title: Effect of low-level laser therapy on odontoblast-like cells exposed to bleaching agent.
abstract: The aim of the present study was to evaluate the effect of low-level laser therapy (LLLT) on odontoblast-like MDPC-23 cells exposed to carbamide peroxide (CP 0.01%-2.21 μg/mL of H2O2). The cells were seeded in sterile 24-well plates for 72 h. Eight groups were established according to the exposure or not to the bleaching agents and the laser energy doses tested (0, 4, 10, and 15 J/cm(2)). After exposing the cells to 0.01% CP for 1 h, this bleaching solution was replaced by fresh culture medium. The cells were then irradiated (three sections) with a near-infrared diode laser (InGaAsP-780 ± 3 nm, 40 mW), with intervals of 24 h. The 0.01% CP solution caused statistically significant reductions in cell metabolism and alkaline phosphate (ALP) activity when compared with those of the groups not exposed to the bleaching agent. The LLLT did not modulate cell metabolism; however, the dose of 4 J/cm(2) increased the ALP activity. It was concluded that 0.01% CP reduces the MDPC-23 cell metabolism and ALP activity. The LLLT in the parameters tested did not influence the cell metabolism of the cultured cells; nevertheless, the laser dose of 4 J/cm(2) increases the ALP activity in groups both with and without exposure to the bleaching agent.
authors.affiliation: Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas-UNICAMP, Avenida Limeira, 901, 13404-903, Piracicaba, Sao Paulo, Brazil.
authors.forename: Adriano Fonseca
authors.initials: AF
authors.lastname: Lima
authors.forename: Ana Paula Dias
authors.initials: AP
authors.lastname: Ribeiro
authors.forename: Fernanda Gonçalves
authors.initials: FG
authors.lastname: Basso
authors.forename: Vanderlei Salvador
authors.initials: VS
authors.lastname: Bagnato
authors.forename: Josimeri
authors.initials: J
authors.lastname: Hebling
authors.forename: Giselle Maria
authors.initials: GM
authors.lastname: Marchi
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: de Souza Costa
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D057886:Bleaching Agents; D000077463:Carbamide Peroxide; D002478:Cells, Cultured; D006861:Hydrogen Peroxide; D028022:Low-Level Light Therapy / Q000379:methods*; D051379:Mice; D009804:Odontoblasts / Q000528:radiation effects*; D010545:Peroxides; D014508:Urea / Q000031:analogs & derivatives
chemical_list: D057886:Bleaching Agents; D010545:Peroxides; D000077463:Carbamide Peroxide; D014508:Urea; D006861:Hydrogen Peroxide; D000469:Alkaline Phosphatase