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。     

四种树脂水门汀黏结牙本质剪切强度的比较

目的:评价4种树脂水门汀与牙本质黏结剪切强度。方法:新鲜拔除的无龋损人第三磨牙48个,随机分为4组(n=12),制备颊侧牙本质黏结面,分别与4种树脂水门汀(Unicem、Panavia F、VariolinkⅡ、Vitique)黏结处理,测试剪切强度,SEM观察牙本质黏结界面。结果:4种树脂水门汀中RelyX Unicem(12.84±2.29)MPa与Panavia F(14.93±3.73)MPa、Vitique(11.03±2.57)MPa之间无显著性差异(P>0.05),而他们均显著高于VariolinkⅡ(5.43±1.25)MPa(P<0.05)。结论:新型自黏结树脂水门汀RelyX Unicem可以取得与牙本质良好的黏结效果,且美观,易于使用,节省操作时间,为黏结修复体提供了一种新的选择。     

甲基丙烯酰氧基丙基三甲氧基硅烷对3种不同金属与Filtek树脂粘接强度的影响

目的研究经甲基丙烯酰氧基丙基三甲氧基硅烷（γ-MPS）偶联剂处理的3种不同金属的粘接表面对FiltekZ350树脂粘接强度的影响。方法用失蜡铸造法制备镍铬合金、纯钛、金钯合金试件各12个,共36个。每种金属随机平分为实验组和对照组,每组6个。实验组用γ-MPS对粘接面进行处理后与Filtek Z350树脂粘接,对照组粘接面不用γ-MPS处理。测试每组试件断裂时的剪切力,并用扫描电子显微镜（SEM）观察试件断面的形貌。结果镍铬合金实验组、纯钛实验组较相应对照组的剪切强度高,差异有统计学意义（P<0.001）;金钯合金实验组与其对照组的剪切强度无明显差异（P>0.05）。实验组内比较：纯钛组剪切强度高于镍铬合金组,两者又均高于金钯合金组（P<0.01）。所有试件均为黏结断裂。与对照组相比,镍铬合金和纯钛实验组断裂面有较多的树脂突,而金钯合金实验组断裂面树脂突较少。结论γ-MPS可以提高金属和树脂的粘接力,但和金属成分有关。γ-MPS能增加纯钛、镍铬合金与树脂的粘接性能,但不能认为γ-MPS可以增加金钯合金与树脂的粘接性能。     

五种全冠合金铸造后的腐蚀性研究

目的 测定五种制作全冠的合金铸造后在体外细胞培养液中析出金属离子的种类及不同时间段析出的各种金属离子的量。方法 本实验用电感藕荷等离子质谱仪（ICP－MS）定量测定金属离子测试。结果 镍铬合金和钴铬合金析出离子最多银钯合金和钯合金有一定的金属离子析出，纯钛只析出微量钛离子。结论 纯钛、钯合金的耐腐蚀性最好，银钯合金次之，镍铬合金和钴铬合金的耐腐蚀性较差。     

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。     

四种烤瓷基底冠金属对人牙龈成纤维细胞分泌前列腺素E2和环加氧酶2的影响

目的 观察4种烤瓷基底冠金属浸提液对人牙龈成纤维细胞分泌前列腺素E2和环加氧酶2的影响.方法 制备镍铬合金、钴铬合金、纯钛、金钯合金金属浸提液,以无金属浸泡的达尔伯克改良伊格尔培养基培养液作为空白对照,培养人牙龈成纤维细胞,分别培养1、6、12、24h,收集上清液,酶联免疫吸附测定法测定前列腺素E2的表达水平;制作细胞爬片,用免疫荧光法观察各组环加氧酶2的表达.结果 镍铬合金、钴铬合金组6、12、24h前列腺素E2表达水平(镍铬:45.568±0.926、60.538±0.988、73.754±0.507;钴铬:40.496±0.693、53.216±0.327、65.470±1.086)高于相应空白对照组(31.122±0.642、31.230±0.634、30.980±0.746),差异均有统计学意义(P＜0.05);纯钛、金钯合金组前列腺素E2表达水平(钛:31.564±0.719、31.998±0.856、32.066±0.513;金钯:31.540±0.821、31.136±0.518、31.340±0.443)与相应空白对照组差异均无统计学意义(P＞0.05).镍铬合金、钴铬合金组环加氧酶2的染色深而均匀;纯钛、金钯合金组与空白对照组染色浅且不均匀.结论 镍铬合金、钴铬合金使人牙龈成纤维细胞分泌前列腺素E2和环加氧酶2增加,而纯钛、金钯合金不影响前列腺素E2和环加氧酶2的分泌.     

异种金属间激光焊接的初步研究

目的:通过对焊件机械强度的测定及熔合区微观结构的分析,探讨口腔常用合金异种金属间激光焊接的可行性。方法:采用钴铬合金、镍铬合金、纯钛进行异种金属间的激光焊接,测定焊件的最大抗拉、抗弯强度,并进行拉伸断口的扫描电镜观察和熔合区的金相分析,探讨激光焊接异种金属的焊接质量及临床应用的可行性。结果:钴铬和镍铬合金异种金属间的激光焊件机械性能较好,钴铬焊丝组和镍铬焊丝组在最大抗拉、抗弯强度上无显著差异(P>0.05)。纯钛与钴铬或者镍铬合金激光熔接接头脆性大,断面可见严重的裂纹和气孔。结论:钴铬合金与镍铬合金异种合金间的激光焊接,不管采用钴铬焊丝或者镍铬焊丝,都可获得良好的焊接接头。纯钛与钴铬合金或者镍铬合金都不能采用激光直接进行熔接     

激光焊熔焊区力学性能及热反应区组织结构的变化

目的：测试和分析不同激光焊接条件下3种不同材料的焊接度、强度和热反应区组织结构的变化,方法：对钴铬合金、镍铬合金、纯钛3种测试棒采用不同电压和脉冲持续时间焊接,与对照组进行比较分析。结果：电压与钴铬合金、镍铬合金的焊接深度和强度呈正比,均值为：250v时335MPa-330v时573MPa。热反应区晶粒生长小,激光束终点呈山峰状,中心留有焊接空白区。电压与纯钛的焊接深度呈正比,其其强度呈反比,均值为：250v时221MPa-330v时154MPa。热反应区晶粒生长较大,伴有相变体膨胀,晶间氧化,组织呈蜂窝状改变。结论：激光对钴镍合金,镍铬合金的焊接性能优良,但对铸造后的纯钛焊接性能有待进一步探讨。     

2种金属表面处理剂对铸造纯钛试件与树脂黏固剂粘接强度的影响

目的研究2种金属表面处理剂对铸造纯钛试件与树脂黏固剂粘接强度的影响。方法用牙科铸钛的方法制作直径分别为4 mm和5 mm的钛棒,并切割成长度为3 mm的小钛片。将2种规格的钛片配对,粘接面用碳化硅砂纸在流水下打磨抛光,使之呈均匀一致的平面,50 μm Al2O3喷砂。试件随机分成3组进行表面处理：第1组不使用金属表面处理剂,第2组使用Alloy Primer进行表面处理,第3组使用V-Primer进行表面处理。然后每组再分为3个小组,分别使用Super-Bond C&B、Panavia F、Rely X Unicem 3种黏固剂粘接。黏固剂固化1 h后,经37 ℃恒温水浴24 h以及5 000次冷热循环后,测试粘接强度,并观察铸造纯钛的表面形态和粘接面的破坏形式。结果AlloyPrimer、Super-Bond C&B的配伍组合与铸造纯钛获得的粘接强度在冷热循环前、后分别为（31.23±4.86）、（34.08±3.36）MPa,高于其他表面处理剂与树脂黏固剂配伍组合获得的粘接强度（P<0.05）。结论金属表面处理剂和树脂黏固剂的组合不同会导致粘接强度不同,经Alloy Primer处理的铸造纯钛试件与Super-Bond C&B的粘接强度最高。     

3种树脂粘接水门汀与铸造纯钛粘接强度研究

目的：研究3种复合树脂粘固剂与铸造纯钛的粘接强度。方法：用牙科铸钛的方法制作直径分别为4mm和5mm的钛棒,切割成长度为4mm的小钛片。2种规格的钛片配对粘接面用400～1200目碳化硅砂纸在流水下打磨抛光,使之呈均匀一致的平面。50μm氧化铝喷砂,另一组表面不喷砂作为对照,分别使用Super-BondC＆B、Panavia F、Rely X Unicem 3种复合树脂粘固剂粘接。扫描电镜观察喷砂前后铸造纯钛的表面形态。复合树脂粘接剂固化后经37℃恒温水浴24h以及5000次5～55℃冷热循环,测试剪切强度。用SAS的ANOVA过程对各组数据进行分析。结果：喷砂前后纯钛与Panavia F的剪切强度最高,分别为（26.62±3.40）MPa、（23.71±5.28）MPa;5000次冷热循环后,喷砂组的铸造纯钛与Panavia F的剪切强度最高（27.12±8.68）MPa;未喷砂的铸造纯钛与Super-Bond C＆B、Rely X Unicem的粘接强度最低,并且有12.5%的脱落率。结论：本实验结果表明喷砂可以提高Super-Bond C＆B、Panavia F、Rely X Unicem的粘结力和粘结耐久力。不喷砂时,Panavia F与铸造纯钛之间能获得较高的粘接强度和良好的粘接耐久性,喷砂以后优势不再明显。     

冷热循环对不同金属与树脂粘接剂粘接强度的影响

目的：冷热循环对不同金属与树脂粘接剂粘接强度的影响。方法：铸造直径分别为4mm和5mm的镍铬合金和纯钛,切割成长度为3mm的标本。2种规格的同种金属标本配对,金属表面经50μmAlzO3喷砂,涂布Al—loy Primer,使用Super—BondC＆B和PanaviaF2种粘接剂粘接。固化后经37℃恒温水浴24h以及10000次冷热循环,测试剪切粘接强度。用spssl7．0统计软件进行统计分析。结果：10000次冷热循环后,镍铬合金与Super—BondC＆B、纯钛与PanaviaF粘接强度显著提高（P〈O．01）,其余各组没有统计学差异。结论：粘接剂的种类对冷热循环前后的粘接强度没有明显影响,金属的种类对冷热循环前后的粘接强度没有明显影响,但是不同金属和不同粘接剂的配伍组合在冷热循环前后的粘接强度变化有统计学意义。     

碳纤维桩与几种桩的剪切抗折强度和剪切粘结强度的测定比较

目的　比较碳纤维桩、IPS Empress 2全瓷桩 (不含二氧化锆芯 )和二氧化锆全瓷桩、铸造镍铬合金桩及牙本质的剪切抗折强度 ;测定碳纤维桩、IPS Empress 2全瓷桩、铸造镍铬合金桩与人离体牙的剪切粘结强度 ,供临床参考应用。方法　碳纤维桩、IPS Empress 2全瓷桩、二氧化锆全瓷桩、铸造镍铬合金桩及牙本质各制作标准圆柱形试件 3个 ,用DCS5 0 0 0力学实验机测试其剪切抗折强度。碳纤维桩、IPS Empress 2全瓷桩和铸造镍铬合金桩各制作标准圆柱形试件 5个 ,用玻璃离子水门汀粘结在根管预备深度 3 0mm、预备直径 2 0mm的天然牙根内 ,用DCS5 0 0 0力学实验机测试其剪切粘结强度。结果　每种试件的平均剪切抗折强度 (MPa) :碳纤维桩 (199)、二氧化锆全瓷桩(193)、镍铬合金桩 (2 10 )的剪切抗折强度明显高于牙本质 (10 0 )和IPS Empress 2全瓷桩 (10 9) ,其间差异有显著性 (P <0 0 5 )。碳纤维桩、镍铬合金桩及二氧化锆全瓷桩之间的剪切抗折强度相近 ,差异无显著性 (P <0 0 5 )。剪切粘结强度 (MPa) :碳纤维桩 (2 4 )、镍铬合金桩 (3 8) ,IPS Empress 2全瓷桩未与水门汀分离前断裂。前 2种试件之间差异无显著性 (P >0 0 5 )。结论　碳纤维桩具有与二氧化锆全瓷桩、铸造镍铬合金桩相近的剪切抗折强度 ,其剪     

Bonding Ni-Cr Alloy to Tooth Structure with Adhesive Resin Cements

This study was to determine the shear bond strengths of Ni-Cr alloy to Ni-Cr alloy (Group I), Ni-Cr alloy to enamel (Group II), and Ni-Cr alloy to dentin (Group III) using Imperva Dual, DC Metabond, All-Bond, Geristore, and Panavla. All bonded specimens were thermocycled 2000 X (5^CC-55°C) after 24 hours and subjected to shear bond testing on a Universal Instron Testing Machine. In all groups of the study, Imperva Dual and CB Metabond had significantly (p < .05) higher bond values than Panavia.     

Interfacial shear bond strength between different base metal alloys and five low fusing feldspathic ceramic systems

This study compared the bond strength between metal alloys and 5 ceramic systems. Ceramic systems (Vita VMK68, Ivoclar IPSd. SIGN, Ceramco II, Matchmaker and Finesse) were fired onto either Ni-Cr or Co-Cr base metal alloy. Metal-ceramic interfaces were subjected to shear loading until failure. The ceramic type significantly affected the bond strength results (p<0.05). For Ni-Cr alloy, the results ranged between 15.4-25.3 MPa and for Co-Cr alloy between 13.3-19.0 MPa. The highest mean bond strength value was obtained with the combination of Ni-Cr alloy-Ceramco II (25.3 MPa), the lowest bond strength was received from the combination of Co-Cr alloy-Ivoclar IPS d.SIGN ceramic (13.3 MPa). Adhesive failures between metal and ceramic were significantly more frequent with Ni-Cr alloy (31 out of 50) than with Co-Cr (20 out of 50) (p<0.05). Ceramco II presented the highest bond strength with both Ni-Cr and Co-Cr being significantly different from one another.     

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.     

A Comparison of the Tensile Strength of Four Prosthodontic Adhesives

Purpose This study compared the in vitro tensile bond strength of four prosthodontic adhesives to sandblasted base-metal alloy. Materials and Methods Alloy cylinders were bonded end-to-end with the various adhesives, thermocycled, stored for 28 days, and subjected to a tensile load. Results Mean tensile bond strengths obtained were: Panavia = 42.3 MPa, Metabond = 31.1 MPa, All-Bond = 28.06 MPa, and F21 = 18.5 MPa. Statistical analysis showed significant differences (P < .05) in mean bond strengths between the adhesive systems. Conclusion Under the conditions of this study, the Panavia system showed the strongest mean tensile bond strengths.     

Effect of a new metal primer on the bond strength between a resin cement and two high-noble alloys

STATEMENT OF PROBLEM: With the development of new adhesive resin cements, the question of surface treatment of noble metal castings with primers has become an important issue. PURPOSE: This study compared the tensile bond strength and its durability of a new metal primer (Alloy Primer, Kuraray) to 2 noble metal alloys (Au-Ag-Cu-Pt and Au-Pt-Pd-Ag-In). MATERIAL AND METHODS: Sixty cast disk specimens of each alloy were polished, grit blasted with 50 microm Al(2)O(3), and ultrasonically cleaned in 96% isopropanol. Then, they were either nonprimed or primed only with the Alloy Primer or Alloy Primer combined with ED Primer (Kuraray). Plexiglas tubes filled with self-curing composite resin (Clearfil FII, Kuraray) were bonded to the metal samples with the use of an alignment apparatus and a self-curing luting cement (Panavia 21 Ex). The samples were stored in water, either for 3 days with no thermal cycling or for 150 days with 37,500 thermal cycles. After the different storage conditions, the tensile bond strengths of the specimens were determined. RESULTS: The mean bond strengths increased over storage time for all groups, except for the grit-blasted Au-Pt-Pd-Ag-In group. However, only in the grit-blasted and the primed groups for the Au-Ag-Cu-Pt alloy was this increase significantly different (P<.01). After 150 days of storage, the mean bond strength to Au-Ag-Cu-Pt alloy was 38.8 MPa without priming, whereas it was 40.6 to 40.8 MPa with the use of the primers. After the same time, the mean bond strength to the Au-Pt-Pd-Ag-In alloy was 20.6 MPa without priming, whereas it was 31. 9 to 37.8 MPa with the use of the primers. When comparing the different bonding methods and different storage times for the alloys, the superiority of the usage of both primers in combination was determined. Conclusion. The tested Alloy Primer significantly improved the bond strength of the dental adhesive resin cement (Panavia 21 Ex) to noble alloys. However, this effect depended on the alloy composition and was much greater for the Au-Pt-Pd-Ag-In alloy than for the Au-Ag-Cu-Pt alloy.