The effect of red, green and blue lasers on healing of oral wounds in diabetic rats

J Photochem Photobiol B. 2015 Jul;148:242-245. doi: 10.1016/j.jphotobiol.2015.04.018. Epub 2015 May 1.


Background and objective: Many studies have demonstrated that low-level laser therapy (LLLT) can improve wound healing in non-diabetic and diabetic animals. We compared the effects of red, green, and blue lasers in terms of accelerating oral wound healing in diabetic rats.

Material and methods: Diabetes was successfully induced in 32 male Wistar rats using intraperitoneal injection of Streptozotocin (150 mg/kg). After intraperitoneal injection of the anesthetic agent, a full-thickness oral wound (10 mm × 2 mm) was created aseptically with a scalpel on hard palate of the diabetic rats. The study was performed using red (630 nm), green (532 nm), and blue (425 nm) lasers and a control group. We used an energy density of 2J/cm2 and a treatment schedule of 3 times/week for 10 days. The area of wounds was measured and recorded on a chart for all rats. On the 10th day, the samples were then sacrificed and a full-thickness sample of wound area was prepared for pathological study.

Results: We observed a significant difference (p<0.001) in the mean slope values of wound healing between treatment and control groups. Moreover, the mean slope of wound healing differed significantly between red laser and two other lasers - blue and green (p<0.001). The mean slopes of wound healing were not significantly different between blue laser and green laser (p=0.777).

Conclusion: The results of the present study provide evidence that wound healing is slower in control rats compared to the treatment groups. Moreover, the findings suggest that wound healing occurs faster with red laser compared to blue and green lasers.

MeSH terms

  • Animals
  • Diabetes Mellitus, Experimental / chemically induced
  • Diabetes Mellitus, Experimental / pathology
  • Lasers*
  • Male
  • Mouth Mucosa / pathology
  • Mouth Mucosa / radiation effects
  • Rats
  • Rats, Wistar
  • Streptozocin / toxicity
  • Wound Healing / radiation effects*


  • Streptozocin