Wiktionary
pulpitis
n. (context dentistry English) A periodontal disease in which the pulp of a tooth becomes inflamed.
Wikipedia
Pulpitis
Pulpitis is inflammation of dental pulp tissue. The pulp contains the blood vessels the nerves and connective tissue inside a tooth and provides the tooth’s blood and nutrients. Pulpitis is mainly caused by bacteria infection which itself is a secondary development of caries (tooth decay). It manifests itself in the form of a toothache.