What is the predominant bacteria found in a healthy gingival sulcus?

Correct answer: D. Aerobic, non-motile, gram-positive bacilli

• A. Gram-negative bacilli predominate in diseased periodontal pockets, not healthy sulci.
• B. Motile organisms are associated with disease states.
• C. Gram-negative anaerobes (e.g., P. gingivalis) are hallmarks of periodontal disease, not a healthy sulcus.
• D. A healthy sulcus is dominated by gram-positive, aerobic, non-motile cocci and bacilli (e.g., Streptococcus, Actinomyces). The environment is relatively aerobic and the flora is largely non-pathogenic.