Effect of Reduced Universal Adhesive Application Time on Enamel Bond Fatigue and Surface Morphology

2019 ◽  
Vol 44 (1) ◽  
pp. 42-53 ◽  
Author(s):  
Y Nagura ◽  
A Tsujimoto ◽  
NG Fischer ◽  
AG Baruth ◽  
WW Barkmeier ◽  
...  
Keyword(s):  
Fatigue Strength ◽  
Surface Area ◽  
Shear Bond Strength ◽  
Test Group ◽  
Application Time ◽  
Universal Adhesive ◽  
Shear Fatigue ◽  
Universal Adhesives ◽  
Geometric Surface ◽  
Geometric Surface Area

SUMMARY Objective: The purpose of this study was to evaluate the effect of reduced application times of universal adhesives on enamel bond fatigue and surface morphology of the treated enamel with constant force atomic force microscopy (AFM). Methods: Four universal adhesives—Adhese Universal (AU), Clearfil Universal Bond Quick (CU), G-Premio Bond (GP), and Scotchbond Universal Adhesive (SU)—were evaluated in a laboratory for their ability to adhesively bond resin composite to enamel. Shear bond strengths were initially determined using 15 specimens per test group for each adhesive. Shear fatigue strengths were then determined using 20 specimens per test group for each the adhesives. The fatigue specimens were loaded using a sine wave at a frequency of 20 Hz for 50,000 cycles or until failure occurred. AFM observations, surface Ra roughness measurements, and geometric surface area evaluations of enamel surface treated with the adhesive agents were also conducted. Results: A strong relationship was found between the initial shear bond strength and shear fatigue strength for enamel surface Ra roughness but not for geometric surface area. The initial shear bond strength and shear fatigue strength of CU and GP were not influenced by different application times, unlike those of AU and SU. While the surface area of enamel treated with the adhesive agents was not significantly influenced by different application times and type of adhesive, surface Ra roughness of the enamel in the AU and SU groups significantly increased with increasing application time, unlike CU and GP. Conclusions: The results of this study suggest that universal adhesives, used with reduced application times, have adequate Ra surface roughness to provide sufficient resistance to enamel bond fatigue at application times from <1 second to 20 seconds, while the geometric surface area of adhesive-treated enamel did not show any significant changes at these different application times.

scholarly journals Effect of extended application time of universal adhesives on bond strength of brackets and enamel integrity

2021 ◽  
Vol 10 (13) ◽  
pp. e199101320832
Author(s):  
May Anny Alves Fraga ◽  
Daniela Feu Rosa Kroeff de Souza Laignier ◽  
Carolina Sandra Yamashita Garfias ◽  
Américo Bortolazzo Correr ◽  
Licia Pacheco Teixeira ◽  
...  
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Test Machine ◽  
Application Time ◽  
Universal Adhesive ◽  
Bonding System ◽  
Adhesive Remnant Index ◽  
Extended Application ◽  
Etch And Rinse ◽  
Universal Adhesives

The objective of this study to evaluate the effect of universal adhesives application time to enamel through shear bond strength (SBS), adhesive remnant index (ARI), and morphological enamel integrity. Bovine incisors were divided into four groups according to bonding system protocol (n=20): (1) conventional etch-and-rise adhesive – Transbond XT Primer (P-XT); (2) one-step self-etching adhesive –­ Transbond Self Etching Primer (T-SEP); (3) one universal adhesive – Single Bond Universal, which were rubbed for 20s (SBU-20) or (4) 40s (SBU-40). Transbond XT composite was used to bond the brackets to enamel. SBS was evaluated in a universal test machine at 0.5mm/minute. ARI was determined under x12.5 magnification and enamel damage was evaluated through scanning electron microscope (SEM) after debonding (n=10). SBS data were compared using one-way ANOVA and Tukey’s test. The Kruskal–Wallis test was used to compare the ARI scores (α =0.05). The P-XT and T-SEP groups showed significantly higher bond strength than SBU-20 and SBU-40 (p<0.05). The ARI was similar for all groups (p>0.05). SEM showed enamel damage only in T-SEP and P-XT groups. Conventional ‘etch and rinse’ and ‘self-etch’ adhesives had the highest shear bond strength, but they were associated with more enamel damage compared to universal adhesives. The application of universal adhesives with the time recommended by the manufacturer — ensure satisfactory bond strength and enamel integrity.

Hydrophobic hydrogen anode with a nickel catalyst

1982 ◽  
Vol 47 (12) ◽  
pp. 3230-3235 ◽  
Author(s):  
Olga Marholová ◽  
Karel Smrček
Keyword(s):  
Surface Area ◽  
Nickel Catalyst ◽  
Raney Nickel ◽  
Platinum Catalyst ◽  
Raney Nickel Catalyst ◽  
Electrochemical Parameters ◽  
Geometric Surface ◽  
Geometric Surface Area ◽  
Hydrogen Anode ◽  
In Cells

A hydrophobic porous hydrogen anode was prepared whose electrochemical parameters are comparable with anodes containing a platinum catalyst. For its successful preparation, oxidation of the Raney nickel catalyst with air oxygen or with fluorine from Teflon must be prevented. The electrodes of a geometric surface area up to 450 cm2 were tested in cells and modules filled with 7M-KOH.

Enamel Etching for Universal Adhesives: Examination of Enamel Etching Protocols for Optimization of Bonding Effectiveness

2020 ◽  
Vol 45 (1) ◽  
pp. 80-91
Author(s):  
J Wong ◽  
A Tsujimoto ◽  
NG Fischer ◽  
AG Baruth ◽  
WW Barkmeier ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Surface Area ◽  
Adhesive Bonding ◽  
Sine Wave ◽  
Etching Time ◽  
Universal Adhesive ◽  
Staircase Method ◽  
Ground Enamel ◽  
Fatigue Durability ◽  
Universal Adhesives

SUMMARY Objective: The purpose of this study was to evaluate whether different enamel etching methods with reduced etching times would improve the bonding effectiveness of universal adhesives. Methods and Materials: Three enamel etching methods, phosphoric acid ester monomer (PPM) etching, phosphoric acid (PPA) etching, and polyalkenoic acid (PLA) etching, and three universal adhesives, G-Premio Bond (GP), Prime&Bond elect (PE), and Scotchbond Universal Adhesive (SU), were evaluated. Initial bond strengths and fatigue strengths of universal adhesives to ground enamel and ground enamel etched for less than one, five, 10, and 15 seconds using different etching methods were determined. The bonded fatigue specimens were loaded using a sine wave at a frequency of 20 Hz for 50,000 cycles or until failure occurred with a staircase method. Atomic force micrograph (AFM) observations along with measurements of surface Ra roughness and modified surface area of enamel with different etching protocols were also conducted. Results: The bond fatigue durability of universal adhesives to enamel with PPA etching from less than one to 15 seconds and PLA etching for 15 seconds was significantly higher than that to ground enamel. The bond fatigue durability to enamel with PPM etching was not increased compared with ground enamel. The surface Ra roughness and surface area obtained with AFM of enamel increased after PPA and PLA etching, and those values were significantly higher than those of ground enamel. Furthermore, surface Ra roughness and surface area with PPA etching were significantly higher than those with PLA etching. However, surface Ra roughness and surface area of enamel with PPM etching were similar to those of ground enamel regardless of etching time. Conclusion: PPA etching for less than one to 15 seconds and PLA etching for 15 seconds improve universal adhesive bonding, surface Ra roughness, and surface area of enamel. However, PPM etching is not effective, regardless of etching time, in improving bonds strengths, increasing surface roughness, and increasing surface area.

A Molecular Dynamics Study on the Effects of Nanostructural Clearances on Thermal Resistance at a Liquid-Solid Interface

2009 ◽  
Author(s):  
Masahiko Shibahara ◽  
Kiyoshi Takeuchi
Keyword(s):  
Molecular Dynamics ◽  
Thermal Resistance ◽  
Surface Area ◽  
Solid Wall ◽  
Potential Parameter ◽  
Liquid Region ◽  
Solid Interface ◽  
Dynamics Simulations ◽  
Geometric Surface ◽  
Geometric Surface Area

The effects of the surface structures and the surface structural clearances at the nanometer scale on the thermal resistance at a liquid water-solid interface, as well as the dynamic behaviors of liquid molecules, were investigated directly by the classical molecular dynamics simulations. The thermal resistance between the solid wall and the liquid region was calculated by the temperature discontinuity at a liquid-solid interface and the energy flux that was added or subtracted by the Langevin method per unit area so as to maintain a constant solid wall temperature. When the potential parameter between liquid molecules and nanostructure atoms is equal to that between liquid molecules and solid wall atoms, the geometric surface area change depending on the nanostructures as well as their clearances and the dynamic behaviour change of the fluid molecules at the interface depending on the nanostructural clearances cause the thermal resistance reduction depending on the nanostructures at the liquid-solid interface. When the potential parameter between liquid molecules and nanostructure atoms is different from that between liquid molecules and solid wall atoms, the thermal resistance at the interface is dependent on the potential parameter between liquid molecules and nanostructure atoms rather than the geometric surface area in a molecular scale depending on the nanostructures as well as their clearances.

scholarly journals Effect of Oxygen Inhibition Layer of Universal Adhesives on Enamel Bond Fatigue Durability and Interfacial Characteristics With Different Etching Modes

2017 ◽  
Vol 42 (6) ◽  
pp. 636-645 ◽  
Author(s):  
H Ouchi ◽  
A Tsujimoto ◽  
K Nojiri ◽  
K Hirai ◽  
T Takamizawa ◽  
...  
Keyword(s):  
Sessile Drop ◽  
Contact Angles ◽  
Inhibition Layer ◽  
Universal Adhesive ◽  
Water Contact ◽  
Oxygen Inhibition ◽  
Fatigue Durability ◽  
Shear Fatigue ◽  
Universal Adhesives ◽  
Interfacial Characteristics

SUMMARY Objective: The purpose of this study was to evaluate the effect of the oxygen inhibition layer of universal adhesive on enamel bond fatigue durability and interfacial characteristics with different etching modes. Methods: The three universal adhesives used were Scotchbond Universal Adhesive (3M ESPE, St Paul, MN, USA), Adhese Universal (Ivoclar Vivadent, Schaan, Lichtenstein), and G-Premio Bond (GC, Tokyo, Japan). The initial shear bond strength and shear fatigue strength to enamel was determined in the presence and absence of the oxygen inhibition layer, with and without phosphoric acid pre-etching. The water contact angle was also measured in all groups using the sessile drop method. Results: The enamel bonding specimens with an oxygen inhibition layer showed significantly higher (p&lt;0.05) initial shear bond strengths and shear fatigue strengths than those without, regardless of the adhesive type and etching mode. Moreover, the water contact angles on the specimens with an oxygen inhibition layer were significantly lower (p&lt;0.05) than on those without, regardless of etching mode. Conclusion: The results of this study suggest that the oxygen inhibition layer of universal adhesives significantly increases the enamel bond fatigue durability and greatly changes interfacial characteristics, suggesting that the bond fatigue durability and interfacial characteristics of these adhesives strongly rely on its presence.

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