A 21-year-old patient complains of blood that oozes from a cavity in an upper jaw tooth during eating. Objectively: the approximal occlusal surface of the 27 tooth has a deep carious cavity filled with soft tissue overgrowth of purple-red colour that bleeds easily when touched by the probe. Probing causes a slight pain. There is a slight pain reaction to cold stimuli. EPT result is 60 mA. Ro-gram shows no pathological changes. What is the most likely diagnosis?