Photobiomodulation of alveolar bone healing in rats with low-level laser and light emitting diode therapy

The present study investigates the potential contribution of Photobiomodulation (PBM) to the regeneration of the bone following the extraction of the first mandibular molar in rats. The study evaluates the efficacy of PBM, using both Low-Level Laser Therapy (LLLT) and Light-Emitting Diode Therapy (LEDT), as promotors of osteoblastic activity and the formation of new bone. Study design, setting, and sample: 45 male Wistar rats were divided randomly into three groups of 15 individuals - (i) control group (left lower molar removed only), (ii) the LLL group (molar removed, followed by LLLT), and (iii) the LED group (molar removed, followed by LEDT). Each of these groups was divided into three subgroups of five rats, which were monitored for 7, 14 or 28 days following the extraction of the tooth. For analysis, the bone of the right mandibular hemiarch was extracted and the specimens were stained with Hematoxylin and Eosin. Microscopic morphological analysis revealed that the LED therapy had promoted greater bone remodeling activity at 7 and 14 days post-extraction, whereas the LLLT promoted the generation of more mature bone tissue, but more slowly overall. The quantitative analysis revealed a significant increase in the area of bone activity and the osteoblast count in both PBM groups in comparison with the control. Photobiomodulation, using either low-level laser or LED therapy, is effective for both bone regeneration and osteoblast activity following dental injury in rats. While the LED therapy initially presented higher levels of remodeling activity, the laser produced more mature bone tissue over time. These findings indicate that PBM is a promising therapeutic alternative for healing bone, with the potential for the improvement of postoperative outcomes in dental practise.