title: Metabolic activity of odontoblast-like cells irradiated with blue LED (455 nm).
abstract: Blue light emitting diodes (LEDs) are frequently used in dentistry for light activation of resin-based materials; however, their photobiostimulatory effects have not yet been fully investigated. This study aimed to investigate the effect of blue LED (455 nm) on the metabolism of odontoblast-like cells MDPC-23. Energy doses of 2 and 4 J/cm(2) were used at 20 mW/cm(2) fixed power density. MDPC-23 cells were seeded at 10,000 cells/cm(2) density in Dulbecco's modified Eagle's medium (DMEM) containing 10 % fetal bovine serum (FBS). After 12 h, the culture medium was replaced with new DMEM supplemented with 0.5 % of FBS, and the cells were incubated for further 12 h. After that, single irradiation was performed to the culture, under selected parameters. Cell viability evaluations (Alamar Blue Assay, n = 12), number of viable cells (Trypan Blue Assay, n = 12), morphological analysis by scanning electron microscopy (SEM, n = 2), gene expression (n = 6) of alkaline phosphatase (Alp), collagen (Col-1a1), and dental matrix protein (Dmp-1) (quantitative polymerase chain reaction (qPCR)) were performed 72 h after irradiation. Data were analyzed by Kruskal-Wallis, ANOVA, and Tukey tests (p < 0.05). Direct light application at 4 J/cm(2) energy dose had no negative effects on cell viability, while irradiation with 2 J/cm(2) reduced cell metabolism. None of doses affected the number of viable cells compared with the control group. The two energy doses downregulated the expression of Alp; however, expression of Col-1a1 and Dmp-1 had no alteration. Cells presented change in the cytoskeleton only when irradiated with 2 J/cm(2). In conclusion, the blue LED (455 nm) irradiation, under the evaluated parameters, had no biostimulatory effects on MDPC-23 cells.
authors.affiliation: Department of Restorative Dentistry, Araraquara Dental School, "Univ. Estadual Paulista-UNESP", Araraquara, SP, Brazil.
authors.forename: Leopoldina Fátima Dantas
authors.initials: LF
authors.lastname: de Almeida
authors.affiliation: Department of Orthodontics and Pediatric Dentistry, Araraquara Dental School, "Univ. Estadual Paulista-UNESP", Rua Humaitá, 1680, Araraquara, SP, Brazil.
authors.forename: Fernanda Gonçalves
authors.initials: FG
authors.lastname: Basso
authors.affiliation: Department of Orthodontics and Pediatric Dentistry, Araraquara Dental School, "Univ. Estadual Paulista-UNESP", Rua Humaitá, 1680, Araraquara, SP, Brazil.
authors.forename: Ana Paula Silveira
authors.initials: AP
authors.lastname: Turrioni
authors.affiliation: Department of Physiology and Pathology, Araraquara Dental School, "Univ. Estadual Paulista-UNESP", Araraquara, SP, Brazil.
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: de-Souza-Costa
authors.affiliation: Department of Orthodontics and Pediatric Dentistry, Araraquara Dental School, "Univ. Estadual Paulista-UNESP", Rua Humaitá, 1680, Araraquara, SP, Brazil. jhebling@foar.unesp.br.
authors.forename: Josimeri
authors.initials: J
authors.lastname: Hebling
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D002417:Cattle; D002460:Cell Line; D002470:Cell Survival / Q000528:radiation effects; D015971:Gene Expression Regulation, Enzymologic / Q000528:radiation effects; D008027:Light; D009804:Odontoblasts / Q000166:cytology / Q000378:metabolism* / Q000528:radiation effects*; D012666:Semiconductors
chemical_list: D000469:Alkaline Phosphatase
keywords: Cell metabolism; Cell proliferation; Odontoblasts; Phototherapy