Impact of zoledronate bisphosphonate gel in virgin coconut oil on the increase of osteoclast apoptosis

Objective: Drug has the potential to support the anchorage in orthodontic treatment through the inhibition of tooth movement resulting from bone resorption due to the apoptosis of osteoclasts. A subperiosteal injection of zoledronate (ZOL) can increase the apoptosis of osteoclasts. Several researchers have reported that a subperiosteal injection of ZOL bisphosphonate (BP) (ZOL) can act against orthodontic tooth movement by increasing the apoptosis of osteoclast cells. However, subperiosteal injection is invasive and painful, so a gel emulsion of ZOL in virgin coconut oil (VCO) was used to substitute the subperiosteal injection. Objective: This study aimed to show the impact of the ZOL in VCO gel (Ge-ZOL) on the extent of osteoclasts apoptosis. Methods: The study used 27 Sprague-Dawley rats which were divided into three groups: Nine rats in the experimental group were given 40 µg of Ge- ZOL, nine rats in the control group were given VCO emulsion gel without ZOL (Ge-), and nine rats in the normal group were not given any treatment. The gel was applied to the buccal mucosa using a cotton bud for 2 min at hour of 0, 4, and 8 on days 0, 1, 2, 3, and 4. The rats were sacrificed on days 1, 3, and 5, and then, evaluated by immunohistochemical caspase-3 staining. Result: The number of apoptotic osteoclast cells in the experimental group was significantly higher than in the control and normal groups (p<0.05). The number of apoptotic osteoclast cells in the experimental group on the day 1 was significantly higher than on the days 3 and 5 (p<0.001). Conclusion: The application of Ge-ZOL to the buccal mucosa proven to improve the number of apoptotic osteoclast cells in the experimental group on the day 1, and this number was higher than on the days 3 and 5.