Nylander M, Friberg L, Lind B. Mercury concentrations in the human brain and kidneys in relation to exposure from dental amalgam fillings. Swedish Dental Journal. 1987;11(5):179-187.
Autopsy tissue talks when blood tests whisper. Nylander, Friberg, and Lind measured mercury in brain regions and kidney cortex and related concentrations to dental amalgam exposure.
What the study found
Samples from the central nervous system (occipital lobe cortex, cerebellar cortex and ganglia semilunare) and kidney cortex were collected from autopsies and analysed for total mercury content using neutron activation analyses. Results from 34 individuals showed a statistically significant regression between the number of tooth surfaces containing amalgam and concentration of mercury in the occipital lobe cortex (mean 10.9, range 2.4-28.7 ng Hg/g wet weight). The regression equation y = 7.2 + 0.24x has a 95% confidence interval for the regression coefficient of 0.11-0.37. In 9 cases with suspected alcohol abuse mercury levels in the occipital lobe were, in most cases, somewhat lower than expected based on the regression line. The observations may be explained by an inhibition of oxidation of mercury vapour. The regression between amalgams and mercury levels remained after exclusion of these cases.
The kidney cortex from 7 amalgam carriers (mean 433, range 48-810 ng Hg/g wet weight) showed on average a significantly higher mercury level than those of 5 amalgam-free individuals (mean 49, range 21-105 ng Hg/g wet weight). In 6 cases analysis of both inorganic and total mercury was carried out. A high proportion (mean 77% SD 17%) of inorganic mercury was found. It is concluded that the cause of the association between amalgam load and accumulation of mercury in tissues is the release of mercury vapour from amalgam fillings.
(PubMed/EuropePMC abstract.)
Why it matters for SMART
Brain and kidney deposition findings are a major reason biological dentistry refuses to treat amalgam as biologically inert. The occipital-cortex regression with amalgam surface count, plus much higher kidney cortex mercury in amalgam carriers versus amalgam-free individuals here, place vapor release—not only diet—in the causal story. SMART’s mission—reduce vapor and particulate during removal—follows: unprotected removal can add an acute plume atop chronic deposition.
Practical takeaways
- Respect target organs — brain and kidney appear repeatedly in amalgam autopsy work.
- Avoid cavalier removal or placement when safer materials fit the clinical need.
- Apply full SMART aerosol/PPE controls whenever removal is needed.
- Consider occupational brain/kidney risk for staff with long amalgam-handling careers.
- Support research literacy among patients asking “where does the mercury go?”
Bottom line: Nylander et al. linked higher brain and kidney mercury to dental amalgam exposure in autopsy samples—foundational tissue evidence behind SMART’s protective removal stance.
For patients and clinics evaluating safe amalgam removal, the practical lesson is consistency: apply the full SMART checklist—barriers, dam, alternate air, water and high-volume evacuation, chunking technique, mercury-rated respiratory protection, air filtration, and maintained separators—rather than relying on any single study in isolation. Educational use of this reference on thesmartchoice.com should link back to the IAOMT SMART protocol page for the complete procedure set.
