Surface microscopy study of metallic and ceramic orthodontic brackets

2015 ◽  
Vol 61 (1) ◽  
pp. 20-24
Author(s):  
Ionuţ-Cornel Ionescu ◽  
◽  
Ecaterina Ionescu ◽  
Keyword(s):  
Electron Microscopy ◽  
Structural Design ◽  
Microscopy Study ◽  
The Other ◽  
Surface Microstructure ◽  
Design Elements ◽  
Ceramic Brackets ◽  
Surface Microscopy ◽  
Orthodontic Forces ◽  
Scanning Electron

An in-depth knowledge of the characteristics of the appliances with which we work is very important because it helps us to better understand the indications, contraindications, strengths and their possible shortcomings. The structural design elements play an important role in this context. One of the most commonly used methods for investigating them is represented by scanning electron microscopy. Using a scanning electron microscope we studied the aspects of the surface microstructure of metal and ceramic brackets. The results show that each of them has design features that help with the delivery of orthodontic forces. These characteristics differ drastically in shape from one type of bracket to the other, a square or diamond-shaped network in the case of metal brackets and an appearance of granules dispersed on the surface of the ceramic brackets.

Surface Microstructure of High Temperature Beryllium Implanted with Deuterium

1993 ◽  
Vol 316 ◽  
Author(s):  
K. Touhouche ◽  
B. Terreault
Keyword(s):  
Electron Microscopy ◽  
Temperature Effects ◽  
Low Energy ◽  
The Other ◽  
Surface Microstructure ◽  
Skin Thickness ◽  
Implantation Temperature ◽  
Projected Range ◽  
Increasing Temperature ◽  
Scanning Electron

ABSTRACTWe have investigated implantation temperature effects on the formation of blisters on the surface of Be foils implanted with low energy, 1.5 keV, deuterium ions to doses ranging from 3×1016 to 1.2×1018 ions cm-2, a dose exceeding by far the saturation (≈1.8×1017 ions cm-2: 30% at.). The implantation temperature was varied from 293 K (RT) to 983 K. The samples have been characterized by scanning electron microscopy (SEM). For saturated samples, blisters were present even at high temperatures, viz 983 K, and no blisters were found for samples implanted below 20% at.. However, on samples in which a dramatic grain growth has been observed, blisters were found to decorate the grain boundaries and to interconnect with each other. The average blister diameter increases with increasing temperature, thus indicating the thermodynamical aspect of blister formation and coalescence. On the other hand, for low temperature (473 K), the surface structure that has developed is similar to that at RT, except for an increased most probable blister diameter and blister density, and there was no indication that the blisters ruptured. The blister skin thickness agrees well with the projected range of the implanted ions. Over-saturated samples at RT retained only ≈30% at., corroborating the observations that some blisters formed on already ruptured ones.

Factors influencing adhesive bonding at the bone/implant interface

1992 ◽  
Vol 50 (2) ◽  
pp. 1114-1115
Author(s):  
Julie A. Martini ◽  
Robert H. Doremus
Keyword(s):  
Electron Microscopy ◽  
Adhesive Bonding ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Bone Implant ◽  
Factors Influencing ◽  
Lr White ◽  
Transmission Electron ◽  
New Zealand White Rabbits ◽  
Scanning Electron

Tracy and Doremus have demonstrated chemical bonding between bone and hydroxylapatite with transmission electron microscopy. Now researchers ponder how to improve upon this bond in turn improving the life expectancy and biocompatibility of implantable orthopedic devices.This report focuses on a study of the- chemical influences on the interfacial integrity and strength. Pure hydroxylapatite (HAP), magnesium doped HAP, strontium doped HAP, bioglass and medical grade titanium cylinders were implanted into the tibial cortices of New Zealand white rabbits. After 12 weeks, the implants were retrieved for a scanning electron microscopy study coupled with energy dispersive spectroscopy.Following sacrifice and careful retrieval, the samples were dehydrated through a graduated series starting with 50% ethanol and continuing through 60, 70, 80, 90, 95, and 100% ethanol over a period of two days. The samples were embedded in LR White. Again a graduated series was used with solutions of 50, 75 and 100% LR White diluted in ethanol.

To morphology, ecology and distribution of rare species Sellaphora hustedtii (Krasske) Lange-Bertalot et Werum (Bacillariophyta) from waterbodies of the Gydan Peninsula

2014 ◽  
Vol 48 ◽  
pp. 57-65 ◽  
Author(s):  
S. I. Genkal ◽  
M. I. Jarushina
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
River Basin ◽  
Rare Species ◽  
Western Siberia ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Diagnostic Features ◽  
Scanning Electron Microscopy Study ◽  
Scanning Electron

A rare species Sellaphora hustedtii, which is also new for the flora of Russia, has been found in waterbodies of the Messoyakha River basin (south-western part of the Gydan Peninsula, Western Siberia). The scanning electron microscopy study revealed variability of the main quantitative and qualitative diagnostic features of the species (length and width of the valve, number of striae and areolae in 10 μm, shape of the valve and structure of the raphe). New data on the ecology and distribution of the species allowed us to specify its diagnosis.

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