scholarly journals Microstructural effect of a laser-activated bleaching agent containing titanium dioxide on human enamel

2020 ◽  
Vol 23 (6) ◽  
pp. 558
Author(s):  
JoaoFelipe Besegato ◽  
AryveltoMiranda Silva ◽  
EranNair Mesquita de Almeida ◽  
AlessandraNara de Souza Rastelli ◽  
Ricardo Takahashi ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Bleaching Agent ◽  
Human Enamel ◽  
Microstructural Effect

Effects of Bleaching Agents on Human Enamel Light Reflectance

2010 ◽  
Vol 35 (4) ◽  
pp. 405-411 ◽  
Author(s):  
L. Markovic ◽  
K. Fotouhi ◽  
H. Lorenz ◽  
R. A. Jordan ◽  
P. Gaengler ◽  
...  
Keyword(s):  
Clinical Relevance ◽  
Color Space ◽  
Bleaching Agent ◽  
Dental Bleaching ◽  
Human Enamel ◽  
Light Reflectance ◽  
Hard Tissues

Clinical Relevance In dental bleaching, the micromorphological alterations of hard tissues have been well investigated, but little is known about the optical changes involved. The results of the current study showed that enamel, irrespective of maturation, is subjected to a shift in reflectance towards blue within the color space and enhanced reflection. This effect was demonstrated in different bleaching agent concentrations and protocols.

Histomorphologic Alterations and Human Enamel after Repeated Applications of a Bleaching Agent

2012 ◽  
Vol 25 (4) ◽  
pp. 1021-1027 ◽  
Author(s):  
M. D'Amario ◽  
M. D'Attilio ◽  
M. Baldi ◽  
F. De Angelis ◽  
G. Marzo ◽  
...  
Keyword(s):  
Bleaching Agent ◽  
Human Enamel ◽  
Repeated Applications

Energy Dispersive X-Ray Spectroscopy Evaluation of Demineralized Human Enamel after Titanium Tetrafluoride Application

2015 ◽  
Vol 39 (2) ◽  
pp. 124-127 ◽  
Author(s):  
PCC Alcântara ◽  
AK Alexandria ◽  
IPR Souza ◽  
LC Maia
Keyword(s):  
Titanium Dioxide ◽  
Tooth Enamel ◽  
Permanent Tooth ◽  
Energy Dispersive ◽  
Control Group ◽  
Third Molars ◽  
Titanium Tetrafluoride ◽  
X Ray ◽  
Human Enamel ◽  
Experimental Group

Objective: Evaluate the presence of a titanium dioxide layer after application of titanium tetrafluoride on human permanent tooth enamel. Study design: The sample consisted of unerupted third molars. After the removal of the roots, each tooth was mesiodistally divided into 2 fragments, one reserved for the experimental group and the other for the control group. Before the treatments the fragments were artificially demineralized. The experimental group (n=5) received an application of 4% titanium tetrafluoride, for one minute and the control group (n=5) did not receive any treatment. The samples were sputter-coated with a 20-30nm gold layer as the energy dispersive x-ray spectrometer analysis was carried out in a scanning electron microscope and the results were descriptively analyzed. Results: The titanium dioxide layer was present on all experimental samples with a titanium peak varying between 6.82 and 26.37%. This layer was not found in the control group. Fluoride and calcium fluoride precipitates were present in the samples treated with titanium tetrafluoride. Conclusion: Titanium dioxide layer was formed after one titanium tetrafluoride application, but it was not uniform. Further studies should be carried out so that both the morphology and thickness of such layers can be better understood.

Microstructural comparison of synthetic bioceramics with natural bioceramics

1991 ◽  
Vol 49 ◽  
pp. 38-39
Author(s):  
Shulin Wen ◽  
Jingwei Feng ◽  
A. Krajewski ◽  
A. Ravaglioli
Keyword(s):  
Recent Work ◽  
Human Body ◽  
Human Tissues ◽  
Main Constituent ◽  
Laboratory Furnace ◽  
Chinese Adult ◽  
Human Enamel ◽  
Biological Compatibility ◽  
Synthetic Hydroxyapatite ◽  
Synthetic Work

Hydroxyapatite bioceramics has attracted many material scientists as it is the main constituent of the bone and the teeth in human body. The synthesis of the bioceramics has been performed for years. Nowadays, the synthetic work is not only focused on the hydroapatite but also on the fluorapatite and chlorapatite bioceramics since later materials have also biological compatibility with human tissues; and they may also be very promising for clinic purpose. However, in comparison of the synthetic bioceramics with natural one on microstructure, a great differences were observed according to our previous results. We have investigated these differences further in this work since they are very important to appraise the synthetic bioceramics for their clinic application.The synthetic hydroxyapatite and chlorapatite were prepared according to A. Krajewski and A. Ravaglioli and their recent work. The briquettes from different hydroxyapatite or chlorapatite powders were fired in a laboratory furnace at the temperature of 900-1300°C. The samples of human enamel selected for the comparison with synthetic bioceramics were from Chinese adult teeth.

Human Enamel Replication

1976 ◽  
Vol 34 ◽  
pp. 180-181
Author(s):  
Norman L. Dockum ◽  
John G. Dockum
Keyword(s):  
Organic Matrix ◽  
Human Teeth ◽  
Human Enamel ◽  
Straight Line ◽  
Ultrastructural Characteristics

Ultrastructural characteristics of fractured human enamel and acid-etched enamel were compared using acetate replicas shadowed with platinum and palladium. Shadowed replications of acid-etched surfaces were also obtained by the same method.Enamel from human teeth has a rod structure within which there are crystals of hydroxyapatite contained within a structureless organic matrix composed of keratin. The rods which run at right angles from the dentino-enamel junction are considered to run in a straight line perpendicular to the perimeter of the enamel, however, in many areas these enamel rods overlap, interlacing and intertwining with one another.

Studies on the mechanism of printing film-coated tablets containing titanium dioxide in the film by using UV laser irradiation

2009 ◽  
Vol 00 (00) ◽  
pp. 090915102728058-8
Author(s):  
Yoshiteru Kato ◽  
Yasuhiko Nakashima ◽  
Naoki Shino ◽  
Koichi Sasaki ◽  
Akihiro Hosokawa ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Laser Irradiation ◽  
Uv Laser

Development and production experience of the multilayer curtain-coated linerboard of Ji’an PM No. 3,

TAPPI Journal ◽  
2014 ◽  
Vol 13 (2) ◽  
pp. 17-25
Author(s):  
JUNMING SHU ◽  
ARTHAS YANG ◽  
PEKKA SALMINEN ◽  
HENRI VAITTINEN
Keyword(s):  
Titanium Dioxide ◽  
High Speed ◽  
Food Packaging ◽  
Production Efficiency ◽  
Positive Impact ◽  
Low Cost ◽  
Board Structure ◽  
Flexographic Printing ◽  
Curtain Coating ◽  
Coating Formulations

The Ji’an PM No. 3 is the first linerboard machine in China to use multilayer curtain coating technology. Since successful startup at the end of 2011, further development has been carried out to optimize running conditions, coating formulations, and the base paper to provide a product with satisfactory quality and lower cost to manufacture. The key challenges include designing the base board structure for the desired mechanical strength, designing the surface properties for subsequent coating operations, optimizing the high-speed running of the curtain coater to enhance production efficiency, minimizing the amount of titanium dioxide in the coating color, and balancing the coated board properties to make them suitable for both offset and flexographic printing. The pilot and mill scale results show that curtain coating has a major positive impact on brightness, while smoothness is improved mainly by the blade coating and calendering conditions. Optimization of base board properties and the blade + curtain + blade concept has resulted in the successful use of 100% recycled fiber to produce base board. The optical, mechanical, and printability properties of the final coated board meet market requirements for both offset and flexographic printing. Machine runnability is excellent at the current speed of 1000 m/min, and titanium dioxide has been eliminated in the coating formulations without affecting the coating coverage. A significant improvement in the total cost of coated white liner production has been achieved, compared to the conventional concept of using virgin fiber in the top ply. Future development will focus on combining low cost with further quality improvements to make linerboard suitable for a wider range of end-use applications, including frozen-food packaging and folding boxboard.

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