received most attention, it is not uncommon to find two or more dissimilar metals so placed in the oral cavity as to be in direct contact with or in close proximity to each other. Such a practice will most certainly be conductive to galvanic action, as will be demonstrated by experiments to be described later in this paper. ... polished amalgam disks and plates of a dental gold alloy...If, however, the above mentioned metals are placed in contact with or in close proximity to each other, for example separated by a liquid film, corrosion of one or both of the metals does occur. In dental practice, examples which fulfil the requirements for this typ of galvanic action are 1. two metals connected by bridgework; 2 two metals in corresponding upper and lower teeth, and 3; two metals next to each other in adjacent teeth.... A polished amalgam disk and a plate of dental gold were so arranged in a 1 percent solution of sodium chloride that contact between them could be periodically interrupted each minute. Corrosion of the amalgam began immediately...amalgam and gold in contact...Corrosion began immediately on the surface the amagam. A white flocculent precipitate was formed. After approximately six months, the amalgams and gold were removed from the solution and examined. The amalgams were badly corroded and contained many pits, which were distributed at random over the surface. In some, cases, pits were found on the side of the amalgam not in contact with the gold alloy. Corrosion was most severe on the amalgam at the points where the edges of the gold came in contact with the amalgam.

#Dissimilar metals i contact constitute a hazard and should be examined for evidence of corrosion... The possibility that the patient may be allergic to metal ions formed from corrosion cells should be considered whenever disturbances are thought to arise from the presence of dissimilar metals or from a corroding amalgam. some cases, corrosion was so severe that the amalgam had apparently lost much of its strength and could be crumbled between the fingers. (Schoonover IC & Souder W, National Bureau of Standards, USA, Corrosion of dental alloys J. Amer Dent Ass 28 1941 1278-1291).

# The third effect that has been reported was the corrosion of restorations due to galvanic current. The potential difference between gold and amalgam in saliva has been reported to be as great as 0.5 volts and some corrosion of amalgam is considered possible. Schoonover and Souder have reported that gold restorations were corroded by mercury released from amalgam fillings because of an electrochemical reaction. Since then most dental textbooks have recommended against the use of gold in contact with amalgam in the mouth. It is a fact, however, that many dental clinicians are routinely using them in contact with each other. Thus, there seems to be some discordance between past basic experiments and clinical practice. (Fusayama T et al Corrosion of gold and amalgam placed in contact with each other, J. Dent. Res 42 1963 1183-1197).


#Finally we strongly recommend the absolute avoidance of contact between metals with large potential differences like gold alloys and silver amalgam. (Laetzsch E Ist es bei zahnärztlich-prothetischen Behandlungen erforderlich, einen einheitligen metallischen Werkstoff anzuwenden? Dtsch Stomatol 22 1972 183-188)

# The placement of an amalgam restoration adjacent to a gold inlay seems to be contraindicated. Phillips Elements of Dental Materials WB Saunders Co 1977

# If two fillings, wet with saliva, are connected through an ordinary microammeter or galvanometer... Early workers reported such currents to be as much as 50 microamperes, and even much more in some cases. These facts indicate that contacts between metallic fillings in place in teeth, must be avoided. If  necessary a plastic plug may be inserted in one of them at the point of contact.....The many case histories that have been reported in the literature lead one to conclude that serious pathologic conditions in the oral cavity have been caused by metallic dental fillings. There appears to be no evidence that such conditions are caused directly by the electric current. However, if the subject happens to exhibit hypersensitivity to certain metallic ions supplied by the dental fillings, then, since the electric current hastyens the solution of the fillings and assists in transporting the ions to and through the tissues, it may exert an indirect detrimental effect on the subject. Schriever W & Diamond LE J. Dent Res 31, 1952, 205-229

# The presence of silver-tin-amalgam in the immediate neighborhood of gold will enhance the corrosion of the amalgam. Harndt E Dtsch Zahärztl Wschr 33 1930 564


#On examination of mouths, it was found, for example, that if the patient has gold and amalgam in his mouth, the amalgam acts as the positive pole, giving out calcium (from the tooth; transl. comment.) and producing decay. Gradually, the amalgam itself is destroyed....When two contigous teeth, or two corresponding upper and lower ones, contain different metals, they are liable to destruction. Wakai E JADA 23 1936 1000-6

# When amalgam is brought into contact with a plate of dental gold alloy in a 1 % sodium chloride solution at 37 degrees a very severe corrosion occurs which after a few days results in formation of substantial amounts of corrosion addition to the loose, powderlike corrosion products, minute drops of mercury. Jörgensen, K.D. Acta Odont Scand 23 1965 347-8





Marek M, Hochman R F
In vitro corrosion of dental amalgam phases.
J Biomed Mater Res 10(5):789-804 (1976)

Matano R, Fusayama T
Corrosion of amalgam.
J Prosthet Dent 28:170-178 (1972)

Osawa J, Kitamura K, Ikezawa Z, Hariya T, Nakajima H
Gold dermatitis due to ear piercing: correlations between gold and mercury
Contact Dermatitis 31(2):89-91 (1994)

Arvidson K
Corrosion studies of a dental gold alloy in contact with amalgam under
different conditions.
Swed Dent J 68:135-139 (1975)

Arvidson K
In vitro corrosion studies of a dental gold alloy in contact with cohesive
gold and amalgam.
Swed Dent J 68:41-47 (1975)

Ayres S Jr
Amalgam and gold dental fillings: reaction from electrogalvanic current :letter:
J Am Acad Dermatol 14(2 Pt 1):277-278 (1986)

Fraunhofer J A, Staheli P J
Gold-Amalgam Galvanic Cells.
Br Dent J 132:357-362 (1972)

Fusayama T, Katayori T, Nomoto S
Corrosion of gold and amalgam placed in contact with each other.
J Dent Res 42:1183-1197 (1963)

Heckmann J, Broomberg J
Mercury intoxication as a result of illicit gold smelting :letter:
S Afr Med J 79(1):51 (1991)

Holland R I
Galvanic Currents Between Gold and Amalgam.
Scand J Dent Res 88:269-272 (1980)

Levin M, Jacobs J, Polos P G
Acute mercury poisoning and mercurial pneumonitis from gold ore purification.
Chest 94:554-556 (1988)

Bergman B, Bergman M, Helander H
Appearance of surfaces of dental amalgam in contact with gold.
Acta Odontol Scand 1982;40:325-332

Bergman B, Bergman M, Söremark R
Dissolution and uptake of cadmium from dental gold solder alloy implants.
Scand J Dent Res 1977;85:623-630

Carter R
Electrolytic action in the presence of gold crowns placed over amalgam
Australian Dental Journal 1965;10:317-319

Moberg L E
Long-term corrosion studies in vitro of gold, cobalt-chromium, and
nickel-chromium alloys in contact.
Acta Odontol Scand 1985;43:215-222

Odén A, Tullberg M
Cracks in gold crowns cemented on amalgam restorations.
Acta Odontol Scand 1985;43:?-?