Pulse Laser Water-mediated Ablation Of Bovine Shank Bone Using High Speed Photography

Laser-induced bone hard tissue ablation has broad applications in dentistry, bone and ear surgery. Improving ablation efficiency and reducing thermal damage are the hot topics in the field of laser ablation. Base on development status and clinical needs of laser ablation technology at home and abroad, the experimental study on the interaction between laser, water and hard tissue was investigated by high speed photography.Firstly, the structure and optical properties of bone hard tissue were summarized; the mechanism of laser-tissue interaction and water-mediated laser ablation were reviewed; the major research methods were discussed.Secondly, the dynamic process of vapor channel formation induced by pulsed CO2laser in water was monitored by high speed camera. The formation threshold was determined and the relationship of radiant exposure, pulsation period, maximum longitudinal depth and corresponding width versus laser power were obtained.Again, the dynamic process of cavitation bubble induced by pulsed Ho:YAG laser under liquid medium was studied by high speed camera. The spatial and temporal dynamics of longitudinal length and transverse width were assessed; the dependents of the maximum longitudinal length and transverse width, volume, pulsation period on incident radiant energy were evaluated; Moreover, the influence of absorption and scattering coefficient on the pulsation characteristics of cavitation bubble were obtained.Finally, the influence of different irradiation conditions (with or without water) on bovine shank bone ablation with CO2laser and Ho:YAG laser were investigated by high speed camera. The surface morphology of bovine shank bone was assessed with stereomicroscope.