scholarly journals Effect of moisture on dental enamel in the interaction of two orthodontic bonding systems

2013 ◽  
Vol 18 (4) ◽  
pp. 89-97 ◽  
Author(s):  
André Pinheiro de Magalhães Bertoz ◽  
Derly Tescaro Narcizo de Oliveira ◽  
Carla Maria Melleiro Gimenez ◽  
André Luiz Fraga Briso ◽  
Francisco Antonio Bertoz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dental Enamel ◽  
Adhesive Systems ◽  
Bonding System ◽  
Group I ◽  
Substrate Moisture ◽  
Bonding Systems ◽  
Moisture Conditions ◽  
Scanning Electron

OBJECTIVE: The purpose of this study was to assess by means of scanning electron microscopy (SEM) the remaining adhesive interface after debonding orthodontic attachments bonded to bovine teeth with the use of hydrophilic and hydrophobic primers under different dental substrate moisture conditions. MATERIAL AND METHODS: Twenty mandibular incisors were divided into four groups (n=5). In Group I, bracket bonding was performed with Transbond MIP hydrophilic primer and Transbond XT adhesive paste applied to moist substrate, and in Group II a bonding system comprising Transbond XT hydrophobic primer and adhesive paste was applied to moist substrate. Brackets were bonded to the specimens in Groups III and IV using the same adhesive systems, but on dry dental enamel. The images were qualitatively assessed by SEM. RESULTS: The absence of moisture in etched enamel enabled better interaction between bonding materials and the adamantine structure. The hydrophobic primer achieved the worst micromechanical interlocking results when applied to a moist dental structure, whereas the hydrophilic system proved versatile, yielding acceptable results in moist conditions and excellent interaction in the absence of contamination. CONCLUSION: The authors assert that the best condition for the application of primers to dental enamel occurs in the absence of moisture.

Comparative Study of Acid Etching on Dental Enamel

2018 ◽  
Vol 69 (10) ◽  
pp. 2913-2915
Author(s):  
Daniela Jumanca ◽  
Anamaria Matichescu ◽  
Atena Galuscan ◽  
Laura Cristina Rusu ◽  
Cornelia Muntean
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Experimental Study ◽  
Orthophosphoric Acid ◽  
Dental Enamel ◽  
Acid Etching ◽  
Sealing Material ◽  
Mechanical Bond ◽  
Materials Used ◽  
Scanning Electron

This experimental study aims to analyse the effectiveness of various materials used in demineralisation of dental enamel. This work aims to create a mechanical bond by filling the pegs with sealing material. In order to achieve this goal, five teeth were compared using different concentrations of orthophosphoric acid and exposure times. In this regard, five different tests were performed and the results were analysed using the SEM technique (scanning electron microscopy). These comparative analyses revealed that etching using 35% orthophosphoric acid for one minute and etching using Icon Etch for two minutes were the most effective.

An Experimental Model for the Study of Venous Thrombosis in Vivo

1975 ◽  
Author(s):  
T. K. Day ◽  
K. G. A. Glark ◽  
V. V. Kakkar
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Experimental Model ◽  
Femoral Vein ◽  
Total Charge ◽  
Small Current ◽  
Group I ◽  
Scanning Electron

The lack of a satisfactory in vivo experimental model has probably been responsible for the delay in the clinical application of recent advances in in vitro research on thrombosis. This paper describes a model in which thrombosis is initiated by an electrical stimulus. The thrombus produced has the histological and biochemical features of human deep vein thrombosis (DVT).The minimum stimulus necessary to induce thrombosis was first determined by passing a fixed current for timed intervals along the femoral veins of 10 rabbits. Thrombi were seen 24 hours later if the total charge passed exceeded a threshold value of 25 millicoulombes. With this small current, no endothelial changes were visible immediately after the passage of the charge on light or scanning electron microscopy. At 24 hours a mural thrombus formed, which had fully cross-linked fibrin and histological features resembling human DVT.In the second series of experiments, the sequence of changes occurring in thrombus production was investigated in 3 groups of 18 rabbits each. After passage of the critical charge along the femoral vein in each animal, veins were removed at fixed intervals, the contralateral vein acting as a control. The veins were examined by scanning electron-microscopy (Group I), transmission electron-microscopy (Group II) and light microscopy (Group III), The earliest changes were detectable at 5 minutes and consisted of the laying down of an organised structure of criss-crossing fibrin strands with small platelet clumps at fibrin intersections. Later the fibrin structure spread towards the lumen; platelet clumps fused and a coralline thrombus was formed by 24 hours. The significance of these changes will be discussed.

scholarly journals Therapeutic Effect of Curcumin on Scanning Electron Microscopy of Rat Adrenal Gland in Experimental Fluorosis

2021 ◽  
pp. 330-344
Author(s):  
A. Shashi ◽  
Manisha Tikka
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Adrenal Gland ◽  
Therapeutic Potential ◽  
Normal Structure ◽  
Post Treatment ◽  
Albino Rats ◽  
Adrenal Tissue ◽  
Group I ◽  
Scanning Electron

Aim: The present study was designed to investigate the therapeutic role of Curcumin against fluoride induced toxicity on adrenal gland of rats by using scanning electron microscopy (SEM). Methodology: Wistar albino rats were divided randomly into six groups The group I was administered with 1 ml of deionized water/kg b.w./day orally for 40 days. The Groups II and III were given 300 and 600 mg of NaF/kg b.w./day for the same period, respectively. The group IV was given 200 mg/kg b.w. of Curcumin for 20 days. The Groups V and VI were treated with 300 and 600 mg of NaF/kg b.w./day for 40 days respectively were post-treated with 200 mg of Curcumin for next 20 days. The animals were excised and adrenal tissue was taken out and processed for SEM. Results: The results revealed that rats exposed to 300 mg/kg b.w./day of NaF showed rough edges, numerous microvilli and damaged surface with crystal depositions. Also, numerous granules were distributed all over the surface. The rats treated with 600 mg/kg b.w./day of NaF showed decellularized adrenal tissue along with network of collagen fibres. Moreover, adrenal gland surface displayed abrasions and distorted cuboidal cells. The filopodia were prominent on the surface and wall of cavity possessed rough outline. After post-treatment with Curcumin, fluoridated adrenal gland of rats showed normal structure, reappearance of cuboidal cells on the surface as well as less number of microvilli and filopodia. Conclusion: The post-treatment with Curcumin possess therapeutic potential against NaF induced toxicity in adrenal gland of rats.

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