Effect of Low-Level Laser Therapy with Output Power of 30 mW and 60 mW in the Viability of a Random Skin Flap

Abstract Objective: To assess the effects of low-level laser therapy (LLLT) with output power of 30 and 60 mW in the viability of a random skin flap in rats. Background Data: Output power values in LLLT are not well defined. Materials and Methods: Controlled, single-blind experimental study. Thirty-six animals were randomly distributed into three groups: sham group (SG), 30-mW output power (30G), and 60-mW output power (60G). In both treated groups, a fluency of 3 J/cm2 was used. Two minutes after elevation of a random-pattern cranially based dorsal flap (4 × 10 cm), laser irradiation was applied and repeated on the first, second, third, and fourth postoperative days. Percentages of flap necrosis were calculated on the seventh postoperative day. Also, four fragments of each flap were collected to allow determination of the percentages of vascular density according to the bidimensional method of the morphometric analysis of blood vessels. Statistical analysis included the Wilcoxon test and Kruskal-Wallis v...