scholarly journals High-speed scanning ablation of dental hard tissues with a λ = 9.3 μm CO2 laser: adhesion, mechanical strength, heat accumulation, and peripheral thermal damage

2011 ◽  
Vol 16 (7) ◽  
pp. 071410 ◽  
Author(s):  
Daniel Nguyen ◽  
Kwang Chang ◽  
Saba Hedayatollahnajafi ◽  
Michal Staninec ◽  
Kenneth Chan ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Co2 Laser ◽  
High Speed ◽  
Thermal Damage ◽  
Heat Accumulation ◽  
Dental Hard Tissues ◽  
Hard Tissues

Acquired Acid Resistance of Dental Hard Tissues by CO2 Laser Irradiation

1999 ◽  
Vol 17 (5) ◽  
pp. 223-226 ◽  
Author(s):  
MOZAMMAL HOSSAIN ◽  
YUKIO NAKAMURA ◽  
YUICHI KIMURA ◽  
MITSUHIRO ITO ◽  
YOSHISHIGE YAMADA ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Co2 Laser ◽  
Acid Resistance ◽  
Dental Hard Tissues ◽  
Hard Tissues

The Effect of CO2Laser on the Microhardness of Human Dental Hard Tissues Compared with That of the High-Speed Drill

2008 ◽  
Vol 26 (1) ◽  
pp. 65-68 ◽  
Author(s):  
Iris Slutzky-Goldberg ◽  
Oren Peleg ◽  
Reuven Liberman ◽  
Adam Stabholtz ◽  
Joshua Moshonov
Keyword(s):  
High Speed ◽  
Dental Hard Tissues ◽  
Hard Tissues

Variation in the Changes Induced by Different Forms of Tobacco in Dental Hard Tissues-A SEM-EDAX Study

2011 ◽  
Vol 53 (4) ◽  
pp. 348-355
Author(s):  
Thakare Eesha ◽  
Chaudhary Minal ◽  
Gawande Madhuri ◽  
Wadhwan Vijay ◽  
Gadbail Amol
Keyword(s):  
Dental Hard Tissues ◽  
Hard Tissues

Accelerating laser processes with a smart two-dimensional polygon mirror scanner for ultra-fast beam deflection

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Florian Roessler ◽  
André Streek
Keyword(s):  
Energy Distribution ◽  
Real Time ◽  
Laser Processing ◽  
High Speed ◽  
Beam Deflection ◽  
Two Dimensional ◽  
Heat Accumulation ◽  
Field Programmable ◽  
Drill Holes ◽  
Average Laser

Abstract In laser processing, the possible throughput is directly scaling with the available average laser power. To avoid unwanted thermal damage due to high pulse energy or heat accumulation during MHz-repetition rates, energy distribution over the workpiece is required. Polygon mirror scanners enable high deflection speeds and thus, a proper energy distribution within a short processing time. The requirements of laser micro processing with up to 10 kW average laser powers and high scan speeds up to 1000 m/s result in a 30 mm aperture two-dimensional polygon mirror scanner with a patented low-distortion mirror configuration. In combination with a field programmable gate array-based real-time logic, position-true high-accuracy laser switching is enabled for 2D, 2.5D, or 3D laser processing capable to drill holes in multi-pass ablation or engraving. A special developed real-time shifter module within the high-speed logic allows, in combination with external axis, the material processing on the fly and hence, processing of workpieces much larger than the scan field.

Primary Teeth and Hair as Indicators of Environmental Pollution

2016 ◽  
Vol 40 (2) ◽  
pp. 152-155 ◽  
Author(s):  
TE Shishniashvili ◽  
NN Suladze ◽  
VV Margvelashvili
Keyword(s):  
Environmental Pollution ◽  
Toxic Elements ◽  
Chemical Elements ◽  
Epidemiological Survey ◽  
Essential Elements ◽  
World Health ◽  
Dental Tissues ◽  
Dental Hard Tissues ◽  
Hard Tissues ◽  
Health Organization

Objectives: To study the influence of environmental pollution on the mineralization of dental hard tissues by using biosubstrates: teeth and hair. :Study design: At the first stage epidemiological survey was conducted in polluted and less polluted areas of Tbilisi (Georgia). We studied 525 children aged 3 and 4 years. Caries prevalence and intensity was defined by the methodology of World Health Organization. At the second stage the chemical elements content was studied in hair and teeth hard tissues of 24 children by X - ray fluorescent spectroscopy method. Results: The prevalence of dental caries in the polluted region was 46%, caries intensity − 1.92 (± 2.842). In the less polluted region prevalence was 37%, caries intensity − 1.47 (± 2.571). These data are statistically reliable (p < 0.05). The study of hair and tooth tissues showed that the toxic elements (Pb, Hg, Sn, Ti) content in these tissues was higher in environmentally unfavorable than in favorable conditions. Conclusion: Hair and dental tissues can be used as indicators of environmental pollution. Our survey showed that toxic elements content in dental hard tissues was higher and the level of essential elements was less in polluted than in less polluted areas of Tbilisi.

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