Saito S, Sugimoto N, Morohashi T, Ozeki M, Kurabayashi H, Shimizu H, Yamasaki K, Shiba A, Yamada S, Shibasaki Y
Department of Orthodontics. School of Dentistry, Showa University, Tokyo, Japan.
Am J Orthod Dentofacial Orthop. 2000 Dec;118(6):601-7. doi: 10.1067/mod.2000.110636.
The purpose of this study was to determine the anchorage potential of titanium implants (Branemark; 3.75 x 7 mm) with the use of a sectional arch wire technique for orthodontic mesiodistal tooth movement, as assessed by the osseointegration of implants and tooth movement. Two implants were surgically placed in healed mandibular extraction sites of the second and third premolars on each side in 4 adult male beagle dogs. The implants were surgically uncovered 18 weeks later, and second-stage abutments with soldered edgewise tubes were attached. Segmented edgewise rectangular archwires (0.017 x 0. 025 inch) with a T-loop or an L-loop were placed between the implants and the fourth premolars on both sides as the anchorage unit. One segment in each dog served as a loaded side, and the archwire was calibrated to produce 200 g of lateral force on the fourth premolar. The contralateral segment served as an unloaded side and was not subjected to orthodontic force. Sectional wires were activated biweekly 24, 28, 28, and 32 weeks, respectively, depending on the magnitude and the appearance of mesial tipping movement of the fourth premolar. After mandibular impressions were taken to measure the distance between the first molar and the fourth premolar, the animals were euthanized and dissected mandibles were prepared. The specimens were then embedded in polyester resin and cut to take backscattered electron images. On the basis of these images, the percentage of peri-implant bone volume was calculated and defined as an index of osseointegration. The differences between the initial and final fourth premolar to first molar distances varied (7.40, 8.85, 10.50, and 3.30 mm) on the loaded side, whereas the unloaded side showed no movement. Not only was there no statistical difference in the percent of peri-implant bone volume between the loaded and unloaded sides, but there was also no statistical difference between the compression and tension sides in both loaded and unloaded implants, which suggests that the implants maintained rigid osseointegration. In conclusion, the present study demonstrated that endosseous titanium implants can function as anchors for long-term orthodontic mesiodistal movement.
本研究的目的是通过种植体的骨结合和牙齿移动情况，确定使用片段弓丝技术进行正畸近远中向牙齿移动时钛种植体（Branemark；3.75×7mm）的支抗潜力。在4只成年雄性比格犬的每侧下颌第二和第三前磨牙愈合的拔牙位点手术植入两枚种植体。18周后手术暴露种植体，并连接带有焊接方丝管的二期基台。将带有T形曲或L形曲的分段方丝弓矩形弓丝（0.017×0.025英寸）置于种植体与两侧第四前磨牙之间作为支抗单位。每只犬的一个片段作为加载侧，对弓丝进行校准，使其在第四前磨牙上产生200g的侧向力。对侧片段作为未加载侧，不施加正畸力。根据第四前磨牙近中倾斜移动的幅度和表现，分别在24、28、28和32周时每两周激活一次片段弓丝。在下颌取印模测量第一磨牙与第四前磨牙之间的距离后，对动物实施安乐死并制备解剖下颌。然后将标本嵌入聚酯树脂中并切割以获取背散射电子图像。根据这些图像，计算种植体周围骨体积百分比并将其定义为骨结合指数。加载侧第四前磨牙与第一磨牙的初始和最终距离差异较大（7.40、8.85、10.50和3.30mm），而未加载侧没有移动。加载侧和未加载侧种植体周围骨体积百分比不仅没有统计学差异，而且加载和未加载种植体的压缩侧和拉伸侧之间也没有统计学差异，这表明种植体保持了刚性骨结合。总之，本研究表明骨内钛种植体可作为正畸近远中向长期移动的支抗。
