J Dent Hyg Sci.  2019 Mar;19(1):39-47. 10.17135/jdhs.2019.19.1.39.

Biological Effects of Light-Emitting Diodes Curing Unit on MDPC-23 Cells and Lipopolysaccharide Stimulated MDPC-23 Cells

• Jeong MJ
• Jeong SJ

• KMID: 2446703
• DOI: http://doi.org/10.17135/jdhs.2019.19.1.39

Abstract

BACKGROUND
Light-emitting diodes curing unit (LCU), which emit blue light, is used for polymerization of composite resins in many dentistry. Although the use of LCU for light-cured composite resin polymerization is considered safe, it is still controversial whether it can directly or indirectly have harmful biological influences on oral tissues. The aim of this study was to elucidate the biological effects of LCU in wavelengths ranging from 440 to 490 nm, on the cell viability and secretion of inflammatory cytokines in MDPC-23 odontoblastic cells and inflammatory-induced MDPC-23 cells by lipopolysaccharide (LPS).
METHODS
The MTT assay and observation using microscope were performed on MDPC-23 cells to investigate the cell viability and cytotoxic effects on LCU irradiation.
RESULTS
MDPC-23 cells and LPS stimulated MDPC-23 cells were found to have no effects on cell viability and cell morphology in the LCU irradiation. Nitric oxide (NO) and prostaglandin E2 which are the pro-inflammatory mediators, and interleukin-1β and tumor necrosis factor-α (TNF-α) which are the proinflammatory cytokines were significantly increased in MCPD-23 cells after LCU irradiation as time increased in comparison with the control. LCU irradiation has the potential to induce inflammation or biological damages in normal dental tissues, including MDPC-23 cells.
CONCLUSION
Therefore, it is necessary to limit the use of LCU except for the appropriate dose and irradiation time. In addition, LCU irradiation of inflammatory-induced MDPC-23 cells by LPS was reduced the secretion of NO compared to the LPS alone treatment group and was significantly reduced the secretion of TNF-α in all the time groups. Therefore, LCU application in LPS stimulated MDPC-23 odontoblastic cells has a photodynamic therapy like effect as well as inflammation relief.

Keyword

Inflammation; Light-emitting diodes curing unit; Lipopolysaccharide; MDPC-23 cell; Photodynamic therapy

MeSH Terms

Cell Survival
Composite Resins
Cytokines
Dentistry
Dinoprostone
Inflammation
Necrosis
Nitric Oxide
Odontoblasts
Photochemotherapy
Polymerization
Polymers
Composite Resins
Cytokines
Dinoprostone
Nitric Oxide
Polymers