Effect of a non-steroidal anti-inflammatory drug on tissue levels of immunoreactive prostaglandin E₂, immunoreactive leukotriene, and pain after periodontal surgery

The aim of this study was to measure tissue levels of immunoreactive prostaglandin E₂ (iPGE₂), immunoreactive leukotriene B4 (iLTB4), and pain after periodontal surgery and to evaluate the effect of the non-steroidal anti-inflammatory drug (NSAID), ibuprofen, on these levels. Two contralateral quadrants in each of nine patients were selected to undergo separate surgical procedures, one with ibuprofen (800 mg 1 hour presurgery and 400 mg postsurgery) and one with a placebo. Intra-operatively, a custom-made microdialysis probe, with a 3,000 dalton molecular weight cut-off, was inserted beneath the soft tissue flap and a dialysate collected every 20 minutes for 4 hours after surgery. Pain perception was measured at the same time intervals using two pain scales. Dialysate samples were assayed using two enzyme immunoassays. Mean tissue levels of iPGE₂ in the placebo group increased from 74 nM at 40 minutes to a peak of 261 nM at 200 minutes. Mean tissue levels of iLTB4 in the placebo group fluctuated between 0.2 and 0.6 nM. Pain levels in this group increased continuously with time, peaking at 4 hours. Mean tissue levels of iPGE₂ in the ibuprofen group were significantly suppressed, exhibiting more than a 95% reduction. This was accompanied by a significant reduction in pain. Ibuprofen had no detectable effect on tissue levels of iLTB4. These data indicate that iPGE₂ and iLTB4 are present at relatively high concentrations in the periodontal tissues after surgery. Since these concentrations exceed the Kd values for binding to their respective receptors, PGE₂ and LTB4 may be associated with the development of postsurgical pain and inflammation. These data also indicate that ibuprofen can successfully inhibit iPGE₂ production in the periodontal tissues and in this way help reduce postoperative pain and inflammation.