History and Use of Dental Amalgam Flashcards
Year silver amalgam was introduced:
1819, Charles Bell, 1836 to U.S.
Amalgam was first marketed as:
Bell’s putty
Who brought amalgam to U.S.
Crawcour brothers ‘Royal Mineral Succedaneum’ silver (coins) and mercury expanded, post op pain, fracture, elevated occl contact
Amalgam War started:
1841-1850
First amalgam placers were called:
Quick Silver Quaks
Year amalgam use would be malpractive:
1843 (american society of dental surgeons)
Amalgam Pledge:
1845-no one in dentistry could use, must sign pledge, rescinded in 1850’s, research began
G.V. Black created:
Classical amalgam cavity design, classification system, formula for “conventional amalgam”
Formula for “conventional” amal circa 1896:
72.5% silver and 27.5% tin-mercury
Yrs of 2nd amal war:
1926-1930
Dr. that started 2nd amal war:
Dr. Alfred Stock, opinion based publication, claimed vapor from amalgam fillings can be significantly damaging to health conditions. Renouned his own claim in 1940
Most pop pos tooth restorative material in 2nd half of 1900’s and today
amalgam
Pos outcome of Stocks allegations that led to the 2nd amal war:
Scientists conducted studies that demonstrated safety of amal
Can mercury be released from filings?
no, it is chemically reacted and tied up in the body of the restoration
This man recommended use of 1:1 ratio of mercury to alloy:
Wilmer Ballou Eames (others were using 8:5 ratio)
Yr spherical amalgam alloy was introduced:
1962
High copper amalgam was invented by who, when?
Innes and Yudelis, 1963, copper added to amalgam alloy
Reasons for decline in use of amal:
esthetics, caries decline, conservation of tooth structure, mercury
Who challenged the Scott study with their own research regarding Hg vapor?
Souder and Sweeney (check)
Hoover study:
Urinary industrial mercury level, different bw pt w and wo dental amal in mouth, found no diff in urinary mercury level, amal restos do NOT contribute to body burden
Frykolm:
Hg is excreted w/in a few days: multiple amal restos, radioactively labelled Hg, urinary analysis/time, levels rose and dropped back down to zero after 8 days (small, measurable amt of mercury vapor exposure, but is excreted quickly)
TF? Hg vapor is released from amalgam when pts chew gum.
T, enough heat is created when masticating, then absorbed into blood, debate about actual amt released and whether this poses a risk to the pt., minute
Cardinal rule of toxicology:
only the dose makes a poison
Amal TLV:
Amal Threshold Limit Value, amt of Hg vapor that can safely be in air where a worker works for 40hr/wk
