Mercury vapor volatilization from particulate generated from dental amalgam removal with a high-speed dental drill – a significant source of exposure

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

Background

The ubiquitous use of dental amalgam for over 180 years has resulted in the exposure of millions of dental workers to mercury. Dental amalgam contains approximately 50% mercury. Dental workers, including dentists, dental assistants, and dental hygienists, have been shown to have increased levels of mercury and suffer more from health issues related to mercury exposure than the general public. Mercury is known to be absorbed via inhalation or through the skin. There are many routine dental procedures that require the removal of dental amalgam by using the dental high-speed drill, which we suspected generates an occupational mercury exposure that is not sufficiently recognized.

Results

We showed that drilling dental amalgam generates particulate that volatilizes significant amounts of mercury vapor generally for more than an hour after removal. The levels of mercury vapor created by this procedure frequently exceed the safety thresholds of several jurisdictions and agencies.

Conclusions

A significant, underrecognized source of localized exposure to mercury vapor was identified in this study. The vapor was created by microgram levels of particulate generated from dental amalgam removal with a high-speed dental drill, even when all feasible engineering controls were used to reduce mercury exposure. This exposure may explain why dental workers incur health effects when safety thresholds are not breached. The dispersion patterns for the particulate are not known, so the use of effective skin barriers and inhalation protection are required during amalgam removal to protect the dental worker from this form of occupational mercury exposure. Standard methodologies for occupational mercury exposure assessment appear to be inadequate when assessing mercury exposure during amalgam removal.

Electronic supplementary material

The online version of this article (10.1186/s12995-019-0240-2) contains supplementary material, which is available to authorized users.

Related collections

Most cited references 38

Record: found
Abstract: found
Article: found

Is Open Access

Mercury Toxicity and Treatment: A Review of the Literature

Robin Bernhoft (2011)

Mercury is a toxic heavy metal which is widely dispersed in nature. Most human exposure results from fish consumption or dental amalgam. Mercury occurs in several chemical forms, with complex pharmacokinetics. Mercury is capable of inducing a wide range of clinical presentations. Diagnosis of mercury toxicity can be challenging but can be obtained with reasonable reliability. Effective therapies for clinical toxicity have been described.

0 comments Cited 202 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Exposure to mercury vapor and impact on health in the dental profession in Sweden.

G Sällsten, Joanne Lind, S Langworth … (1997)

Possible adverse effects of mercury exposure in dentistry have been discussed in several studies. The objective of the present study was to carry out detailed measurements of mercury exposure in the dental profession in Sweden, and to search for adverse health effects from such exposure. We examined 22 dentists and 22 dental nurses, working in teams, at six Swedish dental clinics. Measurements of air mercury, performed with personal, active air samplers, showed a median air Hg of 1.8 micrograms/m3 for the dentists, and 2.1 micrograms/m3 for the dental nurses. Spot measurements with a direct reading instrument displayed temporarily elevated air Hg, especially during the preparation and application of amalgam. The average concentration of mercury in whole blood (B-Hg) was 18 nmol/L, in plasma (P-Hg) 5.1 nmol/L, and in urine (U-Hg) 3.0 nmol/mmol creatinine. Possible effects on the central nervous system (CNS) were registered with three questionnaires: Q16, Eysenck Personality Inventory (EPI), and the Profile of Mood Scales (POMS). In the Q16, the number of symptoms was statistically significantly higher in the dentistry group compared with an age- and gender-matched control group (n = 44). The urinary excretion of albumin and urinary activity of the tubular enzyme N-acetyl-beta-glucose-aminidase (NAG) did not differ between the two groups. The results confirm that exposure to mercury in the dental profession in Sweden is low. The air Hg levels were mainly influenced by the method of amalgam preparation and inserting, and by the method of air evacuation during drilling and polishing.

0 comments Cited 24 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: found

Is Open Access

Is dental amalgam safe for humans? The opinion of the scientific committee of the European Commission

Joachim Mutter (2011)

It was claimed by the Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR)) in a report to the EU-Commission that "....no risks of adverse systemic effects exist and the current use of dental amalgam does not pose a risk of systemic disease..." [1, available from: http://ec.europa.eu/health/ph_risk/committees/04_scenihr/docs/scenihr_o_016.pdf]. SCENIHR disregarded the toxicology of mercury and did not include most important scientific studies in their review. But the real scientific data show that: (a) Dental amalgam is by far the main source of human total mercury body burden. This is proven by autopsy studies which found 2-12 times more mercury in body tissues of individuals with dental amalgam. Autopsy studies are the most valuable and most important studies for examining the amalgam-caused mercury body burden. (b) These autopsy studies have shown consistently that many individuals with amalgam have toxic levels of mercury in their brains or kidneys. (c) There is no correlation between mercury levels in blood or urine, and the levels in body tissues or the severity of clinical symptoms. SCENIHR only relied on levels in urine or blood. (d) The half-life of mercury in the brain can last from several years to decades, thus mercury accumulates over time of amalgam exposure in body tissues to toxic levels. However, SCENIHR state that the half-life of mercury in the body is only "20-90 days". (e) Mercury vapor is about ten times more toxic than lead on human neurons and with synergistic toxicity to other metals. (f) Most studies cited by SCENIHR which conclude that amalgam fillings are safe have severe methodical flaws.

0 comments Cited 23 times – based on 0 reviews      Review now

Bookmark

All references

Author and article information

Contributors

David Warwick:

ORCID: http://orcid.org/0000-0003-0766-446X

drdavid17@mac.com

Matt Young: myoung9718@aol.com

Joe Palmer: jpalmer@palmerdmd.com

Robin Warwick Ermel: robinawarwick@gmail.com

Journal

Journal ID (nlm-ta): J Occup Med Toxicol

Journal ID (iso-abbrev): J Occup Med Toxicol

Title: Journal of Occupational Medicine and Toxicology (London, England)

Publisher: BioMed Central (London )

ISSN (Electronic): 1745-6673

Publication date (Electronic): 17 July 2019

Publication date PMC-release: 17 July 2019

Publication date Collection: 2019

Volume: 14

Electronic Location Identifier: 22

Affiliations

[1 ]Dental Practice, Hanna Dental Clinic, 202, 2nd Ave W, Hanna, Alberta Canada

[2 ]Dental Practice, 728 5th Ave. West, Hendersonville, NC USA

[3 ]Dental Practice, Palmer Distinctive Dentistry, 134 Milestone Way, Greenville, SC USA

Author information

David Warwick http://orcid.org/0000-0003-0766-446X

Article

Publisher ID: 240

DOI: 10.1186/s12995-019-0240-2

PMC ID: 6637613

PubMed ID: 31346345

SO-VID: d5b9160b-0615-4866-977b-9fa410f59963

License:

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License ( http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver ( http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

History

Date received : 28 December 2018

Date accepted : 12 June 2019

Custom metadata

ScienceOpen disciplines: Occupational & Environmental medicine

Keywords: mercury,mercury vapor,dental amalgam,occupational exposure to mercury,amalgam removal

Data availability:

ScienceOpen disciplines: Occupational & Environmental medicine

Keywords: mercury, mercury vapor, dental amalgam, occupational exposure to mercury, amalgam removal

Mercury vapor volatilization from particulate generated from dental amalgam removal with a high-speed dental drill – a significant source of exposure

Read this article at

Abstract

Background

Results

Conclusions

Electronic supplementary material

Related collections

China Occupational Medicine

Most cited references 38

Mercury Toxicity and Treatment: A Review of the Literature

Exposure to mercury vapor and impact on health in the dental profession in Sweden.

Is dental amalgam safe for humans? The opinion of the scientific committee of the European Commission

Author and article information

Contributors

Journal

Affiliations

Author information

Article

History

Categories

Custom metadata

Comments

Comment on this article

Similar content 28

Cited by 2

Most referenced authors 278