effects of diclofenac and celecoxib on osteoclastogenesis during alveolar bone healing, in vivo

background: osteoclastogenesis is coordinated by the interaction of members of the tumor necrosis factor (tnf) superfamily: receptor activator of nuclear factor-κb ligand (rankl) and osteoprotegerin (opg). the aim of this study was to compare the effect of two different types of non-steroidal anti-infl ammatory drugs (nsaids) on the rankl/opg balance during the healing of the alveolar process. materials and methods: this was an experimental study, carried on 45 male wistar rats (200 ± 25 g, 8-10 weeks old). after extraction of the right maxillary fi rst molar, 15 rats received 5 mg/kg/ day of diclofenac and 15 rats received 15 mg/kg/day of celecoxib and 15 rats received normal saline. the animals were sacrifi ced 7, 14 and 21 days after tooth extraction. the number of osteoclasts, opg and rankl messenger ribonucleic acid expression were determined by tartrate-resistant acid phosphate (trap) staining and polymerase chain reaction (pcr) respectively. the data were analyzed by one-way anova followed by tukey’s post-hoc test. values of p < 0.05 were considered signifi cant. results: on days 7, 14 and 21 the ratio of rankl/opg in the control group was higher than diclofenac and celecoxib groups. trap immunolabeling of the control group was more than diclofenac group on day 7 and was more than celecoxib group on day 14. on day 21, no signifi cant differences were noted among the three studied groups. conclusion: both drugs affect rankl/opg gene expression and also osteoclastogenesis in alveolar socket during the experimental period of 21 days. key words: non-steroidal anti-infl ammatory drugs, osteoclastogenesis, osteoprotegerin, receptor activator of nuclear factor-κb ligand, tartrate-resistant acid phosphatase