Effects of Carbon Dioxide Laser Irradiation on Human Pulp Fibroblasts

The aim of this study was to evaluate the effects of pulsed CO2 laser irradiation on human pulp fibroblast. Pulp fibroblasts were collected from extracted human third molars. The fibroblasts were kept in humidified atmosphere at 37°C with 5% CO2. Experiments were performed with cells not exceeding 7 passages. Pulp fibroblast cells were irradiated with CO2 laser device (BEL-LUXER super pulse laser). Laser irradiation was applied continuously with a wave of E16 mode for 90 sec. The specimens were cultured (10-day) with or without CO2 laser irradiation. Laser-irradiated medium was separated from cell culture dish and the protein, calcium and phosphate were quantified from the supernatants. After cultivation, fibroblast count was determined using a hemocytometer (Bright-line Hausser Scientific Horsham, PA USA). Total RNA was extracted from fibroblast cells and RT-PCR analysis was performed. The protein concentration increased in samples treated with CO2 laser irradiation. The number of fibroblast cells in laser irradiated group was significantly higher than the untreated group (n=8, t-test, p‹0.01). HSP27 and 60 mRNA expressions were detected in both untreated and laser irradiated groups. However, HSP 70 was found only in laser irradiation group. OC was presented in both untreated and laser irradiated groups. Other markers of calcification were not detected in all specimens. It was suggested that pulsed CO2 laser irradiation tends to accelerate cell proliferation and induces HSP70 expression.