A 23-year-old female patient complains of short-term pain caused by thermal stimuli in a lower jaw tooth on the right. Objectively: on the occlusal surface of the 46 tooth there is a deep cavity with softened light dentin on the floor and walls. Probing causes a slight pain across the cavity floor. Pulp electroexcitability is 10 mA. During the cavity preparation a drop of blood showed up on its floor. What paste should be applied to the cavity floor?