How is a periodontal abscess best defined?

A periodontal abscess is best defined as a localized infection in the supporting structures of the teeth, typically associated with periodontal disease. The defining characteristics usually include the presence of deep periodontal pockets, often greater than 7mm, which can harbor bacteria and lead to infection. This infection typically manifests with symptoms such as pain and swelling, making option C the most accurate description.

In cases of a periodontal abscess, the involvement of deep pockets indicates significant periodontal tissue destruction and contributes to the acute nature of the abscess, along with its painful presentation. Understanding that this condition arises in areas with severe periodontal issues clarifies the critical connection between pocket depth, inflammation, and the risk of abscess formation.

The other choices do not align with the typical presentation of a periodontal abscess. Shallow pockets wouldn't generally lead to the large, localized infection that characterizes an abscess. Locations within dentin pertain more specifically to dental caries or pulpal conditions rather than periodontal abscesses. Lastly, while gum recession may accompany periodontal disease, it is not a definitive factor for the definition of a periodontal abscess itself.