Compared with a non-smoker who has equivalent plaque levels, how does bleeding on probing present in a smoker?

Correct answer: B. Less bleeding

• A. The difference is well documented and clinically important; the response is not equivalent.
• B. CORRECT. Nicotine-induced vasoconstriction and the altered gingival microvasculature of smokers SUPPRESS the visible inflammatory response. Smokers bleed less on probing than their actual disease burden warrants, which is why BOP systematically under-estimates severity in this population.
• C. This is the intuitive but wrong answer. Smokers have more destruction but less bleeding — the clinical signs are masked, not amplified.
• D. The suppression is systemic and affects the whole dentition, not one arch.

Note: The clinical trap: a smoker's tissue looks fibrotic and pale rather than red and oedematous, and it does not bleed. Do not let that reassure you. Rely on probing depths, attachment level and radiographic bone loss instead of BOP, and remember smokers respond less well to both non-surgical and surgical therapy.