Each of the following directly affects periodontal status EXCEPT:

Correct answer: D. Caries risk level

• A. Home care (plaque control) is the single most important modifiable factor for periodontal health.
• B. Smoking is the strongest modifiable RISK FACTOR for periodontitis.
• C. Diabetes has a well-established BIDIRECTIONAL relationship with periodontitis — poor glycemic control worsens periodontal destruction, and periodontal inflammation worsens glycemic control.
• D. CORRECT — this is the EXCEPTION. CARIES RISK is a separate disease process. Caries is driven by acidogenic organisms (mutans streptococci, lactobacilli) fermenting dietary carbohydrate; periodontitis is driven by anaerobic, gram-negative organisms and the HOST INFLAMMATORY response. A patient can have rampant caries and healthy periodontium, or an intact caries-free dentition with severe periodontitis. Note that individual carious lesions can act as local plaque traps, but caries RISK as a category is not a periodontal determinant.

Note: Two different diseases, two different bacterial ecologies, two different risk profiles. Assess them separately.