Send to

Choose Destination
J Biophotonics. 2016 Dec;9(11-12):1222-1235. doi: 10.1002/jbio.201600016. Epub 2016 Sep 20.

Low-level laser therapy stimulates bone metabolism and inhibits root resorption during tooth movement in a rodent model.

Author information

CLA - Center for Laser and Applications, Nuclear and Energy Research Institute, IPEN-CNEN/SP, Brazil.
Department of Microbiology, São Leopoldo Mandic School and Dental Institute, Campinas, SP, Brazil.
Department of Orthodontics, São Leopoldo Mandic School and Dental Institute, Campinas, SP, Brazil.
Department of Basic Science and Embryology and Histology, Dental School of Araçatuba - UNESP, Brazil.
Section of Orthodontics, UCLA School of Dentistry, Los Angeles, CA, USA.


This study evaluated the biological effects of low-level laser therapy (LLLT) on bone remodeling, tooth displacement and root resorption, occurred during the orthodontic tooth movement. Upper first molars of a total of sixty-eight male rats were subjected to orthodontic tooth movement and euthanized on days 3, 6, 9, 14 and 21 days and divided as negative control, control and LLLT group. Tooth displacement and histomorphometric analysis were performed in all animals; scanning electron microscopy analysis was done on days 3, 6 and 9, as well as the immunohistochemistry analysis of RANKL/OPG and TRAP markers. Volumetric changes in alveolar bone were analyzed using MicroCT images on days 14 and 21. LLLT influenced bone resorption by increasing the number of TRAP-positive osteoclasts and the RANKL expression at the compression side. This resulted in less alveolar bone and hyalinization areas on days 6, 9 and 14. LLLT also induced less bone volume and density, facilitating significant acceleration of tooth movement and potential reduction in root resorption besides stimulating bone formation at the tension side by enhancing OPG expression, increasing trabecular thickness and bone volume on day 21. Taken together, our results indicate that LLLT can stimulate bone remodeling reducing root resorption in a rat model. LLLT improves tooth movement via bone formation and bone resorption in a rat model.


OPG; RANKL; TRAP; bone remodeling; microCT; near infrared laser; root resorption

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center