Application of low-level laser irradiation (LLLI) and rhBMP-2 in critical bone defect of ovariectomized rats:...

The aim of this study was to evaluate the osteogenic potential of recombinant human bone morphogenetic protein-2 (rhBMP-2) and low-level laser irradiation (LLLI), isolated or combined in critical bone defects (5 mm) in parietal bone using ovariectomized female rats as an experimental animal model.

Forty-nine female Wistar rats, bilaterally ovariectomized (OVX), were divided into seven treatment groups of seven animals each: (I) laser in a single application, (II) 7 μg of pure rhBMP-2, (III) laser and 7 μg of pure rhBMP-2, (IV) 7 μg of rhBMP-2/monoolein gel, (V) laser and 7 μg of rhBMP-2/monoolein gel, (VI) laser and pure monoolein gel, and (VII) critical bone defect controls. The low-level laser source used was a gallium aluminum arsenide semiconductor diode laser device (λ = 780 nm, D = 120 J/cm(2)).

Groups II and III presented higher levels of newly formed bone than all other groups with levels of 40.57% and 40.39%, respectively (p < 0.05). The levels of newly formed bone of groups I, IV, V, and VI were similar with levels of 29.67%, 25.75%, 27.75%, and 30.64%, respectively (p > 0.05). The area of new bone formation in group VII was 20.96%, which is significantly lower than groups I, II, III, and VI.

It was concluded that pure rhBMP-2 and a single dose of laser application stimulated new bone formation, but the new bone formation area was significantly increased when only rhBMP-2 was used. Additionally, the laser application in combination with other treatments did not influence the bone formation area.