Abstract:

Objective To investigate the effect of the laser surface hardening technology on the corrosion resistance of dental casting alloy. Methods Twenty -three cobalt -chromium alloy specimens were made in this study. Twenty-two specimens were equally divided into two groups randomly. One was experimental group for laser surface hardening processing and the other was control group without any treatment. In each group, ten specimens were used for corrosion analysis by electrochemical method, and one for surface metallographical structure and morphology observation by scanning electron microscope. Remaining one specimen was partially processed on limited area for surface metallographical structure and morphology comparison. Results Metal grains distributed uniformly and achieved a good refinement with mainly the same size in experimental group. Metal grains in specimen which processed in its partial surface area also achieved a good refinement in the laser processing area. There was statistical difference in electric potential of corrosion and logarithmic value of current of corrosion between experimental group and control group（P<0.01）. Conclusion Laser surface hardening technology has a positive effect in improving the corrosion resistance of dental casting alloy in artificial saliva.

Key words: laser, corrosion resistance, dental casting alloy, cobalt-chromium alloy