Comparative histological analysis of bone healing of standardized bone defects performed with the Er:YAG laser and steel burs

This study compares the bone repair process after ostectomies performed either with the erbium:yttrium-aluminum-garnet (Er:YAG) laser or with the low-speed bur drilling. Eighteen rats were used for this study. In the control group, the ostectomy was performed with a low-speed bur drilling. In the experimental group, the ostectomy was made with an Er:YAG laser (500 mJ, 10 Hz). At 7 and 14 days after surgery, the experimental group presented earlier bone repair in comparison to the control group. The experimental group presented an altered layer of approximately 24-μm thickness, whereas the control group did not present any altered layer in the margins of the ostectomies. At 21 days, the histological features of the two groups were very similar, although the altered layer could still be seen. The Er:YAG laser successfully promoted the ablation of the bone tissue, but caused some thermal damage at the margins of the ostectomies.