<p><b>OBJECTIVE</b>The aim of this study was to examine the levels of
prostaglandin E2 in periapical
exudates before and after
root canal treatment.</p><p><b>
METHODS</b>Periapical
exudates specimens were quantitatively sampled from
root canals of 25
teeth at consecutive
treatment visits, and the concentration of
prostaglandin E2 in each sample was determined using a commercial kit.</p><p><b>RESULTS</b>The mean
prostaglandin E2 levels significantly decreased after the endodontic
therapy. Significant correlations between the levels of
prostaglandin E2 and the clinical features of
periapical periodontitis were also found in this study.</p><p><b>CONCLUSION</b>The results suggest that the level of
prostaglandin E2 in periapical
exudates reflects the
state of
periapical periodontitis.</p>