Effects of the combination of low-level laser irradiation and recombinant human bone morphogenetic protein-2 in bone repair

Author(s):Show less -

Rosa, Anderson Paim ^[1] ; de Sousa, Luiz Gustavo ^[1] ; Hallak Regalo, Simone Cecilio ^[1] ; Mardegan Issa, Joao Paulo ^[1] ; Amorim Barbosa, Ana Paula ^[1] ; Pitol, Dimitrius Leonardo ^[1] ; de Oliveira, Richard Honorato ^[1] ; de Vasconcelos, Paulo Batista ^[1] ; Dias, Fernando Jose ^[1] ; Chimello, Daniela Thomazatti ^[1] ; Siessere, Selma ^[1]

Affiliation

^[1] Univ Sao Paulo, Dept Morphol Stomatol & Physiol, Sch Dent Ribeirao Preto, BR-14040904 Sao Paulo - Brazil

• Document type: Journal article
• Source: Lasers in Medical Science; v. 27, n. 5, p. 971-977, SEP 2012.
• Web of Science Citations: 14

Abstract

Low-level laser irradiation (LLLI) and recombinant human bone morphogenetic protein type 2 (rhBMP-2) have been used to stimulate bone formation. LLLI stimulates proliferation of osteoblast precursor cells and cell differentiation and rhBMP-2 recruits osteoprogenitor cells to the bone healing area. This in vivo study evaluated the effects of LLLI and rhBMP-2 on the bone healing process in rats. Critical bone defects were created in the parietal bone in 42 animals, and the animals were divided into six treatment groups: (1) laser, (2) 7 mu g of rhBMP-2, (3) laser and 7 mu g of rhBMP-2, (4) 7 mu g of rhBMP-2/monoolein gel, (5) laser and 7 mu g rhBMP-2/monoolein gel, and (6) critical bone defect controls. A gallium-aluminum-arsenide diode laser was used (wavelength 780 nm, output power 60 mW, beam area 0.04 cm(2), irradiation time 80 s, energy density 120 J/cm(2), irradiance 1.5 W/cm(2)). After 15 days, the calvarial tissues were removed for histomorphometric analysis. Group 3 defects showed higher amounts of newly formed bone (37.89%) than the defects of all the other groups (P < 0.05). The amounts of new bone in defects of groups 1 and 4 were not significantly different from each other (24.00% and 24.75%, respectively), but were significantly different from the amounts in the other groups (P < 0.05). The amounts of new bone in the defects of groups 2 and 5 were not significantly different from each other (31.42% and 31.96%, respectively), but were significantly different from the amounts in the other groups (P < 0.05). Group 6 defects had 14.10% new bone formation, and this was significantly different from the amounts in the other groups (P < 0.05). It can be concluded that LLLI administered during surgery effectively accelerated healing of critical bone defects filled with pure rhBMP-2, achieving a better result than LLLI alone or the use of rhBMP-2 alone. (AU)