Fernandes Daniel Jogaib, Elias Carlos Nelson, Ruellas Antônio Carlos de Oliveira
Laboratory of Biomaterials, Instituto Militar de Engenharia, Rio de Janeiro, RJ 22290-270, Brazil.
School of Dentistry, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil.
Materials (Basel). 2015 Sep 23;8(9):6558-6569. doi: 10.3390/ma8095322.
The purpose of this work was to study the influence of screw length and bone thickness on the stability of temporary implants. A total of 96 self-drilling temporary screws with two different lengths were inserted into polyurethane blocks (n = 66), bovine femurs (n = 18) and rabbit tibia (n = 12) with different cortical thicknesses (1 to 8 mm). Screws insertion in polyurethane blocks was assisted by a universal testing machine, torque peaks were collected by a digital torquemeter and bone thickness was monitored by micro-CT. The results showed that the insertion torque was significantly increased with the thickness of cortical bone from polyurethane (p < 0.0001), bovine (p = 0.0035) and rabbit (p < 0.05) sources. Cancellous bone improved significantly the mechanical implant stability. Insertion torque and insertion strength was successfully moduled by equations, based on the cortical/cancellous bone behavior. Based on the results, insertion torque and bone strength can be estimate in order to prevent failure of the cortical layer during temporary screw placement. The stability provided by a cortical thickness of 2 or 1 mm coupled to cancellous bone was deemed sufficient for temporary implants stability.
本研究旨在探讨螺钉长度和骨厚度对临时种植体稳定性的影响。将96枚具有两种不同长度的自攻式临时螺钉植入具有不同皮质厚度（1至8毫米）的聚氨酯块（n = 66）、牛股骨（n = 18）和兔胫骨（n = 12）中。在万能试验机的辅助下将螺钉植入聚氨酯块，通过数字扭矩仪收集扭矩峰值，并通过微型CT监测骨厚度。结果表明，来自聚氨酯（p < 0.0001）、牛（p = 0.0035）和兔（p < 0.05）来源的皮质骨厚度增加时，植入扭矩显著增加。松质骨显著提高了种植体的机械稳定性。基于皮质/松质骨的行为，通过公式成功调节了植入扭矩和植入强度。根据结果，可以估算植入扭矩和骨强度，以防止在临时螺钉植入过程中皮质层失效。认为2毫米或1毫米皮质厚度与松质骨相结合所提供的稳定性足以满足临时种植体的稳定性。
