Structural variations in the surface zone of human tooth enamel observed by scanning electron microscopy

1982 ◽  
Vol 27 (5) ◽  
pp. 383-392 ◽  
Author(s):  
D.K. Whittaker
1976 ◽  
Vol 55 (1) ◽  
pp. 107-110 ◽  
Author(s):  
Abraham Abramovich ◽  
Ricardo L. Macchi ◽  
Lucía M. Ribas

The surface of tooth enamel that had been left in contact with a phosphoric acid solution or a zinc phosphate cement mix was studied by scanning electron microscopy. Both treatments modified enamel surface topography. The modifications were represented by cavities of varying extension and depth.


Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 380 ◽  
Author(s):  
José Luis Calvo-Guirado ◽  
Alvaro Ballester-Montilla ◽  
Piedad N De Aza ◽  
Manuel Fernández-Domínguez ◽  
Sergio Alexandre Gehrke ◽  
...  

The aim of the study was to evaluate the chemical composition of crushed, extracted human teeth and the quantity of biomaterial that can be obtained from this process. A total of 100 human teeth, extracted due to trauma, decay, or periodontal disease, were analyzed. After extraction, all the teeth were classified, measured, and weighed on a microscale. The human teeth were crushed immediately using the Smart Dentin Grinder machine (KometaBio Inc., Cresskill, NJ, USA), a device specially designed for this procedure. The human tooth particles obtained were of 300–1200 microns, obtained by sieving through a special sorting filter, which divided the material into two compartments. The crushed teeth were weighed on a microscale, and scanning electron microscopy (SEM) evaluation was performed. After processing, 0.25 gr of human teeth produced 1.0 cc of biomaterial. Significant differences in tooth weight were found between the first and second upper molars compared with the lower molars. The chemical composition of the particulate was clearly similar to natural bone. Scanning electron microscopy–energy dispersive X-ray (SEM–EDX) analysis of the tooth particles obtained mean results of Ca% 23.42 0.34 and P% 9.51 0.11. Pore size distribution curves expressed the interparticle pore range as one small peak at 0.0053 µm. This result is in accordance with helium gas pycnometer findings; the augmented porosity corresponded to interparticle spaces and only 2.533% corresponded to intraparticle porosity. Autogenous tooth particulate biomaterial made from human extracted teeth may be considered a potential material for bone regeneration due to its chemical composition and the quantity obtained. After grinding the teeth, the resulting material increases in quantity by up to three times its original volume, such that two extracted mandibular lateral incisors teeth will provide a sufficient amount of material to fill four empty mandibular alveoli. The tooth particles present intra and extra pores up to 44.48% after pycnometer evaluation in order to increase the blood supply and support slow resorption of the grafted material, which supports healing and replacement resorption to achieve lamellar bone. After SEM–EDX evaluation, it appears that calcium and phosphates are still present within the collagen components even after the particle cleaning procedures that are conducted before use.


2012 ◽  
Vol 63 (1) ◽  
pp. 11-22 ◽  
Author(s):  
Elżbieta Weryszko-Chmielewska ◽  
Marta Dmitruk

The structure, micromorphology and distribution of trichomes on <i>Dracocephalum moldavicum</i> L. shots were investigated using light and scanning electron microscopy (SEM). There were distinguished 3 types of non-glandular trichomes, 3 types of glandular trichomes and papillae of the osmophore in the epidermis of the corolla. The highest density of non-glandular and glandular trichomes was found on the abaxial surface of the calyx, on bracts and in the upper part of the stem. Structural variations in the head and stalk of long glandular trichomes were demonstrated. The dimensions of particular types of trichomes are given in the present paper. Differences in the structure of the trichomes of this species are presented, compared to literature data. The micromorphology of particular trichome types is documented in numerous photographs showing the rich ornamentation of the cuticle of non-glandular trichomes.


1994 ◽  
Vol 9 (11) ◽  
pp. 2899-2906 ◽  
Author(s):  
B. Grushko ◽  
R. Wittmann ◽  
K. Urban

The Al68Cu11Co21 decagonal phase was studied after annealing at 1000 °C for 24-760 h by transmission and scanning electron microscopy. The strong superstructure odd-n reflections in the [1,-2, 1, 0, 0] electron diffractograms were stable under annealing up to about 40 h. As a possible origin of the increased intensities of the odd-n reflections the formation of vacancy-ordered structures is discussed. The structure was modified by prolonged annealing. In several annealed samples a dense net of extra reflections overlapping the quasiperiodic reflections was observed. This observation was explained as an indication of the formation of metastable states during cooling. Differently ordered decagonal structures exhibited different transformation kinetics during cooling from high temperatures.


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