Evaluation of titanium and CO-CR alloys produced by CAD-CAM milling and laser sintering techniques in terms of corrosion, ion release and surface hardness

The aim of the study is to examine the effect of CAD - CAM milling and laser sintering techniques on the microhardness, corrosion properties, ion releases and microstructure of Ti6Al4V and Co-Cr alloys. For this purpose, Ti6Al4V and Co-Cr alloy are produced by CAD - CAM milling and laser sintering techniques and divided into 4 groups (n: 6). Vickers Hardness test was applied to the samples first and open circuit potential measurement was performed. Corrosion test was carried out in artificial saliva with the help of a potentiostat. The samples were kept in artificial saliva solution for 14 days. Inductively coupled plasma mass spectrometry, ICP-MS, was used to measure the release of metal ions. Microstructures of the samples were investigated by scanning electron microscopy at high and low magnification. In the analysis of the data, IBM-SPSS Statistics 22 program, Mann-Whitney U test, Kolmogorov-Smirnov and Shapiro-Wilks tests, Kruskal-Wallis test and Mann-Whitney U test with Bonferroni correction were used. As a result of the study, in the comparisons made with other groups, the titanium sintering group; the hardness level (456 ± 25.64) was statistically significantly higher (p <0.008); OCP level (-0.47 ± 0.04) was significantly lower (p <0.008); Vcorr level (-0.46 ± 0.03) was also found to be significantly lower (p <0.008). While the Icorr level of the cobalt scraping group (0.00006 ± 0.00002) was significantly lower than the titanium scraping and titanium sintering groups (p <0.008), there was no significant difference between the other groups (p> 0.008). The weight change (0,24 ± 0,04) percentage of the titanium sintering group was significantly higher than the cobalt milling, sintering and titanium milling groups (p <0.008); Co emission amount of cobalt sintering group (23.17 ± 0.98) was significantly higher than cobalt milling group (p <0.05) and Cr oscillation amount (16.83 ± 1.47) was significantly higher (p <0.05). The titanium sintering group's Ti release amount (40.17 ± 3.6) was statistically significantly higher than the titanium milling group (p <0.05). There was no statistically significant difference between titanium milling and titanium sintering groups in terms of Al and V release amounts (p> 0.05). Key Words: CAD-CAM milling, Laser sintering, Corrosion, İon release, Vickers Hardness