scholarly journals Bonding ability of adhesive resins to caries-affected and caries-infected dentin

2004 ◽  
Vol 12 (3) ◽  
pp. 171-176 ◽  
Author(s):  
Masahiro Yoshiyama ◽  
Junichi Doi ◽  
Yoshihiro Nishitani ◽  
Toshiyuku Itota ◽  
Franklin R. Tay ◽  
...  

Hybridized dentin permits dental treatments that were previously impossible with conventional techniques, opening new frontiers in modern adhesive dentistry. We have investigated the adhesive property of current bonding systems to caries-infected dentin by a microtensile bond strength test (µTBS) and transmission electron microscopy (TEM), and suggested that bonding resin could infiltrate into caries-infected dentin partially to embed carious bacteria within hybrid layers. We have named this concept of caries control as modified sealed restoration (MSR). On the other hand, Kuraray Medical Inc. (Tokyo, Japan) has developed an antibacterial adhesive system (ABF, now marketed in USA as Protect Bond). So as to evaluate the effectiveness of ABF on root caries control, we have examine the microtensile bond strengths (µTBS) of ABF to normal versus carious root dentin and the interfacial morphology by a scanning electron microscopy (SEM). ABF could form the hybrid-like structures by infiltrating into the surfaces of the root carious dentin, and the mean value of µTBS of ABF to root carious dentin was 23.0 MPa. These results suggested that MSR combined with ABF might be an advantageous minimal invasive therapy for root caries.

Author(s):  
I. G. Romanenko ◽  
N. I. Chepurova ◽  
A. S. Zueva

Adhesive dentistry is the foundation on the basis of which there have been global changes in the concept of adhesion of composite materials in therapeutic dentistry, protocols for fixing ceramic restorations in orthopedic dentistry. But a number of unsolved problems remained – the adhesion of composite materials to sclerosed dentin and tooth root cement, the sensitivity of the components of the adhesive systems to the wet environment of the oral cavity and spatial stability in the presence of dentinal fluid moving centrifugally in the dentinal tubules, the lack of restoration of periodontal attachment to the defect that occurs during tooth root caries. The review analyzes the results of studies on the use of self-etching adhesive systems in the treatment of root caries. The physician's ability to choose an adhesive system in a particular clinical case demonstrates his fundamental knowledge and minimizes the percentage of errors that he can make during the treatment phase. 


2013 ◽  
Vol 9 (5) ◽  
pp. 50-56
Author(s):  
В. Алпатова ◽  
V. Alpatova ◽  
Л. Кисельникова ◽  
L. Kiselnikova ◽  
П, Панфилов ◽  
...  

The structure features of primary tooth hard tissues were studied at teenage, person of young age and patient’s age from 20 to 50 years by means of methods using in physical material science (metallography, x-ray analysis and transmission electron microscopy). The  findings, which agree with the results of dental volume tomography, allow determining the features of microstructure of crown and root dentin of patients at different age. On the basis of the this data the criteria of degree of formation and maturity of the root was objectified that allow variably change the endodontic treatment.


2017 ◽  
Vol 15 (2) ◽  
pp. 158 ◽  
Author(s):  
Bruna Cristina do Nascimento Rechia ◽  
Ruth Peggy Bravo ◽  
Naylin Danyele de Oliveira ◽  
Flares Baratto Filho ◽  
Carla Castiglia Gonzaga ◽  
...  

Aim: To assess the influence of different fiberglass post surface treatments on the bond strength (BS) to root dentin. Methods: Thirty bovine root canals were endodontically treated and filled with gutta-percha and AH Plus sealer. At 24 h after the endodontic filling, the post spaces were prepared with Gates-Glidden drills and #3 drills of the DC White Post system, maintaining a 4 mm apical seal. The roots were randomly divided into three groups: S (fiberglass posts treated with silane), SA (fiberglass posts treated with silane and a hydrophobic adhesive system) and SHA (fiberglass posts treated with silane, followed by drying with hot air). The posts were cemented with a selfadhesive cement (RelyX U200). The specimens were stored in distilled water at 37 °C for 24 h and subjected to the push-out test (0.5 mm/min). Data were statistically analyzed using one-way ANOVA and Tukey's test (α=0.05) Results: SA and SHA groups showed the highest BS mean values (11.29 and 10.85 MPa, respectively), while the S group presented the lowest BS mean value (7.21 MPa). S group was significantly different from SA and SAH groups. Conclusions: The surface treatment of fiberglass posts influenced BS values.


Author(s):  
G. G. Shaw

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.


Author(s):  
R. W. Anderson ◽  
D. L. Senecal

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.


Author(s):  
S. Fujishiro

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.


Author(s):  
P.J. Dailey

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.


Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).


Author(s):  
B. S. Beltz

The cells which are described in this study surround the salivary nerve of the terrestrial mollusc, Limax maximus. The salivary system of Limax consists of bilateral glands, ducts, and nerves. The salivary nerves originate at the buccal ganglia, which are situated on the posterior face of the buccal mass, and run along the salivary duct to the gland. The salivary nerve branches several times near the gland, and eventually sends processes into the gland.The pore cells begin to appear at the first large branch point of the salivary nerve, near the gland (Figure 1). They follow the nerve distally and eventually accompany the nerve branches into the gland tissue. The cells are 20-50 microns in diameter and contain very small nuclei (1-5 microns) (Figure 2).The cytoplasm of the pore cells is segregated into a storage area of glycogen and an organelle region located in a band around the cell periphery (Figure 3).


Author(s):  
R.R. Russell

Transmission electron microscopy of metallic/intermetallic composite materials is most challenging since the microscopist typically has great difficulty preparing specimens with uniform electron thin areas in adjacent phases. The application of ion milling for thinning foils from such materials has been quite effective. Although composite specimens prepared by ion milling have yielded much microstructural information, this technique has some inherent drawbacks such as the possible generation of ion damage near sample surfaces.


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