16 June 1997 High-speed photographic studies of dye-assisted pulsed Nd:YAG laser ablation of dental hard tissues
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Proceedings Volume 2975, Laser-Tissue Interaction VIII; (1997) https://doi.org/10.1117/12.275504
Event: BiOS '97, Part of Photonics West, 1997, San Jose, CA, United States
We have been evaluating the use of a pulsed Nd:YAG laser for ablating hard dental tissue. For this application we apply dye-drops of an IR absorptive fluid on the enamel, then irradiate with a laser pulse from the laser. By using ink- jet technology to deliver the dye-drops, we can attain micron- and millisecond-scale precision in drop delivery, with a 'burst' of drops preceding each laser pulse. To gain better understanding of the ablation process we have used a high- speed CCD camera system with 1 microsecond(s) exposure and 1 microsecond(s) inter-exposure-interval capability. Fast photography of the ablation process showed the following typical events. (i) The laser induced plasma plume erupts immediately after pulse onset, expands to maximum within 50 microsecond(s) , and lasts up to 200 microsecond(s) . (ii) Ejected particles flying away from the site of laser pulse/dye-drop impact are detected within 30 microsecond(s) of laser pulse onset, and continue up to 10 ms. These particles attain velocities up to 50 m/s with lower velocities from lower pulse power. (iii) The plasma plume has a peak height that increases with increasing laser fluence, ranging up to 10 mm for a fluence of 242 J/cm2 on enamel. From this study, the dye-assisted ablation mechanisms are inferred to be plasma-mediated and explosion- mediated tissue removal.
© (1997) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Quiang Lu, Quiang Lu, David B. Wallace, David B. Wallace, Donald J. Hayes, Donald J. Hayes, } "High-speed photographic studies of dye-assisted pulsed Nd:YAG laser ablation of dental hard tissues", Proc. SPIE 2975, Laser-Tissue Interaction VIII, (16 June 1997); doi: 10.1117/12.275504; https://doi.org/10.1117/12.275504

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