A Scanning Electron Microscopic Study of Early Enamel Caries Formed in Vivo beneath Orthodontic Bands

1996 ◽  
Vol 23 (1) ◽  
pp. 43-47 ◽  
Author(s):  
C. A. Melrose ◽  
J. Appleton ◽  
B. B. J. Lovius
Keyword(s):  
Enamel Surface ◽  
White Spot ◽  
Surface Zone ◽  
White Spot Lesions ◽  
Tissue Destruction ◽  
Electron Microscopic ◽  
Metal Wires ◽  
Caries Lesions ◽  
Scanning Electron

A clinical trial was conducted to investigate the development of caries lesions associated with fixed orthodontic appliance therapy. To introduce a cariogenic challenge on Sound buccal enamel surface in vivo, specially designed orthodontic bands were attached to premolars scheduled for extraction for orthodontic reasons. The bands were modified by having two metal wires (0·8 mm in diameter) welded to the inner surface of the band to produce a space for plaque accumulation similar to that occurring under loose orthodontic bands. The bands were cemented with a zinc phosphate cement (Tenet®) an left in situ for 4 weeks. Of 22 premolar teeth banded in eight different patients, eight showed definite white spot lesions, eight showed definite faint enamel opacities, and six showed no discernable lesions. Examination of definite white spot lesions by scanning electron microscopy revealed characteristic patterns of initial tissue destruction. Focal holes and an accentuation of the perikymata were observed affecting the enamel surface zone, an area previously considered to remain relatively intact during the development of a caries lesion. The superficial nature of the caries lesions observed and the rapidly of their formation is significant in the clinical management of decalcified areas forming beneath orthodontics bands.

scholarly journals Scanning electron microscopic examination of enamel surface after fixed orthodontic treatment: In-vivo study

2012 ◽  
Vol 140 (1-2) ◽  
pp. 22-28 ◽  
Author(s):  
Tijana Sessa ◽  
Jelena Civovic ◽  
Tina Pajevic ◽  
Jovana Juloski ◽  
Milos Beloica ◽  
...  
Keyword(s):  
Electron Microscopic Examination ◽  
Surface Damage ◽  
Multivariate Regression Analysis ◽  
Enamel Surface ◽  
Orthodontic Appliances ◽  
Electron Microscopic ◽  
Fixed Orthodontic Appliances ◽  
Tooth Surfaces ◽  
Scanning Electron

Introduction. Therapy with fixed orthodontic appliances starts with bracket bonding and ends with debonding of brackets, leaving enamel surface varied. Objective. The aim of this pilot study was to examine enamel surface before and after debonding of orthodontic brackets by the use of scanning electron microscopy (SEM). Methods. Epoxy replicas of four patients? premolars indicated for therapy with fixed orthodontic appliances were made and brackets were bonded to their teeth with a different adhesives (Enlight, No-mix, Fuji Ortho LC and Heliosit Orthodontic) (n=4). Two months later, brackets on premolars were debonded and amounts of adhesive left on the tooth surfaces and the bracket bases were evaluated with the adhesive remnant index (ARI). After resin removal, epoxy replicas were made and the surface of premolars was evaluated with the enamel surface index (ESI). All replicas of premolars (n=32) were prepared for SEM examination and compared under different magnifications. Tooth damage was estimated based on correlation between ARItooth and ESI. Results. Pearson?s ?2 test showed no significant differences between ARItooth and ARIbracket of four materials used. Nonparametric correlations showed significant differences between ARItooth and ARIbracket, ESI and ARItooth, and between ESI and ARIbracket. Increasing of ARItooth is followed with the descent of ARIbracket and the ascent of ESI. Multivariate regression analysis showed a significant correlation between ESI and ARItooth. Conclusion. Most bond failures took place at enamel-adhesive interface. ARItooth was a predictor to enamel surface damage. The type of material did not affect enamel surface damage.

Cell interactions of Listeria monocytogenes L forms and peritoneal exudative cells in rats

1993 ◽  
Vol 39 (11) ◽  
pp. 1014-1021 ◽  
Author(s):  
L. Mihailova ◽  
N. Markova ◽  
T. Radoucheva ◽  
D. Veljanov ◽  
S. Radoevska
Keyword(s):  
Listeria Monocytogenes ◽  
Peritoneal Cavity ◽  
Electron Microscopic Examination ◽  
Lavage Fluid ◽  
Host Cells ◽  
Electron Microscopic ◽  
Cellular Defense ◽  
Scanning Electron Microscopic ◽  
Scanning Electron

Listeria monocytogenes 4b and its forms without cell walls (L forms of a protoplastic type) were used to study in vivo interactions with host cells. Samples of peritoneal lavage fluid were obtained from rats intraperitoneally inoculated at intervals between 1 and 15 days after challenge, for scanning electron microscopic, bacteriological, biochemical, and cytometrical investigations. Scanning electron microscopic examination revealed continuous adhesion of L forms on the macrophage surface up to 15 days after inoculation. The persistence of the L forms within the peritoneal cavity was also shown bacteriologically at all sample times, while the parental bacterial forms were isolated from the peritoneal cavity up to 7 days after challenge. The total count of peritoneal exudative cells determined by automated flow peroxidase cytometry peaked on the 15th day in animals infected with parental forms, while in animals infected with L forms the peak was lower and the macrophage population was predominant. The glycolytic and acid phosphatase activity of peritoneal exudative cells was two times higher in rats infected with L forms as compared with rats infected with the L. monocytogenes parental forms on the 3rd day after challenge. An understanding of the nature of the interactions between L forms of L. monocytogenes and peritoneal exudative cells found in vivo could be used to establish the influence of L forms on host cellular defense mechanisms.Key words: Listeria monocytogenes, L forms, peritoneal exudative cells, electron microscopy.

scholarly journals Comparative Study of Corneal Endothelial Cell Damage after Femtosecond Laser Assisted Deep Stromal Dissection

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Ting Liu ◽  
Jingjing Zhang ◽  
Dapeng Sun ◽  
Wenjie Sui ◽  
Yangyang Zhang ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Cell Damage ◽  
Endothelial Damage ◽  
Lamellar Keratoplasty ◽  
Control Group ◽  
Electron Microscopic ◽  
Anterior Lamellar Keratoplasty ◽  
Bed Thickness ◽  
Scanning Electron

Purpose.To find a relatively safe designed stromal bed thickness to avoid endothelial damage for lamellar keratoplasty with an Allegretto Wavelight FS200 femtosecond laser.Methods.Twelve rabbits were randomly divided into 50 μm and 150 μm groups according to the anticipated residue stromal bed thickness preparation with a femtosecond laser. Six rabbits without laser cutting were used as a control group. Central endothelial images were analyzed with in vivo confocal microscopy and scanning electron microscopy. The apoptosis of endothelium was evaluated with Hoechst 33342 staining and a TUNEL assay.Results.The endothelium of the 50 μm group had extensive injuries upon in vivo confocal and scanning electron microscopic observation, and minor injuries were observed in the 150 μm group. Moreover, more apoptotic cells were observed in the 50 μm group.Conclusions.When using a FS200 femtosecond laser assisted anterior lamellar keratoplasty, there was minor endothelium damage with a 150 μm stromal bed, and a more than 150 μm thickness stromal bed design may prevent the damage of corneal endothelium.

Microvascular Anastomosis: A Scanning Electron Microscopic Study

1980 ◽  
Vol 88 (3) ◽  
pp. 252-256 ◽  
Author(s):  
Douglas E. Mattox
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Microvascular Anastomosis ◽  
Electron Microscopic ◽  
Technical Errors ◽  
Scanning Electron Microscopic Study ◽  
Scanning Electron Microscopic ◽  
Scanning Electron

The single most important factor determining the patency of a microvascular anastomosis is the surgical precision with which it is performed. Inaccurately placed sutures, damage of the intima, exposed media and adventitia, and stenosis of the lumen at the site anastomosis all contribute to decreased patency rates. The first 50 consecutive microvascular anastomoses performed by a single microvascular surgeon were analyzed in vivo and with the scanning electron microscope. The frequency and significance of various technical errors are discussed. Scanning electron microscopy is recommended as a convenient and quick technique for assessing the evenness and accuracy of intimal apposition in microvascular anastomosis.

scholarly journals Pop-Cola Acids and Tooth Erosion: AnIn Vitro,In Vivo, Electron-Microscopic, and Clinical Report

2010 ◽  
Vol 2010 ◽  
pp. 1-12 ◽  
Author(s):  
Amirfirooz Borjian ◽  
Claudia C. F. Ferrari ◽  
Antoni Anouf ◽  
Louis Z. G. Touyz
Keyword(s):  
Clinical Case ◽  
Dental Erosion ◽  
Clinical Report ◽  
Tooth Erosion ◽  
Electron Microscopic ◽  
Ph Buffering ◽  
Wisdom Teeth ◽  
Scanning Electron

Introduction. Manufactured Colas are consumed universally as soft drinks. Evidence about the acid contents of Cola-beverages and its effects on teeth is rare.Aim. To assess (i) cola acidity and buffering capacityin vitro, (ii) tooth erosion after swishing with colasin vivo(iii) scanning electronmicroscopic effectson teeth of colas, and tooth-brush abrasion, and (iv) report aclinical caseof erosion from cola consumption.Materials and Methods. (i) We measured six commercially available pop “Cola beverages”, pH, and buffering capacities using a pH-Mettler Automatic Titrator, with weak solution of Sodium Hydroxide (ii) two cohorts, onewith teeth, the secondwithout teethrinsed with aliquots of Cola for 60 seconds. Swished cola samples tested for calcium and phosphorus contents using standardized chemical analytical methods (iii) enamel, dentine, and the enamel-cemental junction from unerupted extracted wisdom teeth were examined with a scanning electron microscope after exposure to colas, and tested for tooth-brush abrasion; (iv) a clinical case of pop cola erosion presentation, are all described.Results. Comparisons among pop colas testedin vitroreveal high acidity with very low pH. Buffering capacities in millilitres of 0.5 M NaOH needed to increase one pH unit, to pH 5.5 and pH 7 are reported. Rinsingin vivowith pop cola causes leeching of calcium from teeth; SEM shows dental erosion, and pop-cola consumption induces advanced dental erosion and facilitates abrasion.Conclusions. (i) Pop-Cola acid activity is below the critical pH 5.5 for tooth dissolution, with high buffering capacities countering neutralization effects of saliva; (ii) calcium is leeched out of teeth after rinsing with pop colas; (iii) SEM evidence explains why chronic exposure to acid pop colas causes dental frangibles; (iv) aclinical caseof pop-cola erosion confirms this.

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