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Firing schedules of metal conditioners and feldspathic porcelain based on manufacturers' recommendations
Source publication
Purpose:
The purpose of this study was to evaluate the efficacy of two different metal conditioners for non-precious metal alloys for the bonding of porcelain to a cobalt-chromium (Co-Cr) alloy.
Materials and methods:
Disk-shaped specimens (2.5×10.0 mm) were cast with Co-Cr alloy and used as adherend materials. The bonding surfaces were polished...
Citations
... Another treatment described is the use of a bonding agent 12,24 , which has a higher cost and the applied layer thickness is difficult to standardize, interfering with MCBS 12,15 . Moreover, some proposed protocols require materials that are difficult to access, such as oxidation heat treatment 23,25 , *e-mail: anapaula@forp.usp.br ...
This study aim was to evaluate the influence of 37% hydrochloric acid (37% HCl) treatment of cobalt-chromium (Co-Cr) alloys on the metal-ceramic bond strength (MCBS). The specimens were sandblasted with 100-µm aluminum oxide particles and divided into four groups (n = 10) according to the surface treatment performed: control (C) - no treatment - and treated with 37% HCl for different times: 10 minutes (T1), 20 minutes (T2) and 30 minutes (T3). The samples were submitted to the 3-point bending test, and the type of failure was evaluated. Wald, Bonferroni and Pearson's tests were applied (α = 0.05). There was difference between the treatments (p = 0.019): T3 (61.57 MPa) had higher bond strength than C (51.96 MPa). The specimens presented 17.5% of adhesive and 82.5% of mixed failures. There was a weak correlation between the failure type and the MCBS. Co-Cr surface treatment with 37% HCl for 30 minutes is a promising protocol for an appropriate metal-ceramic bond strength.
... Thus, in order to obtain as much information as possible, the present study evaluated strains as a function of different materials and forces. The current study is based on widely used and modern materials in dentistry: a non-precious metal alloy, ceramics (zirconia), and PEEK [39][40][41]. ...
Purpose: To date, the qualitative and quantitative recording of biomechanical processes in dental implants represents one of the greatest challenges in modern dentistry. Modern, dynamic, 3D optical measurement techniques allow highly constant and highly accurate measurement of biomechanical processes and can be superior to conventional methods. This work serves to establish a new measurement method. Materials and Methods: A comparative analysis was undertaken for two different measurement systems, two conventional strain gauges versus the 3D optical two-camera measurement system ARAMIS (GOM GmbH, Braunschweig, Germany), as they detected surface changes on an artificial bone block under masticatory force application. Two implants (Straumann Standard Implants Regular Neck, Straumann GmbH, Freiburg, Germany) were placed in the bone block, and three different three-unit bridges were fabricated. Increasing masticatory forces, from 0 to 200 N, were applied to the bone block via each of these bridges and the inserted implants. Fifteen repetitions of the test were performed using a universal testing machine. The computer unit of the ARAMIS system was used to simultaneously integrate the surface changes recorded by the strain gauges and the ARAMIS system. The areas on the bone block examined by the dynamic 3D optical measurement method corresponded exactly to the locations and extent of the strain gauges. A statistical comparative analysis was carried out separately for the strain gauges and the corresponding optical measuring surface at the defined force magnitudes. The equivalence test and the intraclass correlation served as statistical means. Results: In the case of the intraclass correlation, a clear concordance of both measurement methods could be shown for all examined cases. For the equivalence test, no significance could be shown in individual cases. Conclusion: The accuracy of the modern, dynamic, 3D optical measurement method is comparable to that of conventional strain gauges. On this basis, versatile new research approaches in the field of biomechanics of dental implants can be pursued by establishing this method.
... This means that the presence of bonding agent narrowed the scatter of values of bond strength; in other words, a more reliable interface between ceramic and metal was produced. A related bond strength study reported a significantly higher bond strength between ceramic and Co-Cr alloy when a metal bonding agent was used [38]. The present study differs from previous studies in that we subjected specimens to thermo-cycling to simulate the oral environment; nevertheless, all specimens with bonding agents had values that were remarkably higher than the minimum 25 MPa value required by ISO 9693 specifications. ...
Bonding agents have been developed to improve bond strength between ceramic and Co-Cr metal. The aim of this study was to investigate the influence of two bonding agents on bond strength of Co-Cr metal fabricated by selective laser melting (SLM). Bond strength was determined by a three-point bending test, and the interfaces of the metal and ceramic, before and after the bending test, were observed by optical microscopy and scanning electron microscopy (SEM) to determine the thickness of the oxide layer and amount of ceramic remaining. To analyze the elemental composition of the bonding agents and fractured surfaces, energy dispersive X-ray spectroscopy (EDS) was used. Co-Cr specimens with bonding agent showed significantly higher bond strength than Co-Cr specimens without bonding agents. The fractured surfaces of most specimens showed mixed failure, but failure mode varied according to bonding agent and fabrication type. Specimens from groups treated with bonding agents had significantly higher remaining ceramic fractions on fractured Co-Cr alloys than specimens from groups that did not receive bonding agent. Mass amounts of silicone (Si) and titanium (Ti) on the fractured alloy surfaces were also different among specimens according to method of fabrication and presence of bonding agent. Together, the results suggest that application of bonding agent to 3D printed Co-Cr metal increases bond strength with ceramics.
... There are three possibilities of retention, including Van der Waals forces, micromechanical retention and chemical bonding, which is the main factor, and is characterized by the exchange of oxides between the metal and the oxidizable elements of ceramics 4-6 . Several surface treatments have been studied, such as airborne particle abrasion (APA) with aluminum oxide (Al 2 O 3 ) particles, which is a commonly used method for providing mechanical retention, resulting in the formation of an oxide layer that facilitates adhesion of the porcelain and increases the metal surface energy [7][8][9][10] . However, the size of the particles used in this process varies. ...
Aim: The aim of this study was to evaluate the influence of tungsten inert gas (TIG) welding and airborne particle abrasion using aluminum oxide particles on the flexural strength of a joint between ceramic and cobalt-chromium alloys. Methods: The specimens were cast and welded using TIG, then divided into 6 groups (n = 10) and subjected to blasting with 250 μm, 100 μm, and 50 μm aluminum oxide particles. Ceramic systems were applied to the central part of all specimens. A three-point bending test using a velocity of 0.5 mm/m was performed on the specimens to measure flexural strength. Data were analyzed using two-way analysis of variance and Tukey’s test. Results: TIG welding demonstrated the lowest resistance compared with the non-welded groups. Airborne particle abrasion using 250 μm aluminum oxide particles demonstrated greater resistance in the welded groups (p < 0.05). Mixed faults were found in all specimens. Conclusion: TIG welding decreased the bond strength, and the particle size of aluminum oxide did not affect the metal-ceramic bond in groups without TIG welding.
... (7,8,9) Estos acondicionadores de metal también son empleados con la intención de mejorar la estética de la porcelana enmascarando el color de óxido oscuro en las estructuras metálicas no nobles. (10) Actualmente las aleaciones de Cobalto-Cromo se pueden trabajar mediante las técnicas de colado y técnicas CAD/CAM (Diseño Asistido por Computador -Maquinado Asistido por Computador), pudiéndose en presentar en pastillas para colar, en forma de bloque para fresar, en polvo para ser sinterizado por láser o en forma de bloque pre sinterizado para ser sinterizado en húmedo y posteriormente sinterizado. (11) Las aleaciones de Cobalto-Cromo están formadas por un porcentaje de Cobalto superior al 60 y de cromo superior al 13. ...
... Estos acondicionadores reaccionan con óxidos metálicos y forman una nueva interfaz que sella la superficie de la aleación y protege de la oxidación adicional, evitando así una capa oxidada gruesa haciendo una buena fusión del opacador. (17,10,18) . Mejorando la estética mediante la regulación del cambio de color de la porcelana durante ciclos de cocción posteriores. ...
RESUMEN El objetivo de este estudio experimental in vitro fue comparar la resistencia adhesiva de una cerámica feldespática a una estructura de Cobalto Cromo, obtenida mediante cuatro técnicas: colado por presión al vacío; fresado, pre sinterizado y sinterización selectiva con láser; usando o no un acondicionador de metal. Se elaboraron 15 especímenes en una aleación Cobalto-Cromo por las diferentes técnicas. A su vez en estos grupos se conformaron 2 subgrupos por cada cofia y técnica según la variable principal uso o no de acondicionador. Se realizó tratamiento de superficie y se procede a aplicar el acondicionador VITA NP BOND Paste en una cara de cada cofia y de forma análoga en la cara contraria se aplica de Wash opaque de VITA, por ultimo opacador y dentina con un espesor de 2mm. La resistencia adhesiva al cizallamiento se midió en la máquina Instron obteniendo el resultado en Newton para cada superficie ajustada a 3.1416 mm 2 para convertirlo a N/mm 2 o sea presión en MPa. El promedio más alto de resistencia adhesiva, pero con la mayor variabilidad, se obtuvo para la combinación: sinterizado con láser y superficie tratada con acondicionador (297.58 ± 92.19 MPa). En este grupo el efecto del acondicionador fue muy favorable, incrementando en 74% la resistencia adhesiva. En las otras técnicas, el acondicionador no produjo un cambio significativo en la resistencia adhesiva. Tanto la técnica de fabricación como el acondicionador producen cambios significativos y la interacción de los dos factores también fue significativa. El uso del acondicionador es muy efectivo en la técnica sinterización laser, que difiere significativamente de la técnica de fresado y pre sinterizado con acondicionador (p<0.0001) pero no de la técnica de colado (p = 0.18). La relevancia clínica es que todos los valores de resistencia adhesiva determinados superan el mínimo clínicamente aceptable. Palabras clave: Acondicionadores de metal. Adhesión. Cerámica. Cizallamiento. Resistencia adhesiva. Sinterización selectiva con láser. ABSTRACT The objective of this in vitro experimental study was to compare the adhesive strength of a feldspathic ceramic to a Cobalt-Chrome alloy structure obtained by four techniques: casting; milling, presintering and laser selective sintering, using or not a metal conditioner. Using each technique were prepared 15 specimens. Each group was divided into 2 subgroups according to the main variable: use/no use of conditioner. The surface treatment was the same for all groups but VITA NP BOND Paste conditioner was applied to a face while in the opposite face VITA Wash opaque was applied, followed by opaque on 2 mm of dentin width. The bond strength was measured applying a shearing force. The value in Newton was divided into the standard area of 3.14 mm 2 to express the results in MPa. The highest bond strength, but most variable, was obtained for the combination of laser sintering and surface treated with primer (189.45 ± 58 MPa). In this group the effect of Vita NP Bond was highly favorable, increasing bond strength by 74% as compared to the same technique without it. In the other techniques, the conditioner did not cause a significant change in adhesive resistance. Both the technique to build the structure and the use of conditioner caused some significant changes. The use of conditioner was very effective in the laser technique, causing a bond strength significantly different to milling and pre-sintering with conditioner (p<0.0001) but not different to the casting technique (p = 0.18). The clinical relevance is that all the average values of bond strength are over the clinically acceptable minimum value.
Aim
(1) The aim of this study was to evaluate the effect of a ceramic bonder at the metal ceramic interface in sintered and casted cobalt–chromium (Co–Cr) alloy. (2) To compare the shear bond strength between the different manufacturing techniques: Casting and direct metal laser sintering (DMLS).
Setting and Design
In vitro comparative study.
Materials and Methods
For the casting group, 40 clear acrylic patterns with dimensions of 20 mm × 10 mm × 2.5 mm were designed in a software and casted with Co–Cr alloy. For DMLS samples, a standard tessellation language file with the abovementioned dimensions was created through a software to fabricate 40 samples. All the samples were equally distributed into the following four groups:
Group A – Casted samples with the application of Cerambond ( n = 20)
Group B – Casted samples without application of Cerambond ( n = 20)
Group C – DMLS samples with application of Cerambond ( n = 20)
Group D – DMLS without application of Cerambond ( n = 20).
Ceramic buildup was done on all 80 samples, followed by firing up to a temperature of 920°C in a ceramic furnace. SBS was evaluated using a universal testing machine and failure modes were examined under the electron microscope.
Statistical Analysis Used
ANOVA test and Tukey’s honestly significance difference post hoc test for multiple comparisons.
Results
One-way analysis of variance test revealed that the shear load and bond strength values of all four groups were statistically different with P < 0.001. Post hoc Tukey’s test showed statistically significant difference among the four groups. The mean shear strength of Group C was significantly greater when compared to other groups, respectively.
Conclusions
Within the limitations of this study, the application of Cerambond to both casted and sintered samples showed significantly increased SBS values and it was also observed that sintered samples had higher strength than casted samples. Altogether, the results indicate that the use of Cerambond increased the shear strength between cobalt Cr alloy and ceramics, thereby prolonging the longevity of the restorations.
The purpose of this paper is to compare the impact of selective laser-sintering (SLS) technology and computer numerical control (CNC) machining methods on the structure and properties of solid Co-Cr-W-Mo-Si alloys. Structural tests were carried out using x-ray structural analysis; energy-dispersive x-ray spectroscopy chemical composition analysis; metallographic investigations using stereoscopic, light, and scanning electron microscopes using computerized methods of quantitative metallography; and tests of tensile, bending, and compression strength. Individually designed microsamples were used, and the results were statistically processed. It was shown that if optimal conditions of SLS technology are used, it is possible to obtain a structure with a pore content of 0.1 % smaller than in the case of solid cast materials. This ensures better mechanical properties than cast materials. At the same time, it was pointed out that even minor technological errors associated with SLS technology caused a lowering of all strength properties associated with a significant increase in porosity by up to 10 %. Allowing small changes in technological conditions, including the width of the laser spot, the width of the laser beam, the allowance associated with the overlap of the laser beam, disturbances in the flow of inert gas, and uncontrolled changes in the laser power, can cause a significant reduction in strength. A plug and play approach is unacceptable. If even one layer with a thickness of 25 μm is produced in suboptimal conditions, the manufactured element cannot meet the assumed requirements. The use of SLS additive technology for the production of prosthetic components made of Co-Cr alloys is the best choice among the methods currently used in dentistry. The use of SLS technology together with the digitization of design and manufacturing processes is an important element in implementing the Dentistry 4.0 approach as part of the Industry 4.0 stage of the industrial revolution.
