title: Transdentinal photobiostimulation of stem cells from human exfoliated primary teeth.
abstract: OBJECTIVE
  To evaluate the effects of infrared light-emitting diode (LED) irradiation on stem cells from human exfoliated deciduous teeth (SHEDs).
  
  
  METHODS
  Exfoliated primary teeth were obtained (n = 3), and SHEDs obtained from the teeth were seeded on the pulpal surface of 0.2-mm-thick dentine discs produced from permanent molars. The cells were incubated for 24 h by placing the discs in plain Dulbecco's modified Eagle's medium (DMEM). The DMEM was then replaced with new culture medium formulated for odontoblast differentiation. After 12 h in the second medium, SHEDs were irradiated through the dentine discs using an infrared LED (850 nm) with a power density of 80 mW cm-2. Energy doses (EDs) delivered to the occlusal surface of the dentine discs were 0 (control), 2 and 4 J cm-2(n = 6). Subsequent tests were performed 72 h after irradiation. These tests included cell viability (MTT), alkaline phosphatase activity (ALP), total protein production (TP), scanning electron microscopy (SEM), as well as gene expression for ALP, Col I, DSPP and DMP-1. Data were analysed using Kruskal-Wallis and Mann-Whitney t-tests (α = 0.05).
  
  
  RESULTS
  Both EDs (2 and 4 J cm-2) significantly increased cell viability and ALP activity. For TP, ALP and Col I gene expression, only the 4 J cm-2group had significantly higher values compared to the control group. Cell morphology was not affected by irradiation.
  
  
  CONCLUSIONS
  Infrared LED irradiation was capable of biostimulating SHEDs through a 0.2 mm thickness of dentine, especially at the 4 J cm-2level.
authors.affiliation: Department of Pediatric Dentistry and Orthodontics, Uberlândia School of Dentistry, Universidade Federal de Uberlândia (UFU), Uberlândia, Minas Gerais, Brazil.
authors.forename: A P
authors.initials: AP
authors.lastname: Turrioni
authors.affiliation: Department of Physiology and Pathology, Araraquara School of Dentistry, Universidade Estadual Paulista (UNESP), Araraquara, São Paulo, Brazil.
authors.forename: F G
authors.initials: FG
authors.lastname: Basso
authors.affiliation: Department of Pediatric Dentistry and Orthodontics, Araraquara School of Dentistry, Universidade Estadual Paulista (UNESP), Araraquara, São Paulo, Brazil.
authors.forename: L A
authors.initials: LA
authors.lastname: Montoro
authors.affiliation: Department of Operative Dentistry, Araraquara School of Dentistry, Universidade Estadual Paulista (UNESP), Araraquara, São Paulo, Brazil.
authors.forename: L F D
authors.initials: LFD
authors.lastname: Almeida
authors.affiliation: Department of Physiology and Pathology, Araraquara School of Dentistry, Universidade Estadual Paulista (UNESP), Araraquara, São Paulo, Brazil.
authors.forename: C A
authors.identifier: http://orcid.org/0000-0002-7455-6867
authors.initials: CA
authors.lastname: de Souza Costa
authors.affiliation: Department of Pediatric Dentistry and Orthodontics, Araraquara School of Dentistry, Universidade Estadual Paulista (UNESP), Araraquara, São Paulo, Brazil.
authors.forename: J
authors.initials: J
authors.lastname: Hebling
mesh_terms: D002470:Cell Survival; D003804:Dentin / Q000528:radiation effects; D006801:Humans; D008027:Light; D013234:Stem Cells / Q000166:cytology* / Q000528:radiation effects; D014080:Tooth Exfoliation / Q000378:metabolism*; D014094:Tooth, Deciduous / Q000166:cytology* / Q000528:radiation effects
keywords: dentine; odontoblasts; phototherapy; protein expression; pulp biology; stem cells