Computerized Morphometric Assessment of the Effect of Low-Level Laser Therapy on Bone Repair: An Experimental Animal Study

Journal of Clinical Laser Medicine & Surgery Volume 20, No 2: 83–87 (2002)

Aurelí Cio N. Silva Junior M.S., Antonio L.B. Pinheiro, Ph.D., Marília G. Oliveira Ph.D., Ruben Weismann Ph.D.,  Luciana Maria Pedreira Ramalho, Ph.D.,  and Renata Amadei Nicolau, M.S. 

Objective: The  aim  of  this  study  was  to  evaluate  morphometricly  the  amount  of  newly  formed  bone  after GaAlAs laser irradiation of surgical wounds created in the femur of rats. Background

Data: Low-level laser therapy (LLLT) has been used in several medical specialties because of its biomodulatory effects on different biological tissues. However, LLLT is still controversial because of contradictory reports. This is a direct result of the different methodologies used in these works.

Materials and Methods: In this study, 40 Wistar rats were divided into four groups of 10 animals each: group A (12 sessions, 4.8 J/ cm 2per session, observation time of 28 days); group C (three sessions, 4.8 J/ cm 2per session, observation time of 7 days). Groups B and D acted as non-irradiated controls. The specimens were routinely processed to wax and cut at 6-mm thickness and stained with H&E. For computerized morphometry, Imagelab ®software was used.

Results: Computerized morphometry  showed  a  significant  difference  between  the  areas  of  mineralized  bone  in  groups  C  and  D  ( p = 0.017). There was no difference between groups A and B (28 days; p = 0.383).

Conclusion: It is concluded that, under this experimental condition, LLLT increased bone repair at early bone healing. 

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