Abstract: The recoil momentum of hard tissue induced by pulsed IR laser exposure was measured in a pendulum experiment using laser Doppler vibrometry. For the experiments bone was irradiated by holmium:YAG laser radiation and dentin by a superpulsed CO$-2$/ laser. Since the initial masses of the samples were known and the ablated masses were measured, this method allowed also an indirect determination of the velocity of the ablated particles. In a second experiment performed with the CO$-2$/ laser the velocities of the ablated particles were measured directly by the time of flight detected by the laser beam of the vibrometer. The technical realization as well as the limitations of the method is discussed; furthermore laser parameters are pointed out which induce critical acceleration risking serious damage to sensitive organs. !2
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