Scanning Electron Microscopy and X-Ray Analyses of Dental Tissues from a Hibernator

Author(s):  
M. L. Zimny ◽  
A. C. Haller

During hibernation the ground squirrel is immobile, body temperature reduced and metabolism depressed. Hibernation has been shown to affect dental tissues varying degrees, although not much work has been done in this area. In limited studies, it has been shown that hibernation results in (1) mobilization of bone minerals; (2) deficient dentinogenesis and degeneration of alveolar bone; (3) presence of calculus and tears in the cementum; and (4) aggrevation of caries and pulpal and apical tooth abscesses. The purpose of this investigation was to study the effects of hibernation on dental tissues employing scanning electron microscopy (SEM) and related x-ray analyses.

2013 ◽  
Vol 19 (3) ◽  
pp. 587-595 ◽  
Author(s):  
Elizabeta S. Gjorgievska ◽  
John W. Nicholson ◽  
Ian J. Slipper ◽  
Marija M. Stevanovic

AbstractRemineralization of hard dental tissues is thought to be a tool that could close the gap between prevention and surgical procedures in clinical dentistry. The purpose of this study was to examine the remineralizing potential of different toothpaste formulations: toothpastes containing bioactive glass, hydroxyapatite, or strontium acetate with fluoride, when applied to demineralized enamel. Results obtained by scanning electron microscopy (SEM) and SEM/energy dispersive X-ray analyses proved that the hydroxyapatite and bioactive glass-containing toothpastes were highly efficient in promoting enamel remineralization by formation of deposits and a protective layer on the surface of the demineralized enamel, whereas the toothpaste containing 8% strontium acetate and 1040 ppm fluoride as NaF had little, if any, remineralization potential. In conclusion, the treatment of demineralized teeth with toothpastes containing hydroxyapatite or bioactive glass resulted in repair of the damaged tissue.


Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.


Author(s):  
Yun Lu ◽  
David C. Joy

High resolution scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDXA) were performed to investigate microparticles in blended cements and their hydration products containing sodium-rich chemical wastes. The physical appearance of powder particles and the morphological development at different hydration stages were characterized by using high resolution SEM Hitachi S-900 and by SEM S-800 with a EDX spectrometer. Microparticles were dispersed on the sample holder and glued by 1% palomino solution. Hydrated bulk samples were dehydrated by acetone and mounted on the holder by silver paste. Both fracture surfaces and flat cutting sections of hydrating samples were prepared and examined. Some specimens were coated with an 3 nm thick Au-Pd or Cr layer to provide good conducting surfaces. For high resolution SEM S-900 observations the accelerating voltage of electrons was 1-2 KeV to protect the electron charging. Microchemical analyses were carried out by S800/EDS equipped with a LINK detector of take-off angle =40°.


Author(s):  
M.G. Baldini ◽  
S. Morinaga ◽  
D. Minasian ◽  
R. Feder ◽  
D. Sayre ◽  
...  

Contact X-ray imaging is presently developing as an important imaging technique in cell biology. Our recent studies on human platelets have demonstrated that the cytoskeleton of these cells contains photondense structures which can preferentially be imaged by soft X-ray imaging. Our present research has dealt with platelet activation, i.e., the complex phenomena which precede platelet appregation and are associated with profound changes in platelet cytoskeleton. Human platelets suspended in plasma were used. Whole cell mounts were fixed and dehydrated, then exposed to a stationary source of soft X-rays as previously described. Developed replicas and respective grids were studied by scanning electron microscopy (SEM).


Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.


2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar

Sebuah penelitian tentang sistem dispersi padat dari asiklovir dengan poloxamer 188 telah dilakukan formulasi dengan pencampuran secara fisika dengan rasio 1 : 1, 1 : 3, 1 : 5 dan dispersi padat 1 : 1, 1 : 3, 1 : 5 dan penggilingan 1:1 sebagai pembanding. Dispersi padat dibuat menggunakan metode pencairan (fusi), yang digabung dengan poloxamer 188 pada hotplate kemudian asiklovir dimasukkan ke dalam hasil poloxamer 188 lalu di kocok hingga membentuk masa homogen. Semua formula yang terbentuk termasuk asiklovir poloxamer 188 murni dianalisis karakterisasinya dengan Differential Thermal Analysis (DTA), X-ray Diffraction, Scanning Electron Microscopy (SEM), dan Fourier Transform Infrared (FTIR), kemudian pengambilan dilakukan  (penentuan kadar) mengunakan spektrofotometer UV pada panjang gelombang 257,08 nm dan uji laju disolusi dengan aquadest bebas CO2 menggunakan metode dayung. Hasil pengambilan  (penentuan kadar) menunjukkan bahwa semua formula memenuhi persyaratan farmakope Amerika edisi 30 dan farmakope Indonesia edisi 4 yaitu 95-110%. Sedangkan hasil uji laju disolusi untuk campuran fisik 1: 1, dan dispersi padat 1: 1, dan penggilingan 1: 1 menunjukkan peningkatan yang nyata dibandingkan asiklovir murni. Hal ini juga dapat dilihat dari hasil perhitungan statistik  menggunakan analisis varian satu arah  SPSS 17.


2017 ◽  
Vol 68 (5) ◽  
pp. 928-932
Author(s):  
Agripina Zaharia ◽  
Viorica Ghisman Plescan ◽  
Elena Maria Anghel ◽  
Viorica Musat

The purpose of this work is to induce biomimetic remineralization of acid etched coronal human dentine in artificial saliva (AS) under agarose (A) hydrogel or chitosan (CS)-A hydrogel action. The investigations focused on the morphology, chemical composition and crystalline structure of the new remineralized layers grown onto the etched dentinal surface (R) using scanning electron microscopy coupled with energy dispersive X-ray spectrometry and micro-Raman spectroscopy. Experimental results showed that remineralized layers grown in the presence of A or CS-A hydrogels consist in B-type Ca-deficient hydroxyapatite (HAP). After 7 days treatment into artificial saliva under agarose hydrogel, nanorod-like extrafibrilar HAP crystals randomly self-assembled in a discontinuous layer were formed, while in presence of chitosan-agarose hydrogel a continuous compact CS-HAP composite layer was obtained. The new biomimetic layer (A-CS4) formed after 4 days on dentine surface under A-CS hydrogel has higher crystallinity. Longer exposed (7 days) dentine in the presence of agarose hydrogel shows a higher mineral-to-collagen ratio (A7). Since dentine mineralization increases, the collagen quality factor decreases in succession A-CS4]R]A7. Results show a benefic effect of chitosan on remineralization of etched dentine.


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