scholarly journals Comparison of bond strength of two porcelains and two base metal alloys in metal-ceramic restorations

2019 ◽  
Vol 16 (5) ◽  
pp. 298
Author(s):  
Saghar Ghanavati ◽  
Asadollah Ahmadzadeh
2009 ◽  
Vol 1 (2) ◽  
pp. 25-29
Author(s):  
Andre Rayne Le Roux

Reduction in base metal alloy thickness will permit additional porcelain depth and improved aesthetics but unfortunately little information exists regarding the thickness to which base metal alloys may be reduced in comparison to noble metal alloys for metal ceramic restorations. Even with comparison of noble metal alloys the aesthetic benefits are restricted to improving aesthetics in base metal restoration further, since noble metal alloys are generally regarded as providing superior aesthetics to base metal restorative alloys. Purpose: The objective of this study was to determine whether a significant reduction in thickness could be achieved using a base metal alloy as compared to a noble metal alloy and the thickness to which base metal alloy substructures could safely be reduced while still providing the same resistance to fracture of the porcelain. Material and methods: Tensile strength tests (N) of the modulus of rupture of the porcelain were performed on 40 base metal alloy (Wiron 99, Bego, Germany) and 12 noble metal alloy rectangular specimens (5.8 mm wide and 15.0 mm long) bonded to a standardized 1.0 mm thickness of dentine Creation porcelain. The base metal alloy thickness varied in 0.1mm increments from 0.1 to 0.4 mm. The results were compared to 12 noble metal alloy (Bio Y 81, Argen, South Africa) specimens of recommended minimum thickness (0.3 mm). Data for the results was obtained using a universal tensile testing instrument, which was set to operate at a cross head speed of 0.5mm (Instron Mini 44, Instron corporation U.S.A). The applied force (N) that measured the modulus of rupture of each specimen was printed from a computer connected to the Instron Mini 44 that operated on a 95% level of confidence. Instron Agents (Durban, South Africa) performed the calibration and setting up of the machine prior to testing the specimens. Results: The results indicated a permissible 33.33% reduction in the base metal alloy specimens as compared to the noble metal alloy control specimens. This was deduced from the reduction in alloy thickness of up to 0.2 mm for base metal alloy specimens as compared to the 0.3 mm noble metal alloy specimens. The recommended thickness to which the base metal alloys could be reduced without distortion of the alloy was also 0.2 mm. The one-way ANOVA showed a level of significance of (α=05).


2013 ◽  
Vol 07 (03) ◽  
pp. 373-376
Author(s):  
Tuncer Burak Ozcelik ◽  
Burak Yilmaz

ABSTRACTMetal ceramic partial fixed dental prostheses have been commonly used for the replacement of missing teeth for many years. Because of an increase in the price of gold, base metal alloys have been the choice of alloy for the fabrication of metal ceramic restorations in many dental clinics. Some major disadvantages of base metals are their corrosion and the dark coloration they may cause at the crown margins. This article describes a galvanic gold-plating technique, which is used to minimize corrosion and improve the esthetics of metal ceramic restorations fabricated with Cr-Co base metal alloys. This technique involves the deposition of a 6 μm to 8 μm 24 K gold layer directly onto the Cr-Co cast prosthesis framework. The technique improves metal surface properties, making them more biocompatible and usable, however, requires additional equipment and experienced laboratory technicians. Clinical studies should be performed to corroborate the long term success of this technique.


2007 ◽  
Vol 18 (3) ◽  
pp. 240-243 ◽  
Author(s):  
Juliano Milczewsky Scolaro ◽  
Jefferson Ricardo Pereira ◽  
Accácio Lins do Valle ◽  
Gerson Bonfante ◽  
Luiz Fernando Pegoraro

Dentists and technicians have used dental ceramics associated with different types of alloys without taking into account the characteristics of compatibility of these materials. Knowing the properties of the alloy and ceramic used in metal/ceramic restorations is a key factor for treatment success. The purpose of this study was to evaluate the bond strength of a palladium-silver alloy (Pors-on 4) to 3 ceramics (Ceramco, Noritake and Vita VMK-68) using shear forces at the metal-ceramic interface. A stainless steel cylindrical matrix was used for preparation of the metal dies, application of ceramic and shear strength testing. Thirty palladium-silver alloy cylinders received two layers of opaque and two layers of body porcelain, and shear tests were performed in a universal testing machine at a cross-head speed of 0.5 mm/min. Shear bond strength means (in MPa) were: 28.21(Ceramco), 28.96 (Noritake) and 24.11 (Vita VMK-68). One-way ANOVA did not show statistically significant differences (p>0.05) among the materials. The results of this study indicate that the three evaluated ceramic systems are suitable to be used in combination with the tested palladium-silver alloy.


2017 ◽  
Vol 18 (9) ◽  
pp. 837-841
Author(s):  
T Meenakshi ◽  
Munagapati Bharathi ◽  
Jayasree Komala

ABSTRACT Aim The aim of this study was to evaluate the effect of recasting base metal alloy on the metal–ceramic bond strength. Materials and methods A total of 60 test samples were prepared from new and recast nickel–chromium alloy and divided into six groups. In group A0, test samples were prepared from 100% new alloy. Groups A1, A2, A3, A4, and A5 were prepared from 50% new alloy and 50% casting remnants (sprue and buttons) of the previous group by weight. All these samples were coated with ceramic (IPS d.SIGN and Ivoclar-Vivadent), and samples were then subjected to three-point bending test to evaluate metal–ceramic bond strength. Results The values were analyzed using one-way analysis of variance and Tukey's post hoc test. The mean bond strength of group A0 was higher than that of groups A1, A2, A3, A4, and A5. Conclusion Metal–ceramic bond strength decreased significantly with multiple recastings. Clinical significance Bond strength between metal and ceramic is a crucial factor for the clinical performance of metal–ceramic restorations. Recasting of alloys may affect the metal oxide layer composition and thickness of metal–ceramic interface, and thereby the metal–ceramic bond. How to cite this article Meenakshi T, Bharathi M, Komala J. Evaluation of the Effect of recasting Nickel–chromium Base Metal Alloy on the Metal–ceramic Bond Strength: An in vitro Study. J Contemp Dent Pract 2017;18(9):837-841.


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