Dental amalgum . Manipluation step Reactions etc

1. DEFINITION:-
An Amalgam is an alloy that contains
mercury as one of it’s constituents
MANIPULATION
-Phillips
Pre-proportioned capsule
SubheadingHand trituration
using motor and pestle.
Amalgamator for mixing
of amalgam.
(A) Normal consistency(B) Undertriturated; and
(C) Overtriturated.
Dental amalgam is a metal like
restorative material composed of
mixture of silver/tin/copper alloy and
mercury
-Sturdevants
Particles of
conventional
lathe-cut alloy for
dental amalgam
(×100).
Particles of spherical
alloy for dental
amalgam
(×100).
Typical admix high-copper
alloy powder show ng the
lathe-cut silver-tin particles
and silver-copper spherical
articles (x500).
Acute Chronic
• HYDRARGYRISM
• Mercury exposure for a prolonged
period
• Workers may get poisoned due to
vapors or dust.
• The lowest level of total blood
mercury at which the earliest
nonspecific symptoms occur is 35
ng/ml.
•Sudden exposure of high
levels of mercury especially
from elemental mercury or
organic mercury.
• It results in immediate and
severe symptoms requiring
urgent medical attention
M
TO
Composition of Some Typical Commercial
Amalgam Alloys.
Composition (mass %)
Setting reaction;-
Low-copper alloy
Ag3Sn + Hg →Ag2Hg + Sn7-8Hg3+ unreacted Ag3Sn
High-copper spherical alloy
[Ag3Sn + Cu3Sn] + Hg ---> Ag2Hg3 + Cu6Sn5 + unreacted [Ag3Sn + Cu3Sn]
High-copper admix alloy
Ag3Sn + Ag-Cu + Hg →Ag2Hg3 + Sn7-8Hg + unreacted Ag-Cu + unreacted Ag3Sn
Secondary solid-state reaction |→ Cu6Sn5 + Ag2Hg3 + unreacted Ag-Cu
Proper carving of amalgam
restoration
The average condensation force
ranges between 3-4lb (13.3-17.8N)
Process of condensation.
Mercury poisoning :-
DENTAL AMALGAM
ANSI/ADA Specification No. 1
SYMBOLS & STOICHIOMETRY OF PHASES THAT ARE
INVOLVED IN THE SETTING OF DENTAL AMALGAM
Delayed expansion
of an amalgam.
TO OVERCOME THE
POSIONING DO FOLLOW
REGULATORY
CODES
GUIDED BY:-
Dr Swetha H B,
Dr Bhavana N
PRESENTED BY:-
Manaf,
Meghashree,Mrinalini,
Yogashree,Sohail,
Ameen,Mazoon
PRONOUNCED SYMPTOMS
•Kidney inflammation
•Swollen gums
•Pronounced tremor and nervous
system disturbances
MILD TO MODERATE SYMPTOMS
•Irritability, depression, memory loss.
•minor tremor and other nervous-system
disturbances
•Early signs of disturbed kidney function
SUBTLE CHANGES ON SOME TESTS,
BUT NO OVERT SYMPTOMS
•Decreased response on tests for nerve
conduction, brain-wave activity and
verbal skills
•Early indication of tremor on testing
NO KNOWN HEALTH EFFECTS
UPPER LIMIT
of urinary mercury attributed to
extensive amalgam fillings