Biological hard tissues, such as those found in bone and teeth, are complex tissues that build a strong mineral structure over an organic matrix framework. The laser-matter interaction for bone hard tissues holds great interest to laser surgery and laser dentistry; the use of short/ultrashort pulses, in particular, shows interesting behaviors not seen in continuous wave lasers. High laser energy densities in ultrashort pulses can be focused on a small irradiated surface (spot diameter is 10-50 μm) leading to rapid temperature rise and thermal ablation of the bone tissue. Ultrashort pulses, specifically those in the picosecond and femtosecond ranges, impose several challenges in modeling bone tissue response. In the present paper we perform time-dependent thermal simulations of short and ultrashort pulse laser-bone interactions in singlepulse and multipulse (set of ultrashort pulses) modes of laser heating. A comparative analysis for both radiation modes is discussed for laser heating of different types of the solid bone on the nanosecond, picosecond and femtosecond time scales. It is shown that ultrashort laser pulses with high energy densities can ablate bone tissue without heating tissues bordering the ablation creator. This reaction is particularly desirable as heat accumulation and thermal damage are the main factors affecting tissue regrowth rates, and thus patient recovery times.

Date Published: 2 March 2010
PDF: 11 pages
Proc. SPIE 7548, Photonic Therapeutics and Diagnostics VI, 75484K (2 March 2010); doi: 10.1117/12.852455

Published in SPIE Proceedings Vol. 7548:
Photonic Therapeutics and Diagnostics VI
Anita Mahadevan-Jansen; Andreas Mandelis; Brian Jet-Fei Wong M.D.; Nikiforos Kollias; Henry Hirschberg M.D.; Kenton W. Gregory M.D.; Reza S. Malek; E. Duco Jansen; Guillermo J. Tearney; Steen J. Madsen; Bernard Choi; Justus F. R. Ilgner; Haishan Zeng; Laura Marcu, Editor(s)