The Effects of Photobiomodulation Therapy on Tensile-Cultured Cementoblasts Cells

<b><i>Background:</i></b> Studies show that photobiomodulation therapy (PBMT) boosts cellular ATP production and cell growth and reduces inflammation. Additionally, mechanical tension affects gene expression, impacting cellular functions like proliferation and migration. <b><i>Objective:</i></b> We investigated the impact of PBMT on OCCM-30 cementoblast cells under tensile stress, focusing on cell survival, differentiation, and inflammatory responses, particularly relating to orthodontic tooth movement and root resorption. <b><i>Methods:</i></b> Cultured OCCM-30 cells under negative pressure received PBMT with a 10.6 μm wavelength in continuous mode at 1.0 W power for 3, 5, or 10 sec, corresponding to energy densities of 3, 5, or 10 J/cm². We assessed cell viability with the Presto Blue assay and inflammatory markers Interleukin 6 (IL-6), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) through western blots at 1, 12, 24 h, and 7 days post-irradiation. <b><i>Results:</i></b> PBMT improved cell viability over time while maintaining levels of inflammatory markers. alkaline phosphatase levels dropped initially but increased after 7 days, suggesting enhanced cementoblast differentiation. IL-6 levels rose gradually, with 3J and 5J treatments showing significantly higher levels than the control. iNOS levels spiked within the first 24 h, then declined by day 7. COX-2 levels consistently rose, with the 5J treatment showing greater increases. <b><i>Conclusions:</i></b> PBMT appears to support cementoblast survival and differentiation while managing inflammation, potentially aiding root repair during orthodontic treatments and reducing inflammatory root resorption.