Vimy MJ, Lorscheider FL. Serial measurements of intra-oral air mercury: estimation of daily dose from dental amalgam. Journal of Dental Research. 1985;64(8):1072-1075.
A single vapor snapshot is not a day. In a companion paper, Vimy and Lorscheider took serial intra-oral air measurements during and after chewing to estimate daily mercury dose from amalgam.
What the study found
Serial measurements of Hg concentration in intra-oral air were made during and after chewing stimulation in 35 subjects with occlusal amalgam restorations. Hg concentrations remained elevated during 30 min of continuous chewing and declined slowly over 90 min after cessation of chewing. By curve-fitting and integration analysis of data during these time periods (including corrections for respiratory volume, retention rate of inspired Hg, oral-to-nasal breathing ratios, and consumption of three meals and three snacks per day), we calculated that all subjects received an average daily Hg dose of approximately 20 micrograms. Subjects with 12 or more occlusal amalgam surfaces were estimated to receive a daily Hg dose of 29 micrograms, whereas in subjects with four or fewer occlusal amalgam surfaces, the dose was 8 micrograms. These Hg dosages from dental amalgam were as much as 18-fold the allowable daily limits established by some countries for Hg exposure from all sources in the environment. The results demonstrate that the amount of elemental Hg released from dental amalgam exceeds or comprises a major percentage of internationally accepted threshold limit values for environmental Hg exposure. It is concluded that dental amalgam Hg makes a major contribution to total daily dose.
Why it matters for SMART
Dose estimation—however debated in later literature—shifted the conversation from “is any vapor detectable?” to “how much cumulative exposure might chewing create?” SMART’s philosophy is to minimize incremental dose whenever amalgam is disturbed, because patients may already carry a stimulation-related baseline.
Practical takeaways
- Think in cumulative dose, not one-time peaks alone.
- Reduce stimulation-related release counseling where clinically relevant.
- Never add an unprotected removal pulse on top of daily vapor.
- Use SMART rinse/dam/air steps to cut procedural intake.
- Document informed consent that discusses mercury release during removal.
Bottom line: Serial intra-oral measurements by Vimy & Lorscheider framed amalgam as a recurring daily mercury-dose contributor—supporting SMART’s mandate to suppress additional procedural exposure.
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.
