fa اندازه گیری فعالیت آنزیم الاستاز عمومی general تحقیقی Research Statement of Problem: Changes in protein levels, host calls enzymes and inflammatory mediators in gingival crevicular Fluid (GCF) are considered as diagnostic indicators of Periodontitis.<br><strong>Purpose:</strong> he aim of the present study was to measure the elastase enzyme activity in gingival crevicular Fluid among patients with periodontitis.<br><strong>Material and Methods:</strong> In this study, 52 periodontitis patients (experimental group) and 51 healthy subjects without any gingival inflammatio (control group) were participated. Subjects of the periodontitis group showed pockets of 4-5 mm depth without gingival enlargement and recession or pockets of 1-2 mm depth with gingival recession. For enzyme activity measurement, lOOu,! of gingival fluid of each sample was mixed with lOOu! of enzyme substrate on the tube. The mixture was incubated at 34°c for lh with a buffer solution<br>of 1ml volume and absorbance was read at 410nm with spectrophotometer. The enzyme activity differences between two groups were analyzed by student t test.<br><strong>Results:</strong> The elastase enzyme activity in gingival crevicular fluid in subjects with periodontium destruction and control subjects was 153±11.3 and 52.7±10.4 enzyme unit in ml per minute, respectively. The difference between groups was statistically significant (PO.05).<br><strong>Conclusion:</strong> Based on the findings of this study, the measurement of elastae enzyme activity could be a useful indication of tissue changes that may ultimately manifest clinically as periodontitis. Gingival crevicular fluid,Elastase 72 78 http://jdm.tums.ac.ir/browse.php?a_code=A-10-25-410&slc_lang=fa&sid=1 D. Qujeq دردی قوجق No B . Amoeian بابک عموئیان No P . Zabihi پریسا ذبیحی No