Bond strength studies of precious, semiprecious, and nonprecious ceramic-metal alloys with two porcelains.

One-hundred cylindrical pull-through ceramic-metal test specimens were subjected to shear loading forces. Two porcelain systems were treated in association with five ceramic alloys--one precious, one semiprecious, and three nonprecious alloys. 1. There was no significant difference in bond strength between Ceramco and Vita porcelains. 2. The various alloys tested demonstrated significantly different bond strengths. 3. Differential statistical tests suggested that nonprecious alloys performed better with Ceramco porcelain than with Vita porcelain. 4. The bond strength of Ceramco porcelain fused to nonprecious alloy N-C2 was significantly greater than that of Ceramic and traditional gold-based alloys. 5. Nonprecious alloy N-C1 produced significantly less bond strength than the traditional gold-based alloys. 6. Semiprecious alloy W produced high bond strengths with both Ceramco and Vita porcelains. 7. The cylindrical pull-through test was a reliable, reproducible method of testing ceramic-metal bond shear strength. 8. The surface roughness appears to be the one common factor in nonprecious alloys that relates to large differences in bond strength. Additional tests must be made to verify this hypothesis.     

Evaluation of some properties of an opaque porcelain fired simultaneously with the body porcelain

Recently, a porcelain-fused-to-metal opaque porcelain was introduced that does not require a separate firing before application of the body porcelain. The objective of this study was to determine the properties of this new opaque porcelain and its ability to bond to metal. The properties studied included flexural strength, linear firing shrinkage, coefficient of thermal expansion, powder particle size, and ability to bond to body porcelain and dental alloys. Sintering of this opaque porcelain was complete when fired at 1760 ° F (960 ° C) with a linear firing shrinkage of 13.1% ± 0.2%. No boundary between the opaque and body porcelains could be found with a scanning electron microscope after firing at 1760 ° F (960 ° C). The mean flexural strengths were 99 ± 7 and 101 ± 8 MPa respectively, for this opaque porcelain and a conventional opaque porcelain, and were not significantly different as assessed with Student's t-test (p = 0.548). The coefficient of thermal expansion for this opaque porcelain was 13.3 ± 0.2 × 10⁻⁶/ ° C. Particle size analysis showed a 63% increase in the particles below 5 μm for this opaque porcelain and bonding to two alloys was adequate as indicated by its cohesive failure. Simultaneous firing of this special opaque porcelain and body porcelain produced satisfactory sintering, strength, and bonding to metal.     

Apparent bond strength of nonnoble alloy-porcelain combinations

The apparent bond strengths of four porcelains and five nonnoble alloys were determined. On the basis of the data, the following conclusions can be drawn: The use of Vita, Ceramco, or Will-Ceram porcelains with Rexillium III, Pentillium, or Bak-On-NP alloy gave similar bond strength values. With the exception of Unibond alloy, the bond strength values obtained with Biobond porcelain were lower than those obtained with the other porcelain materials. The ceramometal bond strength values obtained with Unibond alloy were similar with all of the porcelains tested. The continued availability of a bewildering array of new alloys and porcelains suggests the urgent need for research designed to determine the bonding mechanisms and compatibility of various porcelain-alloy combinations. The data from this investigation provide criteria for the rational selection of bond strength-compatible porcelains and alloys for clinical use.     

Shear bond strength of composite resin to porcelain

This study evaluated the effect of porcelain surface treatment on the shear bond strength of composite resin to various porcelains and porcelain combinations. A variety of feldspathic porcelains with low and medium alumina content were tested. Porcelain/composite resin samples were stored in 37 degrees C water, thermocycled 1,000 times, and tested in shear. A 3-minute etching using hydrofluoric acid significantly increased the bond strength of most of the feldspathic porcelains with low and medium alumina content. Silane application to all types of etched porcelain had no significant effect on bond strength.     

Evaluation of the color and appearance of a new textured opaque porcelain.

Porcelains that are claimed to improve the appearance of metal ceramic restorations by increasing light refraction from a highly textured opaque surface have recently been introduced. This study compared the appearance and color of one of these opaque porcelains with a conventional smooth-surface opaque. The opaque porcelains were applied to alloy substrates, and samples were evaluated colorimetrically. After the application of body and incisal porcelains, the samples were evaluated subjectively by clinicians and again colorimetrically. Subjective determination of the most lifelike porcelain depended on the shade. Color differences existed between the opaque porcelains for all shades examined.     

Shear bond strength of composite resin porcelain repair materials bonded to metal and porcelain

Two composite resins, bonding agents, surface treatment agents, dental porcelains, and nickel-chromium porcelain bonding dental casting alloys were used to test shear bond strengths of composite resins bonded to metal and porcelain. Bond strengths to porcelain were greater than to metal and to oxidized metal were greater than to machined metal. Significant differences were found between types of porcelains and casting alloys.     

不同表面处理方法对陶瓷托槽与不同瓷修复体粘结强度影响的研究

目的:评价不同瓷修复体试件经过3种表面处理方法后与陶瓷托槽粘结强度的关系。方法:钴铬烤瓷、铸瓷、锆瓷及聚合瓷4类试件经过喷砂(SB)、氢氟酸酸蚀(HFA)、喷砂+酸蚀(SB+HFA)处理后表面涂布硅烷偶联剂(SCA),再粘接陶瓷托槽,经37 ℃恒温水浴24 h 后检测粘接强度(SBS),扫描电镜观察托槽粘接前修复体表面的粗糙度及去除后修复体表面粘接剂残留情况。结果:钴铬烤瓷、铸瓷和聚合瓷试件的抗剪切强度分别与锆瓷试件比较差异有统计学意义(P＜0.05);钴铬烤瓷和铸瓷试件的抗剪强度比较差异无统计学意义。扫描电镜结果显示4组试件表面粗糙度都有明显增加。而喷砂组和喷砂+酸蚀组试件表面的粗糙度明显高于酸蚀处理组;喷砂和喷砂+酸蚀组的表面处理效果差异不大,喷砂组的4类试件表面粘结剂残留最少。结论:3种表面处理方法均能满足临床正畸的需求。喷砂组去除托槽后对试件表面的影响最小,喷砂联合酸蚀处理并不能显著增加剪切强度。 [关键词] 陶瓷托槽 剪切强度 瓷修复体 表面处理     

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.     

A qualitative study for the bond and color of ceramometals. Part I

A shear testing method was devised to study and evaluate the effect of various and repeated firing cycles, types of alloy, and brand of porcelain relative to the color and bond strength of ceramometal complexes specifically at the opaque porcelain-metal interface and the opaque-body porcelain juncture. Two alloys and two porcelain brands were chosen on the basis of their widespread clinical use and the marked contrast between them. An increase of the firing temperature significantly raised the bond strength for all alloy-porcelain combinations.     

Effect of opaque porcelain application on strength of bond to silver-palladium alloys

The opaque porcelain layer for porcelain-fused-to-metal restorations is critical for success. This investigation examined opaque porcelain application using one- and two-layer techniques with respect to their effect on the strength of bond to three silver-palladium alloys. There were no significant differences in the flexural bond strengths of the three alloys for the one- and two-layer opaque application techniques. With respect to bond strength, these results afford flexibility in the choice of the one- or two-layer techniques.     

Residual stress in several ceramometal systems

Residual stress caused by a mismatch of alloy-porcelain thermal contraction can contribute to clinical failure of a ceramometal restoration. This investigation assessed thermal compatibility of three ceramometal alloys and two opaque porcelains. Thermal expansions of the alloys and porcelains were measured by using a straight push-rod dilatometer. Porcelain glass transition temperatures and expansion values were derived from length-versus-temperature curves. Residual stress states in alloy-porcelain pairs were assessed by comparing expansion values of the components at the porcelain glass transition temperatures. Above that temperature the porcelain viscosity is low and stress relief is possible, whereas below the glass transition the porcelain acts as a stress-supporting solid. Expansion values were in general agreement and glass transition temperatures were slightly lower than values previously reported for similar materials. Alloy-porcelain thermal compatibility for the materials tested appeared more dependent on the opaque porcelain than the alloy.     

Sprayed opaque porcelain as a retentive surface for resin-bonded restorations

This study investigated the shear bond strength between etched enamel and 4-mm-diameter base metal castings cemented with Panavia EX. Four different methods of casting preparation were used: air abraded, salt crystals placed on the wax patterns, opaque porcelain sprayed on the metal surface, and sprayed opaque porcelain followed by a silane coupling agent. The prepared surfaces were examined before and after testing using SEM and electron dispersive analysis by x-rays. It was determined that there was no significant difference in the shear bond strength between the salt-crystal technique and the nonsilanated sprayed ceramic surfaces. The air-abraded surface was the least retentive, and the silanated opaque porcelain specimens had intermediate retention. The sprayed opaque porcelain technique seems to offer several advantages.     

Sintering of dental porcelain enamels.

This study showed the effects of sintering temperature and atmospheric pressure on the density, tensile strength, and microstructure of porcelain enamels. Although the densities of the opaque porcelains were higher, they were weaker than the gingival porcelains. Gingival porcelains also glazed and sintered at lower temperatures than the opaque porcelains.     

Shear bond strength of dental porcelains to nickel-chromium alloys

The continuous technological advance and increasing availability of new base metal alloys and ceramic systems in the market, coupled to the demands of daily clinical practice, have made the constant evaluation of the bond strength of metal/porcelain combinations necessary. This study evaluated the metal/porcelain shear bond strength of three ceramic systems (Duceram, Williams and Noritake) in combination with three nickel-chromium (Ni-Cr) alloys (Durabond, Verabond and Viron). Thirty cast cylinder specimens (15 mm high; 6 mm in diameter) were obtained for each alloy, in a way that 10 specimens of each alloy were tested with each porcelain. Bond strength was measured with an Emic screw-driven mechanical testing machine by applying parallel shear forces to the specimens until fracture. Shear strength was calculated using the ratio of the force applied to a demarcated area of the opaque layer. Mann-Whitney U test was used for statistical analysis of the alloy/ceramic combinations (p<0.05). Viron/Noritake had the highest shear bond sregnth means (32.93 MPa), while Verabond/Duceram (16.31 MPa) presented the lowest means. Viron/Noritake differed statistically from other combinations (p<0.05). Viron/Duceram had statistically significant higher bond strengths than Verabond/Duceram, Verabond/Williams and Durabond/Noritake (p<0.05). It was also found significant difference (p<0.05) between Verabond/Noritake, Verabond/Duceram and Durabond/Noritake. No statistically significant difference (p>0.05) were observed among the other combinations. In conclusion, the Noritake ceramic system used together with Viron alloy presented the highest resistance to shear forces, while Duceram bonded to Verabond presented the lowest bond strength. Viron/Duceram and Verabond/Noritake provided intermediate results. The combinations between the Williams ceramic system and Ni-Cr alloys had similar shear strengths among each other.     

脉冲Nd:YAG激光影响复合树脂修补烤瓷粘接强度实验研究

目的：评价激光进行瓷面处理对复合树脂修补烤瓷的粘接效果。方法：分别用８％氢氟酸及３组能量参数的脉冲Ｎｄ：ＹＡＧ激光（１５Ｈｚ、４０ｍＪ、０．６Ｗ;１５Ｈｚ、６０ｍＪ、０．９Ｗ;１５Ｈｚ、８０ｍＪ、１．２Ｗ）对烤瓷牙粘接表面进行照射,照射时间均为１ｍｉｎ,涂硅烷液及活化剂后,粘接复合树脂。应用电子万能试验机测试复合树脂－烤瓷的抗剪切粘接强度。采用扫描电镜观察瓷处理面的形貌特征。结果：激光０．６Ｗ组、０．９Ｗ组、１．２Ｗ组及酸蚀组的抗剪切粘接强度分别为８．６１、１４．０７、１１．２２及１３．４７ＭＰａ,激光０．６Ｗ组明显低于酸蚀组,两者具有统计学差异,而０．９Ｗ组及１．２Ｗ组与酸蚀组则无显著性差异。扫描电镜显示经激光处理的瓷面粗糙不平,呈浅凹状及火山口状结构。结论：在适当能量参数下,脉冲Ｎｄ：ＹＡＧ激光可代替酸蚀进     

Effect of cooling rate on shear bond strength of veneering porcelain to a zirconia ceramic material

The purpose of the present study was to evaluate the effect of cooling rates after firing procedures of veneering porcelain on shear bond strength between veneering porcelain and a zirconium dioxide (zirconia; ZrO?) ceramic material. A total of 48 ZrO? disks were divided equally into three groups. Two veneering porcelains that are recommended for ZrO? material - Cerabien ZR (CZR), IPS e.max Ceram (EMX) - and one that is recommended for metal ceramics - Super Porcelain AAA (AAA) were assessed. Each group was then further divided into two subgroups (n = 8) according to cooling time (0 or 4 min) after porcelain firing. Specimens were fabricated by veneering the porcelain on the ZrO? disks, after which shear bond testing was conducted. Bond strength differed significantly by cooling time in ZrO?-AAA (P < 0.001) and ZrO?-EMX (P = 0.001) specimens. There was no significant difference in shear bond strength with respect to cooling time in ZrO?-CZR specimens (P = 0.382). The duration of cooling from firing temperature to room temperature may affect the shear bond strength of veneering porcelain to a zirconia material depending on porcelain material used.     

X-ray diffraction at the metal-ceramic interface. (Part 1) Commercial gold alloy-porcelain interface (author's transl)]

X-ray diffraction technique is one of the most useful method in understanding the exact nature of chemical bonding between metals and ceramics. However, X-ray diffraction at the actual metal-ceramic interface has not yet been performed, though ti has many merits. In this study, the X-ray diffraction at the actual interfaces of six alloy-porcelain composites was performed using a particular method, in addition to the X-ray diffraction of three commercially available precious alloys for porcelain fusing and two commercially available opaque porcelains. The results obtained were summarized as follows: 1) Appreciable reaction layers between alloys and opaque porcelains were not detected. 2) The crystal constituents of two opaque porcelains examined were different considerably. This might affect the metal-ceramic bonding conditions. 3) As for three alloys in this experiments, remarkable differences were not observed in their surface crystal structures after the degassing process.     

VITA不透明瓷及体瓷瓷粉混合颜色的研究

目的 研究VITA不透明瓷及体瓷瓷粉颜色混合规律。方法 应用分光光度仪测试不同比例VITA VMK68 B1和B2色不透明瓷及体瓷瓷粉混合后的颜色，采用Munsell颜色标示系统对瓷粉混合后的颜色变化规律进行研究。结果 随着B1、B2色不透明瓷混合瓷粉中B2色瓷粉的增加，混合瓷粉的色相逐渐偏红，饱和度逐渐增加。随着B1、B2色体瓷混合瓷粉中B2色瓷粉的增加，混合瓷粉的色相逐渐偏黄，明度逐渐增加。不同混合比例的不透明瓷瓷粉问的色差为1．37～4．91，不同混合比例的体瓷瓷粉间的色差为0．56～2．35。结论 瓷粉混合可有效地扩大有限颜色瓷粉的颜色空间。有利于临床上制作颜色更为匹配的烤瓷修复体。     

金沉积基底不同表面处理对金瓷剪切强度的影响

目的研究金沉积基底不同表面处理条件对金瓷结合强度的影响。方法制作45个柱形镍铬合金试件,表面电镀形成金沉积帽状基底,随机分成5组,50μm、110μmAl2O3喷砂组,50μm喷砂+金黏结剂组、110μm喷砂+金黏结剂组及对照组,通过剪切实验测试金瓷结合强度。结果使用金黏结剂组的金沉积基底与瓷的结合强度为最高,喷砂组次之,对照组最小,差异有显著性(P<0.05);金黏结剂组、喷砂组之间结合强度无显著性差异。结论喷砂和金黏结剂能增强金沉积基底与瓷的结合强度。     

The bond strength of porcelain to Ni-Cr alloy--the influence of tin or chromium plating.

Nickel-chromium alloys were plated with tin and chromium to evaluate the effect on porcelain shear bond strength. Six plating methods were used. Additionally, the microstructure of the bond between the plated alloy and porcelain were studied using SEM and EPMA. Tin plating increased the bond strength of porcelain to a nickel-chromium alloy while chromium plating did not.