[Year:2020] [Month:July-September] [Volume:10] [Number:3] [Pages:10] [Pages No:102 - 111]
Aim and objective: To evaluate the influence of surface modification on corrosion behavior of the implant grade titanium alloy Ti-6Al-4V, in simulated body fluids (SBFs). Materials and methods: Seventy disk-shaped samples of implant grade titanium alloy, Ti-6Al-4V were divided into seven groups of 10 each; UMS (unmodified surface/control group), HA (hydroxyapatite coated), LS (LASER sintered), LT (LASER textured), TG (combined chemical and thermal treated), HT850 (oxidized state), and HT1050 (oxidized state) were subjected to corrosion tests, electrochemical impedance, and cyclic polarization tests using GAMRY Potentiostat in SBF. Paired t-test, one-way analysis of variance (ANOVA) test, and Tukey honestly significant difference (HSD) test (p = 0.05). Results: Polarization resistance (Rp) was increased in TG (1,800 ± 10.54 kΩ) with respect to UMS (control group) (1,249 ± 11.25 kΩ) and HA (1,250 ± 8.65 kΩ), further reduced in HT850 (780.00 ± 11.54 kΩ), LT (127 ± 5.37 kΩ), LS (60 ± 18.26 kΩ), and HT1050 (0.00 ± 0.00 kΩ) being lowest at 144 hours. Their mean comparisons were statistically significant except in HT1050 (p = 0.05). Cyclic polarization curves showed hysteresis loops in all the samples (UMS, HA, LS, LT, HT850, and HT1050) indicating susceptibility to localized corrosion (pitting and crevice corrosion) except in the TG sample, which showed forward scan retracing the reverse scan; they showed significantly improved resistance against pitting in TG followed by LS, HA, LT, and HT850 compared to UMS (control) except HT1050 (p = 0.05). Conclusion: Combined chemical and thermal treatment of titanium alloy showed greater corrosion resistance and minimal susceptibility to localized corrosion (pitting and crevice corrosion) than the unmodified surface.