Histometric study of alveolar bone healing in rats treated with the nonsteroidal anti-inflammatory drug nimesulide

There is extensive experimental and clinical evidence in the orthopedic area that prolonged use of nonselective (inhibitor of both cyclooxygenases 1 and 2) nonsteroidal anti-inflammatory drugs can hinder long bone fracture healing, spinal fusion rate, and new bone formation around implants. The purpose of the present study was to investigate whether nimesulide (Nimesulida, Medley S.A., Campinas, SP, Brazil), a preferential cyclooxygenase-2 inhibitor, can hinder alveolar bone healing, in rats. Treated rats received oral doses (5 mg/kg/rat/day) of nimesulide from the day of tooth extraction until euthanasia 2 weeks later and control rats received tap water (n = 5 per group). The volume of neoformed bone inside the alveolar socket was estimated in semiserial longitudinal histological sections by a differential point-counting method, and the significance of the difference between groups was analyzed by Student t test (P < 0.05 for statistical significance). Histometric data confirmed histological observation that the volume fraction of new bone trabeculae in treated rats was not significantly different from that in control rats. Short-term treatment with nimesulide, although its capacity to inhibit preferentially the enzyme cyclooxygenase-2, does not interfere with alveolar bone healing in rats.