• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.2
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• pp.181-191
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• 2006

The objectives of this study were to evaluate the tensile strength of resin-infiltrated demineralized dentin according to the demineralization time, and to evaluate the tensile strength of hybrid layer that is formed by infiltrating different priming adhesives or primer/adhesive into demineralizd dentin matrix. Seventy five hour-glass shaped dentin specimens were prepared in mid-coronal dentin from extracted human molars. Thirty specimens were distributed into three groups according to demineralization time - 2 hours, 4 hours and 8 hours. Each specimen was placed in primer/adhesive of All-Bond 2 for 5 hours of infiltration. Another forty-five specimens of them were demineralized in 37% phosphoric acid for 4 hours. They were randomly assigned to three experimental groups - AB, SB and OS - to designate All-Bond 2, Single Bond and One-Step. Each specimen was placed in one of three different adhesives for 5 hours of infiltration. The specimens were visible light-cured for 5 minutes, and then stored for 24 hours in distilled water at $37^{\circ}C$. After that, microtensile bond strength for each specimen was measured, and the fractured surfaces were then observed by SEM. The data were statistically analysed by one-way ANOVA and Tukey's multiple comparison test and Bonferroni's multiple comparison test. The results were as follows; 1. Tensile strength of the group demineralized for 4 hours was significantly higher than that of groups demineralized for 2 hours and 8 hours (P < .01). 3. Tensile strength of the AB group was significantly higher than that of the SB group and OS group (P < .01).

• Journal of Industrial Technology
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• v.33 no.A
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• pp.101-107
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• 2013

The purpose of this study was to investigate bond strength between substrate and HES-LMS mortar, durability of HES-LMS mortar with latex content(0%, 5%, 10%). To measure the bond strength, the direct tensile test based on uniaxial tensile test was used, which was proposed by Kuhlman(1990). Also, Resistance for water permeability, water absorption and image analysis for air void system were conducted to estimating durability of HES-LMS mortar.

• The Journal of Advanced Prosthodontics
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• v.8 no.4
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• pp.285-289
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• 2016

PURPOSE. This study evaluated the effect of chemical surface treatment using methyl formate-methyl acetate (MF-MA) solution on the tensile bond strength between acrylic denture teeth and auto-polymerized acrylic resin. MATERIALS AND METHODS. Seventy maxillary central incisor acrylic denture teeth for each of three different brands (Yamahachi New Ace; Major Dent; Cosmo HXL) were embedded with incisal edge downwards in auto-polymerized resin in polyethylene pipes and ground with silicone carbide paper on their ridge lap surfaces. The teeth of each brand were divided into seven groups (n=10): no surface treatment (control group), MF-MA solution at a ratio of 25:75 (v/v) for 15 seconds, 30 seconds, 60 seconds, 120 seconds, 180 seconds, and MMA for 180 seconds. Auto-polymerized acrylic resin (Unifast Trad) was applied to the ground surface and polymerized in a pressure cooker. A tensile strength test was performed with a universal testing machine. Statistical analysis of the results was performed using two-way analysis of variance (ANOVA) and post-hoc Dunnett T3 test (${\alpha}$=.05). RESULTS. The surface treatment groups had significantly higher mean tensile bond strengths compared with the control group (P<.05) when compared within the same brand. Among the surface treatment groups of each brand, there were no significantly different tensile bond strengths between the MF-MA groups and the MMA 180 second group (P>.05), except for the Yamahachi New Ace MF-MA 180-second group (P<.05). CONCLUSION. 15-second MF-MA solution can be an alternative chemical surface treatment for repairing a denture base and rebonding acrylic denture teeth with auto-polymerized acrylic resin, for both conventional and cross-linked teeth.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.1
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• pp.13-22
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• 1991

This study investigated the effects of surface treatment on the tensile bond strength of resinbonded prosthesis. The Rexillium III specimens were treated with $50{\mu}m\;Al_2O_3$ blasting. Type IV gold alloy specimens were treated with $400^{\circ}C$ heating and tin plating method. All specimens were bonded with MBAS composite resin cement and followed by immersion test into the $37^{\circ}C$ water bath for 7 days. The specimens were debonded in tension with an Instron machine and observed with SEM. The modes of failure were recorded also. The following conclusions were obtained : 1. The tensile bond strength decreased in following order. $50{\mu}m\;Al_2O_3$ basted Resillium III group, Type IV gold alloy group treated with $400^{\circ}C$ heat and tin plating type IV gold alloy group, and statistical significant differences were observed(p<0.05). 2. The tensile bond strength decreased in all groups after 7 days immersion test, but statistical significant differences were observed in Rexillium III specimens only. 3. The sharp and irregular surface were observed in Rexillium III, but $400^{\circ}C$ heat treated and tin plated groups had round and broad surface in SEM. 4. The models of bond failure were cohesive-adhesive failure mainly.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.1085-1088
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• 2008

Splice of reinforcement is inevitable in reinforced concrete structures and, generally, lap splices are used. Lap length for tension splice is determined from development length in tension. The development length is calculated from an experimental model which was based on data of tests on anchorage and splice. Longitudinal reinforcements in flexural members are deformed and, therefore, prying action happens in spliced reinforcements unlike anchored reinforcements. The prying action induces tensile stress in cover concrete and this tensile stress plays the same role to a circumferential tensile stress caused by bond. Because splitting failure is assumed to occur when the summation of tensile stresses caused by the prying action and the bond is equal to the tensile strength of the concrete, the prying action reduces the bond strength of spliced reinforcements. A theoretical model for the prying action is developed and effects of the prying action on the bond strength are assessed. The tensile stress by the prying action is proportional to tensile strength and modulus of elasticity of reinforcements. In addition, the tensile stress is inversely proportional to spacing of reinforcements. Consequently, longer splice length is required for spliced reinforcements with small spacing in flexible members.

• Journal of the Korean Society of Safety
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• v.25 no.1
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• pp.1-8
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• 2010

The tensile and fatigue experiments were conducted with tensile-shear specimens for investigating the strength of adhesive bonded and mechanical press joints of SPCC steel sheet used in the field of the automobile industry. The optimal punch press force was evaluated 50kN for combining epoxy adhesive bonding and mechanical press joining with a diameter of 8.3mm using SPCC sheet with a thickness of 0.8mm. The combining epoxy adhesive bonding and mechanical press joining exhibits the maximum tensile force of 750N. The fatigue strengths of the combination of adhesive bond and mechanical press joint and pure adhesive joint were evaluated 370N and 320N at 106cycles, respectively. These values correspond to 22% and 20% of their maximum tensile forces, respectively. However, the fatigue strength of the combination of adhesive bond and mechanical press joining was much lower than that of pure mechanical press joining.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.201-202
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• 2022

In this study, the high performance silicone was developed to assure the inter-layer joint in apartment house. The tensile strength, the elongation, the bond strength and the fatigue tests were conducted. As a result, it was confirmed that the performance of high -performance silicone was superior to the existing elastic paint. Therefore, it is expected that it will help to secure the quality of inter-layer joints in apartment houses.

• Restorative Dentistry and Endodontics
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• v.29 no.5
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• pp.423-429
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• 2004

The purpose of this study was to evaluate the effect of multiple application of all-in-one dentin adhesive system on microtensile bond strength using confocal laser scanning microscope and microtensile bond strength test. Flat occlusal dentin surfaces were prepared using low-speed diamond saw. In group I, Scotchbond Multipurpose (SM) was applied by manufacturer's recommendation. In group II, after Adper Prompt L-Pop was applied for 15s and light cured for 10s. the second coat was re-applied and light-cured. In group III, after light-curing the second layer. the third coat was re-applied and light-cured. Specimens bonded with a resin-composite were sectioned into resin-dentin stick for measuring the adhesive layer thickness by confocal laser scanning microscope and evaluating micro-tensile bond strength. The adhesive layers of three-step dentin adhesive system. 3 coats of Adper Prompt L-Pop had significantly thicker than SM. 2 coats of Adper Prompt L-Pop (p < 0.05). However. there was no significant differences in bond strengths between SM and 3 coats of Adper Prompt L-Pop (p > 0.05). And SM. 3 coats of Adper Prompt L-Pop had significantly higher than 2 coats of Adper Prompt L-Pop in bond strengths (p < 0.05).

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.1
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• pp.1-12
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• 1995

For the purpose of this study, the silicoating on Ni-Cr-Be alloy surface was carried out by using the Silicoater MD. The effect of time delay after silicoating on the bond strength between the metal and resin cement was examined. The groups were divided into 4 : group 1 : Sandblasted with $250{\mu}m$ aluminium oxide, immediatly cemented group 2 : Sandblasted with $250{\mu}m$ aluminium oxide, silicoated and immediatly cemented group 3 : Sandblasted with $250{\mu}m$ aluminium oxide, silicoated and cemented after 7 days group 4 : Sandblasted with $250{\mu}m$ aluminium oxide, silicoated and coated with unfilled resin and cemented after 7 days Specimens were luted with Comspan, Superbond C&B or Panavia EX. The tensile bond strength between the metal and resin cement was measured by using the universal testing machine. The results were as follows : 1. The bond strength in groups 2, 3 and 4 was higher than that of group 1 (p<0.05). There was no statistically significant difference among the bond strength in groups 2, 3 and 4 (p>0.05). 2. In Comspan-cemented groups, there was no significant difference among the bond strength in groups 2, 3 and 4 (p<0.05). 3. In Panavia EX-cemented groups, the bond strength of group 3 was higher than that of group 2 (p<0.05) and there was no significant difference between groups 3 and 4. 4. In Superbond C&B-cemented groups, there was significant difference between groups 2 and 3 (p<0.05) and the bond strength of group 4 was higher than that of group 3 (p<0.05). 5. The highest tensile bond strength was obtained by using the Superbond C&B and no difference in the Panavia EX and Comspan. 6. The modes of bond failure were mainly cohesive failure. The method of storage and transport indicated in this study seems recommendable for laboratory and clinical use at least up to 7 days.

• Computers and Concrete
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• v.20 no.3
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• pp.283-290
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• 2017

The aim of this study is to investigate the effect of the bond strength of self-compacting mortars (SCMS) produced from ground pumice powder (GPP) as a mineral additive. In this scope, six series of mortars including control mix were prepared that consist of 7%, 12%, 17%, 22% and 27% of ground pumice powder by weight of cement. A total of 54 specimens of $40{\times}40{\times}160mm$ were produced and cured at the age of 3, 28 and 90-day for compressive and tensile strength tests and 18 specimens of $150{\times}150{\times}150mm$ mortar were prepared and cured at 28 days for bond strength tests. Flexural tensile strength and compressive strength of $40{\times}40{\times}160mm$ specimens were measured at the curing age of 7, 28 and 90-day. Mini V-funnel flow time and mini slump flow diameter tests were also conducted to obtain rheological properties. As a result of the study, it was observed that the SCMs containing 12% of GPP has the highest bond strength as compared to control and GPP mortars. Compressive strength slightly increased up to 12% of GPP.