Assessment of bone repair critical defects treated with biphasic calcium phosphate and low-level laser therapy: histomorphometric study in rats

• Grant number: 15/09614-7
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): July 01, 2015
• Effective date (End): June 30, 2016
• Field of knowledge: Health Sciences - Dentistry - Periodontology
• Principal researcher: Andrea Carvalho de Marco
• Grantee: Tatiana Camacho Ribeiro
• Home Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Estadual Paulista (UNESP). Campus de São José dos Campos. São José dos Campos , SP, Brazil

Abstract

This study aims to investigate the effects of low-level laser therapy associated to Bone Ceramic® in critical defects in rats. Forty eight adult rats (Rattus norvegicus, Albinusvariation, Wistar) will be used, with 90 days of age, weighing approximately 300g. Critical defects will be made in the calvaria's bone with 5 mm diameter. The animals will be randomly divided into 4 groups: G1-bone defect + blood clot, G2-bone defect + biphasic calcium phosphate (BCP), G3-bone-defect + LLLT, G4-bone-defect + biphasic calcium phosphate (BCP) + LLLT. Each group will be subdivided in accordance with the observational periods of 30 to 60 days, with 6 mice in each subgroup. A low-power GaAlAs with a wavelength of 660 nm, 30 mW, 0.04 cm2 area. LLLT will be applied on 5 points so that the entire wound uniformly receive treatment. Four points of application will be distributed along the edges of the surgical wound in clockwise from 3, 6, 9 and 12 hours, respectively. And one point in the central region of the surgical wound. Irradiation will be released by 12 seconds per point (total time of exposure: 1 minute), with a total energy density of 45 J/cm2. Laser irradiation will happen immediately after the procedure. On 30 and60 days, 6 animals in each group will be sacrificed by overdose of general anesthesia. Then the calvarias will be removed for histological, histomorphometric and analysis. All data will be statistically analyzed by ANOVA complemented by Tukey test to verify the statistical differences between groups. significance level will be 5%.