Cell growth modulation of human cells irradiated in vitro with low-level laser therapy.

Objective: The aim of this study was to investigate the effects of different wavelengths and doses of laser radiation on in vitro cell proliferation. We evaluated the biological effects of low-level laser therapy (LLLT) on two human cancer cell lines: HeLa (epithelial adenocarcinoma) and TK6 (lymphoblast). Our attention was focused on the combination of the two laser emissions as it could have a synergic effect greater than the single emission applied separately.