牙科金属与合金材料的腐蚀性能研究

牙科金属与合金材料已广泛地应用于口腔修复、正畸、充填和种植等临床治疗中,在行使功能的同时会与其周围环境发生化学或电化学反应,引起腐蚀。本文对近年来国内外有关牙科金属与合金材料的腐蚀性能研究的化学与电化学腐蚀方法、材料的腐蚀与其本身的化学元素组成及其表面结构的关系、材料的腐蚀性能受周围变化着的环境的影响以及如何从其元素组成、表面结构和周围介质的改变来改善牙科金属与合金的耐蚀性等方面研究作了综述。     

牙科合金微生物腐蚀的研究进展

随着牙科材料的发展,牙科合金如钴铬合金、镍铬合金、钛（钛合金）和贵金属（合金）在口腔修复领域的应用越来越广泛。这些金属在口腔内行使功能时,由于其所处的是一个非常复杂的电解质环境,会发生各种形式的腐蚀。口腔中的金属腐蚀主要包括化学腐蚀和电化学腐蚀两种类型,其中电化学腐蚀又有三种形式：微生物腐蚀、电偶腐蚀、应力腐蚀破裂。     

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随着牙科合金在临床上使用日益广泛,其腐蚀引起的一些不良反应也日渐引起人们的重视。牙科合金的腐蚀主要为各种形式的电化学腐蚀,其主要影响因素包括合金的成分、pH值、介质的成分和异种金属等。关于提高牙科合金耐腐蚀性能的研究众多,主要为改变牙科合金的成分和表面改性。     

牙科金属与合金材料的腐蚀性能研究

本文对近年来国内外有关牙科金属与合金材料的腐蚀性能的化学与电化学腐蚀方法，材料的腐蚀与其人本身的化学元素组成及其表面结构的关系、材料的腐蚀性能受周围变化着的环境的影响以及如何从其元素组成，表面结构和周围介质的改变来改善牙科金属与合金的耐蚀性等方面研究了综述。     

牙科金属材料的微生物腐蚀

牙科金属材料在潮湿的口腔中使用时,可与口腔环境中的许多理化组分发生化学反应,产生腐蚀。同时,口腔是一个多菌群的复杂生态环境,其中的微生物会对金属材料的腐蚀产生一定的影响,即发生微生物腐蚀,微生物腐蚀是由微生物生命活动引起或促进材料的腐蚀破坏。口腔环境的温度、唾液的组成和pH值能对微生物腐蚀产生不同的影响。另外,牙科金属材料本身的元素组成、组织结构和加工处理过程的不同也会产生不同的腐蚀过程和结果。微生物虽然参与了金属的腐蚀过程,但微生物并不会改变金属的腐蚀类型,而是它们会改变金属的腐蚀速度,使金属在口腔环境中更容易腐蚀。牙科金属材料的微生物腐蚀是跨学科的综合研究,可以应用材料学、腐蚀学和生物学领域的研究方法,来对口腔微生物对牙科金属的腐蚀作用机制作进一步的研究。     

牙科铸造合金的离子释出及生物学性能的研究现状

由于牙科铸造合金制作的修复体直接置于口腔内,所以要求具有良好的生物相容性.但大量的实验表明,牙科铸造合金会发生腐蚀,从而引起了机体组织的不良反应.本文旨在对牙科铸造合金离子释出的影响因子及其生物相容性作一综述.     

牙科铸造合金的腐蚀及生物相容性研究进展

由于牙科铸造合金制作的修复体直接置于口腔内，所以要求具有良好的生物相容性。但大量的实验表明，修复体戴用后，牙科铸造合金会发生腐蚀，从而引起了机体组织的不良反应。本文旨在对牙科铸造合金的腐蚀及生物相容性作一综述。     

牙科合金腐蚀行为的电化学研究及影响因素

牙科合金在口腔环境中发生的腐蚀主要是电化学腐蚀。电化学方法是研究合金腐蚀的主要手段。合金的电化学腐蚀与材料的成分和量以及组织结构密切相关。口腔电解质溶液环境和微生物对合金的腐蚀也有显著的影响。     

有关牙科合金腐蚀的研究现状

如今牙科合金被大规模应用于临床，因合金腐蚀造成的临床问题也接踵而至，如镍铬合金腐蚀后引起龈缘黑线等。通过对现有相关文献的检索、整理和分析，对影响牙科合金腐蚀的相关因素研究进展作一综述。     

牙科合金电偶腐蚀的研究进展

牙科合金是重要的口腔修复材料,异种金属同时应用容易引发口内的电偶腐蚀,从而产生电流,释放金属离子,不仅缩短修复体的使用寿命,还会影响人体健康。本文旨在对牙科常用合金材料的电偶腐蚀研究方法、影响因素及缓解方法作一综述。     

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摘要：金属及其合金广泛应用于口腔修复中。镍铬合金等非贵金属合金烤瓷修复体在口腔内应用一段时间后会发生化学及电化学腐蚀,析出有害金属离子,影响健康及美观。因此,有学者开始将应用于工业领域的镀金技术应用于口腔修复领域来提高镍铬合金等非贵金属合金的抗腐蚀性及生物相容性。本文就金属腐蚀,镀金后基体材料的抗腐蚀性及生物相容性,镀金在口腔修复中的应用做一综述。     

A potentiostatic study of the corrosion behavior of anodized and nonanodized aluminum alloy

The clinical implication of this study is that some improvement in the corrosion resistance of denture bases made with aluminum alloy D-214 may be obtained by anodization. However, since this study does not exactly duplicate an oral environment or take into consideration the variation in oral environments, it cannot be assumed that the additional corrosion resistance would be discernible in a particular patient.     

Effect of pellicle on galvanic corrosion of amalgam

Galvanic corrosion of amalgam, induced by contact with a type IV dental casting gold alloy, was determined under simulated oral conditions in an electrochemical cell. The effect of a pellicle layer formed by 1 h exposure to saliva in the oral cavity was determined. Pellicle on the amalgam had no effect on the maximum corrosion rate or the 2 h corrosion charge, whereas pellicle on the gold alloy substantially reduced both these parameters of the conventional low-copper amalgam; the corrosion of the high-copper amalgam was less and was not influenced by pellicle formation.     

Effect of pellicle on galvanic corrosion of amalgam

Abstract – Galvanic corrosion of amalgam, induced by contact with a type IV dental casting gold alloy, was determined under simulated oral conditions in an electrochemical cell. The effect of a pellicle layer formed by 1 h exposure to saliva in the oral cavity was determined. Pellicle on the amalgam had no effect on the maximum corrosion rate or the 2 h corrosion charge, whereas pellicle on the gold alloy substantially reduced both these parameters of the conventional low-copper amalgam; the corrosion of the high-copper amalgam was less and was not influenced by pellicle formation.     

Potentiodynamic polarization study of the in vitro corrosion behavior of 3 high-palladium alloys and a gold-palladium alloy in 5 media.

STATEMENT OF PROBLEM: Corrosion of cast alloy restorations may lead to their failure or adversely affect their biocompatibility. Although some documentation of the corrosion behavior of the high-palladium dental alloys exists, questions remain about their corrosion resistance and mechanisms. PURPOSE: This study compared the in vitro corrosion characteristics of 3 high-palladium alloys and 1 gold-palladium alloy in simulated body fluid and oral environments. MATERIAL AND METHODS: Two Pd-Cu-Ga alloys and 1 Pd-Ga alloy were selected; an Au-Pd alloy served as the control. The corrosion behavior for the as-cast and simulated porcelain-firing (heat-treated) conditions of each alloy (N = 5) was evaluated in 0.9% NaCl, 0.09% NaCl, and Fusayama solutions. Heat-treated specimens of each alloy (N = 5) were also tested in N(2)-deaerated 0.09% NaCl and Fusayama solutions (pH 4). After immersion in the electrolyte for 24 hours, the open-circuit potential (OCP) was measured, and linear polarization was performed from -20 mV to +20 mV (vs. OCP) at a scanning rate of 0.125 mV/s. Cyclic polarization was performed from -300 mV to +1000 mV and back to -300 mV (vs. OCP) at a scanning rate of 1 mV/s. Data were evaluated with analysis of variance and the Ryan-Einot-Gabriel-Welsch multiple-range test (alpha=.05). RESULTS: The OCP of each alloy varied with the condition (as-cast or heat-treated) and electrolyte used. Corrosion resistance was similar for the 4 alloys tested. For cyclic polarization, all alloys showed active-passive or spontaneous passive behavior in nearly all electrolytes. During some reverse scans, the 3 high-palladium alloys displayed 3 or 5 anodic peaks. No positive hysteresis was observed for any of the alloy/electrolyte combinations evaluated. CONCLUSION: The corrosion resistances of the 3 high-palladium alloys in simulated body fluid and oral environments were comparable to that of the gold-palladium alloy. The similar corrosion resistance for the 3 high-palladium alloys was attributed to their high noble metal content and theorized stable structure at the submicron level. Selective corrosion of different phases and elements, surface enrichment of palladium, and adsorption of species are possible corrosion mechanisms. The cyclic polarization results suggest that none of the 4 alloys would be prone to pitting or crevice corrosion under in vivo conditions, but crevice conditions should nonetheless be avoided for these alloys in the oral environment.     

复合弓丝在含酶人工唾液中的抗腐蚀性能研究

目的：探索激光焊接复合弓丝在含有唾液淀粉酶和胰淀粉酶人工唾液中的抗腐蚀能力,对比两种淀粉酶对弓丝抗腐蚀性能的影响及其机制。方法复合弓丝的抗腐蚀能力采用电化学极化和浸泡实验的方法评估,浸泡于含酶的人工唾液28 d后的可溶性腐蚀产物用等离子光谱仪进行检测,表面形貌采用扫描电镜、能谱仪和原子力显微镜进行分析。结果唾液淀粉酶和胰淀粉酶均能够提高复合弓丝的抗腐蚀能力;同工异构酶也会对同种合金的抗腐蚀能力产生不同的影响。结论新型金属生物材料拟应用于口腔时,淀粉酶可能对其抗腐蚀能力有影响。     

口腔环境中纯钛及钛75合金种植体覆盖螺丝缝隙腐蚀的研究

目的 :研究口腔环境中纯钛及钛 75合金种植体覆盖螺丝的缝隙腐蚀 ,及同一环境中纯钛及钛 75合金之间有无电偶腐蚀现象。方法 :将纯钛 (TA2 )及钛 75合金机加工成直径 3.5mm、长10mm的柱状螺纹种植钉及相对应覆盖螺丝 ,清洗、钝化、消毒。选择杂种实验狗6条 ,随机分A、B、C组,A组每条狗口腔中植入纯钛钉4个,B组每条狗植入钛 75合金种植钉4个,C组口内同时植入2个纯钛、2个钛75合金种植钉 ,种植体与对牙合无接触。每组以 12周为时间点 ,扫描电镜观察覆盖螺丝。结果 :A组纯钛机加工处理不清晰、走向改变 ,但未发现点蚀坑 ,B组钛75合金覆盖螺丝机加工纹理清晰、密度细、未发现腐蚀 ,C组未发现纯钛及钛 75合金种植覆盖螺丝的点蚀坑。结论 :钛75合金与纯钛在同一口腔环境中未发现电偶腐蚀 ,提示临床应用中可用钛75合金代替纯钛做上部结构与纯钛匹配 ;钛75合金在口腔中耐磨损性能优于纯钛。     

氟离子对两种不同工艺制作的钴铬合金耐腐蚀性能的影响

目的 在模拟口腔环境下研究氟离子对采用选择性激光熔覆（SLM）技术和传统铸造技术两种工艺制作的钴铬合金耐腐蚀性的影响。方法 选择具有相同材料成分的钴铬合金金属粉末和金属块,分别采用SLM（SLM组）和铸造技术（Cast组）各制作15个试件,置于含不同氟离子质量分数（0、0.05%、0.20%）的酸性人工唾液（pH值为5.0）中浸泡24 h进行电化学试验,采用动电位极化曲线法测试合金的自腐蚀电位Ecorr、自腐蚀电流密度Icorr和极化电阻Rp,同时结合扫描电子显微镜（SEM）观察,分析两组试件的耐腐蚀性能。结果 铸造工艺制作的钴铬合金在酸性人工唾液中的Ecorr随着氟离子质量分数的升高而减小。当氟离子质量分数为0.20%时,两种工艺制作的钴铬合金的Ecorr、Icorr、Rp均有明显改变（P<0.05）,SEM结果也显示合金表面均出现腐蚀现象。当氟离子质量分数为0.20%时,Cast组钴铬合金的Icorr高于SLM组,而Ecorr和Rp低于SLM组（P<0.05）。结论 氟离子可降低两种工艺制作的钴铬合金的耐腐蚀性,在氟离子质量分数较高（0.20%）时,SLM技术制作的钴铬合金的耐腐蚀性优于铸造工艺制作的钴铬合金。     

齿科铸造合金应力腐蚀破裂的研究进展

齿科铸造合金广泛应用于口腔修复,修复体在口腔环境中行使功能时,会发生电化学腐蚀,其中应力腐蚀破裂是危害性最大的一种腐蚀形式。本文就齿科铸造合金应力腐蚀破裂的研究进展作一综述。     

Galvanic corrosion of dental cobalt-chromium alloys and dental amalgam in artificial saliva.

When two or more metals or alloys are placed in contact with one another inside the oral cavity, galvanic coupling may occur which may lead to galvanic corrosion. Galvanic corrosion may release elements from the alloy into the oral cavity with possible harm to the patient. This in vitro study was conducted to determine the extent of galvanic corrosion where different dental amalgams and Co-Cr alloy combinations were placed in contact with artificial saliva as an electrolyte. The tests were conducted with potential measurements as well as potentiodynamic and potentio-static polarisation techniques. Results showed that the galvanic corrosion current density is much lower than the corrosion current density, indicating that galvanic coupling of the samples does not have a substantial effect on the overall corrosion of the samples. The corrosion potential differences between three of the four couples were above the minimum 50 mV potential difference, which is considered a potential harmful level, with only the Wironium Plus and Dispersalloy combination being under 50 mV potential difference. It is concluded that: Galvanic corrosion does not pose a greater threat to the alloys than ordinary corrosion. A Wironium Plus and Dispersalloy combination may be the safest where a Co-Cr and amalgam combination is required in the mouth of a patient.