Pulpitis must be treated promptly. Pulpitis is when the dental pulp inside the tooth cavity, where the nerves are located, gets infected or damaged. Early symptoms often include severe pain such as spontaneous pain, intermittent pain, pain due to temperature stimuli, and nocturnal pain. If the inflammation and lesions are not removed, the pulpitis can spread to the root apex with the necrotic tissue, causing destruction of the root apex tissues and leading to periapical periodontitis. If periapical periodontitis is left untreated, it can lead to cysts at the root apex, causing chronic periapical periodontitis. Periapical periodontitis may also spread to the bone marrow or adjacent interstitial tissues, leading to interstitial infections or osteomyelitis, which are very serious conditions. Therefore, pulpitis must be treated promptly. Since the pulp chamber is a closed tissue, infections typically require root canal treatment for a complete cure.