• Title/Summary/Keyword: bond effect

Search Result 1,649, Processing Time 0.029 seconds

A STUDY ON THE EFFECT OF AMALGAM CAVITY LINER APPLICATION ON THE MARGINAL LEAKAGE AND RETENTION OF AMALGAM RESTORATIONS (Amalgambond Liner의 도포가 amalgam 수복재의 변연누출과 유지력에 미치는 영향에 관한 연구)

  • Kim, Tae-Sung;Kim, Jong-Soo;Kim, Yong-Kee
    • Journal of the korean academy of Pediatric Dentistry
    • /
    • v.23 no.4
    • /
    • pp.800-817
    • /
    • 1996
  • In this study, we tried to evaluate the effect of Amalgambond liner application on the degree of marginal leakage and retention of amalgam restoration by comparing with that of the Copalite and All-bond 2. The results obtained from this experiment were as follows; 1. Tensile strength representing the bond between amalgam and tooth structure was the highest in Amalgambond, and All-Bond 2, Copalite in descending order. There were statistically significant difference between each group(P<0.05). 2. The degree of microleakage in Amalgambond was lower than that of All-Bond 2, and Copalite, but no stastically significant difference could be found (P>0.05). 3. The liner such as Amalgambond or All-Bond 2 were evaluated to be superior to the conventional Copalite in bond strength as well as in microleakage. But the result of this study could not show the superiority of one material over the others; Amalgambond and All-bond 2. Besides the results of the study, other factors, such as practical convenience, should be considered in determining the selection of material. The support of welldesigned clinical studies on this subject are in demand.

  • PDF

Effect of surface and heat treatment on the bond strength of veneering ceramics to zirconia(Y-TZP) (표면처리와 열처리가 전장도재와 지르코니아의 결합력에 미치는 영향)

  • Lee, Jung-Hwan;Ahn, Jae-Seok
    • Journal of Technologic Dentistry
    • /
    • v.35 no.4
    • /
    • pp.271-280
    • /
    • 2013
  • Purpose: This study was to assess the effect of surface and heat treatment on the bond strength of veneering ceramics to zirconia. Methods: The specimens were divided into 7 groups according to surface treatment and heat treatment conditions prior to porcelain application. ten specimens from each group were subjected to a 3-point flexural test. In addition the influence of surface and heat treatment on surface roughness values and phase transformation of zirconia was evaluated. Statistical analysis was performed with one-way ANOVA and post hoc Tukey's test. Results: Bond strength ranged from $20.67{\pm}3.13MPa$ to $32.69{\pm}4.52$. Bond strength of surface treatment group was lower than that of control group but only $Al_2O_3$ sandblasting group was significant difference. Bond strength of heat treatment group was higher than that of surface treatment group but there was no statistical significance. Conclusion: Bond strength of veneering ceramics to zirconia was affected by surface and heat treatment.

The Effect of Paste Composition and Particle Size on the Alumina Ceramics Metallizing (Paste의 조성과 입도 변화가 알루미나 세라믹스의 Metallizing에 미치는 영향에 관한 연구)

  • 김태송;김성태;김종희
    • Journal of the Korean Ceramic Society
    • /
    • v.30 no.5
    • /
    • pp.347-356
    • /
    • 1993
  • In joining alumina ceramics to metal by using Mo-Mn metallizing process the effects of metallizing thickness, temperature, and the composition of paste on the bond strength and the microstructure of joining interface were investigated. The bond strength variation in the range of metallizing temperature, 1350~155$0^{\circ}C$ was more than 150MPa above 145$0^{\circ}C$ and the optimum metallizing thickness was 30${\mu}{\textrm}{m}$. The optimum contents of Mn in Mo-Mn paste was 5% due to the bond strength decrease with the increase of addition. The effect of SiO2 addition in paste on bond strength was saturated around 200MPa. It was also observed that as the particle size of Mo decreased, the joinning with higher bond strength was shown in spite of low metallizing temperature.

  • PDF

Improved numerical approach for the bond-slip behavior under cyclic loads

  • Kwak, H.G.
    • Structural Engineering and Mechanics
    • /
    • v.5 no.5
    • /
    • pp.663-677
    • /
    • 1997
  • Bond-slip behavior between reinforcement and concrete under push-pull cyclic loadings is numerically investigated based on a reinforcement model proposed in this paper. The equivalent reinforcing steel model considering the bond-slip effect without taking double nodes is derived through the equilibrium at each node of steel and the compatibility condition between steel and concrete. Besides a specific transformation algorithm is composed to transfer the forces and displacements from the nodes of the steel element to the nodes of the concrete element. This model first results in an effective use in the case of complex steel arrangements where the steel elements cross the sides of the concrete elements and second turns the impossibility into a possibility in consideration of the bond-slip effect in three dimensional finite element analysis. Finally, the correlation studies between numerical and experimental results under the continuously repeated large deformation stages demonstrate the validity of developed reinforcing steel model and adopted algorithms.

A Study on the Bond Strength According to Retention forms when Complete Denture Repaired (총의치 수리시 유지형태에 따른 접착강도에 관한 연구)

  • Choi, Seog-Soon
    • Journal of Technologic Dentistry
    • /
    • v.12 no.1
    • /
    • pp.121-124
    • /
    • 1990
  • The purpose of this study was to evaluate the effect of three different retention forms on the bond strength when complete denture repaired. Total 75 samples were divided into 3 groups(Dove-tail form, bevel form, rabbit form). The completed resin samples were compressed in Instron Testing Machine until gross fracture occurred to examine the effect on the bond strength of resin base. The results of the experiment were as follows : 1. The difference of bond strength according to three retention forms were not statistically significant(P>0.05). 2. Dove-tail form was strongest to bond strength among the three retention forms.

  • PDF

Pull-out Strengths of GFRP-Concrete Bond Exposed to Applied Environmental Conditions

  • Kabir, Muhammad Ikramul;Samali, Bijan;Shrestha, Rijun
    • International Journal of Concrete Structures and Materials
    • /
    • v.11 no.1
    • /
    • pp.69-84
    • /
    • 2017
  • This paper presents results of an experimental investigation on the behaviour of bond between external glass fibre reinforced polymer reinforcement and concrete exposed to three different environmental conditions, namely, temperature cycles, wet-dry cycles and outdoor environment separately for extended durations. Single shear tests (pull-out test) were conducted to investigate bond strengths (pull-out strengths) of control (unexposed) and exposed specimens. Effect of the exposure conditions on the compressive strength of concrete were also investigated separately to understand the effect of changing concrete compressive strength on the pull-out strength. Based on the comparison of experimental results of exposed specimens to control specimens in terms of bond strengths, failure modes and strain profiles, the most significant degradation of pull-out strength was observed in specimens exposed to outdoor environment, whereas temperature cycles did not cause any deterioration of strength.

The effect of sintering condition and composition on the mechanical properties of bond materials for micro-blades (Micro Blade용 Bond재료의 소결조건과 조성이 기계적 특성에 미치는 영향)

  • Kim, Song-Hee;Moon, Jong-Chul
    • Journal of Industrial Technology
    • /
    • v.27 no.B
    • /
    • pp.137-144
    • /
    • 2007
  • Sintering condition and various chemical composition of bond materials for micro-blades were studied. The methods mixing of pure powders and using pre-alloyed powders for compaction and sintering were compared and optimized in terms of the evaluation of bending strength and fractographic study. The effect of the amount of graphite as a lubricant and diamond abrasive on the strength of sintered bond materials and fracture toughness was investigated. The strength decreased with increasing the amount of graphite and diamond abrasive.

  • PDF

Bond mechanism effect on the flexural behavior of steel reinforced concrete composite members

  • Juang, Jia-Ling;Hsu, Hsieh-Lung
    • Steel and Composite Structures
    • /
    • v.6 no.5
    • /
    • pp.387-400
    • /
    • 2006
  • This paper discusses the composite mechanism and its effect upon the behavior of a steel reinforced concrete (SRC) member subjected to a flexural load. The relationship between member strength and deformation is established using the bond strength between the steel and reinforced concrete. An analytical model is proposed and used to incorporate the sectional strains and bond strength at the elastic and inelastic stages for moment-curvature relationship derivation. The results from the flexural load tests are used to validate the accuracy of the proposed model. Comparisons between the experimental information and the analytical results demonstrate close moment-curvature relevance, which justifies the applicability of the proposed method.

Push-out tests and bond strength of rectangular CFST columns

  • Qu, Xiushu;Chen, Zhihua;Nethercot, David A.;Gardner, Leroy;Theofanous, Marios
    • Steel and Composite Structures
    • /
    • v.19 no.1
    • /
    • pp.21-41
    • /
    • 2015
  • Push-out tests have been conducted on 18 rectangular concrete-filled steel tubular (CFST) columns with the aim of studying the bond behaviour between the steel tube and the concrete infill. The obtained load-slip response and the distribution of the interface bond stress along the member length and around the cross-section for various load levels, as derived from measured axial strain gradients in the steel tube, are reported. Concrete compressive strength, interface length, cross-sectional dimensions and different interface conditions were varied to assess their effect on the ultimate bond stress. The test results indicate that lubricating the steel-concrete interface always had a significant adverse effect on the interface bond strength. Among the other variables considered, concrete compressive strength and cross-section size were found to have a pronounced effect on the bond strength of non-lubricated specimens for the range of cross-section geometries considered, which is not reflected in the European structural design code for composite structures, EN 1994-1-1 (2004). Finally, based on nonlinear regression of the test data generated in the present study, supplemented by additional data obtained from the literature, an empirical equation has been proposed for predicting the average ultimate bond strength for SHS and RHS filled with normal strength concrete.

SHEAR BOND STRENGTH OF PRETREATED DENTIN SURFACE WITH RESIN-REINFORCED GLASS IONOMER CEMENT (상아질의 치면 처리에 따른 합착용 레진 강화형 글라스 아이오노머 시멘트의 전단결합강도)

  • Choi Hye-Souk;Lee Cheong-Hee;Jo Kwang-Hun;Kim Kyo-Han
    • The Journal of Korean Academy of Prosthodontics
    • /
    • v.39 no.5
    • /
    • pp.502-513
    • /
    • 2001
  • The purpose of this study was to evaluate the effect of dentin pretreatment with Dentin Conditioner, Ultra-Etch, conditioner of Fuji Plus cement on the shear bond strength of resin-reinforced glass ionomer cements to dentin and analyze the fractured surfaces. To evaluate the bond strength, the extracted human teeth which had uniform area of exposed dentin were cemented with conventional glass ionomer cement, 3M $RelyX^{TM}$ Luting (Vitremer luting cement), Fuji Plus cement after dentin pretreatment. The shear bond strength was measured using the Universal testing machine (Instron Co., USA) with a crosshead speed of 1mm/m. The effect of dentin pretreatment was evaluated by observing pretreated dentin surfaces under the scanning electron microscope, measuring the shear bond strength and observing the fractured surfaces under the scanning electron microscope. The results were as follows : On the SEM observation of surface morphology, the specimens treated with Dentin Conditioner. Ultra-Etch and conditioner of Fuji Plus cement were removed the smear layer and funneled dentinal tubules in dentin surfaces. In $RelyX^{TM}$ Luting cement group, shear bond strength of pretreated group was significantly higher than control group. In Fuji Plus cement group and Fuji I group, regardless of the type of pretreatment agents, there was tendency of increase in the shear bond strength. On the SEM observation of fractured surfaces, as the shear bond strength increase, it were shown thicker cement layers and were not shown dentinal tubules According to these results. it were shown that dentin pretreatment have much effect on bonding states.

  • PDF