Geomorphologic Study on Root Surface of Human Avulsed Teeth by Scanning Electron Microscopy

2020 ◽  
Author(s):  
Qian-Wen Ding ◽  
Mei Lin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Root Surface ◽  
Scanning Electron

Direct in siut identification of cellulose microfibrils associated with Rhizobium leguminosarum biovar trifolii attached to the root epidermis of white clover

1995 ◽  
Vol 41 (2) ◽  
pp. 202-207 ◽  
Author(s):  
Pedro F. Mateos ◽  
David L. Baker ◽  
Saleela Philip-Hollingsworth ◽  
Andrea Squartini ◽  
Angelo D. B. Paruffo ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
White Clover ◽  
Rhizobium Leguminosarum ◽  
Root Surface ◽  
Cellulose Microfibrils ◽  
Enzyme Cytochemistry ◽  
Root Epidermis ◽  
Scanning Electron

Firm attachment of Rhizobium species to the legume root epidermis involves the elaboration of extracellular microfibrils extending from the bacteria and contacting the root surface at multiple sites. We investigated the nature of these extracellular microfibrils associated in situ with Rhizobium leguminosarum bv. trifolii colonized on the root epidermal surface of its legume host, white clover (Trifoiium repens L.). Scanning electron microscopy of seedling roots inoculated with the wild-type strain ANU843 showed that these extracellular microfibrils were associated with the bacteria attached not only to root hairs but also to the non-root-hair epidermis and the external environment under the influence of the developing root. Polystyrene microspheres adsorbed to the root surface did not accumulate similar microfibrils, ruling out their formation by nonspecific deposition of mucigel or self-assembly of rhizoplane fibrils of plant origin. An isozyme of cellulase was purified from Streptomyces sp. strain A20, shown to exhibit high substrate specificity for β-1,4-glucans, and used in enzyme cytochemistry to investigate the nature of these extracellular microfibrils. Combined scanning electron microscopy and computer-assisted image analysis indicated that the extracellular microfibrils associated with attached bacteria were degraded by a brief exposure to the purified cellulase but not by a broad-spectrum protease. These results provide direct in situ evidence of the cellulosic nature of the extracellular microfibrils associated with cells of R. leguminosarum bv. trifolii that have colonized the root environment of its legume host, white clover.Key words: Rhizobium, clover, cellulose microfibrils, enzyme cytochemistry, surface ecology, rhizoplane.

scholarly journals Removal of Composite Restoration from the Root Surface in the Cervical Region Using Er: YAG Laser and Drill—In Vitro Study

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3027 ◽  
Author(s):  
Wojciech Zakrzewski ◽  
Maciej Dobrzynski ◽  
Piotr Kuropka ◽  
Jacek Matys ◽  
Malgorzata Malecka ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Composite Material ◽  
Fluorescence Microscopy ◽  
High Speed ◽  
Root Surface ◽  
Cervical Region ◽  
Tooth Surface ◽  
Yag Laser ◽  
Scanning Electron

Background: Recently, the defects of the tooth surface in the cervical region are often restored using composite filling materials. It should meet the needs of the patients regarding esthetics and material stability. The aim of the study was to analyze the tooth root surface at the cervical region after the removal of the composite filling material by means of the Erbium-doped Yttrium Aluminium Garnet (Er: YAG) laser or drill using the scanning electron microscopy (SEM) and fluorescence microscopy. Materials and Methods: For the purposes of this study, 14 premolar teeth (n = 14) were removed due to orthodontic reasons. The rectangular shape cavities with 3 mm in width and 1.5 mm in height were prepared with a 0.8 mm bur on high-speed contra-angle in the tooth surface just below cemento-enamel junction (CEJ) and filled with the composite material. The composite material was removed with the Er: YAG laser at a power of 3.4 W, energy 170 mJ, frequency 20 Hz, pulse duration 300 μs, tip diameter 0.8 mm, air/fluid cooling 3 mL/s, and time of irradiation: 6 sec, at a distance from teeth of 2 mm (G1 group, n = 7) or a high-speed contra-angle bur (G2 group, n = 7). After the removal of composite material, the surfaces of teeth were examined using the scanning electron microscopy (SEM) and fluorescence microscopy. Results: The Er: YAG irradiation allowed to remove completely the composite material from the tooth cavity. The study confirmed, that the ends of collagen fibers were only partially denatured after the Er: YAG laser application. Conclusion: It has been proved that using the Er: YAG laser is an effective and safe method of composite removal for the dentin surface.

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