An in vitro study with cultured human gingival fibroblasts in high-glucose medium determined the antiinflammatory effect of low-level laser irradiation by assessing the expression of proinflammatory genes including IL-1β with quantitative real-time polymerase chain reaction, and LBT was suggested as a beneficial tool for the treatment of periodontal disease in DM patients [43]. The gene discussed is IL1B; the disease is periodontal disorder.