Introduction:
Smoking, damages directly the periodontal tissues by the harmful substances it contains and indirectly by changing the host response against them. Although it is not yet a separate disease in the classification, smoking-related periodontal health statu has its own clinical character. Our aim in this study was to investigate the relationship between smoking intensity and periodontal tissues by clinical measurements.

Methods:
Material and metods: In this retrospective study, 300 patients were selected randomly. These patients were divided into 3 groups according to smoking status: non- smokers n=150, light smokers n=75, high smokers n=75. Smoking status, bleeding on probing (BOP), plaque index (PI), calculus index (CI), probing depth, gender, age, education and oral hygiene habit had determined for each individual at their first application to our clinic.

Results:
The relationship between high smoking status and increased probing depth was statistically significant in our results (p<0.002). The relationship between smoking and calculus index is also statistically significant. However, the relationship between smoking and BOP, smoking and plaque index was not statistically significant.

Conclusions:
Smoking has been shown to be a major risk for periodontal disease. The fact that smoking in not associated with BOP is evidence of reduction of tobacco in the gingival vascular inflammatory reaction. The effects of smoking on periodontal tissues depend on the number of cigarettes smoked daily. Lack of relationship between smoking and plaque index maybe relevant age and oral hygiene habit of individuals.