Dependence of Nd:YAG laser derusting and passivation of iron artifacts on pulse duration

Author(s):  
Iacopo Osticioli ◽  
Salvatore Siano
2019 ◽  
Vol 7 (4) ◽  
pp. 99 ◽  
Author(s):  
Namour ◽  
El Mobadder ◽  
Magnin ◽  
Peremans ◽  
Verspecht ◽  
...  

Peri-implantitis (PI) is an inflammatory disease of peri-implant tissues, it represents the most frequent complication of dental implants. Evidence revealed that microorganisms play the chief role in causing PI. The purpose of our study is to evaluate the cleaning of contaminated dental implant surfaces by means of the Q-switch Nd:YAG (Neodymium-doped Yttrium Aluminum Garnet) laser and an increase in temperature at lased implant surfaces during the cleaning process. Seventy-eight implants (titanium grade 4) were used (Euroteknika, Sallanches, France). Thirty-six sterile implants and forty-two contaminated implants were collected from failed clinical implants for different reasons, independent from the study. Thirty-six contaminated implants were partially irradiated by Q-switch Nd:YAG laser (1064 nm). Six other contaminated implants were used for temperature rise evaluation. All laser irradiations were calibrated by means of a powermetter in order to evaluate the effective delivered energy. The irradiation conditions delivered per pulse on the target were effectively: energy density per pulse of 0.597 J/cm2, pick powers density of 56 mW/cm2, 270 mW per pulse with a spot diameter of 2.4 mm, and with repetition rate of 10 Hz for pulse duration of 6 ns. Irradiation was performed during a total time of 2 s in a non-contact mode at a distance of 0.5 mm from implant surfaces. The parameters were chosen according to the results of a theoretical modeling calculation of the Nd:YAG laser fluency on implant surface. Evaluation of contaminants removal showed that the cleaning of the irradiated implant surfaces was statistically similar to those of sterile implants (p-value ≤ 0.05). SEM analysis confirmed that our parameters did not alter the lased surfaces. The increase in temperature generated at lased implant surfaces during cleaning was below 1 °C. According to our findings, Q-switch Nd:YAG laser with short pulse duration in nanoseconds is able to significantly clean contaminated implant surfaces. Irradiation parameters used in our study can be considered safe for periodontal tissue.


2021 ◽  
Author(s):  
Zexin Song ◽  
Qi Bian ◽  
Yu Shen ◽  
Keling Gong ◽  
Nan Zong ◽  
...  

Abstract The influence of pumping laser pulse on the property of quasi-continuous-wave diode-side-pumped Nd:YAG laser is investigated theoretically and experimentally here. Under remaining a fixed duty cycle, the average output power increases, and the corresponding thermal focal length shorten with the increase of the pump pulse duration, which attributes to the decrease of the ratio of pulse buildup time to the pulse duration. At a pump power of 146 W, the laser output power changes from 65.1 W to 81.2 W when the pulse duration is adjusted from 150 μs to 1000 μs, confirming a significant enhancement of 24.7%. A laser rate equation model incorporating the amplified spontaneous emission is also utilized and numerically solved, and the simulated results agree well with the experimental data.


2014 ◽  
Vol 24 (3) ◽  
pp. 391-392
Author(s):  
Samia Esmat ◽  
Mona R.E. Abdel-Halim ◽  
Amira El-Tawdy ◽  
Marwa M. Fawzy ◽  
Asmaa Ragheb ◽  
...  

2019 ◽  
Vol 44 (18) ◽  
pp. 4471 ◽  
Author(s):  
Yan-Jie Song ◽  
Ke Liu ◽  
Nan Zong ◽  
Wei Tu ◽  
Yong Bo ◽  
...  

2011 ◽  
Vol 383-390 ◽  
pp. 6247-6251 ◽  
Author(s):  
M. Moradi ◽  
M. Ghoreishi ◽  
M.J. Torkamany ◽  
J. Sabbaghzadeh ◽  
M.J. Hamedi

In the present study, a low average power pulsed Nd:YAG laser is used for bead-on-plate welding of low carbon steel plate. The effect of laser process parameters on the weld quality and weld bead profile, welding penetration (P), welding surface width (W) and welding pool area (A), is studied. Focal point position, welding speed, pulse duration, and energy are selected as the process variables. The formation of a keyhole and weld bead profile is found to be highly dependent on laser pulse parameters. Results show that the maximum penetration accurse when the focal point is above the surface, in pulse duration of 6 ms, welding speed of 2 mm/s and pulse energy of 16.67 J.


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