scholarly journals Nano-Layering Adds Strength to the Adhesive Interface

2020 ◽  
pp. 002203452097913
Author(s):  
K. Yoshihara ◽  
N. Nagaoka ◽  
A. Nakamura ◽  
T. Hara ◽  
Y. Yoshida ◽  
...  

X-ray diffraction (XRD) surface analysis and ultrastructural interfacial characterization using transmission electron microscopy (TEM) confirmed that the functional monomer 10–methacryloyloxydecyl dihydrogen phosphate (10-MDP) self-assembles into nano-layers at adhesive-tooth interfaces. Self-assembled nano-layering is thought to contribute to the durability of bonding to tooth dentin, although this has not been proven yet. In order to disclose this potential bond-durability contribution of nano-layering, we observed the 3-dimensional (3D) spreading of nano-layering by a series of focused-ion-beam (FIB) milled cross sections by scanning electron microscopy (FIB-SEM) and examined the mechanical properties of self-assembled nano-layering using scanning probe microscopy (SPM). A commercial 10-MDP-containing 3-step self-etch adhesive partially demineralized dentin up to submicron depth, forming a submicron hydroxyapatite-rich hybrid layer. TEM chemically and ultrastructurally confirmed the formation of interfacial nano-layering. FIB-SEM 3D reconstructions disclosed a 3D network of self-assembled nano-layering extending from the hybrid layer up to within the adjacent adhesive-resin layer. SPM revealed that nano-layering within the adhesive-resin layer possessed a higher elastic modulus than that of the surrounding adhesive resin, hereby suggesting that nano-layering contributes to the mechanical strength of adhesives like filler particles do. Nano-layering’s 3D expanded structure is expected to strengthen the surrounding resin, as well to better interconnect the adhesive-resin layer to the hybrid layer. In conclusion, this exploratory study demonstrated that nano-layering constitutes a strong phase at the adhesive interface, which may contribute to the clinical longevity of the 10-MDP-based bond to dentin.

2012 ◽  
Vol 91 (4) ◽  
pp. 376-381 ◽  
Author(s):  
Y. Yoshida ◽  
K. Yoshihara ◽  
N. Nagaoka ◽  
S. Hayakawa ◽  
Y. Torii ◽  
...  

According to the ‘Adhesion–Decalcification’ concept, specific functional monomers within dental adhesives can ionically interact with hydroxyapatite (HAp). Such ionic bonding has been demonstrated for 10-methacryloyloxydecyl dihydrogen phosphate (MDP) to manifest in the form of self-assembled ‘nano-layering’. However, it remained to be explored if such nano-layering also occurs on tooth tissue when commercial MDP-containing adhesives (Clearfil SE Bond, Kuraray; Scotchbond Universal, 3M ESPE) were applied following common clinical application protocols. We therefore characterized adhesive-dentin interfaces chemically, using x-ray diffraction (XRD) and energy-dispersive x-ray spectroscopy (EDS), and ultrastructurally, using (scanning) transmission electron microscopy (TEM/STEM). Both adhesives revealed nano-layering at the adhesive interface, not only within the hybrid layer but also, particularly for Clearfil SE Bond (Kuraray), extending into the adhesive layer. Since such self-assembled nano-layering of two 10-MDP molecules, joined by stable MDP-Ca salt formation, must make the adhesive interface more resistant to biodegradation, it may well explain the documented favorable clinical longevity of bonds produced by 10-MDP-based adhesives.


2015 ◽  
Vol 40 (1) ◽  
pp. E28-E39 ◽  
Author(s):  
HY Marghalani ◽  
T Bakhsh ◽  
A Sadr ◽  
J Tagami

SUMMARY This study assessed dentin-resin interface integration in Class I cavities restored with simplified adhesives by using a focused ion-beam milling (FIB) and transmission electron microscope (TEM). Class I cavities (1.5-mm depth with dentin thickness of ∼0.5 mm, 4-mm length, and 2-mm width) were prepared on freshly extracted, sound human molars. Two all-in-one adhesive systems (Scotchbond/Single Bond Universal [SUD] and Xeno-V+ [X5D]) were used and compared with a two-step etch-and-rinse system (Prime&Bond NT [NTD]). The adhesives were applied according to the manufacturers' guidelines. A universal resin composite (Filtek Z350 XT Universal) was used to restore the cavities in one bulk filling and was irradiated at 550 mW/cm2 for 40 seconds by a quartz-tungsten-halogen light (Optilux 501). After exposure to liquid nitrogen coolant, the specimens were milled to nanoscale thickness by FIB to view and then assess the area of dentin-resin interface by TEM. Unlike the unfilled X5D, a noticeably smooth transition zone at the dentin-resin interface was shown for the SUD and NTD adhesives. The SUD demonstrated an uneven hybrid layer with clearly demineralized collagen bundles. Ultramorphologically, dispersed needlelike apatite crystals were detected within the partially demineralized dentin or the hybrid layer of both compositionally different all-in-one simplified adhesives. Conversely, these crystals were entirely absent from the hybrid layer of the etch-and-rinse NTD adhesive. In the X5D group, a bright band was noted beneath the hybrid layer. The methacryloxydecyl dihydrogen phosphate monomer containing ultramild self-etch adhesive (SUD) was still validated in terms of its capability in dentin adhesion.


Author(s):  
Ching Shan Sung ◽  
Hsiu Ting Lee ◽  
Jian Shing Luo

Abstract Transmission electron microscopy (TEM) plays an important role in the structural analysis and characterization of materials for process evaluation and failure analysis in the integrated circuit (IC) industry as device shrinkage continues. It is well known that a high quality TEM sample is one of the keys which enables to facilitate successful TEM analysis. This paper demonstrates a few examples to show the tricks on positioning, protection deposition, sample dicing, and focused ion beam milling of the TEM sample preparation for advanced DRAMs. The micro-structures of the devices and samples architectures were observed by using cross sectional transmission electron microscopy, scanning electron microscopy, and optical microscopy. Following these tricks can help readers to prepare TEM samples with higher quality and efficiency.


Author(s):  
H.J. Ryu ◽  
A.B. Shah ◽  
Y. Wang ◽  
W.-H. Chuang ◽  
T. Tong

Abstract When failure analysis is performed on a circuit composed of FinFETs, the degree of defect isolation, in some cases, requires isolation to the fin level inside the problematic FinFET for complete understanding of root cause. This work shows successful application of electron beam alteration of current flow combined with nanoprobing for precise isolation of a defect down to fin level. To understand the mechanism of the leakage, transmission electron microscopy (TEM) slice was made along the leaky drain contact (perpendicular to fin direction) by focused ion beam thinning and lift-out. TEM image shows contact and fin. Stacking fault was found in the body of the silicon fin highlighted by the technique described in this paper.


Author(s):  
K. Doong ◽  
J.-M. Fu ◽  
Y.-C. Huang

Abstract The specimen preparation technique using focused ion beam (FIB) to generate cross-sectional transmission electron microscopy (XTEM) samples of chemical vapor deposition (CVD) of Tungsten-plug (W-plug) and Tungsten Silicides (WSix) was studied. Using the combination method including two axes tilting[l], gas enhanced focused ion beam milling[2] and sacrificial metal coating on both sides of electron transmission membrane[3], it was possible to prepare a sample with minimal thickness (less than 1000 A) to get high spatial resolution in TEM observation. Based on this novel thinning technique, some applications such as XTEM observation of W-plug with different aspect ratio (I - 6), and the grain structure of CVD W-plug and CVD WSix were done. Also the problems and artifacts of XTEM sample preparation of high Z-factor material such as CVD W-plug and CVD WSix were given and the ways to avoid or minimize them were suggested.


Author(s):  
Chin Kai Liu ◽  
Chi Jen. Chen ◽  
Jeh Yan.Chiou ◽  
David Su

Abstract Focused ion beam (FIB) has become a useful tool in the Integrated Circuit (IC) industry, It is playing an important role in Failure Analysis (FA), circuit repair and Transmission Electron Microscopy (TEM) specimen preparation. In particular, preparation of TEM samples using FIB has become popular within the last ten years [1]; the progress in this field is well documented. Given the usefulness of FIB, “Artifact” however is a very sensitive issue in TEM inspections. The ability to identify those artifacts in TEM analysis is an important as to understanding the significance of pictures In this paper, we will describe how to measure the damages introduced by FIB sample preparation and introduce a better way to prevent such kind of artifacts.


Author(s):  
J. Douglass ◽  
T. D. Myers ◽  
F. Tsai ◽  
R. Ketcheson ◽  
J. Errett

Abstract This paper describes how the authors used a combination of focused ion beam (FIB) microprobing, transmission electron microscopy (TEM), and data and process analysis to determine that localized water residue was causing a 6% yield loss at die sort.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexey A. Polilov ◽  
Anastasia A. Makarova ◽  
Song Pang ◽  
C. Shan Xu ◽  
Harald Hess

AbstractModern morphological and structural studies are coming to a new level by incorporating the latest methods of three-dimensional electron microscopy (3D-EM). One of the key problems for the wide usage of these methods is posed by difficulties with sample preparation, since the methods work poorly with heterogeneous (consisting of tissues different in structure and in chemical composition) samples and require expensive equipment and usually much time. We have developed a simple protocol allows preparing heterogeneous biological samples suitable for 3D-EM in a laboratory that has a standard supply of equipment and reagents for electron microscopy. This protocol, combined with focused ion-beam scanning electron microscopy, makes it possible to study 3D ultrastructure of complex biological samples, e.g., whole insect heads, over their entire volume at the cellular and subcellular levels. The protocol provides new opportunities for many areas of study, including connectomics.


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