Influence of Screw Length and Bone Thickness on the Stability of Temporary Implants

Materials

Daniel Jogaib Fernandes²  Carlos Nelson Elias²  Antônio Carlos de Oliveira Ruellas¹ 

[1] School of Dentistry, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil; E-Mail:;Laboratory of Biomaterials, Instituto Militar de Engenharia, Rio de Janeiro, RJ 22290-270, Brazil; E-Mail:

关键词: stability;    cortical thickness;    temporary screws;    torque;    bone;   

DOI  :  10.3390/ma8095322

来源: mdpi

【 摘 要 】

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.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.