Comparação de diferentes protocolos de irradiação de laser infravermelho sobre o reparo em áreas enxertadas com osso bovino desproteinizado

Abstract

Objective: To compare the effect of different numbers of sessions of photobiomodulation (PBMT) with infrared light on the repair in grafted areas with deproteinized bovine bone (DBB). Materials and methods: 36 rats were used, divided into 3 groups of 12 animals each. The grouping follows the photobiomodulation protocol (PBMT) with infrared laser to be applied to the grafted area: CTR: non-irradiated grafted area; IRL4: grafted area irradiated with infrared laser in 4 sessions; IRL7: grafted area irradiated with infrared laser in 7 sessions. The surgical procedure to insert capsules containing deproteinized bovine bone and laser application was performed bilaterally on the lateral face of the mandible and after a period of 30 and 90 days, the animals were euthanized by anesthetic overdose, and the branches of the mandible were removed to microtomographic evaluation, to evaluate the volume of mineralized tissues; histomorphometric, to determine the percentage of bone and biomaterial in the space between the dome and the lateral face of the mandibular ramus; and immunohistochemistry to detect bone morphogenetic protein (BMP-2), osteocalcin (OCN), alkaline phosphatase (ALP) and tartar-resistant acid phosphatase (TRAP). Results: The application of PBMT altered the volume, the microstructure of the grafted tissue and improved the tissue repair of the grafted areas, regardless of the number of irradiation sessions. Conclusion: The PBMT improves tissue repair in grafted areas in both 4 and 7 sessions. However, the application of PBMT in 7 sessions is more beneficial in bone formation when compared to non-irradiated grafted areas.