Lowered crushing strength.
(d) Blister formation on the surface of the amalgam.
(2) Avoidance procedures. Moisture can be introduced into amalgam by
triturating below the dew point (temperature at which moisture collects on a surface).
Moisture can also be introduced by the presence of moisture in the cavity being filled or
by accidental contact with saliva. To avoid moisture contamination, all instruments and
equipment encountering the amalgam should be dry. The temperature of equipment
and materials should be high enough so that no moisture collects. Saliva should be
kept out of the cavity preparation during the insertion of the material.
b. Guidance for Amalgam Preparation. Any portion of amalgam that is too dry
or has begun to crystallize must be discarded. Its use would result in a weak,
nonhomogeneous mass. For large restorations, it may be necessary to prepare two or
more mixes. Each mix is prepared as needed.
c. Training of Personnel Required. All dental personnel must be familiar with
the potential hazards and the proper handling of mercury.
MERCURY HYGIENE PRACTICES BY THE DENTAL SPECIALIST
a. General. Amalgam restorations do not constitute a hazard to patients.
However, dental personnel may invite a health hazard if exposed to concentrated
mercurial vapors over an extended period of time. Mercury hygiene precautions should
b. Mercury Hygiene Precautions.
(1) Training. All dental personnel must be instructed regarding the potential
health hazards of mercury and what constitutes proper handling.
(2) Covering cuts and abrasions. All cuts and abrasions of the skin must be
covered when handling amalgam or mercury.
(3) Washing hands and arms. All dental personnel must wash hands and
arms thoroughly after amalgam operations.
(4) Inspection of capsules. Capsules must be checked for general condition
and seal. Cracked capsules or those in poor condition will be discarded.
(5) Use of masks. All dental personnel must wear masks when removing