Medicinsk forskning och utveckling
Leg. Tandl. Christer Malmström

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Amalgam derived mercury in feces


Kvicksilverläckage från amalgam av känd ålder


LMI-Biospectrons feces test


Amalgam ett ostabilt material


Infraktioner och kuspfrakturer på tänder med amalgamfyllningar


Oral Miljöförorening


100 analyser av kvicksilver i feces


Mercury in brain tissue of infants

Amalgam derived mercury in feces

Christer Malmström DDS, Mats Hansson PhD
och Magnus Nylander MD, DDS

ISTERH Third International Conference
and NTES Fourth Nordic Conference on Disease.

Stockholm (Huddinge), may 25 - 29, 1992.

bild av  en flicka

A girl
11 years old,
37 kilos,
no previous amalgamfillings

open mouth  
amalgam filling was made

left arrow

One small
amalgam filling
was made

(0.12 g ANA 70, containing 50% Hg, 34.6% Ag, 9.7% Sn, 5.5% Cu, 0.2% Zn.
Rubber dam and high-velosity evacuation were used.)

Our results show that amalgam dental fillings expose children to considerable amounts of mercury.

Excretion of mercury and silver in feces during 72 days after one amalgam fillings was made.

PPB ww

Test no




No amalgam:







day 1





day 2





day 3


3 200

1 300


day 4





day 35





No amalgam:




day 1





day 2





day 3





day 4





day 35





Control 1





Control 2





Control A
"Normal" amalgam filling two surfaces

14 400

4 100

1 800

PPB = Parts Per Billion = µg/kilo
w w = wet weight
Feces weight = 125g/day

Test 0 = before amalgam filling.

Test 1, 2, 3, 4 and 5 = day 1, 2, 3, 4 and 35 after one small amalgam filling was made.

Test 6, 7, 8, 9 and 10 = day 1, 2, 3, 4 and 35 after removal of the amalgam filling.

C1 and C2 = control person 1 and 2 with no amalgam ever.

Control A = control person, girl, 17 years old. Fecal test third day after one "normal" two surfaces amalgam filling on a molar (0,8g) was placed.

The strong relationship between excretions of mercury and silver (r = 0,81) clearly shows that the mercury is amalgam derived.

WHO standard for maximal acceptable total intake of mercury by food ~ 45 µgHg/24h.

Mercury from one amalgam filling

Mercury (Hg) vapor release from amalgam fillings has been well documented. Urine and feces levels are positively related to oral amalgam surface. However, the major excretion route for Hg is via feces.

Mercury from amalgam

The study shows that the feces contains mercury from dental amalgam fillings in amounts which far exceed WHO limits ~ 45µgHg/24h.

Human experiments demonstrate that even one small amalgam filling, (0,12g ANA 70) in an 11 years old girl (37 kilo) with no previous amalgam fillings, increases HG levels in feces from 23 ppb ~3 µgHg/24h to 3200 ppb ~ 400 µgHg/24h on the third day.

gastrointestinal transit

Mercury has a delayed gastrointestinal transit

Indicator dye, blueberry, in connection with amalgam placement shows that mercury has a delayed gastrointestinal transit.
Blueberry execrated day 1 and 2.
Mercury maximum execration day 3.

"Every medical man of any considerable practice has undoubtly had numerous cases of it, but never knew what it was." (Payne, 1874)

Inorganic mercury is mainly execreted in feces and urine and to some extent sweat. Minimal studies show that the distribution of the execretion between the different routes is dose dependent, Rothstein & Hayes, 1960 and 1964; Ceber 1962; Kristensen & Hansen 1980 i.e. at decreasing doses the importance of fecal route increases, 85% was found in feces. Cherian et al. 1978 exposed human volunteers to radioactively labelled Hg vapor, 79% of the excreted amount was in feces.

Skare & Engqvist, 1992, found fecal excretion of mercury from amalgam in the range 27-190 micrograms/day in persons having from 18-82 amalgam surfaces (crowns counted as 6 surfaces). Urine levels were "normal" with only one value over 8 micrograms/day.

There are only a few previous studies on fecal levels of mercury after amalgam placement. Borinski, 1931, measured a total excreation (feces + urine) of 10-100 micrograms/day in 50% and more than 100 in 50% of the children after amalgam therapy. The increased levels lased for some months and subsequently dropped considerably. The levels in feces were generally five (5) times higher than those in urine.

Frykholm, 1957, found somewhat increased urine mercury levels after amalgam placement in dogs and in humans but up to 87.000 micrograms/100g feces in dog and 1.900 micrograms/100 g in humans where a much smaller amount of amalgam was used. A second peak of mercury excreation occurred after removal of the fillings, irrespective of precautions (rubber dam) or extraction of teeth instead of drilling.

More recent experiments on sheep, Hahn et al, 1989, and monkeys, Hahn et al 1990, clearly shows the major part of amalgam derived mercury to pass via the gastrointestinal tract where some of it is absorbed in tissues. These animal experiments also demonstrated a considerable absorption directly into the jaw bone an Hg accumulation in various tissues.

Skare, 1992, estimated that half of the gastrointestinal mercury might be swallowed material from corrosion and abrasion and half absorbed and execreted into the gastrointestinal tract. More accurate information is difficult to obtain when amalgam is still present in the teeth.

Mercury vapor is generally considered to be the most toxic form of inorganic mercury but also swallowed mercury compounds with low solubility have caused serve poisonings after long exposure. Mercurous chloride (camomel), was considered harmless but caused the acrodynia epidemic with numerous deaths, Warkany, 1966. The cause was discovered after 120 years! Davis et. al., 1974, described two cases of serve brain damage in adults after prolonged use of camomel laxatives.

Regarding metallic mercury in the gastrointestinal tract, experience comes almost exclusively from acute exposure to large amounts in large globules, usually after rupture of Miller- Abbot sonds. The accidents were usually uneventful unless some mercury was trapped.

However, very little information is available on chronic exposure to finely divided metallic mercury, Mörner, 1888, reported that finely divided metallic mercury preparations (mercury mixed with liquorice or chalk) was absorbed in the gastrointestinal tract. Weather the mercury was oxidized or not was not known at that time. Trachtenberg, 1974, also noted the relative harmlessness of large amounts of swallowed metal but that mercury in a highly dispersed stat can cause intoxication.

Metallic mercury mixed with fat (the usual medical treatment for syphilis) is absorbed both from skin and from mucous membranes. An illustrative case is reported by Stutte & Groh, 1961, who described a child receiving metallic mercury mixed with Vaseline in the anal region and subsequently developed serve mercury poisoning with partial and long-lasting paralysis.

The migrating of mercury into the jaw tissues, as described by Hahn et. al. 1990, is more like accidents when mercury has been introduced into tissues. The common manifestation in such accidents (usually from broken thermometers) is a chronic inflammatory also described after accidental introduction of amalgam pieces into oral tissues. Thermometer accidents can have fatal outcomes or cause severe poisonings. Surprisingly, intravenous metallic mercury is less hazardous.

The review of various modes of exposure to mercury (metallic and ionic) shows that no type of exposure is harmless and that finely divided metal and/or mixed with organic materials like fat is very toxic and might be absorbed to the same degree as swallowed mercuric chloride, i.e. average 15% (range 8-25%) Rahola et. al. 1973.

The type of exposure to mercury from amalgam differs from all other described types and involves vapor, metallic and ionic mercury. Medical history reveals that the effects of chronic exposure to mercury/amalgam are not readily recognized: "Every medical man of any considerable practice has undoubtly had numerous cases of it, but never knew what it was." (Payne, 1874)


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