Tissue repair is a dynamic process comprising among others inflammation, proliferation and synthesis of collagen and elastic fibers
Introduction
Tissue repair is a dynamic process comprising among others inflammation, proliferation and synthesis of collagen and elastic fibers. Starts immediately after injury and extends until remodeling phase occurs. In many researches the influence of LLLT on acceleration of biochemical reactions influencing tissue regeneration by mitotic activity, fibroblast growth or angiogenesis has been proved. Still not much is known how laser stimulates cells which synthesize fiber elements.
Purpose of the study
The purpose of the study was evaluation of biostimulative influence of LLLT on cells which synthesize collagen and fiber elements of connective tissue.
Study description
The study was published in Pesqui Odontol Bras in 2003. Original title “The influence of low-level laser therapy on biomodulation of collagen and elastic fibers”
The study covered 72 rats divided into 3 groups of 24, in which 8 mm diameter wound was produced at dorsal region. Group no. 1 was a control group, the animals from the second group received single laser treatment after surgery using Ga-Al-As laser of 670 nm wavelength and power output of 9 mW, with 4 J/cm2 on the surface of the skin. Group no. 3 received the same procedure with dosage of 8 J/cm2. Fragment of the skin with subcutaneous tissue were taken for histological analysis. During post-surgery period, the animals remained healthy, with normal healing, without clinical evidence of infection. After 24 and 48 hours in all rats concentration of necrotic and inflammatory cells mainly eosinophilic were observed but in groups with LLLT, changes were more discreet. After 3, 5 and 7 days regenerative process progress similarly in all groups, but still in laser groups mainly in this irradiated with 4 J/cm2 better vascularisation and production of higher amount of similar to normal skin collagen fibers were observed. After 14 days all animals exhibited complete epithelial formation and fibrous healing tissue, devoid cutaneous attachments.
Conclusions
The research proved that LLLT influences biomodulation of collagen and elastic fibers especially in dose of 4 J/cm2, compared to 8 J/cm2.