Research On Improving The Corrosion Resistance Of Porcelain-fused Nickel-chromium Alloys By Sol-gel Coating

[Background] Because of favorable mechanical properties and low cost, Nickel-chromium alloys are widely used in crowns and bridges to replace compromised teeth . But in clinic , allergic reactions are usually observed. Moreover, increases of gingival fluid and gingival indexes could occur accordingly. At present, most of researches assert that these symptoms are caused by metal ions released from dental alloys. Therefore it is necessary to improve the corrosion resistance of the alloy and abate the release of metal ions for the sake of clinic safety.[Methods] In this research, morphologies of the coatings which are sintered with colloids varying in ingredients, concentration and intervention methods are evaluated through SEM. The bond strength of coating-substrate interfacial sintered at different temperatures is tested by scratching. The corrosion resistance of the sol-gel coating is assessed by a static immersion method. [Results] The results indicate:1. If the coating is sintered by a low-concentration colloid or a colloid including TiO₂, there'll be fewer fissures and a more close-grained surface. Drying the coating at the room temperature makes no difference.