OBJECTIVETo investigate the relationship between smoking and gingival crevicular fluid volume (GCF), level of elastase (EA) in 37 severe periodontitis patients before and after 1 month periodontal initial treatment.

METHODSThe GCF samples were collected from 122 sites in 22 heavy smokers (>or= 20 cigarettes/day) and 90 sites in 15 non-smokers before and after 1 month periodontal initial treatment. There is no difference (P > 0.05) on pocket depth between smoking sites (5.6 +/- 1.2) mm and non-smoking sites (5.4 +/- 1.2) mm at baseline. The volume of each GCF sample was measured by Periotron 6000 and the elastase in GCF were determined by substrate (meosuc-als-als-pro-val-NA) method.

RESULTSAfter non-surgical treatment both GCF volume and elastase level were significantly decreased (P < 0.001) in both smokers and non-smokers. But the decrease of GCF volume (91 sites, 74.6%) and elastase level (70 sites, 76.1%) in smokers were significant lower (P < 0.01) than non-smokers (GCF, 88 sites, 97.8%; EA, 56 sites, 93.3%).

CONCLUSIONThese findings suggest that smoking has effect on gingival crevicular fluid volume and elastase level of patients with periodontitis.