Relationship between prostaglandin E2 concentrations in periapical exudates from root canals and clinical findings of periapical periodontitis.

In this study the relationship of prostaglandin E2 (PGE2) concentrations in periapical exudates with clinical findings of teeth with periapical periodontitis is discussed. Periapical exudate samples were obtained from root canals of 77 endodontically involved teeth during routine root canal treatment by the quantitative sampling method using paper points. PGE2 concentrations in periapical exudates (PE-PGE2) were determined by radioimmunoassay. Significantly higher levels of PGE2 were found in periapical exudates from teeth with radiolucent areas than from teeth without radiolucent areas (236.8 +/- 521.3 pg/microliter vs. 14.9 +/- 23.1 pg/microliter, respectively). The elevated PE-PGE2 levels were associated with the presence of clinical symptoms that reflected an acute inflammation in the periapical lesion. In contrast, a significantly negative association of decreased PE-PGE2 levels with increasing size of radiolucent areas was demonstrated. These results suggested that PGE2 was produced locally in periapical lesions and that the PGE2 concentration in periapical exudate could reflect the state of the disease activity in periapical periodontitis.