The invention relates to the field of dentistry and is used for reinforcing composite materials to eliminate various defects of dental hard tissues of carious and non-carious origin in the process of direct/indirect and reinforced/non-reinforced composite restorations. The claimed method includes vibrational mechanical activation of composite materials by vibrationally acting upon portions of composite material shaped by manual mechanical activation (e.g., roll/ball) and applied layer-by-layer to the region of a defect. A device for vibrational mechanical activation of a composite material includes at least one working portion for applying a composite material to the region of a defect, the working portion fixedly attached to a handle, which is connected by a framework to a micromotor that creates vibrations which are transferred via the working portion to a layer of composite material by distributing the same across the entire surface of the defect and achieving the simultaneous surface plastic deformation thereof.
