scholarly journals Excess Adhesive Flash Upon Bracket Placement

2007 ◽  
Vol 77 (6) ◽  
pp. 1101-1108 ◽  
Author(s):  
David Armstrong ◽  
Gang Shen ◽  
Peter Petocz ◽  
M. Ali Darendeliler

Abstract Objective: To determine if there is any significant difference in excess adhesive flash (EAF) with the use of APC PLUS adhesive coated appliance system and Transbond XT and if other variables such as side of the mouth, time taken to bond the brackets, the age of the orthodontic specialist, or the years of clinical experience affected the amount of EAF. Materials and Methods: Twenty orthodontic specialists bonded 20 preadjusted straight wire brackets (Victory, 3M Unitek) on a typodont with a Class I crowded malocclusion in a split-mouth design, with one-half of the brackets bonded with APC PLUS adhesive system and the other half with Transbond XT. The teeth were sputter coated with gold and an image was taken at 32× magnification in a scanning electron microscope (Philips XL30). The resultant tagged image file (TIF) was opened in AnalySIS Pro 3.1 (Soft Imaging System, Munich, Germany) and the area of EAF was measured. Results: t-Tests demonstrated that: (1) there was no statistically significant difference in EAF between two adhesives when bonding in different quadrants of dentition; and (2) there was no statistically significant difference in EAF between two adhesives overall. Analysis of variance models demonstrated there were no statistically significant differences found regarding the age of the orthodontic specialists, years of clinical experience, and time in performing the bonding. Conclusions: The addition of a coloring agent to assist in the visualization of the excess adhesive does not reduce the amount of excessive adhesive around orthodontic brackets.

2019 ◽  
Vol 30 (6) ◽  
pp. 550-554
Author(s):  
Norberto J Broon ◽  
Claudia Azucena Palafox-Sánchez ◽  
Carlos Estrela ◽  
Diana Celeste Salazar Camarena ◽  
Mario Uribe ◽  
...  

Abstract Electronic apex locators (EAL) have been used to establish the working length (WL) in root canal treatment. In teeth diagnosed with apical periodontitis, resorption of tooth apical structures can lead to difficulties to obtain an appropriate WL. The aim was to compare the capacity of three EAL’s (Root ZX II, Raypex 6 and Endo-Eze Quill) to locate the tip of the K-file between 0 to -0.5 mm from the apical foramen (AF) on teeth diagnosed with asymptomatic apical periodontitis (AAP). Electronic working length was performed on 60 roots with AAP. A K-file #15 was inserted in the root canal until the apical foramen (AF) was located, and followed was re-adjusted to -0.5 mm through observation in EAL display. The K-file was fixed to the tooth with composite and teeth were extracted. The 4 apical millimeters were worn out until the K-file could be seen and were prepared and measured its distance to AF in a scanning electron microscope. Appropriate WL was when the tip of the K-file was located between 0 to -0.5 mm from AF. Results: Root ZX II showed significant difference (p<0.01) with the other two EALs. Root ZX II presented the better performance than Raypex 6 or Endo-Eze Quill in teeth with AAP.


Author(s):  
R. E. Ferrell ◽  
G. G. Paulson

The pore spaces in sandstones are the result of the original depositional fabric and the degree of post-depositional alteration that the rock has experienced. The largest pore volumes are present in coarse-grained, well-sorted materials with high sphericity. The chief mechanisms which alter the shape and size of the pores are precipitation of cementing agents and the dissolution of soluble components. Each process may operate alone or in combination with the other, or there may be several generations of cementation and solution.The scanning electron microscope has ‘been used in this study to reveal the morphology of the pore spaces in a variety of moderate porosity, orthoquartzites.


2015 ◽  
Vol 799-800 ◽  
pp. 125-129
Author(s):  
Mary Donnabelle L. Balela ◽  
April Alexa S. Lagarde ◽  
Stephen Jann A. Tamayo ◽  
Nikko S. Villareal ◽  
Ann Marielle Parreno

Zirconia (ZrO2) nanotubes were synthesized by anodization of zirconium (Zr) foil in NH4Fand (NH4)2SO4 aqueous solution. Different surface preparation methods (electropolishing and etching) were applied on the Zr foil prior to anodizaton. In addition, the anodization time and NH4F concentration were varied. The structure and morphologies of the nanotubes and their crystallinity were confirmed using scanning electron microscope and x-ray diffractometer, respectively. ZrO2 nanotubes with large diameters and thick walls were formed at lower NH4F concentration and longer anodization time. On the other hand, smaller nanotubes with thinner walls were produced when the NH4F concentration was increased. The synthesized nanotubes were predominantly tetragonal ZrO2 with small amounts of monoclinic ZrO2.


Zootaxa ◽  
2007 ◽  
Vol 1544 (1) ◽  
pp. 59-68 ◽  
Author(s):  
NA LI ◽  
BING-ZHONG REN ◽  
MIAO LIU

The types, numbers and distributions of antennal sensilla were studied in both male and female adults of eight Acrididae species in Northeast China using scanning electron microscope (SEM). Totally, there were thirteen types of sensilla found on the antennae. They were identified as trichoid sensilla (I, II), chaetic sensilla (I, II), basiconic sensilla (I, II, III, IV, V), cavity sensilla, coeloconic sensilla, boehm's bristles and paddle-shaped sensilla. The types of antennal sensilla in each Acrididae species ranged from nine to twelve. Each of the species had the same types of antennal sensilla in male and female, and males had more abundant basiconic sensilla, chaetic sensilla, coeloconic sensilla, cavity sensilla than females. Acrida cinerca had the largest total numbers of sensilla, and Euthystria lueifemora had the fewest. Boehm's bristles had a concentration in the base of the pedicel. Paddle-shaped sensilla had a concentration in the base of the scape. There were significant differences in the distribution of the other eleven types of sensilla.


Phytotaxa ◽  
2018 ◽  
Vol 373 (3) ◽  
pp. 169 ◽  
Author(s):  
YUE CAO ◽  
PAN YU ◽  
QINGMIN YOU ◽  
REX L. LOWE ◽  
DAVID M. WILLIAMS ◽  
...  

A new species of Tabularia, Tabularia sinensis, is described from the inland Poyang Lake (Jiangxi Province), the largest lake in China. The description is based on light and scanning electron microscope observations of valve and girdle elements. Given the diversity of forms in the genus, the relationships and status of the genus was investigated in the context of the other known species in the genus and to ascertain if Tabularia, as originally circumscribed, remains monophyletic.


Author(s):  
N. Ollier ◽  
G. Panczer ◽  
B. Champagnon ◽  
P. Jollivet

Abstract Two types of borosilicate leached SON68-type glasses were studied, one doped with uranium and the other with rare-earth element (Nd, Eu). Photoluminescence and cathodoluminescence properties of U doped samples have been correlated to microscopic features of the corroded glass. Nuclear analysis, Electronic Microprobe and Scanning Electron Microscope investigations revealed the heterogeneous composition of the gels with differentiated phases. Enriched U phases (crystallised or not) and phosphorus precipitated phases in rare earth gel have been detected.


Zootaxa ◽  
2009 ◽  
Vol 2093 (1) ◽  
pp. 1-36 ◽  
Author(s):  
ANNE HELENE S. TANDBERG ◽  
WIM VADER

This paper presents redescriptions of amphipods in the genus Metopa (Stenothoidae) in the type-collections of the Zoological Museum of Copenhagen. For Metopa clypeata and M. abyssalis we redescribe the type-specimens, for M. glacialis and M. groenlandica the redescriptions are based on new material and checked against the type-specimens. For all except M. abyssalis a combination of new line drawings and scanning electron microscope (SEM) pictures is provided, for M. abyssalis, line drawings only. A summary of the other species having earlier been designed to Metopa in the Copenhagen collections is given, with a list of their present taxonomic position.


1998 ◽  
Vol 4 (S2) ◽  
pp. 896-897
Author(s):  
W. A. Lambe ◽  
P.M. Brady

The variety of instrumentation available to the researcher today can be overwhelming and confusing. Scanning Electron Microscopes (“SEM's) are no exception, and choosing one can often serve as an exercise in dealing with complexity. First time purchasers are most at risk, being subject to a barrage of information that attempts to sway the purchaser in one direction or the other. As a result, one can sometimes be drawn to the details of the latest “high end” performance parameter, while overlooking the basics. At its worst, the selection process can degrade to one of vague guesswork with little hard data to serve as a compass.By applying a methodical approach to define your individual requirements, carefully designed tests of actual instruments, and discussions with your collaborators, potential and experienced users, one can begin to ensure a successful selection process.


2011 ◽  
Vol 236-238 ◽  
pp. 1949-1953 ◽  
Author(s):  
Ji Yan Liu ◽  
Xue Qing Liu

A biodegradable gradient polymeric membrane based on chitosan (CS) and polyvinyl alcohol (PVA) has been prepared by microwave technique. The composition and morphology variation along the thickness direction in membrane were measured by elemental analysis and scanning electron microscope (SEM). The tensile properties of CS/PVA gradient membrane were tested. Results showed that the content of either polymer shows a gradient variation along the thickness direction. SEM photographs exhibit that morphology also evolves gradually with the varying percentage ratio of two polymers. As a result of such variations in composition and structure, the mechanical properties on both sides exhibit a significant difference. Compared with conventional isotropic membrane, gradient membrane has improved mechanical properties.


2002 ◽  
Vol 26 (4) ◽  
pp. 371-375 ◽  
Author(s):  
Ana Beatriz Alonso Chevitarese ◽  
Orlando Chevitarese ◽  
Ivete Pomarico Ribeiro de Souza ◽  
Roberto Braga de Carvalho Vianna

The aim of this study was to evaluate the influence of prophylaxis on the sealants microleakage in 30 premolars divided into: Group A, Group B and Group C. The teeth were analyzed using the optical microscope (OM) and at scanning electron microscope (SEM). There was a statitical significant difference among the groups regarding the presence of microleakage, but not with the presence of tags.


Sign in / Sign up

Export Citation Format

Share Document