Which diagnostic finding would NOT suggest a periodontal abscess?

Sensitivity to percussion is not typically associated with a periodontal abscess. In the context of periodontal issues, sensitivity to percussion usually indicates other dental problems, such as inflammation or infection associated with the pulp of a tooth rather than the periodontal tissues themselves.

In contrast, dull and localized pain can be a typical symptom of a periodontal abscess, presenting as a localized discomfort that isn't sharp and might be exacerbated by chewing or pressure.

Swelling that includes gingival tissue is also a common finding in cases of periodontal abscess, as the infection often leads to localized edema in the surrounding soft tissues.

Radiographs showing angular bone loss are indicative of periodontal disease and may be evident in a periodontal abscess, as the infection could lead to further bone deterioration. Therefore, sensitivity to percussion is the finding that does not support a diagnosis of a periodontal abscess, whereas the other findings are consistent with it.