| Finishing Surfaces to Receive
Porcelain |
| To avoid bubbling of your
porcelain, do NOT use diamonds to finish
these soft alloys! Use fine aluminum oxide
stones, such as the Shofu Lab Series Pink
or White, and dress the stone often as it
becomes clogged with metal. |
| |
| Polishing Technique 1 |
 |
Pre-polish with a conventional
rubber wheel. Finer grit rubber wheels are
better. |
|
Use a brown rubber point to
pre-polish occlusal grooves. |
|
Mix tin oxide powder with
denatured alcohol to a paste consistency.
|
|
Apply the paste to a soft
Robinson-style bristle brush, or dip the
crown in the paste. |
|
Using Low speed and Light
pressure (use a handpiece rather than a
polishing lathe), polish the crown with
the tin oxide paste. A high shine should
be achieved without much time spent. |
Notes
Some technicians insert a step of tripoli,
red rouge, Jelenko Buffing Bar Compound,
or Denerica "Sapphire" compound
in between the rubber wheel step and the
tin oxide step. This can shorten the amount
of time spent with tin oxide. It is important,
however, to clean all residues of these
compounds off of the metal before starting
the tin oxide step by ultrasonically cleaning
in alcohol or ammonia. Note that tin oxide
removes very little metal, therefore the
quality of the final finish is directly
dependent upon the quality of the prepolish
job. In fact, instead of rubber wheels,
fine sandpaper disks such as Moore's disks
can be used extremely effectively on yellow
ceramic alloys. |
| |
| Polishing Technique 2 |
|
Pre-polish with a conventional
rubber wheel . |
|
Use the "Gold Flash" high shine
wheels from Pacific Abrasives to bring
the metal to a high shine almost instantly.
|
|
Notes
We are told that other high shine wheels,
such as the Ney "Sparkle" wheels,
work very well also. Both the Ney and
the Pacific Abrasives products are available
as polishing points as well.
Comments
We use both of these techniques together.
For example, if the case has no metal
occlusion but simply gold collars, we
will use Technique #2 and skip the tin
oxide. If, on the other hand, the case
has metal occlusal and metal lingual,
we will do the smooth lingual aspect with
Technique #2, and the occlusal with Technique
#1. Finally, we find that a clean rag
wheel with no polishing compound applied
to it can be a valuable tool for removing
any "stuck" polishing materials,
and leaves the metal with a nicely buffed
luster.
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