scholarly journals Temperature Increase in Human Tissues at Maximum Permissible Exposure Conditions of Laser Irradiation

2015 ◽  
Vol 8 (2) ◽  
pp. 99-103
Author(s):  
신성선 ◽  
Jong Rak Park ◽  
백준혁 ◽  
양승진 ◽  
김재영 ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Temperature Increase ◽  
Human Tissues ◽  
Exposure Conditions ◽  
Maximum Permissible Exposure

siRNA release from gold nanoparticles by nanosecond pulsed laser irradiation and analysis of the involved temperature increase

2018 ◽  
Vol 11 (9) ◽  
pp. e201700329 ◽  
Author(s):  
Florian Rudnitzki ◽  
Susanne Feineis ◽  
Ramtin Rahmanzadeh ◽  
Elmar Endl ◽  
Johanna Lutz ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Laser Irradiation ◽  
Temperature Increase ◽  
Pulsed Laser ◽  
Nanosecond Pulsed Laser ◽  
Pulsed Laser Irradiation

scholarly journals Using 445 nm and 970 nm Lasers on Dental Implants—An In Vitro Study on Change in Temperature and Surface Alterations

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3934
Author(s):  
Sebastian Malmqvist ◽  
Anders Liljeborg ◽  
Talat Qadri ◽  
Gunnar Johannsen ◽  
Annsofi Johannsen
Keyword(s):  
Laser Irradiation ◽  
Dental Implants ◽  
Temperature Increase ◽  
Glass Ionomer Cement ◽  
Cooling Water ◽  
In Vitro Study ◽  
Maximum Temperature ◽  
Water Cooling ◽  
Ionomer Cement

The aim of this study was to evaluate the safety of using a 445 nm laser on dental implants by comparing it with a laser with 970 nm wavelength. Two models, a pig mandible and glass ionomer cement, were used to evaluate the temperature increase in dental implants during laser irradiation with both wavelengths. Temperature was measured every second at four different places on the dental implants. Different power settings, effects of water cooling, distance of the laser fibre to the dental implant and continuous comparison to a pulsed laser beam were tested. Surface alterations on titanium discs after laser irradiation for 4 min at 2.0 W, were analysed in a scanning electron microscope (SEM). The maximum temperature and time to reach each of the thresholds were comparable between the 445 nm and 970 nm lasers. Neither the 445 nm nor the 970 nm wavelength showed any signs of surface alterations on the titanium discs. Using a 445 nm laser on dental implants is as safe as using a 970 nm laser, in terms of temperature increase and surface alterations. Applying a generous amount of cooling water and irradiating in short intervals is important when using lasers on dental implants.

Asymptotic Rate Process Calculations of Thermal Injury to the Retina Following Laser Irradiation

1978 ◽  
Vol 100 (1) ◽  
pp. 49-54 ◽  
Author(s):  
L. A. Priebe ◽  
A. J. Welch
Keyword(s):  
Laser Irradiation ◽  
Temperature Increase ◽  
Thermal Damage ◽  
Short Pulse ◽  
Rate Process ◽  
Large Computer ◽  
Damage Prediction ◽  
Steady State Model ◽  
Time Domains ◽  
Long Pulse

Thermal damage to the retina following laser irradiation may be predicted using impulse and steady asymptotes derived from a first-order rate process and a simple thermal model for two time domains. Effects which have been observed experimentally in the short pulse (<10−4s) region such as changes in energy per unit area for threshold damage as a function of image diameter may be explained with this model. The model allows rapid damage prediction without extensive calculations of temperature increase which normally require a large computer. Thermal damage to the ocular fundus resulting from a long pulse exposure may also be easily described with a simple steady-state model for temperature increase and damage.

Root Surface Temperature Increase during Er:YAG Laser Irradiation of Root Canals

2002 ◽  
Vol 28 (2) ◽  
pp. 76-78 ◽  
Author(s):  
Y KIMURA ◽  
K YONAGA ◽  
K YOKOYAMA ◽  
J KINOSHITA ◽  
Y OGATA ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Laser Irradiation ◽  
Temperature Increase ◽  
Er:Yag Laser ◽  
Root Surface ◽  
Root Canals

Photoluminescence of CdS nanoparticles suspended in vacuum and its temperature increase by laser irradiation

2002 ◽  
Vol 14 (41) ◽  
pp. 9743-9752 ◽  
Author(s):  
Takaaki Orii ◽  
Shin-ichi Kaito ◽  
Kiyoto Matsuishi ◽  
Seinosuke Onari ◽  
Toshihiro Arai
Keyword(s):  
Laser Irradiation ◽  
Temperature Increase ◽  
Cds Nanoparticles

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.

Chronic Laser Exposure Effects on Rabbit Retina

1972 ◽  
Vol 30 ◽  
pp. 54-55
Author(s):  
Burton B. Silver ◽  
Theodore Lawwill
Keyword(s):  
Laser Irradiation ◽  
Laser Light ◽  
Broad Band ◽  
Argon Laser ◽  
Atropine Sulfate ◽  
Ultrastructural Changes ◽  
Laser Exposure ◽  
Rabbit Retina ◽  
Histological Changes ◽  
Threshold Doses

Dutch-belted 1 to 2.5 kg anesthetized rabbits were exposed to either xenon or argon laser light administered in a broad band, designed to cover large areas of the retina. For laser exposure, the pupil was dilated with atropine sulfate 1% and pheny lephrine 10%. All of the laser generated power was within a band centered at 5145.0 Anstroms. Established threshold for 4 hour exposures to laser irradiation are in the order of 25-35 microwatts/cm2. Animals examined for ultrastructural changes received 4 hour threshold doses. These animals exhibited ERG, opthalmascopic, and histological changes consistent with threshold damage.One month following exposure the rabbits were killed with pentobarbitol. The eyes were immediately enucleated and dissected while bathed in 3% phosphate buffered gluteraldehyde.

Microstructural changes of Aluminum Nitride after laser irradiation and electroless copper deposition

1994 ◽  
Vol 52 ◽  
pp. 636-637
Author(s):  
S. Cao ◽  
A. J. Pedraza ◽  
L. F. Allard
Keyword(s):  
Aluminum Nitride ◽  
Laser Irradiation ◽  
Electroless Deposition ◽  
Thermal Evaporation ◽  
Surface Region ◽  
Near Surface ◽  
Laser Patterning ◽  
Electroless Copper ◽  
Excimer Laser Irradiation ◽  
Laser Effect

Excimer-laser irradiation strongly modifies the near-surface region of aluminum nitride (AIN) substrates. The surface acquires a distinctive metallic appearance and the electrical resistivity of the near-surface region drastically decreases after laser irradiation. These results indicate that Al forms at the surface as a result of the decomposition of the Al (which has been confirmed by XPS). A computer model that incorporates two opposing phenomena, decomposition of the AIN that leaves a metallic Al film on the surface, and thermal evaporation of the Al, demonstrated that saturation of film thickness and, hence, of electrical resistance is reached when the rate of Al evaporation equals the rate of AIN decomposition. In an electroless copper bath, Cu is only deposited in laser-irradiated areas. This laser effect has been designated laser activation for electroless deposition. Laser activation eliminates the need of seeding for nucleating the initial layer of electroless Cu. Thus, AIN metallization can be achieved by laser patterning followed by electroless deposition.

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