Australian Dental Council (ADC) Practice Test

The presence of spirochaetes and fusobacterium species is characteristic of acute necrotic ulcerative gingivitis (ANUG), which is a clinical condition often associated with poor oral hygiene and stress or systemic conditions. Spirochaetes, particularly Treponema species, are considered pathognomonic for this condition, as they are commonly found in the lesions associated with ANUG. Fusobacterium species also contribute to the necrotic processes and the ulcerative nature of the gingivitis. Together, these organisms create a synergistic effect that exacerbates the inflammation and tissue destruction seen in ANUG.

Understanding the microbial profile associated with this condition is essential for appropriate diagnosis and management. In ANUG, the combination of spirochaetes and fusobacterium indicates a shift in the oral flora towards more pathogenic organisms, reflecting the interplay between bacterial infections and the host's response, which often includes necrosis and ulcers in the gingival tissue.