制作方法对钴铬合金金瓷结合性能的影响

目的 比较铸造钴铬合金与选区激光熔化（SLM）钴铬合金金瓷结合强度的差异。方法 用铸造法和SLM技术制作钴铬合金试件各10个,在中间1/3区域熔附瓷粉,采用剪切力试验测试金瓷结合强度并观察断裂类型。采用SPSS 13.0软件中的t检验对结果进行统计学分析。结果铸造组、SLM组剪切力分别为（33.11±4.98）、（30.94±5.98） MPa,二者间差异无统计学意义（P>0.05）。样本的断裂类型为复合断裂。结论 SLM钴铬合金修复体精密度较高,其金瓷结合强度与铸造钴铬合金相近。     

固态相变对钴铬合金的金瓷匹配性的影响

目的研究钴铬（Co-Cr）合金在烤瓷过程中发生的固态相变对其金瓷匹配性的影响。方法失蜡法铸造Co-Cr、镍铬（Ni-Cr）合金的片状试件各9个,尺寸为25 mm×3 mm×0.5 mm,其中6个用于测定金瓷结合强度（三点弯曲法）,3个去瓷后进行X射线衍射（XRD）分析。铸造2种合金的棒状试件各1个,测定合金的热膨胀系数,并记录冷却曲线。结果Ni-Cr、Co-Cr合金的金瓷结合强度分别为（49.1±3.40）、（40.9±2.02）MPa,二者间的差异具有统计学意义（P=0.00）。Ni-Cr合金与Co-Cr合金在20～500 ℃的平均热膨胀系数分别为13.9×10-6、13.8×10-6·K-1。XRD结果显示,Ni-Cr合金的主要相为奥氏体,Co-Cr合金由fcc相、hcp相及少量σ相组成。结论烤瓷冷却过程中,钴铬合金中的fcc相向hcp相的转变以及σ相的析出导致合金线收缩速度出现突变,降低了金瓷匹配性。     

激光选区熔化成形钴铬合金及钛合金金瓷结合强度的研究

目的　比较激光选区熔化（selective laser melting,SLM）技术与传统方法制作的钴铬合金（Co-Cr）和钛合金（Ti6Al4V）在金瓷结合性能方面的差异。方法　分别采用传统方法（铸造法和锻造法）和SLM技术制作4组直径10 mm、厚1 mm的圆形片状试件,每组各10个,分别记为铸造Co-Cr（CC）组、锻造Ti6Al4V（DT）组、SLM Co-Cr（SC）组、SLM Ti6Al4V（ST）组。流水下打磨抛光试件,氧化铝喷砂剂喷砂后,激光扫描共聚焦显微镜（CLSM）检测试件表面粗糙度。室温下干燥后分别烧结瓷粉,采用剪切强度测试法测定各组的金瓷结合强度,并进行统计学分析。体视显微镜观察瓷层断裂模式。场发射扫描电镜（FE-SEM）对金瓷结合界面形貌进行分析。结果　各组试件表面粗糙度未见明显差异（P > 0.05）。CC组和SC组的剪切强度无明显差异,分别为（25.949 ± 2.708）MPa和（26.707 ± 1.559）MPa,均显著高于DT组［（18.259 ± 1.882）MPa］和ST组［（21.504 ± 3.019）MPa］（P < 0.05）,其中DT组低于ST组（P < 0.05）。各组剪切强度测试后金瓷断裂模式均为混合断裂。FE-SEM下观察显示SC组和CC组金瓷界面结合紧密,DT组和ST组金瓷界面偶见气孔和裂隙。结论　SLM技术制作的Co-Cr金瓷结合强度与传统铸造法相当,SLM技术制作的Ti6Al4V金瓷结合强度明显高于传统锻造法。SLM技术作为一种新型的激光3D打印技术,在口腔修复学领域有极大的应用潜力。     

真空镀膜技术对新型牙用烤瓷支架钴铬合金金瓷结合强度影响的研究

目的研究一种新的工程学真空镀膜技术---等离子磁控反应溅射技术对新型牙用烤瓷支架钴铬合金金瓷结合强度的影响。方法用DA9- 4烤瓷支架钴铬合金制成标准金属基片,并在金属基片上瓷前利用等离子磁控反应溅射技术在其表面溅射生成一层Al2O3陶瓷薄膜,对其表面形貌、结构、厚度进行分析;金属基片与VMK95瓷粉烧结形成标准三点弯曲试件,测定其结合强度,观察金瓷界面的形貌及元素分布情况。同时,以未进行溅射镀膜基片作为对照。结果溅射镀膜组金瓷结合强度为（180.55±16.45）MPa,对照组（143.80±24.49）MPa。经统计学分析,溅射镀膜后的金瓷结合强度明显高于对照组（P<0.01）。结论等离子磁控反应溅射技术有改善新型牙用烤瓷支架钴铬合金金瓷结合强度的作用。     

两种喷砂粒度对钯银合金金瓷结合强度的影响

目的研究上瓷前不同粒度喷砂对钯银合金金瓷结合强度的影响。 方法采用不同粒度（250、120 μm）的Al₂O₃在0.3 MPa压力下,以45°角对钯银合金试件表面进行喷砂10 s粗化处理后,对合金表面的粗糙度、表面接触角进行检测。用ISO 9693规定的三点弯曲测试分别测定其金瓷试件的结合强度。两组表面粗糙度、表面接触角以及金瓷结合强度的数据使用独立样本t检验进行统计学分析（α= 0.05）。使用有X线能谱分析的扫描电镜观察试件的显微特征,元素成分。 结果250 μm喷砂处理后钯银合金金属表面粗糙度2.03 μm,接触角46.02°,与120 μm喷砂处理后的表面粗糙度1.69 μm、接触角63.61°比较,表面更为粗糙,润湿性更好。250 μm组的金瓷结合强度为（51.61 ± 5.91）MPa,120 μm组的金瓷结合强度为（46.62 ± 4.33）MPa,两者间差异有统计学意义（t=2.360,P=0.028）。三点弯曲测试后,所有开裂试件都为混合折裂模式。 结论钯银合金在0.3 MPa压力下,250 μm较120 μm Al₂O₃喷砂后能获得较高的金瓷结合强度。     

纳米过渡性介质对新型牙用烤瓷支架钴铬合金金瓷结合强度影响的研究

目的：研究纳米过渡性介质对新型牙用烤瓷支架钴铬合金（简称DA9-4合金）金瓷结合强度的影响。方法：用DA9-4合金制成金属棒以及金属片,并在金属试件上瓷前涂附纳米二氧化硅和纳米金介质2种不同的过渡性介质;金属棒与VMK95瓷粉烧结生成金瓷棒盘试件用于测定金瓷结合强度;金属片与VMK95瓷粉烧结形成金瓷复合体,分别观察金瓷界面的形貌及元素分布情况。结果：涂附纳米过渡性介质后的金瓷结合强度明显高于对照组（P〈0.01）。结论：纳米过渡性介质有改善新型牙用烤瓷支架钴铬合金金瓷结合强度的作用。     

等离子喷涂技术对新型牙用烤瓷支架钴铬合金金瓷结合强度影响的研究

目的 研究一种新的工程学真空镀膜技术-等离子喷涂技术对新型牙用烤瓷支架钴铬合金金瓷结合强度的影响.方法 用DA9-4钴铬合金制成金属棒以及金属片,并在金属试件上瓷前利用等离子喷涂技术在其表面形成一层Al2O3陶瓷薄膜,对其结构进行X射线衍射分析;金属棒与VMK95瓷粉烧结生成金瓷棒盘试件用于测定金瓷结合强度;金属片与VMK95瓷粉烧结形成金瓷复合体,分别观察金瓷界面的形貌及元素分布情况.结果 等离子喷涂镀膜处理后的金瓷结合强度(71.98±15.37Mpa)明显高于对照组(63.66±14.72MpaP＜0.01).结论 等离子喷涂技术有改善新型牙用烤瓷支架钴铬合金金瓷结合强度的作用.     

表面处理对激光选区熔化成型纯钛钛瓷结合强度的影响

目的 ：探讨表面处理对激光选区熔化（selective laser melting,SLM）成型纯钛钛瓷结合强度的影响。方法 ：采用SLM技术制作纯钛条64个，钴铬合金条16个（25.0 mm×3.0 mm×0.5 mm）。根据喷砂压力及中间层将纯钛试件分为4组，TB1组为0.25 MPa喷砂的粘接瓷组，TG1组为0.25 MPa喷砂的金涂层，TB2组为0.45 MPa喷砂的粘接瓷，TG2组为0.45 MPa喷砂的金涂层，各组一半烤瓷试件进行10 000次冷热循环实验（n=8）。以0.25 MPa及0.45 MPa压力喷砂的钴铬合金金瓷结合强度作为对照，记为C1、C2组（n=8）。利用经典三点弯曲实验测试烤瓷试件的金瓷粘接强度，使用激光扫描共聚焦显微镜测量纯钛表面粗糙度，使用场发射扫描电镜观察钛瓷结合界面形貌，使用体视显微镜观察瓷剥脱后钛表面形貌并分析断裂模式，采用Graphpad Prism 8.0软件包对数据进行统计学分析。结果：钛瓷结合强度TG2组（40.16±3.97） MPa显著高于TB2组（36.32±1.44） MPa,TG1组（37.38±2.39） MPa显著高于TB...     

选择性激光熔覆钴铬合金与瓷的结合性能研究

目的:评价选择性激光熔覆(selective laser melting,SLM)技术制作的钴铬合金与瓷粉的结合强度。方法:根据YY 0621-2008标准采用三点弯曲法测试比较SLM和传统失蜡铸造法的钴铬合金的金瓷结合强度,采用Vita瓷粉和Noritake瓷粉,对金瓷界面进行扫描电镜观察。结果:无论Vita瓷粉或Noritake瓷粉,SLM制作法的钴铬合金的金瓷结合强度均大于传统铸造法的金瓷结合强度(P<0.05)。SEM检测显示SLM钴铬合金的金瓷渗透深度均大于传统铸造钴铬合金的金瓷渗透深度。结论:SLM钴铬合金的金瓷结合强度大于YY0621-2008标准(25 MPa),也大于传统失蜡铸造法所获得的金瓷结合强度。     

钴铬合金表面喷砂及烤瓷厚度对金-瓷结合强度影响

目的探讨不同的喷砂处理及瓷层厚度对钴铬合金烤瓷冠金-瓷结合的影响。方法处理因素有两点：①喷砂直径,60目及90目的氧化铝,压力为0.4MPa,②瓷层厚度,1.5mm及2.0mm。实验分为四组：A组,60目砂、1.5mm厚度瓷层;B组,60目砂2.0mm厚度瓷层;C组,90目砂1.5mm厚度瓷层;D组,90目砂2.0mm厚度瓷层。按照要求制作剪切强度试件,用万能试验机进行剪切强度测试。应用SPSS10.0软件进行统计学分析。结果各实验组抗剪切强度分别为：A组33.5987±5.3926MPa,B组29.0446±2.4165MPa,C组27.9936±2.7097MPa,D组21.9586±0.2209MPa;统计分析结果表明,A组与D组之间的差异有统计学意义（P〈0.05）,而其余各组之间的差异均无统计学意义。结论喷砂用的氧化铝粒径较大者,钴铬合金表面的金瓷结合力较强;1.5mm瓷层组的金瓷结合力大于2.0mm瓷层组。     

Comparison of the bond strength of laser-sintered and cast base metal dental alloys to porcelain

OBJECTIVE: The purpose of this study was to compare shear bond strengths of cast Ni-Cr and Co-Cr alloys and the laser-sintered Co-Cr alloy to dental porcelain. METHODS: Dental porcelain was applied on two cast and one laser-sintered base metal alloy. Ten specimens were prepared for each group for bond strength comparison. ANOVA followed by Tukey HSD multiple comparison test (alpha=0.05) was used for statistical analysis. Fractured specimens were observed with a stereomicroscope to classify the type of failure after shear bond testing. RESULTS: While the mean shear bond strength was highest for the cast Ni-Cr metal-ceramic specimens (81.6+/-14.6MPa), the bond strength was not significantly different (P>0.05) from that for the cast Co-Cr metal-ceramic specimens (72.9+/-14.3MPa) and the laser-sintered Co-Cr metal-ceramic specimens (67.0+/-14.9MPa). All metal-ceramic specimens prepared from cast Ni-Cr and Co-Cr alloys exhibit a mixed mode of cohesive and adhesive failure, whereas five of the metal-ceramic specimens prepared from the laser-sintered Co-Cr alloy exhibited the mixed failure mode and five specimens exhibited adhesive failure in the porcelain. CONCLUSIONS: The new laser-sintering technique for Co-Cr alloy appears promising for dental applications, but additional studies of properties of the laser-sintered alloy and fit of castings prepared by this new technique are needed before its acceptance into dental laboratory practice. SIGNIFICANCE: Laser sintering of Co-Cr alloy seems to be an alternative technique to conventional casting of dental alloys for porcelain fused to metal restorations.     

Porcelain adherence vs force to failure for palladium-gallium alloys: a critique of metal-ceramic bond testing.

OBJECTIVES: The purpose of this study was to characterize the metal-ceramic bond of four commercial Pd-Ga alloys by two separate tests: porcelain adherence and bond failure force. A Pd-Ag alloy was the control. A secondary goal was to investigate a possible correlation between the percent porcelain retained and bond failure forces. METHODS: For adherence testing, five cast plates of each alloy were air abraded and oxidized. The porcelain was applied on a circular area in the center of each plate and fractured using constant-strain flexure. The area fraction of adherent porcelain (%) was calculated via a standardized spectrometric technique. Bond failure forces were measured in three-point bending using bar specimens. The modulus of elasticity of the five alloys was also measured. No attempt was made to calculate bond strength since the residual thermal stresses at the interfacial region were unknown. Data were compared via ANOVA and the Tukey multiple range test (p < 0.05). RESULTS: All failures occurred at the porcelain termination sites with no tensile fracture of the porcelain. Two Pd-Ga alloys exhibited porcelain adherence comparable with previously studied Pd-Cu-Ga alloys. There was no correlation between the porcelain adherence and the force to failure (r2 = 0.0159). Additionally, no statistically significant differences were found among the moduli of elasticity of the five alloys. SIGNIFICANCE: The new Pd-Ga alloys have been commercially introduced with little information on the quality of the bond with porcelain. The use of two different means for assessing the metal-ceramic bond provides information on the relationship of data using different experimental techniques.     

五种烤瓷合金金瓷结合强度的比较

目的：比较镍铬合金、含钛的镍铬合金、钴铬合金、钯银合金和纯钛的金瓷结合强度。方法：执行ISO9693标准,采用三点弯曲试验分别测定镍铬合金、含钛的镍铬合金、钻铬合金、钯银合金、纯钛在常规热处理条件下的金瓷结合强度。结果：金瓷结合强度分别为：镍铬合金（37．82±2．72）Mpa;含钛的镍铬合金（39．23±2．45）Mpa;钴铬合金（39．06±3．41）Npa;钯银合金（47．98±3．74）Npa;纯钛（32．61±5．62）Mpa。镍铬合金、含钛的镍铬合金、钻铬合金组间差异无统计学意义（P〉0．05）,这3种合金与纯钛、钯银合金组间差异都有统计学意义（P〈0．05）,纯钛与钯银合金组间差异也有统计学意义（P〈0．05）。结论：①镍铬合金、含钛的镍铬合金、钴铬合金金瓷结合强度相近,都大于纯钛且小于钯银合金的金瓷结合强度。②镍铬合金、含钛的镍铬合金、钻铬合金、钯银合金和纯钛的金瓷结合强度都大于25Mpa,按ISO9693标准均可应用于临床。     

镍铬合金、钴铬合金和纯钛金瓷结合强度的比较

目的比较镍铬合金、钴铬合金和纯钛的金瓷结合强度和金瓷界面特征。方法执行ISO9693[1]标准,采用三点弯曲试验分别测定在常规热处理条件下的镍铬合金、钴铬合金和纯钛的金瓷结合强度。运用扫描电镜和X射线衍射进行金瓷界面分析。结果金瓷结合强度分别为:镍铬合金:(37.56±2.92)Mpa,钴铬合金:(39.06±2.79)Mpa,纯钛:(32.61±5.62)Mpa,前两者组间差异无统计学意义(P>0.05),后者与前两者组间差异有统计学意义(P<0.05)。扫描电镜和X线衍射:镍铬合金和钴铬合金与瓷之间紧密接触,无裂纹,界面过渡层15～20μm。纯钛与瓷过渡层80μm,可见孔洞。纯钛基体表面可见约2μm黑色带。结论①钴铬合金与镍铬合金的金瓷结合强度接近,都大于纯钛的金瓷结合强度。②钴铬合金、镍铬合金、纯钛的金瓷结合强度都大于25Mpa,按ISO9693标准均可应用于临床。③金瓷之间存在结合介质,形成过渡层。     

Shear bond strengths of a ceramic system to alternative metal alloys

STATEMENT OF PROBLEM: The success of metal-ceramic restorations is influenced by the compatibility between base metal alloys and porcelains. Although porcelain manufacturers recommend their own metal systems as the most compatible for fabricating metal-ceramic prostheses, a number of alloys have been used. Purpose This study evaluated the shear bond strength between a porcelain system and 4 alternative alloys. MATERIAL AND METHODS: Two Ni-Cr alloys: 4 ALL and Wiron 99, and 2 Co-Cr alloys: IPS d.SIGN 20 and Argeloy NP were selected for this study. The porcelain (IPS d.Sign porcelain system) portion of the cylindrical metal-ceramic specimens was 4 mm thick and 4 mm high; the metal portion was machined to 4x4 mm, with a base that was 5 mm thick and 1 mm high. Forty-four specimens were prepared (n=11). Ten specimens from each group were subjected to a shear load on a universal testing machine using a 1 mm/min crosshead speed. One specimen from each group was observed with a scanning electron microscope. Stress at failure (MPa) was determined. The data were analyzed with a 1-way analysis of variance (alpha=.05). RESULTS: The groups, all including IPS d.Sign porcelain, presented the following mean bond strengths (+/-SD) in MPa: 4 ALL, 54.0+/-20.0; Wiron, 63.0+/-13.5; IPS d.SIGN 20, 71.7+/-19.2; Argeloy NP, 55.2+/-13.5. No significant differences were found among the shear bond strength values for the metal-ceramic specimens tested. CONCLUSION: None of the base metal alloys studied demonstrated superior bond strength to the porcelain tested.     

Chemical composition,surface roughness,and ceramic bond strength of additively manufactured cobalt-chromium dental alloys

Statement of problemSelective laser melting (SLM) additive manufacturing (AM) technology is a current option to fabricate cobalt-chromium (Co-Cr) metal frameworks for dental prostheses. However, the Co-Cr alloy composition, surface roughness, and ceramic bond strength values that SLM metals can obtain are not well-defined.PurposeThe purpose of this in vitro study was to compare the chemical composition, surface roughness, and ceramic shear bond strength of the milled and SLM Co-Cr dental alloys.Material and methodsA total of 50 disks of 5 mm in diameter and 1 mm in thickness were fabricated by using subtractive (control group) and AM with each of following SLM providers: SLM-1 (EOS), SLM-2 (3D systems), and SLM-3 (Concept Laser). The milled disks were airborne-particle abraded with 100-μm aluminum oxide particles. All the specimens were cleaned before surface roughness (Ra), weight (Wt%), and atomic (At%) percentages were analyzed. Three-dimensional profilometry was used to analyze the topographical properties of the surface parameters Ra (mean surface roughness). The chemical composition of Co-Cr alloy specimens was determined by using energy dispersive X-ray (EDAX) elemental analysis in a scanning electron microscope (SEM). Thereafter, the specimens were bonded to a ceramic (Dentine A3 and Enamel S-59; Creation CC) interface. Specimens were stored for 24 hours at 23 °C. The bond strength of the SLM-ceramic interface was measured by using the macroshear test (SBT) method (n=10). Adhesion tests were performed in a universal testing machine (1 mm/min). The Shapiro-Wilk test revealed that the chemical composition data were not normally distributed. Therefore, the atomic (At%) and weight percentages (Wt%) were analyzed by using the Kruskal-Wallis test, followed by pairwise Mann-Whitney U tests between the control and AM groups (AM-1 to AM-4). However, the Shapiro-Wilk test revealed that the surface roughness (Ra) and ceramic bond strength data were normally distributed. Therefore, data were analyzed by using 1-way ANOVA, followed by the post hoc Sidak test (α=.05).ResultsSignificant differences were obtained in Wt%, At%, and Ra values among the Co-Cr alloys evaluated (P<.05). Furthermore, the control group revealed significantly lower mean ±standard deviation Ra values (0.79 ±0.11 μm), followed by AM-3 (1.57 ±0.15 μm), AM-2 (1.80 ±0.43 μm), AM-1 (2.43 ±0.34 μm), and AM-4 (2.84 ±0.27 μm). However, no significant differences were obtained in the metal-ceramic shear bond strength among the different groups evaluated, ranging from mean ±standard deviation 75.77 ±11.92 MPa to 83.65 ±12.21 MPa.ConclusionsCo-Cr dental alloys demonstrated a significant difference in their chemical compositions. Subtractive and additive manufacturing procedures demonstrated a significant influence on the surface roughness of the Co-Cr alloy specimens. However, the metal-ceramic shear bond strength of Co-Cr alloys was found to be independent of the manufacturing process.     

Use of metal conditioners to improve bond strengths of autopolymerizing denture base resin to cast Ti-6Al-7Nb and Co-Cr

OBJECTIVE: The shear bond strengths of an autopolymerizing denture base resin to cast Ti-6Al-7Nb and Co-Cr alloys using three metal conditioners were investigated. METHODS: Ti-6Al-7Nb alloy and Co-Cr alloy discs were cast. The disc surfaces were air-abraded with 50 microm alumina particles and treated with three metal conditioners (Alloy Primer; Cesead II Opaque Primer; Metal Primer II). An autopolymerizing denture base resin was applied on the discs within a hole punched in a piece of sticky tape and a Teflon ring to define the bonding area. All specimens were immersed in 37 degrees C water for 24 h. Half of the specimens were thermocycled up to 20,000 cycles. The shear bond strengths were determined at a crosshead speed of 1.0 mm/min. RESULTS: Specimens treated with the three metal conditioners had significantly (p<0.05) improved shear bond strengths of the autopolymerizing denture base resin to both Ti-6Al-7Nb and Co-Cr. Although the bond strengths of the bonded Ti-6Al-7Nb specimens were higher than those of the Co-Cr alloy before thermocycling, the decrease in the bond strength of Ti-6Al-7Nb was considerably greater than that of the Co-Cr after thermocycling. CONCLUSION: Significant improvements in bond strength of the autopolymerizing denture base resin to cast Ti-6Al-7Nb alloy and Co-Cr alloy were achieved through the application of Alloy Primer, Cesead II Opaque Primer and Metal Primer II. The bond durability to Ti-6Al-7Nb alloy was inferior to that to Co-Cr.