Alveolar bone turnover during experimental tooth movement in streptozotocin-induced diabetic rat.

Lee, Ki Soo; Lee, Taek Woo; Kim, Sung Jin

Abstract

The purpose of this study was to investigate the alveolar bone turnover in diabetic rat, and to compare the alveolar bone turnover during tooth movement in diabetes with that in normal control. Eighty Male Sprague-Dawley strain rats(8th week) were divided into normal control(N), normal-tooth movement (N-tm), diabetes(D), and diabetes-tooth movement(D-tm) groups. Eighteen days before the start of the experiment, diabetes was induced with a single injection of streptozotocin 50mg/kg of body weight in citrate buffer as vehicle via the tail vein. Maxillary first molars of rats were moved mesially by 40 grams of the closed coil spring. Experimental animals were sacrificed after 1d, 3d, 7d, and 14d experimental period, and the alveolar bone around the maxillary first molars were assayed biochemically for acid phsophatase(ACP) and tartrate-resistant acid phosphatase (TRAP) as bone resorption markers, and alkaline phosphatase(ALP) and osteocalcin(OC) as bone formation markers. TRAP and OC concentration in serum and alveolar bone of D group were lower than those in N group, and especially OC concentration decreased more following diabetes prolonged, which showed the decreased skeletal and alveolar bone resorption and formation potential in diabetic rats. In N-tm group compared with N group, alveolar bone ACP and TRAP concentrations were highest at 1d and 3d(p<0.01), decreased after then, and showed lowest at 14d, and alveolar bone OC concentration was higher at 3d, 7d, and 14d(p<0.001) and showed a tendency of peak level at 7d. which showed the peak of concentration of bone resorption markers at 1d-3d and those of bone formation markers at 7d. In D-tm group compared with N group, alveolar bone ACP and TRAP concentrations were higher at 3d, 7d and 14d(p<0.001), and tended to reach peak value at 7d and persisted through 14d, and alveolar bone ALP and OC concentration increased but not different from that of N group. The amount of tooth movement in D group were greater than that of N group at all experimental period. Those results were suggested that during diabetes, the alveolar and skeletal bone undergo low bone turnover and the more amount of tooth movement, but because the peak time of alveolar bone resorption activity was delayed and sustained in longer period of tooth movement and alveolar bone formation activity is lower than that of normal tooth movement, the periodontal space is supposed to be larger during tooth movement.