The influence of fluoxetine on orthodontic tooth movement in rats

Abstract This study aimed to evaluate the effects of chronic use of fluoxetine on the amount of orthodontic tooth movement and tissue changes in rats. A total of 192 Wistar rats were divided into 4 groups: S, 0.9% saline solution; F, 20 mg/kg of fluoxetine; SM, 0.9% saline solution with orthodontic movement; and FM, 20 mg/kg of fluoxetine with orthodontic movement. After 30 days of daily saline or fluoxetine administration, an orthodontic device (25cN) was used to mesially displace the first molar in animals of the groups SM and FM. The animals were euthanized 2, 7, 14, and 28 days after placement of the orthodontic appliances and animals of groups S and F were euthanized at the same time. The assessment of tooth movement was made in gypsum castings, the collagen neoformation was assessed by polarization microscopy, the number of osteoclasts and root resorption were evaluated using tartrate-resistant acid phosphatase, and presence of hyalinized areas was assessed by hematoxylin-eosin staining. Fluoxetine did not affect the amount of tooth displacement, percentage of collagen, number of osteoclasts, and presence of hyalinized areas (P>0.05). There was a higher frequency of root resorption areas in the FM group than in the SM group only on the second day (P<0.05). The findings of this study show that chronic use of 20 mg/kg fluoxetine does not affect the amount of tooth movement, collagen neoformation, number of osteoclasts, or hyalinized areas and does not affect root resorption until the last day of orthodontic movement.

摘要 本研究旨在评估长期服用氟西汀对大鼠正畸牙齿移动量及组织变化的影响。共计192只Wistar大鼠被分为4组：S组（0.9%生理盐水）、F组（20 mg/kg氟西汀）、SM组（0.9%生理盐水联合正畸移动）及FM组（20 mg/kg氟西汀联合正畸移动）。每日给予生理盐水或氟西汀干预30天后，对SM组与FM组大鼠施加25cN的正畸矫治装置，使其第一磨牙发生近中移位。于正畸装置佩戴后第2、7、14及28天对各组大鼠实施安乐处死，其中S组与F组大鼠于对应时间点同样接受安乐处死。
通过石膏模型评估牙齿移动量；采用偏振显微镜检测胶原新生情况；利用抗酒石酸酸性磷酸酶染色计数破骨细胞数量并评估牙根吸收程度；通过苏木精-伊红染色观察透明样变区域的存在情况。
结果显示，氟西汀对牙齿移位量、胶原百分比、破骨细胞数量及透明样变区域的存在情况均无显著影响（P>0.05）。仅在正畸装置佩戴后第2天，FM组大鼠的牙根吸收区域出现频率显著高于SM组（P<0.05）。
本研究结果表明，长期服用20 mg/kg氟西汀不会影响大鼠正畸牙齿移动量、胶原新生、破骨细胞数量及透明样变区域的存在情况，且直至正畸移动结束均不会对牙根吸收产生影响。