In the last years, several single-bottle dental adhesives have been developed. They are supposed to chemically adhere to dentin, and a liner to protect pulp is not thought to be necessary. In the case of direct pulp capping, hemorrhage control is an important step in success, but little is known about the effect of these new bonding agents on pulpal bleeding. The aim of this study was to evaluate the effect of a new one-step single-bottle adhesive on the smooth muscle contraction of rat uterine muscle and carotid arteries. Efficacy of the bonding agent was compared with that of epinephrine (control), and the contraction forces induced were recorded using a force displacement transducer. Statistical analysis of data revealed that the bonding material produced epinephrine-like concentration-dependent contractions of the smooth muscle, suggesting that onestep bonding agents may act as candidates for hemorrhage control without the use of an additional agent in direct pulp capping procedures.