Microarray analysis of the developing rat mandible.

To analyze the molecular events that occur in the developing mandible, we examined the expression of 8803 genes from samples taken at different time points during rat postnatal mandible development. Total RNA was extracted from the mandibles of 1-day-old, 1-week-old, and 2-week-old rats. Complementary RNA (cRNA) was synthesized from cDNA and biotinylated.

Generation of free radicals and/or active oxygen by light or laser irradiation of hydrogen peroxide or sodium hypochlorite.

Generation of free radical and/or active oxygen by light or laser irradiation of hydrogen peroxide (H2O2) or sodium hypochlorite (NaClO), which have been used for tooth whitening or root canal irrigation, was investigated using electron spin resonance spectroscopy combined with a spin-trapping technique. When H2O2 was exposed to light or laser radiation, the amount of hydroxyl radical generated changed according to the concentration of H2O2 and irradiation time. The amount of 5,5-dimethyl-1-pyrrolidone-(2)-oxyl-(1) (DMPO-X) also changed in accordance with irradiation time.