The effects of oxalate-containing products on the exposed dentine surface: an SEM investigation

2001 ◽  
Vol 28 (11) ◽  
pp. 1037-1044 ◽  
Author(s):  
D. G. Gillam ◽  
N. J. Mordan ◽  
A. D. Sinodinou ◽  
J. Y. Tang ◽  
J. C. Knowles ◽  
...  
2008 ◽  
Vol 28 (11) ◽  
pp. 1037-1044
Author(s):  
D. G. Gillam ◽  
N. J. Mordan ◽  
A. D. Sinodinou ◽  
J. Y. Tang ◽  
J. C. Knowles ◽  
...  

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.


Phytotaxa ◽  
2015 ◽  
Vol 207 (3) ◽  
pp. 273
Author(s):  
FRITHJOF A.S. STERRENBURG ◽  
STUART R. STIDOLPH ◽  
EUGENIA A. SAR ◽  
Ines Sunesen

In continuation of an earlier paper on Pleurosigma species with an (almost) non-sigmoid valve and raphe sternum, a comparative study was made in LM and SEM of Pleurosigma subrectum and P. acus. For P. subrectum, slides and a subsample of the type material were examined. For P. acus no unmounted material permitting SEM investigation is extant; a sample containing specimens fully matching the type in LM was therefore used as epitype material for SEM. The original data on striation of P. acus are emended. No morphological differences indicating separate specific status of these two taxa were observed and P. acus is therefore here designated a heterotypic synonym of P. subrectum. From the data now available, this is a very widely distributed species. The study demonstrates the indispensable role of collections for investigations on the diversity and distribution of diatom species.


2013 ◽  
Author(s):  
Nadezda O. Bessudnova ◽  
Alexandr Skaptsov ◽  
Sergey B. Venig ◽  
Andrey N. Gribov ◽  
Vsevolod S. Atkin

Biologia ◽  
2011 ◽  
Vol 66 (6) ◽  
Author(s):  
Serkan Köstekci ◽  
Turan Arabaci

AbstractIn this study, the cypsela morphology of 21 (14 species) of the 28 (17 species) Turkish Cirsium Mill. sect. Cirsium (Asteraceae) taxa was examined by stereomicroscope and scanning electron microscope (SEM). The shapes of cypselas are oblong, obovate, narrowly obovate and oblanceolate. The taxa were divided into 7 main types according to the results of SEM investigation on cypsela surface characteristics as: scalariform, ribbed, scrobiculate-ribbed, scrobiculate, scrobiculate-reticulate, reticulate and bireticulate. Taxonomic significance of cypsela morphology is discussed. It is shown that cypsela features can be used as distinguishing characteristics in some Cirsium sect. Cirsium species.


2020 ◽  
Vol 73 (6) ◽  
pp. 1145-1148
Author(s):  
Maryna A. Goray ◽  
Nataliia G. Gadzhula ◽  
Olena V. Muntian ◽  
Olena L. Cherepakha ◽  
Larysa F. Kurdysh

The aim: To compare the quality of root canal system preparation with the use of manual K-files, machine Protaper Universal and Silk files by in vitro studies. Materials and methods: Root canals preparation in 45 extracted premolars was performed in three groups with 15 teeth in each with K-files, Protaper Universal and Silk files. Transverse sections of the dental root were prepared. Histologically were assessed: amount of sawdust and predentin remaining, the purity degree of root canal walls. Results: When calculating the sawdust amount at the distance of 3 mm from an apex, a high degree of contamination was observed in the manual K-file group: 53.3% versus 33.3% in the Protaper Universal group and against 20.0% in the Silk file group. The amount of predentin after root canal treatment with manual files reached 25-30%. At the distance of 5 mm from the apex the root canals with high and medium purity degree were detected in 86.7% with Silk files and 80.0% with Protaper Universal files used. All predentin was removed when working with Protaper Universal and Silk files. Conclusions: In the histological sections of the root canals treated with K-files, the larger amount of dentine particles and predentin has been revealed than when using machine tools. The largest amount of predentin and dentine were removed with Protaper Universal files. Silk endodontic system is better for treatment of the root canals dentine surface in the apical area compared to Protaper Universal and K-files.


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