BOne-Ablation Mechanism Using KrF Excimer Laser

Abstract

Pig femurs are ablated in air with a KrF excimer laser at several fluences below and above plasma-formation threshold.Ablation craters and debris are examined by means of scanning electron microscopy, infrared spectroscopy and X-ray diffraction analysis.The shape of debris is needle-like and spherical, respectively above and below the plasma-formation threshold. Natural structure of the hard-bone components is observed below and above the plasmaformation threshold. The amounts of H₂OandCO₃^2-components of debris are almost unchanged below the plasma-formation threshold, but decrease with sharpening of the X-ray diffraction peak above the plasma-formation threshold.These resultsuggest that in the bone ablation process organic components are decomposed photochemically and vaporized, then entrain and remove the surrounding material, while the debris is thermally influenced above the plasma-formation threshold.