UC Irvine

The purposes of this study were to evaluate the effects on cell growth and migration of fibroblasts derived from human dental pulp by lasers using three-dimensional (3-D) cell culture system, and to compare the results with those from conventional methods using a two-dimensional (2-D) cell culture system. After extirpation from twenty freshly extracted human third molars showing no clinical sign of caries, pulp tissues were cultured in Minimum Essential Medium using a conventional 2-D cell culture. The cells between 5 and 18 passages were used for this experiment, and collagen gel (1 mg/ml) was used for the 3-D cell culture system. The energy densities used were 0.52 and 1.04 J/cm2 for the gallium aluminum arsenide (GaA1As) diode laser emitting at 830 nm, and 0.1 and 1.0 J/cm2 for the argon (Ar)-dye laser emitting at 632 nm. After laser irradiation, cells were counted at 2, 4, 6, and 8 days, and observed at 3 days by stereomicroscopy. There was no significant difference in cell count between the control groups and the laser-irradiated groups (both lasers) on any day using the 2-D cell culture system (p > 0.01). However, there were significant differences in cell count between the control groups and the laser-irradiated groups (both lasers) at 8 days using the 3-D cell culture (p < 0.01). Cell migration appeared more accelerated by laser in 3-D cell culture than in the 2-D system. These results suggest that the 3-D cell culture system is useful for the evaluation of potential stimulative effects of lasers.