Rohner D, Meng C S, Hutmacher D W, Tsai K T
Department of Plastic Surgery, Singapore General Hospital, Singapore.
Int J Oral Maxillofac Surg. 2003 Aug;32(4):383-9. doi: 10.1054/ijom.2002.0367.
The reconstruction of extended maxillary and mandibular defects with prefabricated free flaps is a two stage procedure, that allows immediate function with implant supported dentures. The appropriate delay between prefabrication and reconstruction depends on the interfacial strength of the bone-implant surface. The purpose of this animal study was to evaluate the removal torque of unloaded titanium implants in the fibula, the scapula and the iliac crest. Ninety implants with a sandblasted and acid-etched (SLA) surface were tested after healing periods of 3, 6, and 12 weeks, respectively. Removal torque values (RTV) were collected using a computerized counterclockwise torque driver. The bicortical anchored 8mm implants in the fibula revealed values of 63.73 Ncm, 91.50 Ncm, and 101.83 Ncm at 3, 6, and 12 weeks, respectively. The monocortical anchorage in the iliac crest showed values of 71.40 Ncm, 63.14 Ncm, and 61.59 Ncm with 12 mm implants at the corresponding times. The monocortical anchorage in the scapula demonstrated mean RTV of 62.28 Ncm, 97.63 Ncm, and 99.7 Ncm with 12 mm implants at 3, 6, and 12 weeks, respectively. The study showed an increase of removal torque with increasing healing time. The interfacial strength for bicortical anchored 8mm implants in the fibula was comparable to monocortical anchored 12 mm implants in the iliac crest and the scapula at the corresponding times. The resistance to shear seemed to be determined by the type of anchorage (monocortical vs. bicortical) and the length of the implant with greater amount of bone-implant interface.
采用预制游离皮瓣重建上颌骨和下颌骨大面积缺损是一种两阶段手术,可通过种植体支持的假牙实现即刻功能。预制与重建之间的适当间隔时间取决于骨-种植体表面的界面强度。本动物研究的目的是评估腓骨、肩胛骨和髂嵴中未加载的钛种植体的去除扭矩。分别在愈合3周、6周和12周后,对90个具有喷砂和酸蚀(SLA)表面的种植体进行测试。使用计算机化逆时针扭矩驱动器收集去除扭矩值(RTV)。腓骨中双皮质固定的8mm种植体在3周、6周和12周时的去除扭矩值分别为63.73Ncm、91.50Ncm和101.83Ncm。髂嵴中单皮质固定的12mm种植体在相应时间的去除扭矩值为71.40Ncm、63.14Ncm和61.59Ncm。肩胛骨中单皮质固定的12mm种植体在3周、6周和12周时的平均RTV分别为62.28Ncm、97.63Ncm和99.7Ncm。研究表明,去除扭矩随愈合时间的增加而增加。在相应时间,腓骨中双皮质固定的8mm种植体的界面强度与髂嵴和肩胛骨中单皮质固定的12mm种植体相当。抗剪切力似乎取决于固定类型(单皮质与双皮质)以及种植体长度,骨-种植体界面越大,抗剪切力越大。