Purpose. Epidermal growth factor (EGF) has been used as a vulnerary agent. Epidermal growth factor accelerates wound healing. Nitric oxide (NO) is considered to be an important factor which is involved in wound healing. The objective of this study was to examine the effects of interactions between exogenous EGF and NOx which may have either similar or quite opposed properties in the process of oral wound repair on different days. In addition, lipid peroxidation was found to be an indicator of free radical damage.