title: The effects of helium-neon light therapy on healing of partial osteotomy of the tibia in streptozotocin induced diabetic rats.
abstract: OBJECTIVE
  The effect of light therapy (LT) on surgically created partial osteotomy in streptozotocin (STZ)-induced diabetic rats was examined.
  
  
  BACKGROUND
  LT has been shown to enhance bone repair in healthy human and animal models.
  
  
  METHODS
  Forty male rats were divided into groups 1 to 5. Diabetes was induced in rats of groups 1, 2, and 3 using an intraperitoneal injection of STZ. All diabetic rats were maintained for 30 days after STZ injection. Under general anesthesia and sterile conditions, a partial transversal standardized osteotomy was made in the mid-portion of the right tibia. The defects in groups 2, 3, and 5 were treated using a helium-neon (He-Ne) laser (632.8 nm, 10 mW, circular beam shape). Groups 1 and 4 were diabetic placebo and normal placebo groups, respectively. A dose of 369.4 J/cm2 for groups 2 and 5 and a dose of 66.8 J/cm2 for group 3 were applied three times a week. Six weeks after surgery, the right tibia was collected. The specimen was subjected to a three-point bending test.
  
  
  RESULTS
  LT with 369.4 J/cm2 energy density resulted in significantly greater bending stiffness in group 5 (41.8+/-5.2) than in groups 1 (18.5+/-4.1), 2 (17.7+/-1.6), and 3 (11.5+/-4) (least significant difference (LSD) test, p<0.01, p<0.001, and p<0.001, respectively). LT with 369.4 J/cm2 energy density resulted in a significantly higher stress load in group 5 (10+/-0.4) than in groups 1 (4.9+/-1.5), 2 (5.7+/-0.52), and 3 (3.9+/-1.1) (LSD test, p<0.01, p<0.01, p<0.001, respectively).
  
  
  CONCLUSIONS
  LT with a He-Ne laser in STZ-induced diabetic rats did not enhance bone repair of a partial transversal standardized osteotomy.
authors.affiliation: Medical Faculty, Cellular and Molecular Biology Research Center, Department of Pathology, Ayatollah Taleghani Hospital, Shahid Beheshti University, M.C., Tehran, Iran.
authors.forename: Shabnam
authors.initials: S
authors.lastname: Abdi
authors.forename: Mohammad
authors.initials: M
authors.lastname: Bayat
authors.forename: Farshad
authors.initials: F
authors.lastname: Javadieh
authors.forename: Zhaleh
authors.initials: Z
authors.lastname: Mohsenifar
authors.forename: Fatemesadat
authors.initials: F
authors.lastname: Rezaie
authors.forename: Maryam
authors.initials: M
authors.lastname: Bayat
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D003921:Diabetes Mellitus, Experimental; D004195:Disease Models, Animal; D017102:Fracture Healing / Q000528:radiation effects*; D006371:Helium; D028022:Low-Level Light Therapy / Q000379:methods*; D008297:Male; D009356:Neon; D010027:Osteotomy; D051381:Rats; D017208:Rats, Wistar; D018709:Statistics, Nonparametric; D013311:Streptozocin; D013314:Stress, Mechanical; D013977:Tibia / Q000293:injuries* / Q000601:surgery; D013978:Tibial Fractures / Q000532:radiotherapy*
chemical_list: D006371:Helium; D009356:Neon; D013311:Streptozocin