Effects of photobiomodulation using 980 and 660 nm diode lasers on osteoprotegerin and RANKL expression in periodontal ligament stem cells

energy density for 16 s twice. In group 7 (pressure alone), the cells only underwent static loading. In group 8 (no pressure/no laser), the cells did not undergo static loading or laser irradiation, and were only incubated for 48 h. Expression of OPG and RANKL genes was analyzed by quantitative real-time polymerase chain reaction (PCR). PBM with 660 and 980 nm laser at the beginning of static loading with/without a repeat irradiation at the end caused upregulation of RANKL. PBM with 660 nm laser at the beginning of static loading with/without a repeat irradiation at the end caused upregulation of OPG. PBM with 980 nm laser at the end of loading caused upregulation of OPG. PBM with 660 nm diode laser at the beginning of static loading and a repeat irradiation at the end can cause upregulation of OPG and RANKL in human PDLSCs.