@inproceedings{4ff50b8670b34dd19a3ff002f0585007,
title = "Analysis of peripheral thermal damage during the rapid ablation of dentin and bone using a λ= 9.3-μm TEA CO 2 Laser",
abstract = "TEA CO 2 lasers tuned to the strong mineral absorption of hydroxyapatite at λ=9-μm are ideally suited for the efficient ablation of dental hard tissues if the laser-pulse duration is stretched to greater than 10-μs to avoid plasma formation. CO 2 lasers are capable of operating at high repetition rates for the rapid removal of dentin and bone. The purpose of this study was to test the hypothesis that stretched λ=9.3-μm TEA CO 2 laser pulses can produce lateral incisions in dentin and bone for dental restorations and implants at repetition rates as high as 400-Hz without peripheral thermal damage. A high repetition rate, 0-500-Hz, λ=9.3-μm TEA CO 2 laser with pulse durations of 10-20-μs was used to make incisions in human dentin and porcine alveolar bone with a computer controlled scanning stage and water spray at varying irradiation intensities. The single pulse ablation rates were determined for incident fluence ranging from 1-150-J/cm 2. Lateral incisions 2-3-mm in length were produced in the 2-mm thick sections. Following irradiation, transverse cross-sections were examined using polarized light microscopy (PLM) and Fourier transform infrared spectro-microscopy (SR-FTIR) at the Advanced Light Source at Lawrence Berkeley National Laboratory. The single-pulse ablation rates approached 40-μm per pulse for the stretched TEA laser pulses in dentin and bone. All incisions with and without water spray yielded thermal damage zones of less than 22-μm. Thermal damage zones with water spray were less than 14-μm, even at repetition rates of 400-Hz and SR-FTIR showed no spectral changes around the periphery of the incisions. CO 2 laser pulses at λ=9.3-μm of 10-20-μs duration are well suited for the precise removal of dentin and bone for dental restorations and implants at high repetition rates without peripheral thermal damage.",
keywords = "Bone, CO laser, Dentin, Hard tissue ablation, Laser dentistry, TEA laser, Water-spray",
author = "Bell, {Paul W.} and Kenneth Fan and Jones, {Robert S.} and Daniel Fried",
year = "2006",
doi = "10.1117/12.661793",
language = "English (US)",
isbn = "0819461806",
series = "Progress in Biomedical Optics and Imaging - Proceedings of SPIE",
booktitle = "Lasers in Dentistry XII",
note = "Lasers in Dentristry XII ; Conference date: 22-01-2006 Through 22-01-2006",
}