Corrosion of Metal-Injection Molded Titanium in Three Electrolytes

Introduction: Metal injection molding (MIM) becomes popular in fabricating dental implant fixtures as well as orthodontic brackets. This advanced powder metallurgy technique can provide precise products produced in mass quantities at a low cost than casting. However their corrosion behavior is unknown. Objectives: The purpose of this study was to evaluate the electrochemical corrosion behavior of MIM CpTi in various electrolytes. Materials & Methods: CpTi grade II cast (C), rolled (R), and MIM (M) samples were subjected to electrochemical polarization in Ringer’s solution (R), 1% lactic acid (L), and artificial saliva (A). Averaged values with standard deviation were obtained for ICORR and ECORR and statistically analyzed. Results: (1) In R and A electrolytes, no significant differences were exhibited among the three methods of fabrication (p<0.05). (2) In L, cast CpTi showed inferior ICORR and was significant different from M and R (p<0.05). (3) All CpTi samples (M, C and R) did not exhibit stable passivation when exposed to 1% lactic acid solution. Conclusion: When a titanium dental prosthesis is cast, special precautions should be taken before used due to inferior corrosion resistance, particularly in plaque formation environment which contains lactic acid.