The purpose of this study was to examine the effects of bisphosphonate and indomethacin. blockers of bone resorption with different mechanisms. On alveolar bone remodeling. Male rats were divided into control, bisphosphonate and indomethacin
groups, and
then each group was divided into an experimental side and a control side according to the force application. Bisphosphonate(6.3mg/kg, 2.52×10E-2mol/L) and indomeethacin (9mg/kg, 2.52×10-2mol-L) were injected 6 hours and 1 hours before or 24
hours
after the force application. The rats were killed 72 hours after the force application and histologic examination was perfomed. The values of serum acid phosphatase and lactate dehydrogenase were also measure in the control and experimental
groups
treated with bisphosphonate or indomethacin 1 hour before the force application.
In the experimental side, the least number of osteoclasts was noted in the groups treated 1 hour before the force application with indomethacin or biphosphonate, while there were no differences between the control and the groups treated with
drugs
6
hours before or 24 hours after the force application. In the control side, the number of osteoclasts was not inecreased with no differences among the groups.
Histologic examination revealed a severe alveolar bone resorption in the control group and the groups treated with indomethacin 6 hours before or 24 hours after the force application. Indomethacin treatment 1 hour before the force application and
bisphosphonate treatment at any time significantly attenuated the bone resorption.
Electron microscopically, ruffled border and clear zone of osteoclasts were observe in the control and indomethacin groups, while some osteoclasts were detached from the bone surface and exhibited dull cellular projections in the bisphosphonate
groups.
The bisphosphonate and indomethacin groups showed lower values of acid phosphatase and lactate dehydrogenase than the control group. The acid phosphatase value in the bisphosphonate group was lower than that in the indomethacin group, whereas
there
was
no difference in the lactate dehydrogenase value between the groups.
These results suggest that biphosphonate reduces the activity of osteoclasts as well as the number of osteoclasts and that indomethacin reduces the number of osteoclasts without affecting the activity of osbeoclasts. Bisphosphonate has a larger
inhibitory effect on bone resorption and thus less limitation in the application time than indomethacin.
|