A 16-year-old adolescent girl complains of pain caused by cold stimuli and food particles retained in her upper jaw tooth. Objectively: on the contact surface of the 24 tooth there is a carious cavity within parapulpar dentin. The cavity floor and walls are covered with light softened dentin. The carious cavity floor is sensitive to probing, percussion of the 24 is painless. Cold water stimulus is painful, the pain quickly abates after the stimulus is removed. Make the diagnosis: