Low-level laser therapy improves bone formation: stereology findings for osteoporosis in rat model

Author(s):Show less -

Scalize, Priscilla Hakime ^[1] ; de Sousa, Luiz Gustavo ^[1] ; Hallak Regalo, Simone Cecilio ^[1] ; Semprini, Marisa ^[1] ; Pitol, Dimitrius Leonardo ^[1] ; da Silva, Giselle Aparecida ^[1] ; Coelho, Jessica de Almeida ^[1] ; Coppi, Antonio Augusto ^[2] ; Lobo Laad, Aliny A. B. ^[3] ; Bombonato Prado, Karina Fittipaldi ^[1] ; Siessere, Selma ^[1]

Affiliation

^[1] Univ Sao Paulo, Sch Dent Ribeirao Preto, Dept Morphol Physiol & Basic Pathol, BR-14049 Ribeirao Preto, SP - Brazil

^[2] Univ Surrey, Fac Hlth & Med Sci, Sch Vet Med, Guildford GU2 5XH, Surrey - England

^[3] Univ Sao Paulo, LSSCA, Dept Surg, Coll Vet Med & Anim Sci, Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Lasers in Medical Science; v. 30, n. 5, p. 1599-1607, JUL 2015.
• Web of Science Citations: 9

Abstract

Low-level laser therapy (LLLT) benefits bone metabolism, but its use needs to be standardized. We evaluated the effects of LLLT on bone defects in calvaria of ovariectomized rats. Stereology was used to calculate tissue repair volume (V (tr) ), density of trabecular bone volume (Vv (t) ), total volume of newly formed trabecular bone (Vtot), and the area occupied by collagen fibers (A (C) ). Fifty-four Wistar rats were submitted to bilateral ovariectomy, and bone defects were created in calvaria after 150 days. The animals were divided into nine groups (n = 6), and 24 h after defects, the treatment started with a 780-nm low-intensity GaAlAs laser: G1, G2, and G3 received 3 sessions of 0, 20, and 30 J/cm(2) respectively; G4, G5, and G6 received 6 sessions of 0, 20, and 30 J/cm(2), respectively; and G7, G8, and G9 received 12 sessions of 0, 20, and 30 J/cm(2), respectively. A normal distribution was found for all of the data. The test used to verify the normality was the Kolmogorov-Smirnov (KS, p > 0.05). The one-way ANOVA followed by Tukey's post hoc test was used for data processing. A difference of p < 0.05 was considered statistically significant. Groups G2 and G1 showed significance for V (tr) , Vv (t) , Vtot, and (A (C) ). Results were significant for (Vv (t) ) and (Vtot) between G3 and G1. There were no significant results between G5 and G4 as well as between G8 and G7. Groups G6 and G4 results showed statistical difference for V (tr) , Vv (t) , Vtot, and (A (C) ). Groups G9 and G7 showed significance for V (tr) , Vv (t) , Vtot, and (A (C) ). In conclusion, there was new bone formation in the groups that received 20 and 30 J/cm(2) when compared to control groups, but over time, the dose of 30 J/cm(2) showed better stereological parameters when compared to 20 J/cm(2). (AU)

• FAPESP's process: 12/10184-9 - Influence of different doses and number of applications of low-level laser irradiation on bone repair in calvaria bone defects in Wistar rats with an experimental model of osteoporosis
• Grantee: Priscilla Hakime Scalize
• Support Opportunities: Scholarships in Brazil - Master