A histologic assessment of the influence of low-intensity laser therapy on wound healing in steroid-treated animals.
OBJECTIVE
The aim of the present study was to evaluate the effect of low-intensity laser therapy on the wound healing process treated with steroid.


BACKGROUND
Various biological effects have been associated with low-level laser therapy (LLLT).


METHODS
Forty-eight rats were used, and after execution of a wound on the dorsal region of each animal, they were divided into 4 groups (n = 12), receiving the following treatments: G1 (control), wounds and animals received no treatment; G2, wounds were treated with LLLT; G3, animals received an intraperitoneal injection of steroid dosage (2 mg/kg of body weight); G4, animals received steroid and wounds were treated with LLLT. The laser emission device used was a GaAIAs (904 nm), in a contact mode, with 2.75 mW gated with 2.900 Hz during 120 sec (33 J/cm(2)). After the period of 3, 7, and 14 days, the animals were sacrificed and the parts sent to histological processing and dyed using hematoxylin and eosin (HE) and Masson trichromium (MT) techniques.


RESULTS
The results have shown that the wounds treated with steroid had a delay in healing, while LLLT accelerated the wound healing process. Also, wounds treated with laser in the animals treated with steroid presented a differentiated healing process with a larger collagen deposition and also a decrease in both the inflammatory infiltrated and the delay on the wound healing process.


CONCLUSIONS
LLLT accelerated healing, caused by the steroid, acting as a biostimulative coadjutant agent, balancing the undesirable effects of cortisone on the tissue healing process.
Dental School of Marilia, University of Marilia, Marilia, SP, Brazil.
Eudoro S
ES
Pessoa
Ronaldo M
RM
Melhado
Letícia H
LH
Theodoro
Valdir G
VG
Garcia
D000305:Adrenal Cortex Hormones / Q000494:pharmacology*; D000818:Animals; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D028022:Low-Level Light Therapy / Q000379:methods*; D023421:Models, Animal; D051381:Rats; D017208:Rats, Wistar; D012867:Skin / Q000187:drug effects / Q000503:physiopathology / Q000528:radiation effects; D014945:Wound Healing / Q000187:drug effects* / Q000528:radiation effects*
D000305:Adrenal Cortex Hormones; D007166:Immunosuppressive Agents