Ablation of porcine bone tissue with an ultrashort pulsed laser (USPL) system

Ultrashort pulsed lasers (USPLs) represent a new generation of laser systems in the field of biophotonical applications. In terms of a pilot project, the study was carried out to evaluate the ablation parameters of bone tissue regarding the medical use of such a laser technology in dentistry. Specimens from ribs of freshly slaughtered pigs were assembled and irradiated with an USP Nd:YVO4 laser (pulse duration 8 ps at 1,064 nm with repetition rates between 50 and 500 kHz) using eligible average output powers in the range of 3.5-9 W and fluences between 1 and 2.5 J/cm(2). Square-shaped cavities of 1-mm edge length in the bone compacta were created employing a scanner system. Cavities were analyzed with an optical profilometer to determine the ablated volume. Ablation rate was calculated by the ablated volume and the recorded irradiation time by the scanner software. Additionally, samples were examined histologically to investigate side effects of the surrounding tissue. Formed cavities showed a precise and sharp-edged appearance in bone compacta. Optimized ablation rate of 5.2 mm(3)/min without any accompanying side effects was obtained with an average output power of 9 W, a pulse repetition rate of 500 kHz, and an applied fluence of 2.5 J/cm(2). Provided that the used laser system will be advanced and adjusted for clinical applications, the outcome of this study shows auspicious possibilities for the use of USPL systems in the preparation of bone tissue.