RESUMEN
OBJECTIVE: The purpose of this work is to investigate the morphological changes of the rabbit tibia bone submitted to osteotomy with XeCl excimer laser. BACKGROUND DATA: Laser ablation of tissue is a relevant clinical application of high-power lasers. Due to the variety of laser wavelengths and properties of biological targets, the subject has not yet been completely explored. METHODS: In this study, four tibias were irradiated with six different durations. The applied energy density was 6.7 J/cm(2) per pulse at a 4-Hz repetition rate. RESULTS: The 24 samples had similar and well-defined craters that were free of carbonization. The ablation rates per pulse, at 60-120 seconds, were 3.8 and 1.9 microm at the compact bone and the marrow tissue, respectively. The ablation process ceased after 120 sec, with a 1.6-mm crater depth. CONCLUSIONS: In the present study, the laser used showed a self-limiting characteristic, which is a phenomenon that can be of great value in preserving important structures close to the working area, giving a margin of safety to the surgeon, in case of over-irradiation. This self-limiting effect is attributed to liquid filling the cavity by the bleeding and irrigation process.