AN EXPERIMENTAL STUDY ON THE EFFECT OF PROSTAGLANDIN $E_2$ ON ALVEOLAR BONE RESORPTION INDUCED BY TOOTH MOVEMENT IN RATS

Prostaglandin $E_2$가 백서의 치아이동시 치조골 흡수에 미치는 영향에 관한 실험적 연구

This experiment was performed to study the effect of $PGE_2$ on the bone resorption at the tooth movement by orthodontic force. The experimental animals were the Sprague-Dawley strain rats. The orthodontic force was applied by the insertion of separating clamp made of 0.014' (0.356mm) wire to the interproximal site between the 2nd and the 3rd upper right molars. In experiment I, $0.2{\mu}g,\;0.4{\mu}g,\;0.8{\mu}g,\;and\;1.0{\mu}g\;PGE_2$ were locally injected at the submucosa near the 2nd molar of the maxilla each. The effect was detected by the count of the number of osteoclasts appeared at the compressed surface of interradicular bone. In experiment II, 1.0 mg/kg indomethacin (a specificc inhibitor of prostaglandin synthetas.) was subcutaneously injected. The effect was examined by the count of the number of cateoclasts appeared at the compressed surface of interradicular bone. The obtained results were follows; 1. The number of osteoclasts on the compressed surface of the interradicular bone increased in proportion to the increased dosage of $PGE_2$ administered. The number of osteoclasts increased significantly at the administration of $0.8{\mu}g\;and\;1.0{\mu}g\;PGE_2$ in contrast to the control (P<0.05). 2. The administration of 1.0 mg/kg indomethacin decreased the number of osteoclasts at the compressed bony surface significantly (P<0.01).