Low intensity lasertherapy associated with experimental orthodontic movement in rats: assessment of bone remodeling

• Grant number: 14/09579-4
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): August 01, 2014
• Effective date (End): July 31, 2015
• Field of knowledge: Health Sciences - Dentistry
• Principal researcher: João Paulo Mardegan Issa
• Grantee: Carolina Ferreira Gonçalves
• Home Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

The tooth movement is associated with pathological and physiological responses resulting from the application of external forces with the goal of bone remodeling, resulting in areas of compression and tension of the alveolar bone. With this, there is installation of an inflammatory process responsible for the stimulation of the osteoblasts and osteoclasts. However, this periodontal response involves release of cytokines and prostaglandins that cause bone remodeling as well as soreness. Thus, it has been sought to the supporting tooth movement therapies to reduce the treatment time and improve pain symptoms. In this context, low intensity laser therapy (LLLT) has been effective for pain relief , and can promote the acceleration of tooth movement . However , the biological basis of this treatment are not yet fully understood this way , this project will aim to investigate the cellular events ( osteoclast activity and bone remodeling ) in experimental tooth movement model in rats submitted or not to LLLT ( single session or 3 sessions consecutive days) , 7 days and 14 days after the start of the experiments. For this, Wistar rats ( 250 g) rats are used and subjected to fixation on the upper central incisors an apparatus consisting of double helical spring welded to its ends two bands with an initial distal movement force of 35 g on each end. For LLLT sessions will be used low intensity laser (wavelength 780 nm , output 40 mW, 10 s) in which one of the active light emitting means comprises gallium - aluminum - arsenide ( GaAlAs , energy density of 10 J/cm2 . for analysis , the colorations of masson trichrome , hematoxylin - eosin ( HE ) and picrosirius red will be held . With this project we intend to characterize the cellular events (number of osteoclasts, osteoblasts) and bone remodeling that accompanies LLLT associated tooth movement seeking the rationale for the use of this treatment as an adjunct to clinical dentistry.