History and Use of Dental Amalgam

Question 1

Year silver amalgam was introduced:

Answer 1

1819, Charles Bell, 1836 to U.S.

Question 2

Amalgam was first marketed as:

Answer 2

Bell’s putty

Question 3

Who brought amalgam to U.S.

Answer 3

Crawcour brothers ‘Royal Mineral Succedaneum’ silver (coins) and mercury expanded, post op pain, fracture, elevated occl contact

Question 4

Amalgam War started:

Answer 4

1841-1850

Question 5

First amalgam placers were called:

Answer 5

Quick Silver Quaks

Question 6

Year amalgam use would be malpractive:

Answer 6

1843 (american society of dental surgeons)

Question 7

Amalgam Pledge:

Answer 7

1845-no one in dentistry could use, must sign pledge, rescinded in 1850’s, research began

Question 8

G.V. Black created:

Answer 8

Classical amalgam cavity design, classification system, formula for “conventional amalgam”

Question 9

Formula for “conventional” amal circa 1896:

Answer 9

72.5% silver and 27.5% tin-mercury

Question 10

Yrs of 2nd amal war:

Answer 10

1926-1930

Question 11

Dr. that started 2nd amal war:

Answer 11

Dr. Alfred Stock, opinion based publication, claimed vapor from amalgam fillings can be significantly damaging to health conditions. Renouned his own claim in 1940

Question 12

Most pop pos tooth restorative material in 2nd half of 1900’s and today

Answer 12

amalgam

Question 13

Pos outcome of Stocks allegations that led to the 2nd amal war:

Answer 13

Scientists conducted studies that demonstrated safety of amal

Question 14

Can mercury be released from filings?

Answer 14

no, it is chemically reacted and tied up in the body of the restoration

Question 15

This man recommended use of 1:1 ratio of mercury to alloy:

Answer 15

Wilmer Ballou Eames (others were using 8:5 ratio)

Question 16

Yr spherical amalgam alloy was introduced:

Answer 16

1962

Question 17

High copper amalgam was invented by who, when?

Answer 17

Innes and Yudelis, 1963, copper added to amalgam alloy

Question 18

Reasons for decline in use of amal:

Answer 18

esthetics, caries decline, conservation of tooth structure, mercury

Question 19

Who challenged the Scott study with their own research regarding Hg vapor?

Answer 19

Souder and Sweeney (check)

Question 20

Hoover study:

Answer 20

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

Question 21

Frykolm:

Answer 21

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)

Question 22

TF? Hg vapor is released from amalgam when pts chew gum.

Answer 22

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

Question 23

Cardinal rule of toxicology:

Answer 23

only the dose makes a poison

Question 24

Amal TLV:

Answer 24

Amal Threshold Limit Value, amt of Hg vapor that can safely be in air where a worker works for 40hr/wk

Question 25

Amal TLV for OSHA and WHO:

Answer 25

OSHA: 50ug/mm3, WHO: 25ug/mm3

Question 26

How would the highest dose possible a pt could receive from 10-12 amal restorations compare with the TLV levels

Answer 26

1/100th of the “current” (didn’t specify OSHA or WHO)

Question 27

Amal level in normal diet/ day:

Answer 27

10-20 ug

Question 28

Highest level suggested by research of Hg exposure to pt from amal restos:

Answer 28

10 ug/day, measures inside mouth and not environment so this number should be much lower

Question 29

How does the amt of Hg exposure a pt would experience to amal compare to that exposure from their every day diet?

Answer 29

1/10 - 1/20 of dietary levels

Question 30

For the most sensitive pt to demonstrate the most minor symptoms:

Answer 30

450 to 500 amalgams would have to be places

Question 31

How does Dental Amal and nickel alloys affect the circulating T-lympho levels/ wbc levels?

Answer 31

it doesn’t

Question 32

What type of toxin is Hg?

Answer 32

neurotoxin

Question 33

First time Amal was used in dentistry

Answer 33

1826 o.t.

Question 34

Why use silver amal?

Answer 34

Strong, inexpensive

Question 35

Detector of mercury content in air:

Answer 35

Selenium sulfide mercury detector, souder and sweeney testing release from fillings, acid solutions, no vapor, no dissolution of mercury

Question 36

Amount of mercury in human vs sheep, etc

Answer 36

12-20 times less

Question 37

Health organizations that support the continued use of amalgam:

Answer 37

FDI World Dental Federation, WHO, Alzheimer’s association, FDA, U.S. Health Service, Lupus Foundation, National MS Society,Agency for Toxic Substances and Disease Registry, CDC, National Counsel Against Health Fraud, NIH/ NIDR Consensus Development Conference, USPHS, Consumer Reports, Swedish Medical Counsel

Question 38

Effect of unecessary amal removal:

Answer 38

Preparation enlarged, chance of pulpal trauma, cost, longevity

Question 39

How to determine bw composite and tooth structure for composite removal:

Answer 39

air dry, composite appears chaulky