A 6-year-old child complains of pain in the mandibular tooth on the left during eating. Objectively: masticatory surface of the 36 tooth exhibits a carious cavity within the mantle dentin. The cavity is full of light softened dentin which can be easily removed with an excavator. Probing of the cavity walls causes pain response. The teeth are sensitive to thermal stimuli, the pain is of short-term nature. There is no response to percussion. Select the optimal filling material: