Appeal No. 95-0992
Application 08/014,104
restorations (col. 3, lines 50-61). Stoner states that he
believes that the improved corrosion results from mercury from
the bulk of the amalgam diffusing into the metal of the lining
and forming an alloy zone free of tin atoms next to the cavity
surfaces (col. 3, lines 61-64). Since no tin atoms are present
next to the cavity surfaces, Stoner states, there is no oxidation
in this region (col. 3, lines 64-66).
Appellant’s specification (page 5, lines 1-2) states that
the primary components of dental amalgams include metallic
mercury, silver and tin. The following table shows the
potentials for oxidation-reduction half-reactions at 25EC for
these elements taken from the CRC Handbook, pages D-158 to D-159.
Following these potentials in the table are the potentials for
platinum and gold, which are two of the elements disclosed by
Stoner. The oxidation strengths increase in the downward
direction in the table, as EE increases.
EE
(volts)
Sn + 2e = Sn -0.1364+2 -
Ag + e = Ag .7996+ -
Hg + 2e = Hg .851+2 -
Pt + 2e = Pt -1.2+2 -
Au + e = Au 1.68+ -
The first three entries in the table indicate that an
4-4-
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Last modified: November 3, 2007