Department of Biomedical Sciences and Human Oncology, Universita di Torino, Torino, Italy.
Int J Prosthodont. 2012 Sep-Oct;25(5):465-71.
Implant geometry has a major impact on insertion torque values and primary stability, and bone engagement during implant insertion differs according to implant morphology. Primary stability of straight-walled and tapered implants was compared using insertion torque monitoring.
A total of 57 implants (36 straight-walled OSSEOTITE and 21 tapered OSSEOTITE NT) were inserted in 20 patients. Implant torque values and insertion times were recorded, and the data were processed and interpolated to determine torque as a function of time.
Tapered implants required less insertion time and a higher insertion torque than straight-walled implants; this provided better primary stability, although the success rate was 86% for tapered and 100% for straight-walled implants.
Tapered implants showed better primary stability than straight-walled implants but had a lower success rate. The authors suggest that in low-density bone, in which only a thin dense cortical layer can contribute to primary stability, a higher insertion torque can lead to the destruction of peri-implant bone, compromising osseointegration.
种植体的几何形态对种植体的初始稳定性和旋入扭矩值有很大的影响，而且不同种植体的形态在种植体旋入过程中对骨质的初始嵌合力也不同。本研究通过扭矩监测对直壁式和非直壁式种植体的初始稳定性进行了比较。
20 例患者共植入 57 枚种植体（36 枚 OSSEOTITE 直壁式种植体和 21 枚 OSSEOTITE NT 非直壁式种植体）。记录了种植体的扭矩值和旋入时间，并对数据进行了处理和内插，以确定扭矩随时间的变化。
与直壁式种植体相比，非直壁式种植体需要的旋入时间更短，初始扭矩更高，因此初始稳定性更好，但其成功率为 86%，而直壁式种植体的成功率为 100%。
与直壁式种植体相比，非直壁式种植体具有更好的初始稳定性，但成功率较低。作者认为，在骨密度较低的情况下，只有较薄的致密皮质骨层能对初始稳定性产生影响，较高的初始扭矩可能导致种植体周围骨的破坏，影响骨整合。
