含氟人工唾液对选择性激光熔积钴铬合金耐腐蚀性的影响

目的观察含氟人工唾液对选择性激光熔积技术（SLM）制作的钴铬合金耐腐蚀性的影响。方法将具有相同成分的钻铬合金粉未和金属块，分别运用SLM技术（SLM组）和铸造工艺（对照组）制作试件，每组40个。分别在pH为5．0和2．5以及模拟口腔含氟0、0．05％、0．10％和0．20％的条件下，将试件置于Fusayam人工唾液中浸泡24h。采用极化曲线Tafel外延法求得两组试样的极化阻力Rp值，比较两组试件的耐腐蚀性。结果pH值为5．0时，在含氟0和0．05％的条件下，两组间Rp值比较差异无统计学意义（P〉0．05）；而在含氟0．1％和0．2％的条件下，SLM组的Rp值显著大于对照组（P〈0．05），当pH为2．5时，往含氟0、0．05％、0．10％和0．20％的条件下，SLM组的Rp值均品著大于对照组（P〈0．05）.结论氟化物能影响铺铬合金的耐腐蚀性能，SLM钴铬合会的耐腐蚀性优于铸造钻铬合金。

Effects of different fluorine-containing oral artificial saliva solution on anti-corrosion behavior of selective laser melting cobalt-chromium alloy

Objective To evaluate the effects of different fluoride-containing artificial saliva solution on the corrosion of the dental cobalt-chromium （Co-Cr） alloy fabricated by selective laser melting （SLM）. Methods The study involved two groups, each group has 40 cylinder specimens and all specimens were fabricated by the same Co-Cr alloy. One group adopted SLM, while the other group used the cast method. Under conditions of two different pHs （2.5 and 5.0） and four different fluoride-containing artificial saliva solution concentration （0, 0. 05%, 0. 1%, and 0.2% ）, polarization curve tests were performed to compare the anti-corrosion ability of two groups. Results For pH of 5. 0 （fluoride- containing artificial saliva solution concentrations were 0 and 0. 05% ）, differences of Rp values between two groups were not statistically significant （P 〉 0. 05）. For pH of 5. 0 （fluoride-containing artificial saliva solution concentration were 0. 1% and 0. 2% ） and pH of 2.5 （fluoride-containing artificial saliva solution concentration were 0, 0. 05%, 0. 1%, and 0. 2% ）, the Rp value of SLM specimens were significantly higher than those of the cast ones （P 〈 0. 05）. Conclusion Fluorine can affect the anti-corrosion ability of Co-Cr alloy. SLM specimens exhibited a significantly better anti-corrosion ability than cast ones.