The effect of thermal and mechanical cycling on bond strength of a ceramic to nickel-chromium (Ni-Cr) and cobalt-chromium (Co-Cr) alloys

Ceramometal bond strength has played an important role for the replacement of gold alloys by nickel-chromium alloys in dentistry. This study evaluated the metal/porcelain bond strength of three ceramic systems (Vita VMK 88, Williams and Duceram) associated with three nickel-chromium alloys (Durabond, Lite Cast B and Resistal P) and one experimental cobalt-chromium-titanium alloy. Thirty cast cylinder specimens (15 mm in height; 6 mm in diameter) were obtained for each alloy, in away 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. Kruskal-Wallis and Mann-Whitney U tests were used for statistical analysis of the alloy/ceramic combinations (p<0.05). Resistal P/Duceram had significantly higher bond strength (44.38±9.12 MPa) (p<0.05) than the other combinations, except for Co-Cr-Ti alloy/Vita VMK 88 (38.41±12.64 MPa). The association of the experimental Co-Cr-Ti alloy with Williams porcelain had significantly higher bond strength (28.20±3.86 MPa) than the combination of other alloys with the same porcelain (p<0.05). Based of these results and within the limitations of an in vitro study, it may be concluded that the bond strength of the three ceramic systems to the Ni-Cr and Co-Cr-Ti alloys varied significantly, indicating that metal/ceramic compatibility was very important to the bond strength.

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Mechanical properties of metal-ceramic systems from nickel-chromium and cobalt-chromium alloys

Vojnosanitetski pregled ◽

10.2298/vsp0704241m ◽

2007 ◽

Vol 64 (4) ◽

pp. 241-245 ◽

Cited By ~ 2

Author(s):

Nemanja Mirkovic

Keyword(s):

Elastic Modulus ◽

Bond Strength ◽

Testing Machine ◽

Bending Test ◽

Chromium Alloy ◽

Cobalt Chromium ◽

Nickel Chromium ◽

Chromium Alloys ◽

Ceramic Bond ◽

Metal Ceramic

Background/Aim. Metal-ceramic bond strength and alloys' elastic modulus clearly determine the potential of alloy application, because the ceramic integrity during mastication depends on these two characteristics. The aim of this study was to evaluate metal-ceramic bond strength and elastic modulus of cobalt-chromium alloys in making porcelainfused- to-metal restorations, regarding the application of the most frequent nickel-chromium alloy. Methods. The research was performed as an experimental study. Six metalceramic samples were made from nickel-chromium alloy (Wiron 99) and cobalt-chromium alloy (Wirobond C), according to the manufactures manuals and instructions from ISO 9693: 1996. Three-point bending test was performed up to the ceramic fracture. The fracture load was measured on an universal testing machine (Zwick, type 1464), with cross-head speed of 0,05mm/min. Results. The results of this study confirmed the significant differences between the metal-ceramic bond strength (p < 0.01) and elastic modulus (p < 0.001) of nickel-chromium and cobalt-chromium alloys, where cobalt-chromium alloys showed higher values for both tested parameters. Conclusion. Cobalt-chromium metal-ceramic alloys can successfully replace nickel-chromium alloys, especially for fabrication of long-span metal-ceramic bridges due to the great flexural strength.

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Interfacial integrity of bonded restorations with self-etching adhesives: Water storage and thermo-mechanical cycling

European Journal of Dentistry ◽

10.1055/s-0039-1698947 ◽

2012 ◽

Vol 06 (02) ◽

pp. 169-177

Author(s):

Gislaine Cristine Martins ◽

Alfonso Sánchez-Ayala ◽

Paulo Henrique Perlatti D’Alpino ◽

Abraham Lincoln Calixto ◽

João Carlos Gomes ◽

...

Keyword(s):

Bond Strength ◽

Water Storage ◽

Single Bond ◽

Third Molars ◽

Class V ◽

Mean Values ◽

Composite Restorations ◽

Mechanical Cycling ◽

Interfacial Gap ◽

Made In

ABSTRACTObjectives: Objective: To evaluate the effect of thermo-mechanical cycling (TMC) on the microleakage (μL) and axial gap width (AG) of Class V bonded restorations in premolars using self-etching adhesive systems. The bond strength of composite restorations to dentin (μTBS) using the same adhesives was also evaluated in third molars after water storage: 24 h and 6 months. The research hypotheses were tested for the results of two self-etching adhesives in comparison when a conventional two-step adhesive was used: (1) the μL and AG would be lower, regardless of TMC; (2) the μTBS of self-etching adhesives would be higher, irrespective of evaluation times.Methods: Sixty Class V composite restorations were made in 30 premolars and bonded with Adper Single Bond 2 (ASB2), AdheSE (ASE), and Adper Prompt L-Pop (APL-P) (n=20). Dentin μL and AG were immediately measured for half of the sample. The other half was evaluated after TMC. Eighteen third molars were also selected and bonded using the same adhesives to test the μTBS to dentin. Specimens were evaluated after 24 h and 6 months of water storage.Results: No differences in μL and AG were found among the groups (P>.05). The μTBS mean values were: ASB2>ASE>APL-P (P<.05); only Adper Single Bond 2 presented a significantly lower μTBS after water storage (P<.05)Conclusions: The bonding approach does not influence the microleakage and interfacial gap extension. Despite the decrease in the mean values, the bond strength to dentin of the conventional, two-step adhesive remains high after 6 months of water storage. (Eur J Dent 2012;6:169-177)

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Spectrophotometric Analysis of Saliva for Metal Ion Release in Patients Prior to and After Cementation of Cobalt Chromium or Nickel-Chromium Alloy Crowns: An in Vivo Study

Journal of Contemporary Dentistry ◽

10.5005/jp-journals-10031-1229 ◽

2018 ◽

Vol 8 (2) ◽

pp. 92-96

Author(s):

Sabita M Ram ◽

Jyoti B Nadgere ◽

Naisargi P Shah ◽

Bhoomi A Parmar

Keyword(s):

Metal Ion ◽

Spectrophotometric Analysis ◽

In Vivo Study ◽

Chromium Alloy ◽

Cobalt Chromium ◽

Ion Release ◽

Nickel Chromium ◽

Metal Ion Release

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Effect of recasting on the elastic modulus of metal-ceramic systems from nickel-chromium and cobalt-chromium alloys

Vojnosanitetski pregled ◽

10.2298/vsp0707469m ◽

2007 ◽

Vol 64 (7) ◽

pp. 469-473 ◽

Cited By ~ 4

Author(s):

Nemanja Mirkovic

Keyword(s):

Elastic Modulus ◽

Testing Machine ◽

Fracture Load ◽

Bending Test ◽

Chromium Alloy ◽

Cobalt Chromium ◽

Nickel Chromium ◽

Ceramic Samples ◽

Chromium Alloys ◽

Metal Ceramic

Background/Aim. Elastic modulus of metal-ceramic systems determines their flexural strength and prevents damages on ceramics during mastication. Recycling of basic alloys is often a clinical practice, despite the possible effects on the quality of the future metal-ceramic dentures. This research was done to establish recasting effects of nickel-chromium and cobalt-chromium alloys on the elastic modulus of metalceramic systems in making fixed partial dentures. Methods. The research was performed as an experimental study. Six metal-ceramic samples of nickel-chromium alloy (Wiron 99) and cobalt-chromium alloy (Wirobond C) were made. Alloy residues were recycled through twelve casting generations with the addition of 50% of new alloy on the occasion of every recasting. Three- point bending test was used to determine elastic modulus, recommended by the standard ISO 9693:1999. Fracture load for damaging ceramic layer was recorded on the universal testing machine (Zwick, type 1464), with the speed of 0,05 mm/min. Results. The results of this research revealed significant differences between elasticity modules of metal-ceramic samples in every examined recycle generation. Recasting had negative effect on the elastic modulus of the examined alloys. This research showed the slight linear reduction of elastic modulus up to the 6th generation of recycling. After the 6th recycling there was a sudden fall of elastic modulus. Conclusion. Recasting of nickelchromium and cobalt-chromium alloys is not recommended because of the reduced elastic modulus of these alloys. Instead of reusing previously recasted alloys, the alloy residues should be returned to the manufacturer. .

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