microscopic analyses of welding defects in rpd technology

measurements indicated that, the corrosion resistance
of the laser-welded joints was better than that of the
brazed one.
Reclaru 3 shows that, precious metal based dental
alloys generally have a superior corrosion resistance,
in particular enhanced resistance to pitting and crevice
corrosion, compared to non-precious metal based
alloys such as CoCr alloys. A new generation of Co-Cr
alloys enriched with precious metals (Au, Pt, Ru) have
now appeared on the market.
Burkhardt, Reichert 11,18 compared laser and
microimpulse welding. They concluded that, laser
welding is superior, but more expensive due to the
working equipment.
conclUsions
Because of mechanical stress to which they are
exposed, cracks can appear in dental prosthesis. The
repairing method studied by the authors is welding
through a laser beam in a pulse operating system. Since
the cracks that tend to appear do not have a regular
shape, it is highly recommended the use of welding
by hand.
Laser welding is a performing method for metallic
prostheses repairs. Selecting the adequate combination
of pulse energy, pulse duration and peak power for
each welding step is decisive in the success of welding
procedure.
It is important to know the quality and structural
defects of our repairs, both base metal and welded
metal, in order to obtain high resistance prosthesis.
Microscopically non-invasive analyses and tests show
good or poor quality of the welded joints.
AcKnoWledgeMents
This study was supported by the CNCSIS Grant
Ideas, 1878/2009, from the Ministry of Education
and Research of Romania
_____________________________
28 TMJ 2010, Vol. 60, No. 1
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