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T Okabe - One of the best experts on this subject based on the ideXlab platform.
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Wear resistance of experimental Ti-Cu Alloys.
Biomaterials, 2003Co-Authors: Chiyoji Ohkubo, Tomoki Hosoi, I. Shimura, S. Hanatani, M. Hattori, T Aoki, T OkabeAbstract:Abstract After using cast titanium prostheses in clinical dental practice, severe wear of titanium teeth has been observed. This in vitro study evaluated the wear behavior of teeth made with several cast titanium Alloys containing copper (CP Ti+3.0 wt% Cu; CP Ti+5.0 wt% Cu; Ti–6Al–4 V +1.0 wt% Cu; Ti–6Al–4 V+4.0 wt% Cu) and compared the results with those for commercially pure (CP) titanium, Ti–6Al–4 V, and Gold Alloy. Wear testing was performed by repeatedly grinding upper and lower teeth under flowing water in an experimental testing apparatus. Wear resistance was assessed as volume loss (mm 3 ) at 5 kgf (grinding force) after 50,000 strokes. Greater wear was found for the six types of titanium than for the Gold Alloy. The wear resistance of the experimental CP Ti+Cu and Ti–6Al–4 V+Cu Alloys was better than that of CP titanium and Ti–6Al–4 V, respectively. Although the Gold Alloy had the best wear property, the 4% Cu in Ti–6Al–4 V Alloy exhibited the best results among the titanium metals. Alloying with copper, which introduced the α Ti/Ti 2 Cu eutectoid, seemed to improve the wear resistance.
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Wear resistance of experimental Ti-Cu Alloys
Biomaterials, 2003Co-Authors: Chiyoji Ohkubo, Tomoki Hosoi, I. Shimura, S. Hanatani, Y. Oda, M. Hattori, T Aoki, T OkabeAbstract:After using cast titanium prostheses in clinical dental practice, severe wear of titanium teeth has been observed. This in vitro study evaluated the wear behavior of teeth made with several cast titanium Alloys containing copper (CP Ti+3.0wt% Cu; CP Ti+5.0wt% Cu; Ti-6Al-4V +1.0wt% Cu; Ti-6Al-4V+4.0wt% Cu) and compared the results with those for commercially pure (CP) titanium, Ti-6Al-4V, and Gold Alloy. Wear testing was performed by repeatedly grinding upper and lower teeth under flowing water in an experimental testing apparatus. Wear resistance was assessed as volume loss (mm3) at 5kgf (grinding force) after 50,000 strokes. Greater wear was found for the six types of titanium than for the Gold Alloy. The wear resistance of the experimental CP Ti+Cu and Ti-6Al-4V+Cu Alloys was better than that of CP titanium and Ti-6Al-4V, respectively. Although the Gold Alloy had the best wear property, the 4% Cu in Ti-6Al-4V Alloy exhibited the best results among the titanium metals. Alloying with copper, which introduced the α Ti/Ti2Cu eutectoid, seemed to improve the wear resistance. © 2003 Elsevier Science Ltd. All rights reserved.
Chiyoji Ohkubo - One of the best experts on this subject based on the ideXlab platform.
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Wear resistance of experimental Ti-Cu Alloys.
Biomaterials, 2003Co-Authors: Chiyoji Ohkubo, Tomoki Hosoi, I. Shimura, S. Hanatani, M. Hattori, T Aoki, T OkabeAbstract:Abstract After using cast titanium prostheses in clinical dental practice, severe wear of titanium teeth has been observed. This in vitro study evaluated the wear behavior of teeth made with several cast titanium Alloys containing copper (CP Ti+3.0 wt% Cu; CP Ti+5.0 wt% Cu; Ti–6Al–4 V +1.0 wt% Cu; Ti–6Al–4 V+4.0 wt% Cu) and compared the results with those for commercially pure (CP) titanium, Ti–6Al–4 V, and Gold Alloy. Wear testing was performed by repeatedly grinding upper and lower teeth under flowing water in an experimental testing apparatus. Wear resistance was assessed as volume loss (mm 3 ) at 5 kgf (grinding force) after 50,000 strokes. Greater wear was found for the six types of titanium than for the Gold Alloy. The wear resistance of the experimental CP Ti+Cu and Ti–6Al–4 V+Cu Alloys was better than that of CP titanium and Ti–6Al–4 V, respectively. Although the Gold Alloy had the best wear property, the 4% Cu in Ti–6Al–4 V Alloy exhibited the best results among the titanium metals. Alloying with copper, which introduced the α Ti/Ti 2 Cu eutectoid, seemed to improve the wear resistance.
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Wear resistance of experimental Ti-Cu Alloys
Biomaterials, 2003Co-Authors: Chiyoji Ohkubo, Tomoki Hosoi, I. Shimura, S. Hanatani, Y. Oda, M. Hattori, T Aoki, T OkabeAbstract:After using cast titanium prostheses in clinical dental practice, severe wear of titanium teeth has been observed. This in vitro study evaluated the wear behavior of teeth made with several cast titanium Alloys containing copper (CP Ti+3.0wt% Cu; CP Ti+5.0wt% Cu; Ti-6Al-4V +1.0wt% Cu; Ti-6Al-4V+4.0wt% Cu) and compared the results with those for commercially pure (CP) titanium, Ti-6Al-4V, and Gold Alloy. Wear testing was performed by repeatedly grinding upper and lower teeth under flowing water in an experimental testing apparatus. Wear resistance was assessed as volume loss (mm3) at 5kgf (grinding force) after 50,000 strokes. Greater wear was found for the six types of titanium than for the Gold Alloy. The wear resistance of the experimental CP Ti+Cu and Ti-6Al-4V+Cu Alloys was better than that of CP titanium and Ti-6Al-4V, respectively. Although the Gold Alloy had the best wear property, the 4% Cu in Ti-6Al-4V Alloy exhibited the best results among the titanium metals. Alloying with copper, which introduced the α Ti/Ti2Cu eutectoid, seemed to improve the wear resistance. © 2003 Elsevier Science Ltd. All rights reserved.
Mitsuru Atsuta - One of the best experts on this subject based on the ideXlab platform.
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Optimizing mechanical properties of laser-welded Gold Alloy through heat treatment.
Dental Materials, 2004Co-Authors: Ikuya Watanabe, N Baba, Mitsuru Atsuta, Toru OkabeAbstract:Abstract Objective . The goal of this work was to improve the mechanical strength of laser-welded Gold Alloy with age-hardenability at intraoral temperature. Methods . The Gold Alloy was cast conventionally in plate patterns (0.5 mm ×3.0 mm ×20 mm ). After bench-cooling the mold to room temperature (as-cast state), transverse sections of the plate were made at mid-span. They were butted against one another and welded using Nd:YAG laser (current: 320 A; time: 10 ms; spot diameter: 1 mm). Three laser pulses were applied from both sides to cover the joint width (3.0 mm) of the specimens before or after solution heat treatment at 700 °C/5 min. Uncut control specimens (non-welded) were also prepared. After solution treatment, two different heat treatments were given the laser-welded specimens: high-temperature aging at 250 °C/15 min, or intraoral aging at 37 °C/3 days. Control specimens underwent all of the heat treatments after solution treatment. Tensile testing was conducted at a crosshead speed of 2 mm/min and a gauge length of 10 mm. Results . Solution treatment of the Gold Alloy before laser-welding did not improve the mechanical strength of laser-welded Gold Alloy after high-temperature aging or intraoral aging. The joint strengths of laser-welded Gold Alloy were improved only by solution heat treatments after laser-welding and subsequent aging treatment at high or intraoral temperatures. Significance . The results of this study indicated that laser-welded cast Gold Alloy prostheses aged at high or intraoral temperatures produce high strength when they are solution-treated after laser-welding.
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Optimizing mechanical properties of laser-welded Gold Alloy through heat treatment.
Dental Materials, 2004Co-Authors: Ikuya Watanabe, N Baba, Mitsuru Atsuta, Toru OkabeAbstract:OBJECTIVE: The goal of this work was to improve the mechanical strength of laser-welded Gold Alloy with age-hardenability at intraoral temperature. METHODS: The Gold Alloy was cast conventionally in plate patterns (0.5 mm x 3.0 mm x 20 mm). After bench-cooling the mold to room temperature (as-cast state), transverse sections of the plate were made at mid-span. They were butted against one another and welded using Nd:YAG laser (current: 320 A; time: 10 ms; spot diameter: 1 mm). Three laser pulses were applied from both sides to cover the joint width (3.0 mm) of the specimens before or after solution heat treatment at 700 degrees C/5 min. Uncut control specimens (non-welded) were also prepared. After solution treatment, two different heat treatments were given the laser-welded specimens: high-temperature aging at 250 degrees C/15 min, or intraoral aging at 37 degrees C/3 days. Control specimens underwent all of the heat treatments after solution treatment. Tensile testing was conducted at a crosshead speed of 2 mm/min and a gauge length of 10 mm. RESULTS: Solution treatment of the Gold Alloy before laser-welding did not improve the mechanical strength of laser-welded Gold Alloy after high-temperature aging or intraoral aging. The joint strengths of laser-welded Gold Alloy were improved only by solution heat treatments after laser-welding and subsequent aging treatment at high or intraoral temperatures. SIGNIFICANCE: The results of this study indicated that laser-welded cast Gold Alloy prostheses aged at high or intraoral temperatures produce high strength when they are solution-treated after laser-welding.
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Effect of heat treatments on machinability of Gold Alloy with age-hardenability at intraoral temperature.
Journal of Dentistry, 2004Co-Authors: Ikuya Watanabe, N Baba, Mitsuru Atsuta, Etsuko Watanabe, Toru OkabeAbstract:Objective. This study investigated the effect of heat treatment on the machinability of heat-treated cast Gold Alloy with age-hardenability at intraoral temperature using a handpiece engine with SiC wheels and an air-turbine handpiece with carbide burs and diamond points. Methods. Cast Gold Alloy specimens underwent various heat treatments [As-cast (AC); Solution treatment (ST); High-temperature aging (HA), Intraoral aging (IA)] before machinability testing. The machinability test was conducted at a constant machining force of 0.784N. The three circumferential speeds used for the handpiece engine were 500, 1,000 and 1,500 m/min. The machinability index (M-index) was determined as the amount of metal removed by machining (volume loss, mm3). The results were analyzed by ANOVA and Scheffe's test. Results. When an air-turbine handpiece was used, there was no difference in the M-index of the Gold Alloy among the heat treatments. The air-turbine carbide burs showed significantly (p
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Tensile strength of soldered Gold Alloy joints
Journal of Prosthetic Dentistry, 1997Co-Authors: Ikuya Watanabe, Mitsuru Atsuta, Etsuko Watanabe, Toru OkabeAbstract:Abstract Statement of problem. Little information is available about the mechanical properties of soldered Gold Alloys after they have undergone various heat treatments. Purpose. This study investigated the influence of heat treating on the strength properties of soldered joints of two Gold Alloys (NC Type IV and Sofard), which can be age-hardened at intraoral temperature. Material and methods. Dumbbell-shaped specimens were cast with each Gold Alloy and were cut at the center of the connecting bar for soldering. The two halves of the casting were then soldered with two different Gold-based solders (MainGold and Degulor). Three different heat treatments were performed on the soldered Gold Alloy assemblies: solution heat treatment (ST) at 700° C for 5 minutes (treatment A); aging at 37° C for 7 days after ST (treatment B); and aging at 250° C (Sofard) or 400° C (NC type IV) for 15 minutes after ST (treatment C). The tensile strength, elongation and microhardness were evaluated after each heat treatment. Results. The hardness values of Sofard significantly ( p Conclusions. The results of this study indicated the possibility of strengthening soldered joints in the oral environment, thus eliminating the necessity for any additional hardening heat treatment. (J Prosthet Dent 1997;78:260-6.)
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Effect of two metal primers on adhesive bonding with type IV Gold Alloys
Journal of Prosthetic Dentistry, 1995Co-Authors: Ikuya Watanabe, Hideo Matsumura, Mitsuru AtsutaAbstract:Bond strengths of an adhesive resin bonded to two types of Gold Alloys wereinvestigated in vitro with two different metal primers. Disk specimens were cast in a type IV Gold Alloy designed for resin-bonded restorations and in a low-temperature age-hardenable Gold Alloy. The specimens were primed with either a vinylthiol primer or a thiophosphate primer, then bonded with an adhesive resin initiated with tri- n -butyl borane derivative. Both primers effectively enhanced bond between Gold Alloys and the adhesive. The use of metal primers in conjunction with type IV Gold Alloys is useful for resin-bonded fixed partial dentures
Lorika S. Beukes - One of the best experts on this subject based on the ideXlab platform.
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silver Gold Alloy nanoparticles biofabricated by fungal xylanases exhibited potent biomedical and catalytic activities
Biotechnology Progress, 2019Co-Authors: Joseph Adetunji Elegbede, Agbaje Lateef, Musibau A. Azeez, Tesleem B. Asafa, Taofeek A. Yekeen, I. C. Oladipo, Abbas Saeed Hakeem, Lorika S. Beukes, Evariste B GueguimkanaAbstract:The search for biocompatible nanoparticles with vast applicability has impacted on exploration of various biomaterials for the synthesis of mono and bimetallic nanoparticles. Xylanase is widely regarded as an industrially important enzyme but its potentials in nanotechnological applications are yet to be fully explored. The current study investigates the exploit of xylanases of Aspergillus niger L3 (NE) and Trichoderma longibrachiatum L2 (TE) produced through valorization of corn-cob, to synthesize silver-Gold Alloy nanoparticles (Ag-AuNPs). Characterization of the Ag-AuNPs involved UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy and transmission electron microscopy, while their prospective use as antimicrobial, antioxidant, catalytic, anticoagulant, and thrombolytic agents were studied. The biosynthesized Ag-AuNPs were ruby red and light purple with surface plasmon resonance at 520 and 534 nm for NEAg-AuNPs and TEAg-AuNPs, respectively; while FTIR showed that protein molecules capped and stabilized the nanoparticles. The Ag-AuNPs were anisotropic with spherical, oval, and irregular shapes having sizes ranging from 6.98 to 52.51 nm. The nanoparticles appreciably inhibited the growth of tested clinical bacteria (23.40-90.70%) and fungi (70.10-89.05%), and also scavenged 2,2-diphenyl-1-picrylhydrazyl (48.51-53.79%) and hydrogen peroxide (80.5-95.50%). Furthermore, the Ag-AuNPs degraded malachite green (91.39%) and methylene blue (47.10%). Moreover, the Ag-AuNPs displayed outstanding anticoagulant and thrombolytic activities using human blood. This study further emphasizes the significance of xylanases in nanobiotechnology as it has established the potential of xylanases to synthesize Ag-AuNPs, which is being reported for the first time.
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Silver‐Gold Alloy nanoparticles biofabricated by fungal xylanases exhibited potent biomedical and catalytic activities
Biotechnology Progress, 2019Co-Authors: Joseph Adetunji Elegbede, Agbaje Lateef, Musibau A. Azeez, Tesleem B. Asafa, Taofeek A. Yekeen, I. C. Oladipo, Abbas Saeed Hakeem, Lorika S. Beukes, Evariste B. Gueguim-kanaAbstract:The search for biocompatible nanoparticles with vast applicability has impacted on exploration of various biomaterials for the synthesis of mono and bimetallic nanoparticles. Xylanase is widely regarded as an industrially important enzyme but its potentials in nanotechnological applications are yet to be fully explored. The current study investigates the exploit of xylanases of Aspergillus niger L3 (NE) and Trichoderma longibrachiatum L2 (TE) produced through valorization of corn-cob, to synthesize silver-Gold Alloy nanoparticles (Ag-AuNPs). Characterization of the Ag-AuNPs involved UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy and transmission electron microscopy, while their prospective use as antimicrobial, antioxidant, catalytic, anticoagulant, and thrombolytic agents were studied. The biosynthesized Ag-AuNPs were ruby red and light purple with surface plasmon resonance at 520 and 534 nm for NEAg-AuNPs and TEAg-AuNPs, respectively; while FTIR showed that protein molecules capped and stabilized the nanoparticles. The Ag-AuNPs were anisotropic with spherical, oval, and irregular shapes having sizes ranging from 6.98 to 52.51 nm. The nanoparticles appreciably inhibited the growth of tested clinical bacteria (23.40-90.70%) and fungi (70.10-89.05%), and also scavenged 2,2-diphenyl-1-picrylhydrazyl (48.51-53.79%) and hydrogen peroxide (80.5-95.50%). Furthermore, the Ag-AuNPs degraded malachite green (91.39%) and methylene blue (47.10%). Moreover, the Ag-AuNPs displayed outstanding anticoagulant and thrombolytic activities using human blood. This study further emphasizes the significance of xylanases in nanobiotechnology as it has established the potential of xylanases to synthesize Ag-AuNPs, which is being reported for the first time.
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Biomedical and Catalytic Applications of Gold and Silver-Gold Alloy Nanoparticles Biosynthesized Using Cell-Free Extract of Bacillus Safensis LAU 13: Antifungal, Dye Degradation, Anti-Coagulant and Thrombolytic Activities
IEEE Transactions on NanoBioscience, 2016Co-Authors: Agbaje Lateef, Musibau A. Azeez, Tesleem B. Asafa, Taofeek A. Yekeen, I. C. Oladipo, Evariste B. Gueguim-kana, Suliat M. Oladejo, Abiola S. Akinwale, Akeem Akinboro, Lorika S. BeukesAbstract:This study investigated the green biosynthesis of Gold (Au) and silver-Gold Alloy (Ag-Au) nanoparticles using cell-free extract of Bacillus safensis LAU 13 strain (GenBank accession No: KJ461434). The biosynthesized AuNPs and Ag-AuNPs were characterized using UV-Vis spectroscopy, Fourier-transform infrared spectroscopy, and transmission electron microscopy. Evaluation of the antifungal activities, degradation of malachite green, anti-coagulation of blood, and thrombolysis of human blood clot by the biosynthesized nanoparticles were investigated. The AuNPs and Ag-AuNPs had maximum absorbance at 561 and 545 nm, respectively. The FTIR peaks at 3318, 2378, 2114, 1998, 1636, 1287, 446, 421 cm-1 for AuNPs; and 3310, 2345, 2203, 2033, 1636, 1273, 502, 453, 424 cm-1 for Ag-AuNPs indicated that proteins were the capping and stabilization molecules in the biosynthesized nanoparticles. The particles were fairly spherical in shape with size of 10-45 nm for AuNPs and 13-80 nm for Ag-AuNPs. Moreover, energy dispersive X-ray analysis of AuNPs revealed Gold as the most prominent metal in the AuNPs solution, while silver and Gold were the most prominent in the case of Ag-AuNPs. Selected area electron diffraction showed the biosynthesized nanoparticles as crystal structures with ring shape pattern. AuNPs and Ag-AuNPs displayed growth inhibitions of 66.67-90.78% against strains of Aspergillus fumigatus and A. niger at concentration of 200 μg/ml, and remarkable degradation (> 90%) of malachite green after 48 h. Furthermore, the nanoparticles prevented coagulation of blood, and also completely dissolved blood clots, indicating the biomedical potential of AuNPs and Ag-AuNPs in the management of blood coagulation disorders. This is the first report of the synthesis of AuNPs and Ag-AuNPs using a strain of B. safensis for biomedical and catalytic applications.
Ikuya Watanabe - One of the best experts on this subject based on the ideXlab platform.
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Optimizing mechanical properties of laser-welded Gold Alloy through heat treatment.
Dental Materials, 2004Co-Authors: Ikuya Watanabe, N Baba, Mitsuru Atsuta, Toru OkabeAbstract:Abstract Objective . The goal of this work was to improve the mechanical strength of laser-welded Gold Alloy with age-hardenability at intraoral temperature. Methods . The Gold Alloy was cast conventionally in plate patterns (0.5 mm ×3.0 mm ×20 mm ). After bench-cooling the mold to room temperature (as-cast state), transverse sections of the plate were made at mid-span. They were butted against one another and welded using Nd:YAG laser (current: 320 A; time: 10 ms; spot diameter: 1 mm). Three laser pulses were applied from both sides to cover the joint width (3.0 mm) of the specimens before or after solution heat treatment at 700 °C/5 min. Uncut control specimens (non-welded) were also prepared. After solution treatment, two different heat treatments were given the laser-welded specimens: high-temperature aging at 250 °C/15 min, or intraoral aging at 37 °C/3 days. Control specimens underwent all of the heat treatments after solution treatment. Tensile testing was conducted at a crosshead speed of 2 mm/min and a gauge length of 10 mm. Results . Solution treatment of the Gold Alloy before laser-welding did not improve the mechanical strength of laser-welded Gold Alloy after high-temperature aging or intraoral aging. The joint strengths of laser-welded Gold Alloy were improved only by solution heat treatments after laser-welding and subsequent aging treatment at high or intraoral temperatures. Significance . The results of this study indicated that laser-welded cast Gold Alloy prostheses aged at high or intraoral temperatures produce high strength when they are solution-treated after laser-welding.
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Optimizing mechanical properties of laser-welded Gold Alloy through heat treatment.
Dental Materials, 2004Co-Authors: Ikuya Watanabe, N Baba, Mitsuru Atsuta, Toru OkabeAbstract:OBJECTIVE: The goal of this work was to improve the mechanical strength of laser-welded Gold Alloy with age-hardenability at intraoral temperature. METHODS: The Gold Alloy was cast conventionally in plate patterns (0.5 mm x 3.0 mm x 20 mm). After bench-cooling the mold to room temperature (as-cast state), transverse sections of the plate were made at mid-span. They were butted against one another and welded using Nd:YAG laser (current: 320 A; time: 10 ms; spot diameter: 1 mm). Three laser pulses were applied from both sides to cover the joint width (3.0 mm) of the specimens before or after solution heat treatment at 700 degrees C/5 min. Uncut control specimens (non-welded) were also prepared. After solution treatment, two different heat treatments were given the laser-welded specimens: high-temperature aging at 250 degrees C/15 min, or intraoral aging at 37 degrees C/3 days. Control specimens underwent all of the heat treatments after solution treatment. Tensile testing was conducted at a crosshead speed of 2 mm/min and a gauge length of 10 mm. RESULTS: Solution treatment of the Gold Alloy before laser-welding did not improve the mechanical strength of laser-welded Gold Alloy after high-temperature aging or intraoral aging. The joint strengths of laser-welded Gold Alloy were improved only by solution heat treatments after laser-welding and subsequent aging treatment at high or intraoral temperatures. SIGNIFICANCE: The results of this study indicated that laser-welded cast Gold Alloy prostheses aged at high or intraoral temperatures produce high strength when they are solution-treated after laser-welding.
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Effect of heat treatments on machinability of Gold Alloy with age-hardenability at intraoral temperature.
Journal of Dentistry, 2004Co-Authors: Ikuya Watanabe, N Baba, Mitsuru Atsuta, Etsuko Watanabe, Toru OkabeAbstract:Objective. This study investigated the effect of heat treatment on the machinability of heat-treated cast Gold Alloy with age-hardenability at intraoral temperature using a handpiece engine with SiC wheels and an air-turbine handpiece with carbide burs and diamond points. Methods. Cast Gold Alloy specimens underwent various heat treatments [As-cast (AC); Solution treatment (ST); High-temperature aging (HA), Intraoral aging (IA)] before machinability testing. The machinability test was conducted at a constant machining force of 0.784N. The three circumferential speeds used for the handpiece engine were 500, 1,000 and 1,500 m/min. The machinability index (M-index) was determined as the amount of metal removed by machining (volume loss, mm3). The results were analyzed by ANOVA and Scheffe's test. Results. When an air-turbine handpiece was used, there was no difference in the M-index of the Gold Alloy among the heat treatments. The air-turbine carbide burs showed significantly (p
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Tensile strength of soldered Gold Alloy joints
Journal of Prosthetic Dentistry, 1997Co-Authors: Ikuya Watanabe, Mitsuru Atsuta, Etsuko Watanabe, Toru OkabeAbstract:Abstract Statement of problem. Little information is available about the mechanical properties of soldered Gold Alloys after they have undergone various heat treatments. Purpose. This study investigated the influence of heat treating on the strength properties of soldered joints of two Gold Alloys (NC Type IV and Sofard), which can be age-hardened at intraoral temperature. Material and methods. Dumbbell-shaped specimens were cast with each Gold Alloy and were cut at the center of the connecting bar for soldering. The two halves of the casting were then soldered with two different Gold-based solders (MainGold and Degulor). Three different heat treatments were performed on the soldered Gold Alloy assemblies: solution heat treatment (ST) at 700° C for 5 minutes (treatment A); aging at 37° C for 7 days after ST (treatment B); and aging at 250° C (Sofard) or 400° C (NC type IV) for 15 minutes after ST (treatment C). The tensile strength, elongation and microhardness were evaluated after each heat treatment. Results. The hardness values of Sofard significantly ( p Conclusions. The results of this study indicated the possibility of strengthening soldered joints in the oral environment, thus eliminating the necessity for any additional hardening heat treatment. (J Prosthet Dent 1997;78:260-6.)
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Effect of two metal primers on adhesive bonding with type IV Gold Alloys
Journal of Prosthetic Dentistry, 1995Co-Authors: Ikuya Watanabe, Hideo Matsumura, Mitsuru AtsutaAbstract:Bond strengths of an adhesive resin bonded to two types of Gold Alloys wereinvestigated in vitro with two different metal primers. Disk specimens were cast in a type IV Gold Alloy designed for resin-bonded restorations and in a low-temperature age-hardenable Gold Alloy. The specimens were primed with either a vinylthiol primer or a thiophosphate primer, then bonded with an adhesive resin initiated with tri- n -butyl borane derivative. Both primers effectively enhanced bond between Gold Alloys and the adhesive. The use of metal primers in conjunction with type IV Gold Alloys is useful for resin-bonded fixed partial dentures