Measurements of the recoil momentum and the velocity of ablation products after CO2-laser exposure

Using the pendulum method the recoil momentum on dentin samples after pulsed irradiation (pulselength 80 - 100 microsecond(s) ) with a medical CO2-laser (Sharplan 40C, 10.6 micrometers ) was measured. Therefore a Laser-Doppler-vibrometer was used to deliver the velocity and the direction of movement. Because of known masses of the samples and measurement of the ablated masses the velocity of the ablated particles was calculated. As a second method to measure the velocity of the ablated particles the vibrometer was used in a time of flight experiment. Both methods delivered the same results at a mean power of 0.5 Watt. The velocity of the ablated particles was 50 - 60 m/s. At higher mean powers the thermal behavior of the tooth material leads to higher velocities.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.