American Board of Dental Examiners (ADEX) Dental Hygiene Licensing Examination 2025 – 400 Free Practice Questions to Pass the Exam

The bacterium predominantly involved in acute necrotizing ulcerative gingivitis (ANUG) is Treponema denticola. This condition is characterized by the presence of necrotizing lesions, ulceration, and pain in the gingival tissues, often considered a part of a polymicrobial complex in severe periodontal diseases, but Treponema denticola has been identified as a key pathogen in the pathogenesis of ANUG.

Treponema denticola is a spirochete, and its unique morphology and motility allow it to invade the gingival tissues effectively, leading to the characteristic symptoms of ANUG. Its role in disrupting the host's immune response while promoting tissue destruction contributes significantly to the progression of this condition.

In contrast, other bacteria listed may play a role in different forms of periodontal disease or other dental conditions, but they are not primarily associated with ANUG. For instance, Porphyromonas gingivalis is commonly linked to chronic periodontitis, while Fusobacterium nucleatum is often associated with a variety of oral infections, including those encountered in mixed infections but is not specific to ANUG. Streptococcus sanguinis, on the other hand, is more typically found in healthy oral environments and does not have