scholarly journals Safe Debonding of Fixed Appliances: A Comparison of Traditional Techniques and LODI Devices on Different Bracket Types in Terms of Enamel Cracks, Site of Bond Failure, and Bracket Reusability

2021 ◽  
Vol 18 (19) ◽  
pp. 10267
Author(s):  
Marta Gibas-Stanek ◽  
Małgorzata Pihut
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Third Molars ◽  
Bond Failure ◽  
Adhesive Remnant Index ◽  
Ceramic Brackets ◽  
Fixed Appliances ◽  
Ceramic Bracket ◽  
Lift Off ◽  
Scanning Electron

The objective of this study was to compare the effects of the debonding of three different bracket types by means of three popular debonding methods. A total of 180 human third molars was divided into six groups, consisting of 20 teeth each. Three bracket types were bonded to the enamel (metal brackets with an integral base and a foil mesh base, and ceramic brackets) and three methods of bracket debonding were employed (bracket removal pliers, Weingart pliers, and Lift-Off Debonding Instrument). The samples were examined with scanning electron microscopy to assess the number of enamel cracks, measure the area of adhesive remaining on the enamel, and calculate the adhesive remnant index (ARI). There were no statistically significant differences between the groups in terms of the number of enamel cracks after bracket debonding. The amount of adhesive remaining on the teeth after the brackets were removed was significantly different between the groups. LODI and Weingart pliers are considered to be the safest methods of debonding brackets with an integral base, while LODI is the best tool for brackets with foil mesh. Bracket removal pliers are considered to be the preferred method for ceramic bracket debonding.

scholarly journals An in situ evaluation of Bioactives on the morphology of bleached Enamel

2016 ◽  
Vol 17 (3) ◽  
pp. 192-197
Author(s):  
Yasmin do Socorro Batista de Lima Gomes ◽  
Larissa Dias Alexandrino ◽  
Cecy Martins Silva ◽  
Thiago da Rosa Nogueira ◽  
Cristiane de Melo Alencar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Peroxide ◽  
Scanning Electron Microscopy ◽  
Third Molars ◽  
Double Blind ◽  
Human Morphology ◽  
Before And After ◽  
Post Hoc ◽  
Scanning Electron

ABSTRACT Aim The aim of this study was to use surface rugosity analysis (Ra) and scanning electron microscopy (SEM) comparing effects of nano-hydroxyapatite (NANO), casein phosphopeptideamorphous calcium phosphate (CPP-ACP), and NovaMin (NOVA) on enamel's human morphology bleached with 37.5% hydrogen peroxide. Materials and methods Forty specimens (3 × 3 × 3 mm) were obtained from fully included third molars and four specimens were attached in the first molars of the volunteers. The POLApositive control has only been bleached. Three experimental groups were bleached and treated with respective bioactive: NANO, CPP-ACP, and NovaMin. The Ra analyses were performed before and after the treatment using a rugosimeter. The obtained photomicrographs were analyzed using SEM (n = 3) by three examiners, and the study was double blind. Results The Ra results were analyzed by one-way analysis of variance and Tukey's post hoc test (p < 0.05). All experimental groups showed significant differences of the others; however, the experimental groups were not significantly different from each other. Conclusion The enamel morphology of the bioactive-treated groups had more regular surfaces, than the others. How to cite this article da Rosa Nogueira T, Alexandrino LD, de Lima Gomes YSB, de Melo Alencar C, Alves EB, Silva CM. An in situ evaluation of Bioactives on the morphology of bleached Enamel. J Contemp Dent Pract 2016;17(3):192-197.

Scanning electron microscopy of the developing chick anterior corneal epithelium

Development ◽  
1978 ◽  
Vol 44 (1) ◽  
pp. 217-225
Author(s):  
Phillip R. Waggoner
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Corneal Epithelium ◽  
Stages Of Development ◽  
Corneal Surface ◽  
Lift Off ◽  
Scanning Electron

The anterior corneal epithelium of the developing chick was observed with the scanning electron microscope at various stages of development. In the earlier stages, up to about 15 days of incubation, the cells are characterized by regular polygonal outlines and a proliferation of microvilli on the surface. The microvilli then begin to coalesce and flatten so that the surface is rather smooth by about 19 days of incubation. Just prior to hatching, however, the cells begin to round up and once again become covered by microvilli. The cells then lift off the surface and expose the underlying cells. After hatching, the surface cells lose the synchrony of development that characterized the embryo and are found in various stages of senescence. The cells eventually lose their regular polygonal outlines and the corneal surface takes on a patchwork appearance.

scholarly journals Evaluation of enamel surface after bracket debonding and polishing

2012 ◽  
Vol 17 (4) ◽  
pp. 77-84 ◽  
Author(s):  
Lilian Maria Brisque Pignatta ◽  
Sillas Duarte Júnior ◽  
Eduardo César Almada Santos
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Tungsten Carbide ◽  
High Speed ◽  
Dental Enamel ◽  
Enamel Surface ◽  
Evidence Based ◽  
Enamel Structure ◽  
Lift Off ◽  
Scanning Electron

INTRODUCTION: Preserving the dental enamel structure during removal of orthodontic accessories is a clinician's obligation. Hence the search for an evidence based debonding protocol. OBJECTIVE: to evaluate and compare, by means of scanning electron microscopy (SEM), the effects of four different protocols of bracket debonding and subsequent polishing on enamel surface, and to propose a protocol that minimizes damage to enamel surface. METHODS: Twelve bovine permanent incisors were divided into four groups according to the instrument used for debonding and removal of the adhesive remnant. In groups 1 and 2, brackets were debonded with a straight debonding plier (Ormco Corp., Glendora, California, USA), and in groups 3 and 4, debonding was performed with the instrument Lift-Off (3M Unitek, Monrovia, California, USA). In groups 1 and 3, the adhesive remnant was removed using a long adhesive removing plier (Ormco Corp., Glendora, California, USA) and in groups 2 and 4, residual adhesive was removed with a tungsten carbide bur (Beavers Dental) at high-speed. After each stage of debonding and polishing, enamel surfaces were replicated and electron micrographs were obtained with 50 and 200X magnification. RESULTS: All four protocols of debonding and polishing caused enamel irregularities. CONCLUSION: Debonding brackets with straight debonding plier, removal of adhesive remnant with a tungsten carbide bur and polishing with pumice and rubber cup was found to be the protocol that caused less damage to enamel surface, therefore this protocol is suggested for debonding brackets.

Microstructures in thin BaTiO3 Films by Hydrothermal Method

1997 ◽  
Vol 495 ◽  
Author(s):  
T. Hoffmann ◽  
V. M. Fuenzalida
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Barium Titanate ◽  
Hydrothermal Reaction ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Titanium Layer ◽  
X Ray ◽  
Lift Off ◽  
Scanning Electron

ABSTRACTBarium titanate microstructures are fabricated on silicon(100)/platinum substrates coated with photoresist and titanium by a combination of hydrothermal and lift-off techniques. The microstructures of 10μm width are well defined. The barium titanate films grow in its cubic phase. Analysis by means of x-ray diffraction and scanning electron microscopy shows that only a part of the titanium layer is affected by the hydrothermal reaction. This limitation may be overcome by application of electrochemistry.

scholarly journals In vitro analysis of shear bond strength and adhesive remnant index comparing light curing and self-curing composites

2013 ◽  
Vol 18 (3) ◽  
pp. 124-129 ◽  
Author(s):  
Murilo Gaby Neves ◽  
Gustavo Antônio Martins Brandão ◽  
Haroldo Amorim de Almeida ◽  
Ana Maria Martins Brandão ◽  
Dário Ribeiro de Azevedo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Bond Strength ◽  
Shear Bond Strength ◽  
Statistical Difference ◽  
Testing Machine ◽  
Adhesive Remnant Index ◽  
Light Curing ◽  
Scanning Electron

OBJECTIVE: To evaluate, in vitro, the shear bond strength of self-curing (ConciseTM - 3M and Alpha Plast - DFL) and light-curing composites (TransbondTM XT - 3M and Natural Ortho - DFL) used in orthodontics bonding, associated to Morelli metal brackets, with further analysis of adhesive remnant index (ARI) and enamel condition in scanning electron microscopy (SEM). METHODS: Forty human premolars, just extracted and stored in physiologic solution 0.9 % were used. Randomly, these samples were divided in four groups: G1 group, the brackets were bonded with ConciseTM - 3M composite; in G2 group, Alpha Plast - DFL composite was used; in G3 group, TransbondTM XT - 3M was used; in G4 group, Natural Ortho - DFL composite was used. These groups were submitted to shear strength tests in universal testing machine, at 0.5 mm per minute speed. RESULTS: Statistical difference between G3 and G4 groups was recorded, as G4 showing higher strength resistance than G3. In the other hand, there were no statistical differences between G1, G2 and G3 and G1, G2 and G4 groups. ARI analysis showed that there was no statistical difference between the groups, and low scores were recorded among then. The scanning electron microscopy (SEM) analysis revealed the debonding spots and the enamel surface integrity. CONCLUSIONS: Shear bond strength was satisfactory and similar between the composites, however Natural Ortho - DFL revealed best comparing to TransbondTM XT - 3M.

Flowable resin used as a sealant in molars affected by dental fluorosis: a comparative study

2006 ◽  
Vol 30 (1) ◽  
pp. 39-43 ◽  
Author(s):  
Juan Pablo Loyola-Rodriguez ◽  
Veronica Mendoza-Razo ◽  
Fernando Rodriguez-Juarez ◽  
Rafael Campos-Cambranis
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Dental Caries ◽  
Reliable Method ◽  
Dental Fluorosis ◽  
Developed Countries ◽  
Third Molars ◽  
Prevention Approach ◽  
Resin Penetration ◽  
Scanning Electron

The decline in prevalence and incidence of dental caries in developed countries over the last two decades is considered to be due mainly to the widespread use of fluoride in different forms, but simultaneously with decline in caries, an increase in dental fluorosis has been reported. The aim of this study was to compare the Conventional Sealant Technique (CST) and Enameloplasty Sealant Technique (EST) using a flowable resin as sealant in molars affected by dental fluorosis.A total of 40 extracted third molars affected by dental fluorosis were divided at random into two groups of 20 teeth each, and Tetric Flow resin was used as sealant. All teeth were studied for lateral adaptation and resin penetration by direct and indirect techniques; all samples were replicated in epoxy resin and were evaluated with Scanning Electron Microscopy (SEM). The results demonstrated that EST allowed a deeper sealant penetration and a superior sealant adaptation than CST, both in direct and indirect evaluations by SEM. The most important variables being penetration-interface and penetration depth both being statistically significant (p&lt;0.05). The CST did not flow into the bottom of the fissures, leaving spaces that can favor the fracture of the material and initiate the process of dental caries.We conclude that a flowable ceromer is an excellent material alternative to be used as sealant and that EST is quite necessary in molars affected by dental fluorosis, the combination of both being a reliable method to be used as primary prevention approach of dental caries in endemic areas of dental fluorosis.

Pathogenesis of Human Hair Defects

1974 ◽  
Vol 32 ◽  
pp. 12-13
Author(s):  
P.S. Porter ◽  
T. Aoyagi ◽  
R. Matta
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Human Hair ◽  
Standard Techniques ◽  
Scanning Electron

Using standard techniques of scanning electron microscopy (SEM), over 1000 human hair defects have been studied. In several of the defects, the pathogenesis of the abnormality has been clarified using these techniques. It is the purpose of this paper to present several distinct morphologic abnormalities of hair and to discuss their pathogenesis as elucidated through techniques of scanning electron microscopy.

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

1977 ◽  
Vol 35 ◽  
pp. 638-639
Author(s):  
P.J. Dailey
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Salivary Glands ◽  
Secretory Vesicles ◽  
The Past ◽  
Transmission Electron ◽  
Means Of Transmission ◽  
Gromphadorhina Portentosa ◽  
Scanning Electron ◽  
Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

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