Low-level laser therapy affects dentinogenesis and angiogenesis of in vitro 3D cultures of dentin-pulp complex

Lasers Med Sci. 2019 Oct;34(8):1689-1698. doi: 10.1007/s10103-019-02804-6. Epub 2019 May 27.

Abstract

To investigate the effects of gallium-aluminum-arsenide (GaAlAs) diode laser low-level laser therapy (LLLT) on angiogenesis and dentinogenesis of the dentin-pulp complex in a human tooth slice-based in vitro model. Forty tooth slices were prepared from 31 human third molars. Slices were cultured at 37 °C, 5% CO2, and 95% humidity and randomly assigned to one of the following groups: group I: no laser treatment, group II: 660-nm diode laser; energy density = 1 J/cm2, group III: 660-nm diode laser; energy density = 3 J/cm2, group IV: 810-nm diode laser; energy density = 1 J/cm2 and group V: 810-nm diode laser; energy density = 3 J/cm2. LLLT was applied on the third and fifth days of culture. After 7 days, tissues were retrieved for real-time RT-PCR analysis to investigate the expression of VEGF, VEGFR2, DSPP, DMP-1, and BSP in respect to controls. Lower energy density (1 J/cm2) with the 660 nm wavelength showed a statistically significant up-regulation of both angiogenic (VEGF: 15.3-folds and VEGFR2: 3.8-folds) and odontogenic genes (DSPP: 6.1-folds, DMP-1: 3-fold, and BSP: 6.7-folds). While the higher energy density (3 J/cm2) with the 810 nm wavelength resulted in statistically significant up-regulation of odontogenic genes (DSPP: 2.5-folds, DMP-1: 17.7-folds, and BSP: 7.1-folds), however, the angiogenic genes had variable results where VEGF was up-regulated while VEGFR2 was down-regulated. Low-level laser therapy could be a useful tool to promote angiogenesis and dentinogenesis of the dentin-pulp complex when parameters are optimized.

Keywords: Angiogenesis; Dentin-pulp complex; Dentinogenesis; Low-level laser therapy; Tooth slice model.

MeSH terms

  • Adult
  • Cell Culture Techniques*
  • Dental Pulp / radiation effects*
  • Dentinogenesis / radiation effects*
  • Female
  • Humans
  • Low-Level Light Therapy* / methods
  • Male
  • Neovascularization, Physiologic / radiation effects
  • Odontogenesis / radiation effects
  • Young Adult