The mechanisms underlying the formation and composition of gingival crevicular fluid (GCF) and its flow into and from periodontal pockets are not understood very well. The aim of this study was to evaluate the length of sampling time and sequential sampling of GCF neutrophil elastase (NE) enzyme activity by using intracrevicular and orifice methods.

Twenty adults (mean age of 41.8 years. ranged 31-60 years. 18 males. 2 females) with chronic periodontitis were enrolled and all completed the 3-day study. Three-hundred-sixty samples of GCF were harvested from the interproximal sites of each of the two maxillary non-molar teeth according to the orifice method. Each site was sampled three times with 1-min intervals between repeat samples. By using intracrevicular method, the other 360 samples of GCF were collected on the same sites following 10-minutes interval. In first day, 2nd day and 3rd day the length of sampling time in seconds and order were 5. 10. 30; 10. 30. 5 and 30. 5. 10. respectively. GCF elastase activity was determined by hydrolysis of neutrophil specific substrate N-methoxysuccinyl-Ala-Ala-Pro-Val-p-nitroanilide and was expressed as concentration (microU/microl) and total enzyme activity (microU).

Inclusion Criteria:

• no history of systemic disease;
• no history of antibiotics and/or anti-inflammatory drugs within the past 6 months;
• no received any oral hygiene prophylaxis and scaling and root planing within the past 6 months;
• at least 2 interproximal sites exhibiting higher than 5 mm probing depth, radiographic bone loss and gingival index of 2 (with preference of two maxillary non-molar teeth)

Exclusion Criteria:

• with metabolic diseases
• pregnancy, lactation etc.